diff --git a/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposebinding/HelloBindingActivity.kt b/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposebinding/HelloBindingActivity.kt
index 12821d38f7..4e99b10bcf 100644
--- a/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposebinding/HelloBindingActivity.kt
+++ b/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposebinding/HelloBindingActivity.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.sample.compose.hellocomposebinding
 
 import android.os.Bundle
diff --git a/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposeworkflow/HelloComposeWorkflowActivity.kt b/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposeworkflow/HelloComposeWorkflowActivity.kt
index f666a1690f..22e91a3844 100644
--- a/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposeworkflow/HelloComposeWorkflowActivity.kt
+++ b/samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposeworkflow/HelloComposeWorkflowActivity.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.sample.compose.hellocomposeworkflow
 
 import android.os.Bundle
diff --git a/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingActivity.kt b/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingActivity.kt
index ae13885466..1435fe3fcd 100644
--- a/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingActivity.kt
+++ b/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingActivity.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.sample.compose.inlinerendering
 
 import android.os.Bundle
diff --git a/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingWorkflow.kt b/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingWorkflow.kt
index 17badd16ce..727da411ab 100644
--- a/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingWorkflow.kt
+++ b/samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingWorkflow.kt
@@ -1,3 +1,4 @@
+@file:Suppress("DEPRECATION")
 @file:OptIn(WorkflowUiExperimentalApi::class)
 
 package com.squareup.sample.compose.inlinerendering
diff --git a/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/LegacyRunner.kt b/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/LegacyRunner.kt
index 12f785019e..bb56b5ad75 100644
--- a/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/LegacyRunner.kt
+++ b/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/LegacyRunner.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.sample.compose.nestedrenderings
 
 import androidx.compose.foundation.layout.fillMaxSize
diff --git a/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/NestedRenderingsActivity.kt b/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/NestedRenderingsActivity.kt
index 0eecc3cbde..dd4849b9f4 100644
--- a/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/NestedRenderingsActivity.kt
+++ b/samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/NestedRenderingsActivity.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.sample.compose.nestedrenderings
 
 import android.os.Bundle
diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonScreen.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonScreen.kt
index d6314e309b..7627ab75c0 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonScreen.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonScreen.kt
@@ -1,5 +1,6 @@
 package com.squareup.sample.container
 
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 /**
@@ -16,8 +17,8 @@ import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
  * is pressed, or null to set no handler. Defaults to `null`.
  */
 @WorkflowUiExperimentalApi
-data class BackButtonScreen<W : Any>(
+data class BackButtonScreen<W : Screen>(
   val wrapped: W,
   val override: Boolean = false,
   val onBackPressed: (() -> Unit)? = null
-)
+) : Screen
diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
index 214b977529..7e4ba2b328 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/BackButtonViewFactory.kt
@@ -1,30 +1,31 @@
 package com.squareup.sample.container
 
-import com.squareup.workflow1.ui.DecorativeViewFactory
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.DecorativeScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 /**
- * [ViewFactory] that performs the work required by [BackButtonScreen].
+ * [ScreenViewFactory] that performs the work required by [BackButtonScreen].
  */
 @WorkflowUiExperimentalApi
-object BackButtonViewFactory : ViewFactory<BackButtonScreen<*>>
-by DecorativeViewFactory(
-    type = BackButtonScreen::class,
-    map = { outer -> outer.wrapped },
-    doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
-      if (!outerRendering.override) {
-        // Place our handler before invoking innerShowRendering, so that
-        // its later calls to view.backPressedHandler will take precedence
-        // over ours.
-        view.backPressedHandler = outerRendering.onBackPressed
-      }
+object BackButtonViewFactory : ScreenViewFactory<BackButtonScreen<*>>
+by DecorativeScreenViewFactory(
+  type = BackButtonScreen::class,
+  map = { outer -> outer.wrapped },
+  doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
+    if (!outerRendering.override) {
+      // Place our handler before invoking innerShowRendering, so that
+      // its later calls to view.backPressedHandler will take precedence
+      // over ours.
+      view.backPressedHandler = outerRendering.onBackPressed
+    }
 
-      innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
+    innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
 
-      if (outerRendering.override) {
-        // Place our handler after invoking innerShowRendering, so that ours wins.
-        view.backPressedHandler = outerRendering.onBackPressed
-      }
-    })
+    if (outerRendering.override) {
+      // Place our handler after invoking innerShowRendering, so that ours wins.
+      view.backPressedHandler = outerRendering.onBackPressed
+    }
+  }
+)
diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
index 3c83be2696..47b8b2c17c 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailContainer.kt
@@ -7,13 +7,13 @@ import com.squareup.sample.container.R
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Detail
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Single
-import com.squareup.workflow1.ui.LayoutRunner
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.backstack.BackStackScreen
-import com.squareup.workflow1.ui.backstack.withBackStackStateKeyPrefix
+import com.squareup.workflow1.ui.container.BackStackScreen
+import com.squareup.workflow1.ui.container.withBackStackStateKeyPrefix
 
 /**
  * Displays [OverviewDetailScreen] renderings in either split pane or single pane
@@ -25,7 +25,7 @@ import com.squareup.workflow1.ui.backstack.withBackStackStateKeyPrefix
  * with [OverviewDetailScreen.overviewRendering] as the base of the stack.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class OverviewDetailContainer(view: View) : LayoutRunner<OverviewDetailScreen> {
+class OverviewDetailContainer(view: View) : ScreenViewRunner<OverviewDetailScreen> {
 
   private val overviewStub: WorkflowViewStub? = view.findViewById(R.id.overview_stub)
   private val detailStub: WorkflowViewStub? = view.findViewById(R.id.detail_stub)
@@ -53,15 +53,15 @@ class OverviewDetailContainer(view: View) : LayoutRunner<OverviewDetailScreen> {
     if (rendering.detailRendering == null && rendering.selectDefault != null) {
       rendering.selectDefault!!.invoke()
     } else {
-      // Since we have two sibling backstacks, we need to give them each different
+      // Since we have two sibling back stacks, we need to give them each different
       // SavedStateRegistry key prefixes.
       val overviewViewEnvironment = viewEnvironment
         .withBackStackStateKeyPrefix(OverviewBackStackKey) + (OverviewDetailConfig to Overview)
-      overviewStub!!.update(rendering.overviewRendering, overviewViewEnvironment)
+      overviewStub!!.show(rendering.overviewRendering, overviewViewEnvironment)
       rendering.detailRendering
         ?.let { detail ->
           detailStub!!.actual.visibility = VISIBLE
-          detailStub.update(
+          detailStub.show(
             detail,
             viewEnvironment + (OverviewDetailConfig to Detail)
           )
@@ -81,10 +81,10 @@ class OverviewDetailContainer(view: View) : LayoutRunner<OverviewDetailScreen> {
       ?.let { rendering.overviewRendering + it }
       ?: rendering.overviewRendering
 
-    stub.update(combined, viewEnvironment + (OverviewDetailConfig to Single))
+    stub.show(combined, viewEnvironment + (OverviewDetailConfig to Single))
   }
 
-  companion object : ViewFactory<OverviewDetailScreen> by LayoutRunner.bind(
+  companion object : ScreenViewFactory<OverviewDetailScreen> by ScreenViewRunner.bind(
     layoutId = R.layout.overview_detail,
     constructor = ::OverviewDetailContainer
   ) {
diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelContainer.kt
index 08081526b9..9fadf2f180 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/PanelContainer.kt
@@ -10,8 +10,8 @@ import android.view.View
 import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import com.squareup.sample.container.R
-import com.squareup.workflow1.ui.BuilderViewFactory
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.modal.ModalViewContainer
@@ -59,7 +59,7 @@ class PanelContainer @JvmOverloads constructor(
     }
   }
 
-  companion object : ViewFactory<PanelContainerScreen<*, *>> by BuilderViewFactory(
+  companion object : ScreenViewFactory<PanelContainerScreen<*, *>> by ManualScreenViewFactory(
       type = PanelContainerScreen::class,
       viewConstructor = { initialRendering, initialEnv, contextForNewView, _ ->
         PanelContainer(contextForNewView).apply {
diff --git a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/ScrimContainer.kt b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/ScrimContainer.kt
index e10338ba2a..2bd40d659e 100644
--- a/samples/containers/android/src/main/java/com/squareup/sample/container/panel/ScrimContainer.kt
+++ b/samples/containers/android/src/main/java/com/squareup/sample/container/panel/ScrimContainer.kt
@@ -7,9 +7,9 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.core.content.ContextCompat
 import com.squareup.sample.container.R
-import com.squareup.workflow1.ui.BuilderViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.WorkflowViewStub
 import com.squareup.workflow1.ui.bindShowRendering
 
@@ -91,7 +91,7 @@ class ScrimContainer @JvmOverloads constructor(
   }
 
   @OptIn(WorkflowUiExperimentalApi::class)
-  companion object : ViewFactory<ScrimContainerScreen<*>> by BuilderViewFactory(
+  companion object : ScreenViewFactory<ScrimContainerScreen<*>> by ManualScreenViewFactory(
       type = ScrimContainerScreen::class,
       viewConstructor = { initialRendering, initialViewEnvironment, contextForNewView, _ ->
         val stub = WorkflowViewStub(contextForNewView)
@@ -104,7 +104,7 @@ class ScrimContainer @JvmOverloads constructor(
               bindShowRendering(
                   initialRendering, initialViewEnvironment
               ) { rendering, environment ->
-                stub.update(rendering.wrapped, environment)
+                stub.show(rendering.wrapped, environment)
                 isDimmed = rendering.dimmed
               }
             }
diff --git a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListRendering.kt b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
similarity index 86%
rename from samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListRendering.kt
rename to samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
index 27ec18e244..c6cfb50dac 100644
--- a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListRendering.kt
+++ b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListScreen.kt
@@ -11,25 +11,25 @@ import com.squareup.sample.container.overviewdetail.OverviewDetailConfig
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.container.poetryapp.R
 import com.squareup.sample.poetry.model.Poem
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
-data class PoemListRendering(
+data class PoemListScreen(
   val poems: List<Poem>,
   val onPoemSelected: (Int) -> Unit,
   val selection: Int = -1
-) : AndroidViewRendering<PoemListRendering> {
-  override val viewFactory = LayoutRunner.bind(
+) : AndroidScreen<PoemListScreen> {
+  override val viewFactory = ScreenViewRunner.bind(
     R.layout.list,
     ::PoemListLayoutRunner
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering> {
+private class PoemListLayoutRunner(view: View) : ScreenViewRunner<PoemListScreen> {
   init {
     view.findViewById<Toolbar>(R.id.list_toolbar)
       .apply {
@@ -44,7 +44,7 @@ private class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering>
   private val adapter = Adapter()
 
   override fun showRendering(
-    rendering: PoemListRendering,
+    rendering: PoemListScreen,
     viewEnvironment: ViewEnvironment
   ) {
     adapter.rendering = rendering
@@ -58,7 +58,7 @@ private class PoemListLayoutRunner(view: View) : LayoutRunner<PoemListRendering>
   private class ViewHolder(val view: TextView) : RecyclerView.ViewHolder(view)
 
   private class Adapter : RecyclerView.Adapter<ViewHolder>() {
-    lateinit var rendering: PoemListRendering
+    lateinit var rendering: PoemListScreen
     lateinit var environment: ViewEnvironment
 
     override fun onCreateViewHolder(
diff --git a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListWorkflow.kt b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListWorkflow.kt
index 9daebd00e5..932f97d1be 100644
--- a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListWorkflow.kt
+++ b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListWorkflow.kt
@@ -6,13 +6,13 @@ import com.squareup.workflow1.StatelessWorkflow
 /**
  * Renders a given ordered list of [Poem]s. Reports the index of any that are clicked.
  */
-object PoemListWorkflow : StatelessWorkflow<List<Poem>, Int, PoemListRendering>() {
+object PoemListWorkflow : StatelessWorkflow<List<Poem>, Int, PoemListScreen>() {
 
   override fun render(
     renderProps: List<Poem>,
     context: RenderContext
-  ): PoemListRendering {
-    return PoemListRendering(
+  ): PoemListScreen {
+    return PoemListScreen(
         poems = renderProps,
         onPoemSelected = context.eventHandler { index -> setOutput(index) }
     )
diff --git a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemsBrowserWorkflow.kt b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemsBrowserWorkflow.kt
index 13d039a7c8..3faaa3f4f6 100644
--- a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemsBrowserWorkflow.kt
+++ b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemsBrowserWorkflow.kt
@@ -8,7 +8,7 @@ import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
 import com.squareup.workflow1.parse
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 
 typealias SelectedPoem = Int
 
diff --git a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoetryActivity.kt b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoetryActivity.kt
index bd29b51d64..5a1f7cde26 100644
--- a/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoetryActivity.kt
+++ b/samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoetryActivity.kt
@@ -8,16 +8,17 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.squareup.sample.container.SampleContainers
 import com.squareup.sample.poetry.model.Poem
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackContainer
-import com.squareup.workflow1.ui.plus
+import com.squareup.workflow1.ui.container.withRegistry
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import timber.log.Timber
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private val viewRegistry = SampleContainers + BackStackContainer
+private val viewRegistry = SampleContainers
 
 class PoetryActivity : AppCompatActivity() {
   @OptIn(WorkflowUiExperimentalApi::class)
@@ -26,7 +27,7 @@ class PoetryActivity : AppCompatActivity() {
 
     val model: PoetryModel by viewModels()
     setContentView(
-      WorkflowLayout(this).apply { start(model.renderings, viewRegistry) }
+      WorkflowLayout(this).apply { take(model.renderings.map { it.withRegistry(viewRegistry) }) }
     )
   }
 
@@ -39,7 +40,7 @@ class PoetryActivity : AppCompatActivity() {
 
 class PoetryModel(savedState: SavedStateHandle) : ViewModel() {
   @OptIn(WorkflowUiExperimentalApi::class)
-  val renderings: StateFlow<Any> by lazy {
+  val renderings: StateFlow<Screen> by lazy {
     renderWorkflowIn(
       workflow = PoemsBrowserWorkflow,
       scope = viewModelScope,
diff --git a/samples/containers/app-raven/src/main/java/com/squareup/sample/ravenapp/RavenActivity.kt b/samples/containers/app-raven/src/main/java/com/squareup/sample/ravenapp/RavenActivity.kt
index 05dd90088f..fa4f43653a 100644
--- a/samples/containers/app-raven/src/main/java/com/squareup/sample/ravenapp/RavenActivity.kt
+++ b/samples/containers/app-raven/src/main/java/com/squareup/sample/ravenapp/RavenActivity.kt
@@ -1,3 +1,5 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.sample.ravenapp
 
 import android.os.Bundle
@@ -10,27 +12,26 @@ import androidx.lifecycle.viewModelScope
 import com.squareup.sample.container.SampleContainers
 import com.squareup.sample.poetry.PoemWorkflow
 import com.squareup.sample.poetry.model.Raven
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackContainer
-import com.squareup.workflow1.ui.plus
+import com.squareup.workflow1.ui.container.withRegistry
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import timber.log.Timber
 
-@OptIn(WorkflowUiExperimentalApi::class)
-private val viewRegistry = SampleContainers + BackStackContainer
+private val viewRegistry = SampleContainers
 
 class RavenActivity : AppCompatActivity() {
-  @OptIn(WorkflowUiExperimentalApi::class)
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
 
     val model: RavenModel by viewModels()
     setContentView(
-      WorkflowLayout(this).apply { start(model.renderings, viewRegistry) }
+      WorkflowLayout(this).apply { take(model.renderings.map { it.withRegistry(viewRegistry) }) }
     )
 
     lifecycleScope.launch {
@@ -49,8 +50,7 @@ class RavenActivity : AppCompatActivity() {
 class RavenModel(savedState: SavedStateHandle) : ViewModel() {
   private val running = Job()
 
-  @OptIn(WorkflowUiExperimentalApi::class)
-  val renderings: StateFlow<Any> by lazy {
+  val renderings: StateFlow<Screen> by lazy {
     renderWorkflowIn(
       workflow = PoemWorkflow,
       scope = viewModelScope,
diff --git a/samples/containers/common/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreen.kt b/samples/containers/common/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreen.kt
index fce395bfb8..a8ce8860c7 100644
--- a/samples/containers/common/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreen.kt
+++ b/samples/containers/common/src/main/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreen.kt
@@ -1,7 +1,8 @@
 package com.squareup.sample.container.overviewdetail
 
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 
 /**
  * Rendering type for overview / detail containers, with [BackStackScreen] in both roles.
@@ -16,13 +17,13 @@ import com.squareup.workflow1.ui.backstack.BackStackScreen
  */
 @OptIn(WorkflowUiExperimentalApi::class)
 class OverviewDetailScreen private constructor(
-  val overviewRendering: BackStackScreen<Any>,
-  val detailRendering: BackStackScreen<Any>? = null,
+  val overviewRendering: BackStackScreen<Screen>,
+  val detailRendering: BackStackScreen<Screen>? = null,
   val selectDefault: (() -> Unit)? = null
-) {
+) : Screen {
   constructor(
-    overviewRendering: BackStackScreen<Any>,
-    detailRendering: BackStackScreen<Any>
+    overviewRendering: BackStackScreen<Screen>,
+    detailRendering: BackStackScreen<Screen>
   ) : this(overviewRendering, detailRendering, null)
 
   /**
@@ -30,12 +31,12 @@ class OverviewDetailScreen private constructor(
    * that a selection be made to fill a null [detailRendering].
    */
   constructor(
-    overviewRendering: BackStackScreen<Any>,
+    overviewRendering: BackStackScreen<Screen>,
     selectDefault: (() -> Unit)? = null
   ) : this(overviewRendering, null, selectDefault)
 
-  operator fun component1(): BackStackScreen<Any> = overviewRendering
-  operator fun component2(): BackStackScreen<Any>? = detailRendering
+  operator fun component1(): BackStackScreen<Screen> = overviewRendering
+  operator fun component2(): BackStackScreen<Screen>? = detailRendering
 
   /**
    * Returns a new [OverviewDetailScreen] appending the [overviewRendering] and
@@ -45,8 +46,8 @@ class OverviewDetailScreen private constructor(
   operator fun plus(other: OverviewDetailScreen): OverviewDetailScreen {
     val newOverview = overviewRendering + other.overviewRendering
     val newDetail = detailRendering
-        ?.let { it + other.detailRendering }
-        ?: other.detailRendering
+      ?.let { it + other.detailRendering }
+      ?: other.detailRendering
 
     return if (newDetail == null) OverviewDetailScreen(newOverview, other.selectDefault)
     else OverviewDetailScreen(newOverview, newDetail)
@@ -59,8 +60,8 @@ class OverviewDetailScreen private constructor(
     other as OverviewDetailScreen
 
     return overviewRendering == other.overviewRendering &&
-        detailRendering == other.detailRendering &&
-        selectDefault == other.selectDefault
+      detailRendering == other.detailRendering &&
+      selectDefault == other.selectDefault
   }
 
   override fun hashCode(): Int {
@@ -72,7 +73,7 @@ class OverviewDetailScreen private constructor(
 
   override fun toString(): String {
     return "OverviewDetailScreen(overviewRendering=$overviewRendering, " +
-        "detailRendering=$detailRendering, " +
-        "selectDefault=$selectDefault)"
+      "detailRendering=$detailRendering, " +
+      "selectDefault=$selectDefault)"
   }
 }
diff --git a/samples/containers/common/src/main/java/com/squareup/sample/container/panel/PanelContainerScreen.kt b/samples/containers/common/src/main/java/com/squareup/sample/container/panel/PanelContainerScreen.kt
index c9a22e0bf9..9743298435 100644
--- a/samples/containers/common/src/main/java/com/squareup/sample/container/panel/PanelContainerScreen.kt
+++ b/samples/containers/common/src/main/java/com/squareup/sample/container/panel/PanelContainerScreen.kt
@@ -1,7 +1,8 @@
 package com.squareup.sample.container.panel
 
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 import com.squareup.workflow1.ui.modal.HasModals
 
 /**
@@ -22,14 +23,14 @@ import com.squareup.workflow1.ui.modal.HasModals
  *    tasks which take multiple steps and involve going backward and forward.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-data class PanelContainerScreen<B : Any, T : Any> constructor(
+data class PanelContainerScreen<B : Screen, T : Screen> constructor(
   val baseScreen: B,
   override val modals: List<BackStackScreen<T>> = emptyList()
-) : HasModals<ScrimContainerScreen<B>, BackStackScreen<T>> {
+) : Screen, HasModals<ScrimContainerScreen<B>, BackStackScreen<T>> {
   override val beneathModals: ScrimContainerScreen<B>
     get() = ScrimContainerScreen(
-        wrapped = baseScreen,
-        dimmed = modals.isNotEmpty()
+      wrapped = baseScreen,
+      dimmed = modals.isNotEmpty()
     )
 }
 
@@ -37,7 +38,9 @@ data class PanelContainerScreen<B : Any, T : Any> constructor(
  * Shows the receiving [BackStackScreen] in the only panel over [baseScreen].
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-fun <B : Any, T : Any> BackStackScreen<T>.inPanelOver(baseScreen: B): PanelContainerScreen<B, T> {
+fun <B : Screen, T : Screen> BackStackScreen<T>.inPanelOver(
+  baseScreen: B
+): PanelContainerScreen<B, T> {
   return PanelContainerScreen(baseScreen, listOf(this))
 }
 
@@ -45,6 +48,6 @@ fun <B : Any, T : Any> BackStackScreen<T>.inPanelOver(baseScreen: B): PanelConta
  * Shows the receiver as the only panel over [baseScreen], with no back stack.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-fun <B : Any, T : Any> T.firstInPanelOver(baseScreen: B): PanelContainerScreen<B, T> {
+fun <B : Screen, T : Screen> T.firstInPanelOver(baseScreen: B): PanelContainerScreen<B, T> {
   return BackStackScreen(this, emptyList()).inPanelOver(baseScreen)
 }
diff --git a/samples/containers/common/src/main/java/com/squareup/sample/container/panel/ScrimContainerScreen.kt b/samples/containers/common/src/main/java/com/squareup/sample/container/panel/ScrimContainerScreen.kt
index eb5f6b202d..ae5e86b6aa 100644
--- a/samples/containers/common/src/main/java/com/squareup/sample/container/panel/ScrimContainerScreen.kt
+++ b/samples/containers/common/src/main/java/com/squareup/sample/container/panel/ScrimContainerScreen.kt
@@ -1,10 +1,14 @@
 package com.squareup.sample.container.panel
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
 /**
  * Show a scrim over the [wrapped] item, which is invisible if [dimmed] is false,
  * dark if it is true.
  */
-class ScrimContainerScreen<T : Any>(
+@OptIn(WorkflowUiExperimentalApi::class)
+class ScrimContainerScreen<T : Screen>(
   val wrapped: T,
   val dimmed: Boolean
-)
+) : Screen
diff --git a/samples/containers/common/src/test/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreenTest.kt b/samples/containers/common/src/test/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreenTest.kt
index cfdd58e783..f65601ed88 100644
--- a/samples/containers/common/src/test/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreenTest.kt
+++ b/samples/containers/common/src/test/java/com/squareup/sample/container/overviewdetail/OverviewDetailScreenTest.kt
@@ -1,64 +1,68 @@
 package com.squareup.sample.container.overviewdetail
 
 import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 import org.junit.Test
 
 @OptIn(WorkflowUiExperimentalApi::class)
-class OverviewDetailScreenTest {
+internal class OverviewDetailScreenTest {
+  data class S<T>(val value: T) : Screen
 
   @Test fun `minimal structure`() {
-    val screen = OverviewDetailScreen(BackStackScreen(1))
-    assertThat(screen.overviewRendering).isEqualTo(BackStackScreen(1))
+    val screen = OverviewDetailScreen(BackStackScreen(S(1)))
+    assertThat(screen.overviewRendering).isEqualTo(BackStackScreen(S(1)))
     assertThat(screen.detailRendering).isNull()
     assertThat(screen.selectDefault).isNull()
   }
 
   @Test fun `minimal equality`() {
-    val screen = OverviewDetailScreen(BackStackScreen(1))
-    assertThat(screen).isEqualTo(OverviewDetailScreen(BackStackScreen(1)))
-    assertThat(screen).isNotEqualTo(OverviewDetailScreen(BackStackScreen(2)))
+    val screen = OverviewDetailScreen(BackStackScreen(S(1)))
+    assertThat(screen).isEqualTo(OverviewDetailScreen(BackStackScreen(S(1))))
+    assertThat(screen).isNotEqualTo(OverviewDetailScreen(BackStackScreen(S(2))))
   }
 
   @Test fun `minimal hash`() {
-    val screen = OverviewDetailScreen(BackStackScreen(1))
-    assertThat(screen.hashCode()).isEqualTo(OverviewDetailScreen(BackStackScreen(1)).hashCode())
-    assertThat(screen.hashCode()).isNotEqualTo(OverviewDetailScreen(BackStackScreen(2)).hashCode())
+    val screen = OverviewDetailScreen(BackStackScreen(S(1)))
+    assertThat(screen.hashCode()).isEqualTo(OverviewDetailScreen(BackStackScreen(S(1))).hashCode())
+    assertThat(screen.hashCode())
+      .isNotEqualTo(OverviewDetailScreen(BackStackScreen(S(2))).hashCode())
   }
 
   @Test fun `combine minimal`() {
-    val left = OverviewDetailScreen(BackStackScreen(1, 2))
-    val right = OverviewDetailScreen(BackStackScreen(11, 12))
+    val left = OverviewDetailScreen(BackStackScreen(S(1), S(2)))
+    val right = OverviewDetailScreen(BackStackScreen(S(11), S(12)))
 
-    assertThat(left + right).isEqualTo(OverviewDetailScreen(BackStackScreen(1, 2, 11, 12)))
+    assertThat(left + right)
+      .isEqualTo(OverviewDetailScreen(BackStackScreen(S(1), S(2), S(11), S(12))))
   }
 
   @Test fun `full structure`() {
     val screen = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4))
     )
 
-    assertThat(screen.overviewRendering).isEqualTo(BackStackScreen(1, 2))
-    assertThat(screen.detailRendering).isEqualTo(BackStackScreen(3, 4))
+    assertThat(screen.overviewRendering).isEqualTo(BackStackScreen(S(1), S(2)))
+    assertThat(screen.detailRendering).isEqualTo(BackStackScreen(S(3), S(4)))
     assertThat(screen.selectDefault).isNull()
   }
 
   @Test fun `full equality`() {
     val screen1 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4))
     )
 
     val screen2 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4))
     )
 
     val screen3 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4, 5)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4), S(5))
     )
 
     assertThat(screen1).isEqualTo(screen2)
@@ -67,18 +71,18 @@ class OverviewDetailScreenTest {
 
   @Test fun `full hash`() {
     val screen1 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4))
     )
 
     val screen2 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4))
     )
 
     val screen3 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4, 5)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4), S(5))
     )
 
     assertThat(screen1.hashCode()).isEqualTo(screen2.hashCode())
@@ -87,18 +91,18 @@ class OverviewDetailScreenTest {
 
   @Test fun `combine full`() {
     val left = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
-        detailRendering = BackStackScreen(3, 4)
+        overviewRendering = BackStackScreen(S(1), S(2)),
+        detailRendering = BackStackScreen(S(3), S(4))
     )
     val right = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(11, 12),
-        detailRendering = BackStackScreen(13, 14)
+        overviewRendering = BackStackScreen(S(11), S(12)),
+        detailRendering = BackStackScreen(S(13), S(14))
     )
 
     assertThat(left + right).isEqualTo(
         OverviewDetailScreen(
-            overviewRendering = BackStackScreen(1, 2, 11, 12),
-            detailRendering = BackStackScreen(3, 4, 13, 14)
+            overviewRendering = BackStackScreen(S(1), S(2), S(11), S(12)),
+            detailRendering = BackStackScreen(S(3), S(4), S(13), S(14))
         )
     )
   }
@@ -106,11 +110,11 @@ class OverviewDetailScreenTest {
   @Test fun `selectDefault structure`() {
     val selectDefault = {}
     val screen = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = selectDefault
     )
 
-    assertThat(screen.overviewRendering).isEqualTo(BackStackScreen(1, 2))
+    assertThat(screen.overviewRendering).isEqualTo(BackStackScreen(S(1), S(2)))
     assertThat(screen.detailRendering).isNull()
     assertThat(screen.selectDefault).isEqualTo(selectDefault)
   }
@@ -119,17 +123,17 @@ class OverviewDetailScreenTest {
     val selectDefault = {}
 
     val screen1 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = selectDefault
     )
 
     val screen2 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = selectDefault
     )
 
     val screen3 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = {}
     )
 
@@ -141,17 +145,17 @@ class OverviewDetailScreenTest {
     val selectDefault = {}
 
     val screen1 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = selectDefault
     )
 
     val screen2 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = selectDefault
     )
 
     val screen3 = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = {}
     )
 
@@ -162,18 +166,18 @@ class OverviewDetailScreenTest {
   @Test fun `combine selectDefault`() {
     val selectDefaultLeft = {}
     val left = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(1, 2),
+        overviewRendering = BackStackScreen(S(1), S(2)),
         selectDefault = selectDefaultLeft
     )
     val selectDefaultRight = {}
     val right = OverviewDetailScreen(
-        overviewRendering = BackStackScreen(11, 12),
+        overviewRendering = BackStackScreen(S(11), S(12)),
         selectDefault = selectDefaultRight
     )
 
     assertThat(left + right).isEqualTo(
         OverviewDetailScreen(
-            overviewRendering = BackStackScreen(1, 2, 11, 12),
+            overviewRendering = BackStackScreen(S(1), S(2), S(11), S(12)),
             selectDefault = selectDefaultRight
         )
     )
diff --git a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonActivity.kt b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonActivity.kt
index 084658a45a..a324a88f1a 100644
--- a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonActivity.kt
+++ b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonActivity.kt
@@ -1,3 +1,5 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.sample.hellobackbutton
 
 import android.os.Bundle
@@ -8,26 +10,27 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.viewModelScope
 import com.squareup.sample.container.SampleContainers
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.container.withRegistry
 import com.squareup.workflow1.ui.modal.AlertContainer
 import com.squareup.workflow1.ui.plus
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 
-@OptIn(WorkflowUiExperimentalApi::class)
 private val viewRegistry = SampleContainers + AlertContainer
 
 class HelloBackButtonActivity : AppCompatActivity() {
-  @OptIn(WorkflowUiExperimentalApi::class)
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
 
     val model: HelloBackButtonModel by viewModels()
     setContentView(
-      WorkflowLayout(this).apply { start(model.renderings, viewRegistry) }
+      WorkflowLayout(this).apply { take(model.renderings.map { it.withRegistry(viewRegistry) }) }
     )
 
     lifecycleScope.launch {
@@ -40,8 +43,7 @@ class HelloBackButtonActivity : AppCompatActivity() {
 class HelloBackButtonModel(savedState: SavedStateHandle) : ViewModel() {
   private val running = Job()
 
-  @OptIn(WorkflowUiExperimentalApi::class)
-  val renderings: StateFlow<Any> by lazy {
+  val renderings: StateFlow<Screen> by lazy {
     renderWorkflowIn(
       workflow = AreYouSureWorkflow,
       scope = viewModelScope,
diff --git a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt
index c8d81522ec..5250b429f2 100644
--- a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt
+++ b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonLayoutRunner.kt
@@ -2,30 +2,30 @@ package com.squareup.sample.hellobackbutton
 
 import android.view.View
 import android.widget.TextView
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-data class HelloBackButtonRendering(
+data class HelloBackButtonScreen(
   val message: String,
   val onClick: () -> Unit,
   val onBackPressed: (() -> Unit)?
-) : AndroidViewRendering<HelloBackButtonRendering> {
-  override val viewFactory: ViewFactory<HelloBackButtonRendering> = LayoutRunner.bind(
+) : AndroidScreen<HelloBackButtonScreen> {
+  override val viewFactory: ScreenViewFactory<HelloBackButtonScreen> = ScreenViewRunner.bind(
     R.layout.hello_back_button_layout, ::HelloBackButtonLayoutRunner
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class HelloBackButtonLayoutRunner(view: View) : LayoutRunner<HelloBackButtonRendering> {
+private class HelloBackButtonLayoutRunner(view: View) : ScreenViewRunner<HelloBackButtonScreen> {
   private val messageView: TextView = view.findViewById(R.id.hello_message)
 
   override fun showRendering(
-    rendering: HelloBackButtonRendering,
+    rendering: HelloBackButtonScreen,
     viewEnvironment: ViewEnvironment
   ) {
     messageView.text = rendering.message
diff --git a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonWorkflow.kt b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonWorkflow.kt
index a8f28e7117..8f9524cf1d 100644
--- a/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonWorkflow.kt
+++ b/samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonWorkflow.kt
@@ -15,7 +15,7 @@ object HelloBackButtonWorkflow : StatefulWorkflow<
   Unit,
   State,
   Nothing,
-  HelloBackButtonRendering
+  HelloBackButtonScreen
   >() {
 
   @Parcelize
@@ -34,8 +34,8 @@ object HelloBackButtonWorkflow : StatefulWorkflow<
     renderProps: Unit,
     renderState: State,
     context: RenderContext
-  ): HelloBackButtonRendering {
-    return HelloBackButtonRendering(
+  ): HelloBackButtonScreen {
+    return HelloBackButtonScreen(
         message = "$renderState",
         onClick = context.eventHandler {
           state = when (state) {
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/PoemWorkflow.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/PoemWorkflow.kt
index 9fd63ae03e..af3d9bb4d3 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/PoemWorkflow.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/PoemWorkflow.kt
@@ -16,13 +16,14 @@ import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
 import com.squareup.workflow1.WorkflowAction.Companion.noAction
 import com.squareup.workflow1.parse
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
-import com.squareup.workflow1.ui.backstack.toBackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
+import com.squareup.workflow1.ui.container.toBackStackScreen
 
 /**
- * Renders a [Poem] as a [OverviewDetailScreen], whose overview is a [StanzaListRendering]
- * for the poem, and whose detail traverses through [StanzaRendering]s.
+ * Renders a [Poem] as a [OverviewDetailScreen], whose overview is a [StanzaListScreen]
+ * for the poem, and whose detail traverses through [StanzaScreen]s.
  */
 object PoemWorkflow : StatefulWorkflow<Poem, Int, ClosePoem, OverviewDetailScreen>() {
   object ClosePoem
@@ -41,7 +42,7 @@ object PoemWorkflow : StatefulWorkflow<Poem, Int, ClosePoem, OverviewDetailScree
     renderState: Int,
     context: RenderContext
   ): OverviewDetailScreen {
-    val previousStanzas: List<StanzaRendering> =
+    val previousStanzas: List<StanzaScreen> =
       if (renderState == -1) emptyList()
       else renderProps.stanzas.subList(0, renderState)
           .mapIndexed { index, _ ->
@@ -66,7 +67,7 @@ object PoemWorkflow : StatefulWorkflow<Poem, Int, ClosePoem, OverviewDetailScree
       }
 
     val stackedStanzas = visibleStanza?.let {
-      (previousStanzas + visibleStanza).toBackStackScreen<Any>()
+      (previousStanzas + visibleStanza).toBackStackScreen<Screen>()
     }
 
     val stanzaIndex =
@@ -74,7 +75,7 @@ object PoemWorkflow : StatefulWorkflow<Poem, Int, ClosePoem, OverviewDetailScree
         HandleStanzaListOutput(selected)
       }
           .copy(selection = renderState)
-          .let { BackStackScreen<Any>(it) }
+          .let { BackStackScreen<Screen>(it) }
 
     return stackedStanzas
         ?.let { OverviewDetailScreen(overviewRendering = stanzaIndex, detailRendering = it) }
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListRendering.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
similarity index 82%
rename from samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListRendering.kt
rename to samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
index 3ce403f503..ec5ebe70c6 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListRendering.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListScreen.kt
@@ -10,32 +10,32 @@ import androidx.recyclerview.widget.RecyclerView
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.container.poetry.R
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
-import com.squareup.workflow1.ui.backstack.BackStackConfig
-import com.squareup.workflow1.ui.backstack.BackStackConfig.Other
+import com.squareup.workflow1.ui.container.BackStackConfig
+import com.squareup.workflow1.ui.container.BackStackConfig.Other
 
 @OptIn(WorkflowUiExperimentalApi::class)
-data class StanzaListRendering(
+data class StanzaListScreen(
   val title: String,
   val subtitle: String,
   val firstLines: List<String>,
   val onStanzaSelected: (Int) -> Unit,
   val onExit: () -> Unit,
   val selection: Int = -1
-) : AndroidViewRendering<StanzaListRendering> {
-  override val viewFactory: ViewFactory<StanzaListRendering> = LayoutRunner.bind(
+) : AndroidScreen<StanzaListScreen> {
+  override val viewFactory: ScreenViewFactory<StanzaListScreen> = ScreenViewRunner.bind(
     R.layout.list,
     ::StanzaListLayoutRunner
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class StanzaListLayoutRunner(view: View) : LayoutRunner<StanzaListRendering> {
+private class StanzaListLayoutRunner(view: View) : ScreenViewRunner<StanzaListScreen> {
   private val toolbar = view.findViewById<Toolbar>(R.id.list_toolbar)
   private val recyclerView = view.findViewById<RecyclerView>(R.id.list_body)
     .apply { layoutManager = LinearLayoutManager(context) }
@@ -43,7 +43,7 @@ private class StanzaListLayoutRunner(view: View) : LayoutRunner<StanzaListRender
   private val adapter = Adapter()
 
   override fun showRendering(
-    rendering: StanzaListRendering,
+    rendering: StanzaListScreen,
     viewEnvironment: ViewEnvironment
   ) {
     adapter.view = rendering
@@ -67,7 +67,7 @@ private class StanzaListLayoutRunner(view: View) : LayoutRunner<StanzaListRender
   private class ViewHolder(val view: TextView) : RecyclerView.ViewHolder(view)
 
   private class Adapter : RecyclerView.Adapter<ViewHolder>() {
-    lateinit var view: StanzaListRendering
+    lateinit var view: StanzaListScreen
     lateinit var environment: ViewEnvironment
 
     override fun onCreateViewHolder(
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListWorkflow.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListWorkflow.kt
index b111760192..425adc179d 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListWorkflow.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListWorkflow.kt
@@ -8,13 +8,13 @@ import com.squareup.workflow1.StatelessWorkflow
  *
  * Output is the index of a clicked stanza, or -1 on exit.
  */
-object StanzaListWorkflow : StatelessWorkflow<Poem, Int, StanzaListRendering>() {
+object StanzaListWorkflow : StatelessWorkflow<Poem, Int, StanzaListScreen>() {
 
   override fun render(
     renderProps: Poem,
     context: RenderContext
-  ): StanzaListRendering {
-    return StanzaListRendering(
+  ): StanzaListScreen {
+    return StanzaListScreen(
         title = renderProps.title,
         subtitle = renderProps.poet.fullName,
         firstLines = renderProps.initialStanzas,
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaRendering.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
similarity index 84%
rename from samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaRendering.kt
rename to samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
index c429755257..7f3bdf8a57 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaRendering.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaScreen.kt
@@ -11,35 +11,35 @@ import androidx.appcompat.widget.Toolbar
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Detail
 import com.squareup.sample.container.poetry.R
-import com.squareup.workflow1.ui.AndroidViewRendering
+import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.Compatible
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
-import com.squareup.workflow1.ui.backstack.BackStackConfig
-import com.squareup.workflow1.ui.backstack.BackStackConfig.None
+import com.squareup.workflow1.ui.container.BackStackConfig
+import com.squareup.workflow1.ui.container.BackStackConfig.None
 
 @OptIn(WorkflowUiExperimentalApi::class)
-data class StanzaRendering(
+data class StanzaScreen(
   val title: String,
   val stanzaNumber: Int,
   val lines: List<String>,
   val onGoUp: () -> Unit,
   val onGoBack: (() -> Unit)? = null,
   val onGoForth: (() -> Unit)? = null
-) : AndroidViewRendering<StanzaRendering>, Compatible {
+) : AndroidScreen<StanzaScreen>, Compatible {
   override val compatibilityKey = "$title: $stanzaNumber"
 
-  override val viewFactory: ViewFactory<StanzaRendering> = LayoutRunner.bind(
+  override val viewFactory: ScreenViewFactory<StanzaScreen> = ScreenViewRunner.bind(
     R.layout.stanza_layout,
     ::StanzaLayoutRunner
   )
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class StanzaLayoutRunner(private val view: View) : LayoutRunner<StanzaRendering> {
+private class StanzaLayoutRunner(private val view: View) : ScreenViewRunner<StanzaScreen> {
   private val tabSize = TypedValue
       .applyDimension(TypedValue.COMPLEX_UNIT_SP, 24f, view.resources.displayMetrics)
       .toInt()
@@ -52,7 +52,7 @@ private class StanzaLayoutRunner(private val view: View) : LayoutRunner<StanzaRe
   private val goBack = view.findViewById<TextView>(R.id.stanza_back)
 
   override fun showRendering(
-    rendering: StanzaRendering,
+    rendering: StanzaScreen,
     viewEnvironment: ViewEnvironment
   ) {
     if (viewEnvironment[OverviewDetailConfig] == Detail) {
@@ -114,7 +114,7 @@ private class StanzaLayoutRunner(private val view: View) : LayoutRunner<StanzaRe
     setText(spans, SPANNABLE)
   }
 
-  companion object : ViewFactory<StanzaRendering> by LayoutRunner.bind(
+  companion object : ScreenViewFactory<StanzaScreen> by ScreenViewRunner.bind(
       R.layout.stanza_layout,
       ::StanzaLayoutRunner
   )
diff --git a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaWorkflow.kt b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaWorkflow.kt
index d3333ebdd6..9a9147cfaf 100644
--- a/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaWorkflow.kt
+++ b/samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaWorkflow.kt
@@ -8,7 +8,7 @@ import com.squareup.sample.poetry.StanzaWorkflow.Props
 import com.squareup.sample.poetry.model.Poem
 import com.squareup.workflow1.StatelessWorkflow
 
-object StanzaWorkflow : StatelessWorkflow<Props, Output, StanzaRendering>() {
+object StanzaWorkflow : StatelessWorkflow<Props, Output, StanzaScreen>() {
   data class Props(
     val poem: Poem,
     val index: Int
@@ -23,7 +23,7 @@ object StanzaWorkflow : StatelessWorkflow<Props, Output, StanzaRendering>() {
   override fun render(
     renderProps: Props,
     context: RenderContext
-  ): StanzaRendering {
+  ): StanzaScreen {
     with(renderProps) {
       val onGoBack: (() -> Unit)? = when (index) {
         0 -> null
@@ -39,7 +39,7 @@ object StanzaWorkflow : StatelessWorkflow<Props, Output, StanzaRendering>() {
         }
       }
 
-      return StanzaRendering(
+      return StanzaScreen(
           onGoUp = context.eventHandler { setOutput(CloseStanzas) },
           title = poem.title,
           stanzaNumber = index + 1,
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt
index 8dff8f2d3b..bdb070c080 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardView.kt
@@ -8,9 +8,9 @@ import android.graphics.Rect
 import android.view.View
 import androidx.core.content.ContextCompat
 import com.squareup.sample.dungeon.board.Board
-import com.squareup.workflow1.ui.BuilderViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.bindShowRendering
 import kotlin.math.abs
 import kotlin.math.min
@@ -83,10 +83,10 @@ class BoardView(context: Context) : View(context) {
   }
 
   @OptIn(WorkflowUiExperimentalApi::class)
-  companion object : ViewFactory<Board> by BuilderViewFactory(
-      type = Board::class,
-      viewConstructor = { initialRendering, initialEnv, contextForNewView, _ ->
-        BoardView(contextForNewView)
-            .apply { bindShowRendering(initialRendering, initialEnv) { r, _ -> update(r) } }
-      })
+  companion object : ScreenViewFactory<Board> by ManualScreenViewFactory(
+    type = Board::class,
+    viewConstructor = { initialRendering, initialEnv, contextForNewView, _ ->
+      BoardView(contextForNewView)
+        .apply { bindShowRendering(initialRendering, initialEnv) { r, _ -> update(r) } }
+    })
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt
index 240e15d8ad..24db11abde 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/BoardsListLayoutRunner.kt
@@ -10,10 +10,10 @@ import com.squareup.cycler.Recycler
 import com.squareup.cycler.toDataSource
 import com.squareup.sample.dungeon.DungeonAppWorkflow.DisplayBoardsListScreen
 import com.squareup.sample.dungeon.board.Board
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
 
@@ -24,7 +24,7 @@ import com.squareup.workflow1.ui.WorkflowViewStub
  * a `RecyclerView`.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class BoardsListLayoutRunner(rootView: View) : LayoutRunner<DisplayBoardsListScreen> {
+class BoardsListLayoutRunner(rootView: View) : ScreenViewRunner<DisplayBoardsListScreen> {
 
   /**
    * Used to associate a single [ViewEnvironment] and [DisplayBoardsListScreen.onBoardSelected]
@@ -48,13 +48,13 @@ class BoardsListLayoutRunner(rootView: View) : LayoutRunner<DisplayBoardsListScr
           bind { _, item ->
             val card: CardView = view.findViewById(R.id.board_card)
             val boardNameView: TextView = view.findViewById(R.id.board_name)
-            // The board preview is actually rendered using the same LayoutRunner as the actual
+            // The board preview is actually rendered using the same ScreenViewRunner as the actual
             // live game. It's easy to delegate to it by just putting a WorkflowViewStub in our
             // layout and giving it the Board.
             val boardPreviewView: WorkflowViewStub = view.findViewById(R.id.board_preview_stub)
 
             boardNameView.text = item.board.metadata.name
-            boardPreviewView.update(item.board, item.viewEnvironment)
+            boardPreviewView.show(item.board, item.viewEnvironment)
 
             // Gratuitous, hacky, inline test of WorkflowViewStub features.
             check(boardPreviewView.actual.visibility == INVISIBLE) {
@@ -101,7 +101,7 @@ class BoardsListLayoutRunner(rootView: View) : LayoutRunner<DisplayBoardsListScr
     )
   }
 
-  companion object : ViewFactory<DisplayBoardsListScreen> by bind(
+  companion object : ScreenViewFactory<DisplayBoardsListScreen> by bind(
       R.layout.boards_list_layout, ::BoardsListLayoutRunner
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonActivity.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonActivity.kt
index 4ce4b130b1..51c9612564 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonActivity.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonActivity.kt
@@ -5,6 +5,8 @@ import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.container.withRegistry
+import kotlinx.coroutines.flow.map
 
 class DungeonActivity : AppCompatActivity() {
 
@@ -16,8 +18,9 @@ class DungeonActivity : AppCompatActivity() {
     val component = Component(this)
     val model: TimeMachineModel by viewModels { component.timeMachineModelFactory }
 
-    setContentView(
-      WorkflowLayout(this).apply { start(model.renderings, component.viewRegistry) }
-    )
+    val contentView = WorkflowLayout(this).apply {
+      take(model.renderings.map { it.withRegistry(component.viewRegistry) })
+    }
+    setContentView(contentView)
   }
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonAppWorkflow.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonAppWorkflow.kt
index 01490e2693..5aa3973fcd 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonAppWorkflow.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonAppWorkflow.kt
@@ -11,6 +11,7 @@ import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
 import com.squareup.workflow1.renderChild
 import com.squareup.workflow1.runningWorker
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.modal.AlertContainerScreen
 
@@ -23,7 +24,7 @@ class DungeonAppWorkflow(
   data class Props(val paused: Boolean = false)
 
   sealed class State {
-    object LoadingBoardList : State()
+    object LoadingBoardList : State(), Screen
     data class ChoosingBoard(val boards: List<Pair<String, Board>>) : State()
     data class PlayingGame(val boardPath: BoardPath) : State()
   }
@@ -31,7 +32,7 @@ class DungeonAppWorkflow(
   data class DisplayBoardsListScreen(
     val boards: List<Board>,
     val onBoardSelected: (index: Int) -> Unit
-  )
+  ) : Screen
 
   override fun initialState(
     props: Props,
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt
index 84cdf4e456..7a096283f1 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameLayoutRunner.kt
@@ -1,5 +1,6 @@
 package com.squareup.sample.dungeon
 
+import android.annotation.SuppressLint
 import android.view.MotionEvent.ACTION_DOWN
 import android.view.MotionEvent.ACTION_MASK
 import android.view.MotionEvent.ACTION_UP
@@ -9,11 +10,11 @@ import com.squareup.sample.dungeon.Direction.LEFT
 import com.squareup.sample.dungeon.Direction.RIGHT
 import com.squareup.sample.dungeon.Direction.UP
 import com.squareup.sample.dungeon.GameWorkflow.GameRendering
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
 
 /**
@@ -21,7 +22,7 @@ import com.squareup.workflow1.ui.WorkflowViewStub
  * the player.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-class GameLayoutRunner(view: View) : LayoutRunner<GameRendering> {
+class GameLayoutRunner(view: View) : ScreenViewRunner<GameRendering> {
 
   private val boardView: WorkflowViewStub = view.findViewById(R.id.board_stub)
   private val moveLeft: View = view.findViewById(R.id.move_left)
@@ -42,7 +43,7 @@ class GameLayoutRunner(view: View) : LayoutRunner<GameRendering> {
     rendering: GameRendering,
     viewEnvironment: ViewEnvironment
   ) {
-    boardView.update(rendering.board, viewEnvironment)
+    boardView.show(rendering.board, viewEnvironment)
     this.rendering = rendering
 
     // Disable the views if we don't have an event handler, e.g. when the game has finished.
@@ -53,6 +54,7 @@ class GameLayoutRunner(view: View) : LayoutRunner<GameRendering> {
     moveDown.isEnabled = controlsEnabled
   }
 
+  @SuppressLint("ClickableViewAccessibility")
   private fun View.registerPlayerEventHandlers(direction: Direction) {
     setOnTouchListener { _, motionEvent ->
       when (motionEvent.action and ACTION_MASK) {
@@ -64,7 +66,7 @@ class GameLayoutRunner(view: View) : LayoutRunner<GameRendering> {
     }
   }
 
-  companion object : ViewFactory<GameRendering> by bind(
+  companion object : ScreenViewFactory<GameRendering> by bind(
       R.layout.game_layout, ::GameLayoutRunner
   )
 }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameSessionWorkflow.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameSessionWorkflow.kt
index 9ad76f98dd..f655f455c7 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameSessionWorkflow.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameSessionWorkflow.kt
@@ -15,6 +15,7 @@ import com.squareup.workflow1.WorkflowAction
 import com.squareup.workflow1.WorkflowAction.Companion.noAction
 import com.squareup.workflow1.action
 import com.squareup.workflow1.runningWorker
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.modal.AlertContainerScreen
 import com.squareup.workflow1.ui.modal.AlertScreen
@@ -38,7 +39,7 @@ class GameSessionWorkflow(
   )
 
   sealed class State {
-    object Loading : State()
+    object Loading : State(), Screen
     data class Running(val board: Board) : State()
     data class GameOver(val board: Board) : State()
   }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
index 8f1a1b3cef..019c97c2dc 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/LoadingBinding.kt
@@ -1,13 +1,16 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.sample.dungeon
 
 import android.view.View
 import android.widget.TextView
 import androidx.annotation.StringRes
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 /**
  * Factory function for [ViewFactory]s that show a full-screen loading indicator with some text
@@ -16,19 +19,17 @@ import com.squareup.workflow1.ui.ViewEnvironment
  * The binding is parameterized on two things: the type of the rendering that this binding is
  * keyed off of, and the resource ID of the string to use for the label.
  */
-@OptIn(WorkflowUiExperimentalApi::class)
 @Suppress("FunctionName")
-inline fun <reified RenderingT : Any> LoadingBinding(
+inline fun <reified RenderingT : Screen> LoadingBinding(
   @StringRes loadingLabelRes: Int
-): ViewFactory<RenderingT> =
-  bind(R.layout.loading_layout) { view -> LoadingLayoutRunner<RenderingT>(loadingLabelRes, view) }
+): ScreenViewFactory<RenderingT> =
+  bind(R.layout.loading_layout) { view -> LoadingLayoutRunner(loadingLabelRes, view) }
 
-@OptIn(WorkflowUiExperimentalApi::class)
 @PublishedApi
-internal class LoadingLayoutRunner<RenderingT : Any>(
+internal class LoadingLayoutRunner<RenderingT : Screen>(
   @StringRes private val labelRes: Int,
   view: View
-) : LayoutRunner<RenderingT> {
+) : ScreenViewRunner<RenderingT> {
 
   init {
     view.findViewById<TextView>(R.id.loading_label)
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineAppWorkflow.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineAppWorkflow.kt
index b6fb62ca70..eb011836a0 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineAppWorkflow.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineAppWorkflow.kt
@@ -3,7 +3,7 @@ package com.squareup.sample.dungeon
 import android.content.Context
 import com.squareup.sample.dungeon.DungeonAppWorkflow.Props
 import com.squareup.sample.timemachine.TimeMachineWorkflow
-import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineRendering
+import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineScreen
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow.PropsFactory
 import com.squareup.workflow1.StatelessWorkflow
@@ -20,7 +20,7 @@ class TimeMachineAppWorkflow(
   appWorkflow: DungeonAppWorkflow,
   clock: TimeSource,
   context: Context
-) : StatelessWorkflow<BoardPath, Nothing, ShakeableTimeMachineRendering>() {
+) : StatelessWorkflow<BoardPath, Nothing, ShakeableTimeMachineScreen>() {
 
   private val timeMachineWorkflow =
     ShakeableTimeMachineWorkflow(TimeMachineWorkflow(appWorkflow, clock), context)
@@ -28,7 +28,7 @@ class TimeMachineAppWorkflow(
   override fun render(
     renderProps: BoardPath,
     context: RenderContext
-  ): ShakeableTimeMachineRendering {
+  ): ShakeableTimeMachineScreen {
     val propsFactory = PropsFactory { recording ->
       Props(paused = !recording)
     }
diff --git a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineModel.kt b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineModel.kt
index 0c231feaf6..992f3cdbc0 100644
--- a/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineModel.kt
+++ b/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineModel.kt
@@ -6,17 +6,20 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import androidx.savedstate.SavedStateRegistryOwner
 import com.squareup.workflow1.diagnostic.tracing.TracingWorkflowInterceptor
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.flow.StateFlow
 import java.io.File
+import kotlin.time.ExperimentalTime
 
 class TimeMachineModel(
   private val savedState: SavedStateHandle,
   private val workflow: TimeMachineAppWorkflow,
   private val traceFilesDir: File
 ) : ViewModel() {
-  val renderings: StateFlow<Any> by lazy {
+  @OptIn(WorkflowUiExperimentalApi::class, ExperimentalTime::class)
+  val renderings: StateFlow<Screen> by lazy {
     val traceFile = traceFilesDir.resolve("workflow-trace-dungeon.json")
 
     @OptIn(WorkflowUiExperimentalApi::class)
diff --git a/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/GameWorkflow.kt b/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/GameWorkflow.kt
index 4c9c11ac2e..56932e1def 100644
--- a/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/GameWorkflow.kt
+++ b/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/GameWorkflow.kt
@@ -21,6 +21,8 @@ import com.squareup.workflow1.Worker
 import com.squareup.workflow1.action
 import com.squareup.workflow1.renderChild
 import com.squareup.workflow1.runningWorker
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
@@ -60,12 +62,13 @@ class GameWorkflow(
     object PlayerWasEaten : Output()
   }
 
+  @OptIn(WorkflowUiExperimentalApi::class)
   data class GameRendering(
     val board: Board,
     val gameOver: Boolean = false,
     val onStartMoving: (Direction) -> Unit,
     val onStopMoving: (Direction) -> Unit
-  )
+  ) : Screen
 
   override fun initialState(
     props: Props,
diff --git a/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/board/Board.kt b/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/board/Board.kt
index a459bf772b..9ea482883d 100644
--- a/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/board/Board.kt
+++ b/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/board/Board.kt
@@ -1,5 +1,7 @@
 package com.squareup.sample.dungeon.board
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import kotlinx.serialization.Serializable
 
 /**
@@ -17,12 +19,13 @@ data class BoardMetadata(val name: String)
  *
  * @see parseBoard
  */
+@OptIn(WorkflowUiExperimentalApi::class)
 data class Board(
   val metadata: BoardMetadata,
   val width: Int,
   val height: Int,
   val cells: List<BoardCell>
-) {
+) : Screen {
   data class Location(
     val x: Int,
     val y: Int
@@ -50,10 +53,10 @@ data class Board(
 
   override fun toString(): String {
     return cells.asSequence()
-        .chunked(width)
-        .joinToString(separator = "\n") {
-          it.joinToString(separator = "")
-        }
+      .chunked(width)
+      .joinToString(separator = "\n") {
+        it.joinToString(separator = "")
+      }
   }
 
   private fun cellIndexOf(
@@ -70,9 +73,9 @@ data class Board(
       rows: List<List<BoardCell>>
     ): Board {
       val width = rows.map { it.size }
-          .distinct()
-          .singleOrNull()
-          ?: throw IllegalArgumentException("Expected all rows to be the same length.")
+        .distinct()
+        .singleOrNull()
+        ?: throw IllegalArgumentException("Expected all rows to be the same length.")
       val height = rows.size
       require(width == height) { "Expected board to be square, but was $width × $height" }
       val cells = rows.reduce { acc, row -> acc + row }
diff --git a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt
index f65d42daf1..c955a91404 100644
--- a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt
+++ b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineLayoutRunner.kt
@@ -8,10 +8,10 @@ import androidx.constraintlayout.widget.Group
 import androidx.transition.TransitionManager
 import com.squareup.sample.timemachine.shakeable.internal.GlassFrameLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowViewStub
 import com.squareup.workflow1.ui.backPressedHandler
 import kotlin.time.Duration
@@ -19,12 +19,12 @@ import kotlin.time.ExperimentalTime
 
 /**
  * Renders [ShakeableTimeMachineWorkflow][ShakeableTimeMachineWorkflow]
- * [renderings][ShakeableTimeMachineRendering].
+ * [renderings][ShakeableTimeMachineScreen].
  */
 @OptIn(ExperimentalTime::class, WorkflowUiExperimentalApi::class)
 class ShakeableTimeMachineLayoutRunner(
   private val view: View
-) : LayoutRunner<ShakeableTimeMachineRendering> {
+) : ScreenViewRunner<ShakeableTimeMachineScreen> {
 
   private val glassView: GlassFrameLayout = view.findViewById(R.id.glass_view)
   private val childStub: WorkflowViewStub = view.findViewById(R.id.child_stub)
@@ -39,7 +39,7 @@ class ShakeableTimeMachineLayoutRunner(
   }
 
   override fun showRendering(
-    rendering: ShakeableTimeMachineRendering,
+    rendering: ShakeableTimeMachineScreen,
     viewEnvironment: ViewEnvironment
   ) {
     // Only handle back presses explicitly if in playback mode.
@@ -79,7 +79,7 @@ class ShakeableTimeMachineLayoutRunner(
     }
 
     // Show the child screen.
-    childStub.update(rendering.rendering, viewEnvironment)
+    childStub.show(rendering.rendering, viewEnvironment)
   }
 
   private fun Duration.toProgressInt(): Int = this.inWholeMilliseconds.toInt()
@@ -87,7 +87,7 @@ class ShakeableTimeMachineLayoutRunner(
 
   private fun Duration.toUiString(): String = toString()
 
-  companion object : ViewFactory<ShakeableTimeMachineRendering> by bind(
+  companion object : ScreenViewFactory<ShakeableTimeMachineScreen> by bind(
       R.layout.shakeable_time_machine_layout, ::ShakeableTimeMachineLayoutRunner
   )
 }
diff --git a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineRendering.kt b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineScreen.kt
similarity index 81%
rename from samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineRendering.kt
rename to samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineScreen.kt
index e48a7907ed..0f5d9332b0 100644
--- a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineRendering.kt
+++ b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineScreen.kt
@@ -1,5 +1,7 @@
 package com.squareup.sample.timemachine.shakeable
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import kotlin.time.Duration
 import kotlin.time.ExperimentalTime
 
@@ -15,12 +17,13 @@ import kotlin.time.ExperimentalTime
  * @param onResumeRecording Event handler that will be called when [recording] is false and the user
  * wants to go back to the live delegate workflow.
  */
+@OptIn(WorkflowUiExperimentalApi::class)
 @ExperimentalTime
-data class ShakeableTimeMachineRendering(
-  val rendering: Any,
+data class ShakeableTimeMachineScreen(
+  val rendering: Screen,
   val totalDuration: Duration,
   val playbackPosition: Duration,
   val recording: Boolean,
   val onSeek: (Duration) -> Unit = {},
   val onResumeRecording: () -> Unit
-)
+) : Screen
diff --git a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt
index f5f94f8db2..0a3fea30fe 100644
--- a/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt
+++ b/samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt
@@ -12,6 +12,8 @@ import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
 import com.squareup.workflow1.action
 import com.squareup.workflow1.runningWorker
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import kotlin.time.Duration
 import kotlin.time.ExperimentalTime
 
@@ -22,11 +24,12 @@ import kotlin.time.ExperimentalTime
  *
  * This workflow takes a [PropsFactory] as its props. See that class for more documentation.
  */
+@OptIn(WorkflowUiExperimentalApi::class)
 @ExperimentalTime
-class ShakeableTimeMachineWorkflow<in P, O : Any, out R : Any>(
+class ShakeableTimeMachineWorkflow<in P, O : Any, out R : Screen>(
   private val timeMachineWorkflow: TimeMachineWorkflow<P, O, R>,
   context: Context
-) : StatefulWorkflow<PropsFactory<P>, State, O, ShakeableTimeMachineRendering>() {
+) : StatefulWorkflow<PropsFactory<P>, State, O, ShakeableTimeMachineScreen>() {
 
   /**
    * A factory that knows how to create the props for a [TimeMachineWorkflow.delegateWorkflow],
@@ -54,7 +57,7 @@ class ShakeableTimeMachineWorkflow<in P, O : Any, out R : Any>(
     renderProps: PropsFactory<P>,
     renderState: State,
     context: RenderContext
-  ): ShakeableTimeMachineRendering {
+  ): ShakeableTimeMachineScreen {
     // Only listen to shakes when recording.
     if (renderState === Recording) context.runningWorker(shakeWorker) { onShake }
 
@@ -70,7 +73,7 @@ class ShakeableTimeMachineWorkflow<in P, O : Any, out R : Any>(
         forwardOutput(output)
       }
 
-    return ShakeableTimeMachineRendering(
+    return ShakeableTimeMachineScreen(
         rendering = timeMachineRendering.value,
         totalDuration = timeMachineRendering.totalDuration,
         playbackPosition = if (renderState is PlayingBack) {
diff --git a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
index f7f7ca6407..3757079052 100644
--- a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
+++ b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloRendering.kt
@@ -1,18 +1,18 @@
 package com.squareup.sample.helloworkflowfragment
 
 import com.squareup.sample.helloworkflowfragment.databinding.HelloGoodbyeLayoutBinding
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
 data class HelloRendering(
   val message: String,
   val onClick: () -> Unit
-) : AndroidViewRendering<HelloRendering> {
-  override val viewFactory: ViewFactory<HelloRendering> =
-    LayoutRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
+) : AndroidScreen<HelloRendering> {
+  override val viewFactory: ScreenViewFactory<HelloRendering> =
+    ScreenViewRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
       helloMessage.text = "${r.message} Fragment"
       helloMessage.setOnClickListener { r.onClick() }
     }
diff --git a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloWorkflowFragment.kt b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloWorkflowFragment.kt
index ccd6787034..ec31c50f95 100644
--- a/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloWorkflowFragment.kt
+++ b/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloWorkflowFragment.kt
@@ -26,7 +26,7 @@ class HelloWorkflowFragment : Fragment() {
     val model: HelloViewModel = ViewModelProvider(this).get(HelloViewModel::class.java)
 
     return WorkflowLayout(inflater.context).apply {
-      start(model.renderings)
+      take(model.renderings)
     }
   }
 }
diff --git a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
index a6a0d7add8..ee34b15391 100644
--- a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
+++ b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloRendering.kt
@@ -1,18 +1,18 @@
 package com.squareup.sample.helloworkflow
 
 import com.squareup.sample.helloworkflow.databinding.HelloGoodbyeLayoutBinding
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
 data class HelloRendering(
   val message: String,
   val onClick: () -> Unit
-) : AndroidViewRendering<HelloRendering> {
-  override val viewFactory: ViewFactory<HelloRendering> =
-    LayoutRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
+) : AndroidScreen<HelloRendering> {
+  override val viewFactory: ScreenViewFactory<HelloRendering> =
+    ScreenViewRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
       helloMessage.text = r.message
       helloMessage.setOnClickListener { r.onClick() }
     }
diff --git a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloWorkflowActivity.kt b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloWorkflowActivity.kt
index 99318b4eb0..5170f60f62 100644
--- a/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloWorkflowActivity.kt
+++ b/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloWorkflowActivity.kt
@@ -21,7 +21,7 @@ class HelloWorkflowActivity : AppCompatActivity() {
     // succeeding calls.
     val model: HelloViewModel by viewModels()
     setContentView(
-      WorkflowLayout(this).apply { start(model.renderings) }
+      WorkflowLayout(this).apply { take(model.renderings) }
     )
   }
 }
diff --git a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt
index c89d0a0185..2a68a552a5 100644
--- a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt
+++ b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/ClickyTextRendering.kt
@@ -8,8 +8,8 @@ import android.view.View.VISIBLE
 import android.view.ViewGroup.LayoutParams
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.widget.TextView
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.BuilderViewFactory
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.bindShowRendering
 
@@ -18,8 +18,8 @@ data class ClickyTextRendering(
   val message: String,
   val visible: Boolean = true,
   val onClick: (() -> Unit)? = null
-) : AndroidViewRendering<ClickyTextRendering> {
-  override val viewFactory = BuilderViewFactory(
+) : AndroidScreen<ClickyTextRendering> {
+  override val viewFactory = ManualScreenViewFactory(
     type = ClickyTextRendering::class,
     viewConstructor = { initialRendering, initialEnv, context, _ ->
       TextView(context).also { textView ->
diff --git a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
index 4f15b0cfb3..ac22b64f52 100644
--- a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
+++ b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/OuterRendering.kt
@@ -1,18 +1,19 @@
 package com.squareup.sample.stubvisibility
+
 import com.squareup.sample.stubvisibility.databinding.StubVisibilityLayoutBinding
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 @OptIn(WorkflowUiExperimentalApi::class)
 data class OuterRendering(
   val top: ClickyTextRendering,
   val bottom: ClickyTextRendering
-) : AndroidViewRendering<OuterRendering> {
-  override val viewFactory: ViewFactory<OuterRendering> =
-    LayoutRunner.bind(StubVisibilityLayoutBinding::inflate) { rendering, env ->
-      shouldBeFilledStub.update(rendering.top, env)
-      shouldBeWrappedStub.update(rendering.bottom, env)
+) : AndroidScreen<OuterRendering> {
+  override val viewFactory: ScreenViewFactory<OuterRendering> =
+    ScreenViewRunner.bind(StubVisibilityLayoutBinding::inflate) { rendering, env ->
+      shouldBeFilledStub.show(rendering.top, env)
+      shouldBeWrappedStub.show(rendering.bottom, env)
     }
 }
diff --git a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/StubVisibilityActivity.kt b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/StubVisibilityActivity.kt
index 82d29114cc..a68ed589ab 100644
--- a/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/StubVisibilityActivity.kt
+++ b/samples/stub-visibility/src/main/java/com/squareup/sample/stubvisibility/StubVisibilityActivity.kt
@@ -1,3 +1,5 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.sample.stubvisibility
 
 import android.os.Bundle
@@ -6,25 +8,25 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.flow.StateFlow
 
-@OptIn(WorkflowUiExperimentalApi::class)
 class StubVisibilityActivity : AppCompatActivity() {
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
 
     val model: StubVisibilityModel by viewModels()
     setContentView(
-      WorkflowLayout(this).apply { start(model.renderings) }
+      WorkflowLayout(this).apply { take(model.renderings) }
     )
   }
 }
 
 class StubVisibilityModel(savedState: SavedStateHandle) : ViewModel() {
-  val renderings: StateFlow<Any> by lazy {
+  val renderings: StateFlow<Screen> by lazy {
     @OptIn(WorkflowUiExperimentalApi::class)
     renderWorkflowIn(
       workflow = StubVisibilityWorkflow,
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
index c20f8bce08..a9f2411280 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/AuthorizingViewFactory.kt
@@ -1,12 +1,12 @@
 package com.squareup.sample.authworkflow
 
 import com.squareup.sample.tictactoe.databinding.AuthorizingLayoutBinding
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal val AuthorizingViewFactory: ViewFactory<AuthorizingScreen> =
-  LayoutRunner.bind(AuthorizingLayoutBinding::inflate) { rendering, _ ->
+internal val AuthorizingViewFactory: ScreenViewFactory<AuthorizingScreen> =
+  ScreenViewRunner.bind(AuthorizingLayoutBinding::inflate) { rendering, _ ->
     authorizingMessage.text = rendering.message
   }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
index ccbb5715bc..b16254b150 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/LoginViewFactory.kt
@@ -1,14 +1,14 @@
 package com.squareup.sample.authworkflow
 
 import com.squareup.sample.tictactoe.databinding.LoginLayoutBinding
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal val LoginViewFactory: ViewFactory<LoginScreen> =
-  LayoutRunner.bind(LoginLayoutBinding::inflate) { rendering, _ ->
+internal val LoginViewFactory: ScreenViewFactory<LoginScreen> =
+  ScreenViewRunner.bind(LoginLayoutBinding::inflate) { rendering, _ ->
     loginErrorMessage.text = rendering.errorMessage
 
     loginButton.setOnClickListener {
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
index 687780e38a..411a8db473 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/authworkflow/SecondFactorViewFactory.kt
@@ -1,14 +1,14 @@
 package com.squareup.sample.authworkflow
 
 import com.squareup.sample.tictactoe.databinding.SecondFactorLayoutBinding
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal val SecondFactorViewFactory: ViewFactory<SecondFactorScreen> =
-  LayoutRunner.bind(SecondFactorLayoutBinding::inflate) { rendering, _ ->
+internal val SecondFactorViewFactory: ScreenViewFactory<SecondFactorScreen> =
+  ScreenViewRunner.bind(SecondFactorLayoutBinding::inflate) { rendering, _ ->
     root.backPressedHandler = { rendering.onCancel() }
     secondFactorToolbar.setNavigationOnClickListener { rendering.onCancel() }
 
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt
index 25ef50f297..2a2bf057f1 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GameOverLayoutRunner.kt
@@ -10,17 +10,17 @@ import com.squareup.sample.gameworkflow.SyncState.SAVE_FAILED
 import com.squareup.sample.gameworkflow.SyncState.SAVING
 import com.squareup.sample.tictactoe.databinding.BoardBinding
 import com.squareup.sample.tictactoe.databinding.GamePlayLayoutBinding
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
 internal class GameOverLayoutRunner(
   private val binding: GamePlayLayoutBinding
-) : LayoutRunner<GameOverScreen> {
+) : ScreenViewRunner<GameOverScreen> {
 
   private val saveItem: MenuItem = binding.gamePlayToolbar.menu.add("")
       .apply {
@@ -102,7 +102,7 @@ internal class GameOverLayoutRunner(
   }
 
   /** Note how easily we're sharing this layout with [GamePlayViewFactory]. */
-  companion object : ViewFactory<GameOverScreen> by bind(
+  companion object : ScreenViewFactory<GameOverScreen> by bind(
       GamePlayLayoutBinding::inflate, ::GameOverLayoutRunner
   )
 }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
index 11c6c1cb03..d1eace7626 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/GamePlayViewFactory.kt
@@ -4,13 +4,13 @@ import android.view.View
 import android.view.ViewGroup
 import com.squareup.sample.tictactoe.databinding.GamePlayLayoutBinding
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal val GamePlayViewFactory: ViewFactory<GamePlayScreen> =
-  LayoutRunner.bind(GamePlayLayoutBinding::inflate) { rendering, _ ->
+internal val GamePlayViewFactory: ScreenViewFactory<GamePlayScreen> =
+  ScreenViewRunner.bind(GamePlayLayoutBinding::inflate) { rendering, _ ->
     renderBanner(rendering.gameState, rendering.playerInfo)
     rendering.gameState.board.render(gamePlayBoard.root)
 
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
index 4d01e1b622..53a4341e72 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/gameworkflow/NewGameViewFactory.kt
@@ -2,13 +2,13 @@ package com.squareup.sample.gameworkflow
 
 import com.squareup.sample.tictactoe.databinding.NewGameLayoutBinding
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.backPressedHandler
 
 @OptIn(WorkflowUiExperimentalApi::class)
-internal val NewGameViewFactory: ViewFactory<NewGameScreen> =
-  LayoutRunner.bind(NewGameLayoutBinding::inflate) { rendering, _ ->
+internal val NewGameViewFactory: ScreenViewFactory<NewGameScreen> =
+  ScreenViewRunner.bind(NewGameLayoutBinding::inflate) { rendering, _ ->
     if (playerX.text.isBlank()) playerX.setText(rendering.defaultNameX)
     if (playerO.text.isBlank()) playerO.setText(rendering.defaultNameO)
 
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeActivity.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeActivity.kt
index 38490140e2..a31890d891 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeActivity.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeActivity.kt
@@ -10,10 +10,11 @@ import com.squareup.sample.container.SampleContainers
 import com.squareup.sample.gameworkflow.TicTacToeViewFactories
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackContainer
+import com.squareup.workflow1.ui.container.withRegistry
 import com.squareup.workflow1.ui.modal.AlertContainer
 import com.squareup.workflow1.ui.plus
 import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import timber.log.Timber
 
@@ -31,7 +32,7 @@ class TicTacToeActivity : AppCompatActivity() {
     idlingResource = component.idlingResource
 
     setContentView(
-      WorkflowLayout(this).apply { start(model.renderings, viewRegistry) }
+      WorkflowLayout(this).apply { take(model.renderings.map { it.withRegistry(viewRegistry) }) }
     )
 
     lifecycleScope.launch {
@@ -47,7 +48,6 @@ class TicTacToeActivity : AppCompatActivity() {
     val viewRegistry = SampleContainers +
       AuthViewFactories +
       TicTacToeViewFactories +
-      BackStackContainer +
       AlertContainer
   }
 }
diff --git a/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeModel.kt b/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeModel.kt
index 0cfb0c459c..9e56bd4f6d 100644
--- a/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeModel.kt
+++ b/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/TicTacToeModel.kt
@@ -7,6 +7,7 @@ import androidx.lifecycle.viewModelScope
 import androidx.savedstate.SavedStateRegistryOwner
 import com.squareup.sample.mainworkflow.TicTacToeWorkflow
 import com.squareup.workflow1.diagnostic.tracing.TracingWorkflowInterceptor
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.Job
@@ -21,7 +22,7 @@ class TicTacToeModel(
   private val running = Job()
 
   @OptIn(WorkflowUiExperimentalApi::class)
-  val renderings: StateFlow<Any> by lazy {
+  val renderings: StateFlow<Screen> by lazy {
     val traceFile = traceFilesDir.resolve("workflow-trace-tictactoe.json")
 
     renderWorkflowIn(
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthWorkflow.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthWorkflow.kt
index 67c8d405ca..c1a474be36 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthWorkflow.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthWorkflow.kt
@@ -15,15 +15,16 @@ import com.squareup.workflow1.Workflow
 import com.squareup.workflow1.action
 import com.squareup.workflow1.runningWorker
 import com.squareup.workflow1.rx2.asWorker
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 
 /**
  * We define this otherwise redundant typealias to keep composite workflows
  * that build on [AuthWorkflow] decoupled from it, for ease of testing.
  */
 @OptIn(WorkflowUiExperimentalApi::class)
-typealias AuthWorkflow = Workflow<Unit, AuthResult, BackStackScreen<Any>>
+typealias AuthWorkflow = Workflow<Unit, AuthResult, BackStackScreen<Screen>>
 
 sealed class AuthState {
   internal data class LoginPrompt(val errorMessage: String = "") : AuthState()
@@ -61,7 +62,7 @@ sealed class AuthResult {
  */
 @OptIn(WorkflowUiExperimentalApi::class)
 class RealAuthWorkflow(private val authService: AuthService) : AuthWorkflow,
-    StatefulWorkflow<Unit, AuthState, AuthResult, BackStackScreen<Any>>() {
+    StatefulWorkflow<Unit, AuthState, AuthResult, BackStackScreen<Screen>>() {
 
   override fun initialState(
     props: Unit,
@@ -72,7 +73,7 @@ class RealAuthWorkflow(private val authService: AuthService) : AuthWorkflow,
     renderProps: Unit,
     renderState: AuthState,
     context: RenderContext
-  ): BackStackScreen<Any> = when (renderState) {
+  ): BackStackScreen<Screen> = when (renderState) {
     is LoginPrompt -> {
       BackStackScreen(
           LoginScreen(
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthorizingScreen.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthorizingScreen.kt
index 795d7fe933..41878b251b 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthorizingScreen.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthorizingScreen.kt
@@ -1,5 +1,9 @@
 package com.squareup.sample.authworkflow
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+@OptIn(WorkflowUiExperimentalApi::class)
 data class AuthorizingScreen(
   val message: String
-)
+) : Screen
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/LoginScreen.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/LoginScreen.kt
index 9d45becfc5..8f375ad0b3 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/LoginScreen.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/LoginScreen.kt
@@ -1,7 +1,11 @@
 package com.squareup.sample.authworkflow
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+@OptIn(WorkflowUiExperimentalApi::class)
 data class LoginScreen(
   val errorMessage: String = "",
   val onLogin: (email: String, password: String) -> Unit = { _, _ -> },
   val onCancel: () -> Unit = {}
-)
+) : Screen
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/SecondFactorScreen.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/SecondFactorScreen.kt
index de0c37d728..7595cd8f6a 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/SecondFactorScreen.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/SecondFactorScreen.kt
@@ -1,7 +1,11 @@
 package com.squareup.sample.authworkflow
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+@OptIn(WorkflowUiExperimentalApi::class)
 data class SecondFactorScreen(
   val errorMessage: String = "",
   val onSubmit: (String) -> Unit = {},
   val onCancel: () -> Unit = {}
-)
+) : Screen
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GameOverScreen.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GameOverScreen.kt
index 3a4ed377d3..2b22ca2831 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GameOverScreen.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GameOverScreen.kt
@@ -1,8 +1,12 @@
 package com.squareup.sample.gameworkflow
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+@OptIn(WorkflowUiExperimentalApi::class)
 data class GameOverScreen(
   val endGameState: RunGameState.GameOver,
   val onTrySaveAgain: () -> Unit,
   val onPlayAgain: () -> Unit,
   val onExit: () -> Unit
-)
+) : Screen
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GamePlayScreen.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GamePlayScreen.kt
index 42a928ce9a..6f2c9042f8 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GamePlayScreen.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/GamePlayScreen.kt
@@ -1,8 +1,12 @@
 package com.squareup.sample.gameworkflow
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+@OptIn(WorkflowUiExperimentalApi::class)
 data class GamePlayScreen(
   val playerInfo: PlayerInfo = PlayerInfo(),
   val gameState: Turn = Turn(),
   val onQuit: () -> Unit = {},
   val onClick: (row: Int, col: Int) -> Unit = { _, _ -> }
-)
+) : Screen
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/NewGameScreen.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/NewGameScreen.kt
index e5b27e59fb..bb16547123 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/NewGameScreen.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/NewGameScreen.kt
@@ -1,8 +1,12 @@
 package com.squareup.sample.gameworkflow
 
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+@OptIn(WorkflowUiExperimentalApi::class)
 data class NewGameScreen(
   val defaultNameX: String,
   val defaultNameO: String,
   val onCancel: () -> Unit,
   val onStartGame: (x: String, o: String) -> Unit
-)
+) : Screen
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/RunGameWorkflow.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/RunGameWorkflow.kt
index 0d6cc223aa..7b39099048 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/RunGameWorkflow.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/gameworkflow/RunGameWorkflow.kt
@@ -1,3 +1,5 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.sample.gameworkflow
 
 import com.squareup.sample.container.panel.PanelContainerScreen
@@ -21,6 +23,7 @@ import com.squareup.workflow1.Workflow
 import com.squareup.workflow1.action
 import com.squareup.workflow1.runningWorker
 import com.squareup.workflow1.rx2.asWorker
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.modal.AlertContainerScreen
 import com.squareup.workflow1.ui.modal.AlertScreen
@@ -35,8 +38,7 @@ enum class RunGameResult {
   FinishedPlaying
 }
 
-@OptIn(WorkflowUiExperimentalApi::class)
-typealias RunGameScreen = AlertContainerScreen<PanelContainerScreen<Any, Any>>
+typealias RunGameScreen = AlertContainerScreen<PanelContainerScreen<Screen, Screen>>
 
 /**
  * We define this otherwise redundant typealias to keep composite workflows
@@ -49,20 +51,18 @@ typealias RunGameWorkflow = Workflow<Unit, RunGameResult, RunGameScreen>
  * confirm quit screen, and offers a chance to play again. Delegates to [TakeTurnsWorkflow]
  * for the actual playing of the game.
  */
-@OptIn(WorkflowUiExperimentalApi::class)
 class RealRunGameWorkflow(
   private val takeTurnsWorkflow: TakeTurnsWorkflow,
   private val gameLog: GameLog
 ) : RunGameWorkflow,
-    StatefulWorkflow<Unit, RunGameState, RunGameResult,
-        RunGameScreen>() {
+  StatefulWorkflow<Unit, RunGameState, RunGameResult, RunGameScreen>() {
 
   override fun initialState(
     props: Unit,
     snapshot: Snapshot?
   ): RunGameState {
     return snapshot?.let { RunGameState.fromSnapshot(snapshot.bytes) }
-        ?: NewGame()
+      ?: NewGame()
   }
 
   override fun render(
@@ -74,13 +74,13 @@ class RealRunGameWorkflow(
       val emptyGameScreen = GamePlayScreen()
 
       subflowScreen(
-          base = emptyGameScreen,
-          subflow = NewGameScreen(
-              renderState.defaultXName,
-              renderState.defaultOName,
-              onCancel = context.eventHandler { setOutput(CanceledStart) },
-              onStartGame = context.eventHandler { x, o -> state = Playing(PlayerInfo(x, o)) }
-          )
+        base = emptyGameScreen,
+        subflow = NewGameScreen(
+          renderState.defaultXName,
+          renderState.defaultOName,
+          onCancel = context.eventHandler { setOutput(CanceledStart) },
+          onStartGame = context.eventHandler { x, o -> state = Playing(PlayerInfo(x, o)) }
+        )
       )
     }
 
@@ -89,10 +89,10 @@ class RealRunGameWorkflow(
       // already going. TakeTurnsWorkflow.render is immediately called,
       // and the GamePlayScreen it renders is immediately returned.
       val takeTurnsScreen = context.renderChild(
-          takeTurnsWorkflow,
-          props = renderState.resume
-              ?.let { TakeTurnsProps.resumeGame(renderState.playerInfo, it) }
-              ?: TakeTurnsProps.newGame(renderState.playerInfo)
+        takeTurnsWorkflow,
+        props = renderState.resume
+          ?.let { TakeTurnsProps.resumeGame(renderState.playerInfo, it) }
+          ?: TakeTurnsProps.newGame(renderState.playerInfo)
       ) { stopPlaying(it) }
 
       simpleScreen(takeTurnsScreen)
@@ -100,41 +100,41 @@ class RealRunGameWorkflow(
 
     is MaybeQuitting -> {
       alertScreen(
-          base = GamePlayScreen(renderState.playerInfo, renderState.completedGame.lastTurn),
-          alert = maybeQuitScreen(
-              confirmQuit = context.eventHandler {
-                (state as? MaybeQuitting)?.let { oldState ->
-                  state = MaybeQuittingForSure(oldState.playerInfo, oldState.completedGame)
-                }
-              },
-              continuePlaying = context.eventHandler {
-                (state as? MaybeQuitting)?.let { oldState ->
-                  state = Playing(oldState.playerInfo, oldState.completedGame.lastTurn)
-                }
-              }
-          )
+        base = GamePlayScreen(renderState.playerInfo, renderState.completedGame.lastTurn),
+        alert = maybeQuitScreen(
+          confirmQuit = context.eventHandler {
+            (state as? MaybeQuitting)?.let { oldState ->
+              state = MaybeQuittingForSure(oldState.playerInfo, oldState.completedGame)
+            }
+          },
+          continuePlaying = context.eventHandler {
+            (state as? MaybeQuitting)?.let { oldState ->
+              state = Playing(oldState.playerInfo, oldState.completedGame.lastTurn)
+            }
+          }
+        )
       )
     }
 
     is MaybeQuittingForSure -> {
       nestedAlertsScreen(
-          GamePlayScreen(renderState.playerInfo, renderState.completedGame.lastTurn),
-          maybeQuitScreen(),
-          maybeQuitScreen(
-              message = "Really?",
-              positive = "Yes!!",
-              negative = "Sigh, no",
-              confirmQuit = context.eventHandler {
-                (state as? MaybeQuittingForSure)?.let { oldState ->
-                  state = GameOver(oldState.playerInfo, oldState.completedGame)
-                }
-              },
-              continuePlaying = context.eventHandler {
-                (state as? MaybeQuittingForSure)?.let { oldState ->
-                  state = Playing(oldState.playerInfo, oldState.completedGame.lastTurn)
-                }
-              }
-          )
+        GamePlayScreen(renderState.playerInfo, renderState.completedGame.lastTurn),
+        maybeQuitScreen(),
+        maybeQuitScreen(
+          message = "Really?",
+          positive = "Yes!!",
+          negative = "Sigh, no",
+          confirmQuit = context.eventHandler {
+            (state as? MaybeQuittingForSure)?.let { oldState ->
+              state = GameOver(oldState.playerInfo, oldState.completedGame)
+            }
+          },
+          continuePlaying = context.eventHandler {
+            (state as? MaybeQuittingForSure)?.let { oldState ->
+              state = Playing(oldState.playerInfo, oldState.completedGame.lastTurn)
+            }
+          }
+        )
       )
     }
 
@@ -147,9 +147,9 @@ class RealRunGameWorkflow(
 
       GameOverScreen(
         renderState,
-          onTrySaveAgain = context.trySaveAgain(),
-          onPlayAgain = context.playAgain(),
-          onExit = context.eventHandler { setOutput(FinishedPlaying) }
+        onTrySaveAgain = context.trySaveAgain(),
+        onPlayAgain = context.playAgain(),
+        onExit = context.eventHandler { setOutput(FinishedPlaying) }
       ).let(::simpleScreen)
     }
   }
@@ -181,7 +181,7 @@ class RealRunGameWorkflow(
     (state as? GameOver)?.let { oldState ->
       check(oldState.syncState == SAVE_FAILED) {
         "Should only fire trySaveAgain in syncState $SAVE_FAILED, " +
-            "was ${oldState.syncState}"
+          "was ${oldState.syncState}"
       }
       state = oldState.copy(syncState = SAVING)
     }
@@ -190,31 +190,31 @@ class RealRunGameWorkflow(
   override fun snapshotState(state: RunGameState): Snapshot = state.toSnapshot()
 
   private fun nestedAlertsScreen(
-    base: Any,
+    base: Screen,
     vararg alerts: AlertScreen
   ): RunGameScreen {
     return AlertContainerScreen(
-        PanelContainerScreen(base), *alerts
+      PanelContainerScreen(base), *alerts
     )
   }
 
   private fun alertScreen(
-    base: Any,
+    base: Screen,
     alert: AlertScreen
   ): RunGameScreen {
     return AlertContainerScreen(
-        PanelContainerScreen(base), alert
+      PanelContainerScreen(base), alert
     )
   }
 
   private fun subflowScreen(
-    base: Any,
-    subflow: Any
+    base: Screen,
+    subflow: Screen
   ): RunGameScreen {
     return AlertContainerScreen(subflow.firstInPanelOver(base))
   }
 
-  private fun simpleScreen(screen: Any): RunGameScreen {
+  private fun simpleScreen(screen: Screen): RunGameScreen {
     return AlertContainerScreen(PanelContainerScreen(screen))
   }
 
@@ -226,21 +226,21 @@ class RealRunGameWorkflow(
     continuePlaying: () -> Unit = { }
   ): AlertScreen {
     return AlertScreen(
-        buttons = mapOf(
-            POSITIVE to positive,
-            NEGATIVE to negative
-        ),
-        message = message,
-        onEvent = { alertEvent ->
-          when (alertEvent) {
-            is ButtonClicked -> when (alertEvent.button) {
-              POSITIVE -> confirmQuit()
-              NEGATIVE -> continuePlaying()
-              NEUTRAL -> throw IllegalArgumentException()
-            }
-            Canceled -> continuePlaying()
+      buttons = mapOf(
+        POSITIVE to positive,
+        NEGATIVE to negative
+      ),
+      message = message,
+      onEvent = { alertEvent ->
+        when (alertEvent) {
+          is ButtonClicked -> when (alertEvent.button) {
+            POSITIVE -> confirmQuit()
+            NEGATIVE -> continuePlaying()
+            NEUTRAL -> throw IllegalArgumentException()
           }
+          Canceled -> continuePlaying()
         }
+      }
     )
   }
 }
diff --git a/samples/tictactoe/common/src/main/java/com/squareup/sample/mainworkflow/TicTacToeWorkflow.kt b/samples/tictactoe/common/src/main/java/com/squareup/sample/mainworkflow/TicTacToeWorkflow.kt
index 5b3b5d4485..be84a6e1d8 100644
--- a/samples/tictactoe/common/src/main/java/com/squareup/sample/mainworkflow/TicTacToeWorkflow.kt
+++ b/samples/tictactoe/common/src/main/java/com/squareup/sample/mainworkflow/TicTacToeWorkflow.kt
@@ -1,3 +1,4 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
 @file:Suppress("DEPRECATION")
 
 package com.squareup.sample.mainworkflow
@@ -47,7 +48,6 @@ class TicTacToeWorkflow(
   ): MainState = snapshot?.let { MainState.fromSnapshot(snapshot.bytes) }
     ?: Authenticating
 
-  @OptIn(WorkflowUiExperimentalApi::class)
   override fun render(
     renderProps: Unit,
     renderState: MainState,
@@ -61,7 +61,7 @@ class TicTacToeWorkflow(
       // Probably due to https://youtrack.jetbrains.com/issue/KT-32869
       @Suppress("RemoveExplicitTypeArguments")
       (AlertContainerScreen(
-        authScreen.inPanelOver<Any, Any>(emptyGameScreen)
+        authScreen.inPanelOver(emptyGameScreen)
       ))
     }
 
diff --git a/samples/tictactoe/common/src/test/java/com/squareup/sample/mainworkflow/TicTacToeWorkflowTest.kt b/samples/tictactoe/common/src/test/java/com/squareup/sample/mainworkflow/TicTacToeWorkflowTest.kt
index d3dcc788fd..52f46c2363 100644
--- a/samples/tictactoe/common/src/test/java/com/squareup/sample/mainworkflow/TicTacToeWorkflowTest.kt
+++ b/samples/tictactoe/common/src/test/java/com/squareup/sample/mainworkflow/TicTacToeWorkflowTest.kt
@@ -14,8 +14,9 @@ import com.squareup.workflow1.rendering
 import com.squareup.workflow1.runningWorker
 import com.squareup.workflow1.stateless
 import com.squareup.workflow1.testing.launchForTestingFromStartWith
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 import org.junit.Test
 
 /**
@@ -27,19 +28,19 @@ class TicTacToeWorkflowTest {
   @Test fun `starts in auth over empty game`() {
     TicTacToeWorkflow(authWorkflow(), runGameWorkflow()).launchForTestingFromStartWith {
       awaitNextRendering()
-          .let { screen ->
-            assertThat(screen.panels).hasSize(1)
-            assertThat(screen.panels[0]).isEqualTo(DEFAULT_AUTH)
+        .let { screen ->
+          assertThat(screen.panels).hasSize(1)
+          assertThat(screen.panels[0]).isEqualTo(S(DEFAULT_AUTH))
 
-            // This GamePlayScreen() is emitted by MainWorkflow itself.
-            assertThat(screen.body).isEqualTo(GamePlayScreen())
-          }
+          // This GamePlayScreen() is emitted by MainWorkflow itself.
+          assertThat(screen.body).isEqualTo(GamePlayScreen())
+        }
     }
   }
 
   @Test fun `starts game on auth`() {
     val authWorkflow: AuthWorkflow = Workflow.stateless {
-      runningWorker(Worker.from { Unit }) {
+      runningWorker(Worker.from { }) {
         action { setOutput(Authorized("auth")) }
       }
       authScreen()
@@ -47,19 +48,21 @@ class TicTacToeWorkflowTest {
 
     TicTacToeWorkflow(authWorkflow, runGameWorkflow()).launchForTestingFromStartWith {
       awaitNextRendering()
-          .let { screen ->
-            assertThat(screen.panels).isEmpty()
-            assertThat(screen.body).isEqualTo(DEFAULT_RUN_GAME)
-          }
+        .let { screen ->
+          assertThat(screen.panels).isEmpty()
+          assertThat(screen.body).isEqualTo(S(DEFAULT_RUN_GAME))
+        }
     }
   }
 
+  private data class S<T>(val value: T) : Screen
+
   private fun runGameScreen(
     body: String = DEFAULT_RUN_GAME
-  ) = RunGameScreen(PanelContainerScreen(body))
+  ) = RunGameScreen(PanelContainerScreen(S(body)))
 
   private fun authScreen(wrapped: String = DEFAULT_AUTH) =
-    BackStackScreen<Any>(wrapped)
+    BackStackScreen<Screen>(S(wrapped))
 
   private val RunGameScreen.panels: List<Any> get() = beneathModals.modals.map { it.top }
   private val RunGameScreen.body: Any get() = beneathModals.beneathModals.wrapped
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/ToDoActivity.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/ToDoActivity.kt
index ce33f281cf..b8df57a76c 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/ToDoActivity.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/ToDoActivity.kt
@@ -1,3 +1,5 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.sample.todo
 
 import android.os.Bundle
@@ -8,15 +10,16 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.squareup.sample.container.overviewdetail.OverviewDetailContainer
 import com.squareup.workflow1.diagnostic.tracing.TracingWorkflowInterceptor
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowLayout
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackContainer
+import com.squareup.workflow1.ui.container.withRegistry
 import com.squareup.workflow1.ui.renderWorkflowIn
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import java.io.File
 
-@OptIn(WorkflowUiExperimentalApi::class)
 class ToDoActivity : AppCompatActivity() {
 
   override fun onCreate(savedInstanceState: Bundle?) {
@@ -26,21 +29,20 @@ class ToDoActivity : AppCompatActivity() {
 
     setContentView(
       WorkflowLayout(this).apply {
-        start(model.ensureWorkflow(traceFilesDir = filesDir), viewRegistry)
+        take(model.ensureWorkflow(traceFilesDir = filesDir).map { it.withRegistry(viewRegistry) })
       }
     )
   }
 
   private companion object {
-    val viewRegistry = ViewRegistry(OverviewDetailContainer, BackStackContainer)
+    val viewRegistry = ViewRegistry(OverviewDetailContainer)
   }
 }
 
 class ToDoModel(private val savedState: SavedStateHandle) : ViewModel() {
-  private var renderings: StateFlow<Any>? = null
+  private var renderings: StateFlow<Screen>? = null
 
-  @OptIn(WorkflowUiExperimentalApi::class)
-  fun ensureWorkflow(traceFilesDir: File): StateFlow<Any> {
+  fun ensureWorkflow(traceFilesDir: File): StateFlow<Screen> {
     if (renderings == null) {
       val traceFile = traceFilesDir.resolve("workflow-trace-todo.json")
 
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
index ca72af9356..72ef00d114 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoEditorScreen.kt
@@ -1,18 +1,19 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
 package com.squareup.sample.todo
 
 import android.content.Context.INPUT_METHOD_SERVICE
 import android.view.View
 import android.view.inputmethod.InputMethodManager
 import com.squareup.sample.todo.databinding.TodoEditorLayoutBinding
-import com.squareup.workflow1.ui.AndroidViewRendering
+import com.squareup.workflow1.ui.AndroidScreen
 import com.squareup.workflow1.ui.Compatible
-import com.squareup.workflow1.ui.LayoutRunner
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
+import com.squareup.workflow1.ui.ScreenViewRunner
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
-import com.squareup.workflow1.ui.backstack.BackStackConfig
-import com.squareup.workflow1.ui.backstack.BackStackConfig.Other
+import com.squareup.workflow1.ui.container.BackStackConfig
+import com.squareup.workflow1.ui.container.BackStackConfig.Other
 import com.squareup.workflow1.ui.control
 
 @OptIn(WorkflowUiExperimentalApi::class)
@@ -21,16 +22,16 @@ data class TodoEditorScreen(
   val onCheckboxClicked: (index: Int) -> Unit,
   val onDeleteClicked: (index: Int) -> Unit,
   val onGoBackClicked: () -> Unit
-) : AndroidViewRendering<TodoEditorScreen>, Compatible {
+) : AndroidScreen<TodoEditorScreen>, Compatible {
 
   override val compatibilityKey = Compatible.keyFor(this, "${session.id}")
-  override val viewFactory = bind(TodoEditorLayoutBinding::inflate, ::TodoEditorLayoutRunner)
+  override val viewFactory = bind(TodoEditorLayoutBinding::inflate, ::Runner)
 }
 
 @OptIn(WorkflowUiExperimentalApi::class)
-private class TodoEditorLayoutRunner(
+private class Runner(
   private val binding: TodoEditorLayoutBinding
-) : LayoutRunner<TodoEditorScreen> {
+) : ScreenViewRunner<TodoEditorScreen> {
 
   private val itemListView = ItemListView.fromLinearLayout(binding.itemContainer)
 
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsAppWorkflow.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsAppWorkflow.kt
index b4db736b45..d49b9ad092 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsAppWorkflow.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsAppWorkflow.kt
@@ -10,7 +10,7 @@ import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreen
 
 sealed class TodoListsAppState {
   abstract val lists: List<TodoList>
diff --git a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
index 90bcdaf57d..573dfd40c9 100644
--- a/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
+++ b/samples/todo-android/app/src/main/java/com/squareup/sample/todo/TodoListsScreen.kt
@@ -5,9 +5,9 @@ import android.widget.TextView
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig
 import com.squareup.sample.container.overviewdetail.OverviewDetailConfig.Overview
 import com.squareup.sample.todo.databinding.TodoListsLayoutBinding
-import com.squareup.workflow1.ui.AndroidViewRendering
-import com.squareup.workflow1.ui.LayoutRunner.Companion.bind
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.AndroidScreen
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewRunner.Companion.bind
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 /**
@@ -24,8 +24,8 @@ data class TodoListsScreen(
   val lists: List<TodoList>,
   val onRowClicked: (Int) -> Unit,
   val selection: Int = -1
-) : AndroidViewRendering<TodoListsScreen> {
-  override val viewFactory: ViewFactory<TodoListsScreen> =
+) : AndroidScreen<TodoListsScreen> {
+  override val viewFactory: ScreenViewFactory<TodoListsScreen> =
     bind(TodoListsLayoutBinding::inflate) { rendering, viewEnvironment ->
       for ((index, list) in rendering.lists.withIndex()) {
         addRow(
diff --git a/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/PreviewViewEnvironment.kt b/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/PreviewViewEnvironment.kt
index 85168c257c..40b98e51b8 100644
--- a/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/PreviewViewEnvironment.kt
+++ b/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/PreviewViewEnvironment.kt
@@ -1,3 +1,4 @@
+@file:Suppress("DEPRECATION")
 @file:OptIn(WorkflowUiExperimentalApi::class)
 
 package com.squareup.workflow1.ui.compose.tooling
@@ -48,7 +49,7 @@ private class PreviewViewRegistry<RenderingT : Any>(
   override val keys: Set<KClass<*>> get() = mainFactory?.let { setOf(it.type) } ?: emptySet()
 
   @Suppress("UNCHECKED_CAST")
-  override fun <RenderingT : Any> getFactoryFor(
+  override fun <RenderingT : Any> getEntryFor(
     renderingType: KClass<out RenderingT>
   ): ViewFactory<RenderingT> = when (renderingType) {
     mainFactory?.type -> mainFactory
diff --git a/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/ViewFactories.kt b/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/ViewFactories.kt
index ed5d6050c1..42c5fd3cbb 100644
--- a/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/ViewFactories.kt
+++ b/workflow-ui/compose-tooling/src/main/java/com/squareup/workflow1/ui/compose/tooling/ViewFactories.kt
@@ -1,3 +1,4 @@
+@file:Suppress("DEPRECATION", "FunctionName")
 package com.squareup.workflow1.ui.compose.tooling
 
 import androidx.compose.foundation.layout.Arrangement.Absolute.spacedBy
diff --git a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewFactoryTest.kt b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewFactoryTest.kt
index b334a0e3d6..82d7e56eb2 100644
--- a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewFactoryTest.kt
+++ b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewFactoryTest.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.compose
 
 import android.content.Context
diff --git a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewTreeIntegrationTest.kt b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewTreeIntegrationTest.kt
index a2338173a5..e88e443f66 100644
--- a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewTreeIntegrationTest.kt
+++ b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/ComposeViewTreeIntegrationTest.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.compose
 
 import android.content.Context
@@ -25,14 +27,15 @@ import androidx.compose.ui.test.onNodeWithText
 import androidx.compose.ui.test.performClick
 import com.google.common.truth.Truth.assertThat
 import com.squareup.workflow1.ui.AndroidViewRendering
+import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.Compatible
-import com.squareup.workflow1.ui.Named
+import com.squareup.workflow1.ui.NamedScreen
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackScreen
 import com.squareup.workflow1.ui.bindShowRendering
+import com.squareup.workflow1.ui.container.BackStackScreen
 import com.squareup.workflow1.ui.internal.test.IdleAfterTestRule
 import com.squareup.workflow1.ui.internal.test.WorkflowUiTestActivity
 import com.squareup.workflow1.ui.modal.HasModals
@@ -355,7 +358,7 @@ internal class ComposeViewTreeIntegrationTest {
   }
 
   @Test fun composition_is_restored_in_modal_after_config_change() {
-    val firstScreen = ComposeRendering(compatibilityKey = "") {
+    val firstScreen = asScreen(ComposeRendering(compatibilityKey = "") {
       var counter by rememberSaveable { mutableStateOf(0) }
       BasicText(
         "Counter: $counter",
@@ -363,15 +366,13 @@ internal class ComposeViewTreeIntegrationTest {
           .clickable { counter++ }
           .testTag(CounterTag)
       )
-    }
+    })
 
     // Show first screen to initialize state.
     scenario.onActivity {
       it.setRendering(
-        TestModalScreen(
-          listOf(
-            BackStackScreen(EmptyRendering, firstScreen)
-          )
+        asScreen(
+          TestModalScreen(listOf(BackStackScreen(EmptyRendering, firstScreen)))
         )
       )
     }
@@ -388,7 +389,7 @@ internal class ComposeViewTreeIntegrationTest {
   }
 
   @Test fun composition_is_restored_in_multiple_modals_after_config_change() {
-    val firstScreen = ComposeRendering(compatibilityKey = "first") {
+    val firstScreen = asScreen(ComposeRendering(compatibilityKey = "first") {
       var counter by rememberSaveable { mutableStateOf(0) }
       BasicText(
         "Counter: $counter",
@@ -396,8 +397,8 @@ internal class ComposeViewTreeIntegrationTest {
           .clickable { counter++ }
           .testTag(CounterTag)
       )
-    }
-    val secondScreen = ComposeRendering(compatibilityKey = "second") {
+    })
+    val secondScreen = asScreen(ComposeRendering(compatibilityKey = "second") {
       var counter by rememberSaveable { mutableStateOf(0) }
       BasicText(
         "Counter2: $counter",
@@ -405,18 +406,20 @@ internal class ComposeViewTreeIntegrationTest {
           .clickable { counter++ }
           .testTag(CounterTag2)
       )
-    }
+    })
 
     // Show first screen to initialize state.
     scenario.onActivity {
       it.setRendering(
-        TestModalScreen(
-          listOf(
-            // Name each BackStackScreen to give them unique state registry keys.
-            // TODO(https://github.com/square/workflow-kotlin/issues/469) Should this naming be
-            //  done automatically in ModalContainer?
-            Named(BackStackScreen(EmptyRendering, firstScreen), "modal1"),
-            Named(BackStackScreen(EmptyRendering, secondScreen), "modal2")
+        asScreen(
+          TestModalScreen(
+            listOf(
+              // Name each BackStackScreen to give them unique state registry keys.
+              // TODO(https://github.com/square/workflow-kotlin/issues/469) Should this naming be
+              //  done automatically in ModalContainer?
+              NamedScreen(BackStackScreen(EmptyRendering, firstScreen), "modal1"),
+              NamedScreen(BackStackScreen(EmptyRendering, secondScreen), "modal2")
+            )
           )
         )
       )
@@ -442,7 +445,7 @@ internal class ComposeViewTreeIntegrationTest {
   }
 
   private fun WorkflowUiTestActivity.setBackstack(vararg backstack: ComposeRendering) {
-    setRendering(BackStackScreen(EmptyRendering, backstack.asList()))
+    setRendering(BackStackScreen(EmptyRendering, backstack.asList().map { asScreen(it) }))
   }
 
   data class TestModalScreen(
@@ -485,7 +488,7 @@ internal class ComposeViewTreeIntegrationTest {
   companion object {
     // Use a ComposeView here because the Compose test infra doesn't like it if there are no
     // Compose views at all. See https://issuetracker.google.com/issues/179455327.
-    val EmptyRendering = ComposeRendering(compatibilityKey = "") {}
+    val EmptyRendering = asScreen(ComposeRendering(compatibilityKey = "") {})
 
     const val CounterTag = "counter"
     const val CounterTag2 = "counter2"
diff --git a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/NoTransitionBackStackContainer.kt b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/NoTransitionBackStackContainer.kt
index fc4008ffc0..517965d87c 100644
--- a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/NoTransitionBackStackContainer.kt
+++ b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/NoTransitionBackStackContainer.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.compose
 
 import android.content.Context
@@ -6,10 +8,11 @@ import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import com.squareup.workflow1.ui.BuilderViewFactory
 import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackContainer
 import com.squareup.workflow1.ui.backstack.BackStackScreen
-import com.squareup.workflow1.ui.container.R
+import com.squareup.workflow1.ui.backstack.asNonLegacy
 import com.squareup.workflow1.ui.bindShowRendering
+import com.squareup.workflow1.ui.container.BackStackContainer
+import com.squareup.workflow1.ui.container.R
 
 /**
  * A subclass of [BackStackContainer] that disables transitions to make it simpler to test the
@@ -20,7 +23,11 @@ import com.squareup.workflow1.ui.bindShowRendering
 @OptIn(WorkflowUiExperimentalApi::class)
 internal class NoTransitionBackStackContainer(context: Context) : BackStackContainer(context) {
 
-  override fun performTransition(oldViewMaybe: View?, newView: View, popped: Boolean) {
+  override fun performTransition(
+    oldViewMaybe: View?,
+    newView: View,
+    popped: Boolean
+  ) {
     oldViewMaybe?.let(::removeView)
     addView(newView)
   }
@@ -33,7 +40,13 @@ internal class NoTransitionBackStackContainer(context: Context) : BackStackConta
         .apply {
           id = R.id.workflow_back_stack_container
           layoutParams = LayoutParams(MATCH_PARENT, MATCH_PARENT)
-          bindShowRendering(initialRendering, initialEnv, ::update)
+          bindShowRendering(
+            initialRendering,
+            initialEnv,
+            { newRendering, newViewEnvironment ->
+              update(newRendering.asNonLegacy(), newViewEnvironment)
+            }
+          )
         }
     }
   )
diff --git a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/WorkflowRenderingTest.kt b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/WorkflowRenderingTest.kt
index a09e87c32b..8573e35998 100644
--- a/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/WorkflowRenderingTest.kt
+++ b/workflow-ui/compose/src/androidTest/java/com/squareup/workflow1/ui/compose/WorkflowRenderingTest.kt
@@ -1,4 +1,4 @@
-@file:Suppress("TestFunctionName")
+@file:Suppress("TestFunctionName", "DEPRECATION")
 
 package com.squareup.workflow1.ui.compose
 
diff --git a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeRendering.kt b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeRendering.kt
index 9fbc6d3f66..dd7d88da8a 100644
--- a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeRendering.kt
+++ b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeRendering.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.compose
 
 import androidx.compose.runtime.Composable
diff --git a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeViewFactory.kt b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeViewFactory.kt
index bf4b5144ac..46804e2b14 100644
--- a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeViewFactory.kt
+++ b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/ComposeViewFactory.kt
@@ -1,5 +1,5 @@
 // See https://youtrack.jetbrains.com/issue/KT-31734
-@file:Suppress("RemoveEmptyParenthesesFromAnnotationEntry")
+@file:Suppress("RemoveEmptyParenthesesFromAnnotationEntry", "DEPRECATION")
 
 package com.squareup.workflow1.ui.compose
 
diff --git a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/CompositionRoot.kt b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/CompositionRoot.kt
index 110fdce67c..73db130338 100644
--- a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/CompositionRoot.kt
+++ b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/CompositionRoot.kt
@@ -1,4 +1,4 @@
-@file:Suppress("RemoveEmptyParenthesesFromAnnotationEntry")
+@file:Suppress("RemoveEmptyParenthesesFromAnnotationEntry", "DEPRECATION", "FunctionName")
 
 package com.squareup.workflow1.ui.compose
 
@@ -7,7 +7,6 @@ import androidx.annotation.VisibleForTesting.PRIVATE
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.staticCompositionLocalOf
-import com.squareup.workflow1.ui.AndroidViewRendering
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.ViewRegistry
@@ -84,7 +83,7 @@ public fun ViewRegistry.withCompositionRoot(root: CompositionRoot): ViewRegistry
 
 /**
  * Applies [transform] to each [ViewFactory] in this registry. Transformations are applied lazily,
- * at the time of lookup via [ViewRegistry.getFactoryFor].
+ * at the time of lookup via [ViewRegistry.getEntryFor].
  */
 @WorkflowUiExperimentalApi
 private fun ViewRegistry.mapFactories(
@@ -92,15 +91,11 @@ private fun ViewRegistry.mapFactories(
 ): ViewRegistry = object : ViewRegistry {
   override val keys: Set<KClass<*>> get() = this@mapFactories.keys
 
-  override fun <RenderingT : Any> getFactoryFor(
+  override fun <RenderingT : Any> getEntryFor(
     renderingType: KClass<out RenderingT>
-  ): ViewFactory<RenderingT> {
-    val factoryFor =
-      this@mapFactories.getFactoryFor(renderingType) ?: throw IllegalArgumentException(
-        "A ${ViewFactory::class.qualifiedName} should have been registered to display " +
-          "${renderingType.qualifiedName} instances, or that class should implement " +
-          "${AndroidViewRendering::class.simpleName}<${renderingType.simpleName}>."
-      )
+  ): ViewFactory<RenderingT>? {
+    val factoryFor = (this@mapFactories.getEntryFor(renderingType) as? ViewFactory<*>)
+        ?: return null
     val transformedFactory = transform(factoryFor)
     check(transformedFactory.type == renderingType) {
       "Expected transform to return a ViewFactory that is compatible with $renderingType, " +
diff --git a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/WorkflowRendering.kt b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/WorkflowRendering.kt
index 7b086a53a7..cd5a45b1ff 100644
--- a/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/WorkflowRendering.kt
+++ b/workflow-ui/compose/src/main/java/com/squareup/workflow1/ui/compose/WorkflowRendering.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.compose
 
 import android.view.View
diff --git a/workflow-ui/container-android/api/container-android.api b/workflow-ui/container-android/api/container-android.api
index db97d77857..995c5d5166 100644
--- a/workflow-ui/container-android/api/container-android.api
+++ b/workflow-ui/container-android/api/container-android.api
@@ -1,30 +1,6 @@
-public final class com/squareup/workflow1/ui/backstack/BackStackConfig : java/lang/Enum {
-	public static final field Companion Lcom/squareup/workflow1/ui/backstack/BackStackConfig$Companion;
-	public static final field First Lcom/squareup/workflow1/ui/backstack/BackStackConfig;
-	public static final field None Lcom/squareup/workflow1/ui/backstack/BackStackConfig;
-	public static final field Other Lcom/squareup/workflow1/ui/backstack/BackStackConfig;
-	public static fun valueOf (Ljava/lang/String;)Lcom/squareup/workflow1/ui/backstack/BackStackConfig;
-	public static fun values ()[Lcom/squareup/workflow1/ui/backstack/BackStackConfig;
-}
-
-public final class com/squareup/workflow1/ui/backstack/BackStackConfig$Companion : com/squareup/workflow1/ui/ViewEnvironmentKey {
-	public fun getDefault ()Lcom/squareup/workflow1/ui/backstack/BackStackConfig;
-	public synthetic fun getDefault ()Ljava/lang/Object;
-}
-
-public class com/squareup/workflow1/ui/backstack/BackStackContainer : android/widget/FrameLayout {
+public final class com/squareup/workflow1/ui/backstack/BackStackContainer {
 	public static final field Companion Lcom/squareup/workflow1/ui/backstack/BackStackContainer$Companion;
-	public fun <init> (Landroid/content/Context;)V
-	public fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;)V
-	public fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;I)V
-	public fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;II)V
-	public synthetic fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;IIILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	protected fun onAttachedToWindow ()V
-	protected fun onDetachedFromWindow ()V
-	protected fun onRestoreInstanceState (Landroid/os/Parcelable;)V
-	protected fun onSaveInstanceState ()Landroid/os/Parcelable;
-	protected fun performTransition (Landroid/view/View;Landroid/view/View;Z)V
-	protected final fun update (Lcom/squareup/workflow1/ui/backstack/BackStackScreen;Lcom/squareup/workflow1/ui/ViewEnvironment;)V
+	public fun <init> ()V
 }
 
 public final class com/squareup/workflow1/ui/backstack/BackStackContainer$Companion : com/squareup/workflow1/ui/ViewFactory {
@@ -33,44 +9,6 @@ public final class com/squareup/workflow1/ui/backstack/BackStackContainer$Compan
 	public fun getType ()Lkotlin/reflect/KClass;
 }
 
-public final class com/squareup/workflow1/ui/backstack/BackStackStateKeyKt {
-	public static final fun withBackStackStateKeyPrefix (Lcom/squareup/workflow1/ui/ViewEnvironment;Ljava/lang/String;)Lcom/squareup/workflow1/ui/ViewEnvironment;
-}
-
-public final class com/squareup/workflow1/ui/backstack/ViewStateCache : android/os/Parcelable {
-	public static final field CREATOR Lcom/squareup/workflow1/ui/backstack/ViewStateCache$CREATOR;
-	public fun <init> ()V
-	public final fun attachToParentRegistry (Ljava/lang/String;Landroidx/savedstate/SavedStateRegistryOwner;)V
-	public fun describeContents ()I
-	public final fun detachFromParentRegistry ()V
-	public final fun prune (Ljava/util/Collection;)V
-	public final fun restore (Lcom/squareup/workflow1/ui/backstack/ViewStateCache;)V
-	public final fun update (Ljava/util/Collection;Landroid/view/View;Landroid/view/View;)V
-	public fun writeToParcel (Landroid/os/Parcel;I)V
-}
-
-public final class com/squareup/workflow1/ui/backstack/ViewStateCache$CREATOR : android/os/Parcelable$Creator {
-	public fun createFromParcel (Landroid/os/Parcel;)Lcom/squareup/workflow1/ui/backstack/ViewStateCache;
-	public synthetic fun createFromParcel (Landroid/os/Parcel;)Ljava/lang/Object;
-	public fun newArray (I)[Lcom/squareup/workflow1/ui/backstack/ViewStateCache;
-	public synthetic fun newArray (I)[Ljava/lang/Object;
-}
-
-public final class com/squareup/workflow1/ui/backstack/ViewStateCache$SavedState : android/view/View$BaseSavedState {
-	public static final field CREATOR Lcom/squareup/workflow1/ui/backstack/ViewStateCache$SavedState$CREATOR;
-	public fun <init> (Landroid/os/Parcel;)V
-	public fun <init> (Landroid/os/Parcelable;Lcom/squareup/workflow1/ui/backstack/ViewStateCache;)V
-	public final fun getViewStateCache ()Lcom/squareup/workflow1/ui/backstack/ViewStateCache;
-	public fun writeToParcel (Landroid/os/Parcel;I)V
-}
-
-public final class com/squareup/workflow1/ui/backstack/ViewStateCache$SavedState$CREATOR : android/os/Parcelable$Creator {
-	public fun createFromParcel (Landroid/os/Parcel;)Lcom/squareup/workflow1/ui/backstack/ViewStateCache$SavedState;
-	public synthetic fun createFromParcel (Landroid/os/Parcel;)Ljava/lang/Object;
-	public fun newArray (I)[Lcom/squareup/workflow1/ui/backstack/ViewStateCache$SavedState;
-	public synthetic fun newArray (I)[Ljava/lang/Object;
-}
-
 public final class com/squareup/workflow1/ui/modal/AlertContainer : com/squareup/workflow1/ui/modal/ModalContainer {
 	public static final field Companion Lcom/squareup/workflow1/ui/modal/AlertContainer$Companion;
 	public fun <init> (Landroid/content/Context;)V
@@ -82,11 +20,11 @@ public final class com/squareup/workflow1/ui/modal/AlertContainer : com/squareup
 	public synthetic fun buildDialog (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;)Lcom/squareup/workflow1/ui/modal/ModalContainer$DialogRef;
 }
 
-public final class com/squareup/workflow1/ui/modal/AlertContainer$Companion : com/squareup/workflow1/ui/ViewFactory {
+public final class com/squareup/workflow1/ui/modal/AlertContainer$Companion : com/squareup/workflow1/ui/ScreenViewFactory {
+	public synthetic fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
 	public fun buildView (Lcom/squareup/workflow1/ui/modal/AlertContainerScreen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
-	public synthetic fun buildView (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
-	public final fun customThemeBinding (I)Lcom/squareup/workflow1/ui/ViewFactory;
-	public static synthetic fun customThemeBinding$default (Lcom/squareup/workflow1/ui/modal/AlertContainer$Companion;IILjava/lang/Object;)Lcom/squareup/workflow1/ui/ViewFactory;
+	public final fun customThemeBinding (I)Lcom/squareup/workflow1/ui/ScreenViewFactory;
+	public static synthetic fun customThemeBinding$default (Lcom/squareup/workflow1/ui/modal/AlertContainer$Companion;IILjava/lang/Object;)Lcom/squareup/workflow1/ui/ScreenViewFactory;
 	public fun getType ()Lkotlin/reflect/KClass;
 }
 
diff --git a/workflow-ui/container-android/src/androidTest/AndroidManifest.xml b/workflow-ui/container-android/src/androidTest/AndroidManifest.xml
index 1f57b16026..59a52a2dd4 100644
--- a/workflow-ui/container-android/src/androidTest/AndroidManifest.xml
+++ b/workflow-ui/container-android/src/androidTest/AndroidManifest.xml
@@ -5,8 +5,5 @@
     <activity
         android:name="com.squareup.workflow1.ui.modal.test.ModalViewContainerLifecycleActivity"
         android:theme="@style/Theme.AppCompat.NoActionBar"/>
-    <activity
-        android:name="com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity"
-        android:theme="@style/Theme.AppCompat.NoActionBar"/>
   </application>
 </manifest>
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
index 05fc271c01..68b2541d6e 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
+++ b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleActivity.kt
@@ -1,13 +1,17 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.modal.test
 
 import android.content.Context
 import android.view.View
 import android.view.ViewGroup
 import android.widget.FrameLayout
-import com.squareup.workflow1.ui.BuilderViewFactory
+import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.Compatible
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -22,7 +26,7 @@ import kotlin.reflect.KClass
 @OptIn(WorkflowUiExperimentalApi::class)
 internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivity() {
 
-  object BaseRendering : ViewFactory<BaseRendering> {
+  object BaseRendering : Screen, ScreenViewFactory<BaseRendering> {
     override val type: KClass<in BaseRendering> = BaseRendering::class
     override fun buildView(
       initialRendering: BaseRendering,
@@ -40,7 +44,7 @@ internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivi
     override val beneathModals: BaseRendering get() = BaseRendering
   }
 
-  sealed class TestRendering {
+  sealed class TestRendering : Screen {
     data class LeafRendering(val name: String) : TestRendering(), Compatible {
       override val compatibilityKey: String get() = name
     }
@@ -52,7 +56,7 @@ internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivi
     ModalViewContainer.binding<TestModals>(),
     BaseRendering,
     leafViewBinding(LeafRendering::class, lifecycleLoggingViewObserver { it.name }),
-    BuilderViewFactory(RecurseRendering::class) { initialRendering,
+    ManualScreenViewFactory(RecurseRendering::class) { initialRendering,
       initialViewEnvironment,
       contextForNewView, _ ->
       FrameLayout(contextForNewView).also { container ->
@@ -62,11 +66,12 @@ internal class ModalViewContainerLifecycleActivity : AbstractLifecycleTestActivi
           initialRendering,
           initialViewEnvironment
         ) { rendering, env ->
-          stub.update(TestModals(listOf(rendering.wrapped)), env)
+          stub.show(asScreen(TestModals(listOf(rendering.wrapped))), env)
         }
       }
     },
   )
 
-  fun update(vararg modals: TestRendering) = setRendering(TestModals(modals.asList()))
+  fun update(vararg modals: TestRendering) =
+    setRendering(asScreen(TestModals(modals.asList())))
 }
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleTest.kt b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleTest.kt
index 48a2a7aec0..bf366a15eb 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleTest.kt
+++ b/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/modal/test/ModalViewContainerLifecycleTest.kt
@@ -1,3 +1,5 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
 package com.squareup.workflow1.ui.modal.test
 
 import androidx.lifecycle.Lifecycle.State.CREATED
@@ -5,6 +7,7 @@ import androidx.lifecycle.Lifecycle.State.RESUMED
 import androidx.lifecycle.LifecycleOwner
 import androidx.test.ext.junit.rules.ActivityScenarioRule
 import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.modal.ModalViewContainer
 import com.squareup.workflow1.ui.modal.test.ModalViewContainerLifecycleActivity.TestRendering.LeafRendering
 import com.squareup.workflow1.ui.modal.test.ModalViewContainerLifecycleActivity.TestRendering.RecurseRendering
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackContainer.kt
index 72bcd19d32..35ee23476c 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackContainer.kt
@@ -1,261 +1,21 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.backstack
 
-import android.content.Context
-import android.os.Parcelable
-import android.util.AttributeSet
-import android.util.Log
-import android.view.Gravity
-import android.view.View
-import android.view.ViewGroup
-import android.view.ViewGroup.LayoutParams.MATCH_PARENT
-import android.view.animation.AccelerateDecelerateInterpolator
-import android.widget.FrameLayout
-import androidx.savedstate.SavedStateRegistry
-import androidx.savedstate.ViewTreeSavedStateRegistryOwner
-import androidx.transition.Scene
-import androidx.transition.Slide
-import androidx.transition.TransitionManager
-import androidx.transition.TransitionSet
-import com.squareup.workflow1.ui.BuilderViewFactory
-import com.squareup.workflow1.ui.Named
-import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.DecorativeViewFactory
 import com.squareup.workflow1.ui.ViewFactory
-import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.androidx.WorkflowAndroidXSupport.stateRegistryOwnerFromViewTreeOrContext
-import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
-import com.squareup.workflow1.ui.backstack.BackStackConfig.First
-import com.squareup.workflow1.ui.backstack.BackStackConfig.Other
-import com.squareup.workflow1.ui.bindShowRendering
-import com.squareup.workflow1.ui.buildView
-import com.squareup.workflow1.ui.canShowRendering
-import com.squareup.workflow1.ui.compatible
-import com.squareup.workflow1.ui.container.R
-import com.squareup.workflow1.ui.getRendering
-import com.squareup.workflow1.ui.showFirstRendering
-import com.squareup.workflow1.ui.showRendering
 
 /**
- * A container view that can display a stream of [BackStackScreen] instances.
- *
- * This container supports saving and restoring the view state of each of its subviews corresponding
- * to the renderings in its [BackStackScreen]. It supports two distinct state mechanisms:
- *  1. Classic view hierarchy state ([View.onSaveInstanceState]/[View.onRestoreInstanceState])
- *  2. AndroidX [SavedStateRegistry] via [ViewTreeSavedStateRegistryOwner].
- *
- * ## A note about `SavedStateRegistry` support.
- *
- * The [SavedStateRegistry] API involves defining string keys to associate with state bundles. These
- * keys must be unique relative to the instance of the registry they are saved in. To support this
- * requirement, [BackStackContainer] tries to generate a best-effort unique key by combining its
- * fully-qualified class name with both its [view ID][View.getId] and the
- * [compatibility key][com.squareup.workflow1.ui.Compatible.compatibilityKey] of its rendering.
- * This method isn't guaranteed to give a unique registry key, but it should be good enough: If you
- * need to nest multiple [BackStackContainer]s under the same `SavedStateRegistry`, just wrap each
- * [BackStackScreen] with a [Named], or give each [BackStackContainer] a unique view ID.
+ * BackStackContainer has been promoted to the core workflow-ui modules,
+ * and is now built into [ViewRegistry][com.squareup.workflow1.ui.ViewRegistry] by default.
  *
- * There's a potential issue here where if our ID is changed to something else, then another
- * [BackStackContainer] is added with our old ID, that container will overwrite our state. Since
- * they'd both be using the same key, [SavedStateRegistry] would throw an exception. As long as this
- * container is detached before its ID is changed, it shouldn't be a problem.
+ * This stub has been left in place to preserve the name of the legacy [ViewFactory],
+ * to ease conversion.
  */
+@Deprecated("Use com.squareup.workflow1.ui.container.BackStackContainer")
 @WorkflowUiExperimentalApi
-public open class BackStackContainer @JvmOverloads constructor(
-  context: Context,
-  attributeSet: AttributeSet? = null,
-  defStyle: Int = 0,
-  defStyleRes: Int = 0
-) : FrameLayout(context, attributeSet, defStyle, defStyleRes) {
-
-  private val viewStateCache = ViewStateCache()
-
-  private val currentView: View? get() = if (childCount > 0) getChildAt(0) else null
-  private var currentRendering: BackStackScreen<Named<*>>? = null
-  private var stateRegistryKey: String? = null
-
-  protected fun update(
-    newRendering: BackStackScreen<*>,
-    newViewEnvironment: ViewEnvironment
-  ) {
-    updateStateRegistryKey(newViewEnvironment)
-
-    val config = if (newRendering.backStack.isEmpty()) First else Other
-    val environment = newViewEnvironment + (BackStackConfig to config)
-
-    val named: BackStackScreen<Named<*>> = newRendering
-      // ViewStateCache requires that everything be Named.
-      // It's fine if client code is already using Named for its own purposes, recursion works.
-      .map { Named(it, "backstack") }
-
-    val oldViewMaybe = currentView
-
-    // If existing view is compatible, just update it.
-    oldViewMaybe
-      ?.takeIf { it.canShowRendering(named.top) }
-      ?.let {
-        viewStateCache.prune(named.frames)
-        it.showRendering(named.top, environment)
-        return
-      }
-
-    val newView = environment[ViewRegistry].buildView(
-      initialRendering = named.top,
-      initialViewEnvironment = environment,
-      contextForNewView = this.context,
-      container = this,
-      initializeView = {
-        WorkflowLifecycleOwner.installOn(this)
-        showFirstRendering()
-      }
-    )
-    viewStateCache.update(named.backStack, oldViewMaybe, newView)
-
-    val popped = currentRendering?.backStack?.any { compatible(it, named.top) } == true
-
-    performTransition(oldViewMaybe, newView, popped)
-    // Notify the view we're about to replace that it's going away.
-    oldViewMaybe?.let(WorkflowLifecycleOwner::get)?.destroyOnDetach()
-
-    currentRendering = named
-  }
-
-  /**
-   * Called from [View.showRendering] to swap between views.
-   * Subclasses can override to customize visual effects. There is no need to call super.
-   * Note that views are showing renderings of type [Named]`<BackStackScreen<*>>`.
-   *
-   * @param oldViewMaybe the outgoing view, or null if this is the initial rendering.
-   * @param newView the view that should replace [oldViewMaybe] (if it exists), and become
-   * this view's only child
-   * @param popped true if we should give the appearance of popping "back" to a previous rendering,
-   * false if a new rendering is being "pushed". Should be ignored if [oldViewMaybe] is null.
-   */
-  protected open fun performTransition(
-    oldViewMaybe: View?,
-    newView: View,
-    popped: Boolean
-  ) {
-    // Showing something already, transition with push or pop effect.
-    oldViewMaybe
-      ?.let { oldView ->
-        val oldBody: View? = oldView.findViewById(R.id.back_stack_body)
-        val newBody: View? = newView.findViewById(R.id.back_stack_body)
-
-        val oldTarget: View
-        val newTarget: View
-        if (oldBody != null && newBody != null) {
-          oldTarget = oldBody
-          newTarget = newBody
-        } else {
-          oldTarget = oldView
-          newTarget = newView
-        }
-
-        val (outEdge, inEdge) = when (popped) {
-          false -> Gravity.START to Gravity.END
-          true -> Gravity.END to Gravity.START
-        }
-
-        val transition = TransitionSet()
-          .addTransition(Slide(outEdge).addTarget(oldTarget))
-          .addTransition(Slide(inEdge).addTarget(newTarget))
-          .setInterpolator(AccelerateDecelerateInterpolator())
-
-        TransitionManager.go(Scene(this, newView), transition)
-        return
-      }
-
-    // This is the first view, just show it.
-    addView(newView)
-  }
-
-  override fun onSaveInstanceState(): Parcelable {
-    return ViewStateCache.SavedState(super.onSaveInstanceState(), viewStateCache)
-  }
-
-  override fun onRestoreInstanceState(state: Parcelable) {
-    (state as? ViewStateCache.SavedState)
-      ?.let {
-        viewStateCache.restore(it.viewStateCache)
-        super.onRestoreInstanceState(state.superState)
-      }
-      ?: super.onRestoreInstanceState(super.onSaveInstanceState())
-    // Some other class wrote state, but we're not allowed to skip
-    // the call to super. Make a no-op call.
-  }
-
-  override fun onAttachedToWindow() {
-    super.onAttachedToWindow()
-
-    // Wire up our viewStateCache to our parent SavedStateRegistry.
-    val parentRegistryOwner = stateRegistryOwnerFromViewTreeOrContext(this)!!
-    val key = checkNotNull(stateRegistryKey) {
-      "Expected stateRegistryKey to have been set – the view seems to be getting attached before " +
-        "its first update: $this"
-    }
-
-    viewStateCache.attachToParentRegistry(key, parentRegistryOwner)
-  }
-
-  override fun onDetachedFromWindow() {
-    // Disconnect our state cache from our parent SavedStateRegistry so that it doesn't get asked
-    // to save state anymore.
-    viewStateCache.detachFromParentRegistry()
-    super.onDetachedFromWindow()
-  }
-
-  /**
-   * See the note about SavedStateRegistry support in this class's kdoc for some caveats.
-   */
-  private fun getStateRegistryKey(): String {
-    val namedKeyOrNull = run {
-      val rendering = getRendering<Any>() as? Named<*>
-      rendering?.compatibilityKey
-    }
-    val nameSuffix = namedKeyOrNull?.let { "-$it" } ?: ""
-    val idSuffix = if (id == NO_ID) "" else "-$id"
-    return BackStackContainer::class.java.name + nameSuffix + idSuffix
-  }
-
-  /**
-   * In order to save our state with a unique ID in our parent's registry, we use a combination
-   * of this class name, our [compatibility key][Named.compatibilityKey] if specified, and our view
-   * ID if specified. This method isn't guaranteed to give a unique registry key, but it should be
-   * good enough: If you need to nest multiple [BackStackContainer]s under the same
-   * `SavedStateRegistry`, just wrap each [BackStackScreen] with a [Named], or give each
-   * [BackStackContainer] a unique view ID.
-   *
-   * There's a potential issue here where if our ID is changed to something else, then another
-   * BackStackContainer is added with our old ID, that container will overwrite our state. Since
-   * they'd both be using the same key, SavedStateRegistry would throw an exception. That's a
-   * pretty unlikely situation though I think. And as long as this container is detached before
-   * its ID is changed, it won't be a problem.
-   */
-  private fun updateStateRegistryKey(environment: ViewEnvironment) {
-    val idSuffix = if (id == NO_ID) "" else "-$id"
-    val keyPrefix = environment.getBackStackStateKeyPrefix
-    val newKey = keyPrefix + BackStackContainer::class.java.name + idSuffix
-
-    if (stateRegistryKey != null && stateRegistryKey != newKey) {
-      Log.wtf(
-        "workflow1",
-        "BackStackContainer state registry key changed – view state may be lost:" +
-          " from $stateRegistryKey to $newKey"
-      )
-    }
-    stateRegistryKey = newKey
-  }
-
+public class BackStackContainer {
   public companion object : ViewFactory<BackStackScreen<*>>
-  by BuilderViewFactory(
-    type = BackStackScreen::class,
-    viewConstructor = { initialRendering, initialEnv, context, _ ->
-      BackStackContainer(context)
-        .apply {
-          id = R.id.workflow_back_stack_container
-          layoutParams = (ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT))
-          bindShowRendering(initialRendering, initialEnv, ::update)
-        }
-    }
-  )
+  by DecorativeViewFactory(BackStackScreen::class, { legacy -> legacy.asNonLegacy() })
 }
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt
index 27e4acb165..e415ba0050 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/AlertContainer.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.modal
 
 import android.content.Context
@@ -8,10 +10,10 @@ import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import androidx.annotation.StyleRes
 import androidx.appcompat.app.AlertDialog
-import com.squareup.workflow1.ui.BuilderViewFactory
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.container.R
 import com.squareup.workflow1.ui.modal.AlertScreen.Button
@@ -38,7 +40,7 @@ public class AlertContainer @JvmOverloads constructor(
     initialViewEnvironment: ViewEnvironment
   ): DialogRef<AlertScreen> {
     val dialog = AlertDialog.Builder(context, dialogThemeResId)
-        .create()
+      .create()
     val ref = DialogRef(initialModalRendering, initialViewEnvironment, dialog)
     updateDialog(ref)
     return ref
@@ -57,15 +59,15 @@ public class AlertContainer @JvmOverloads constructor(
 
     for (button in Button.values()) {
       rendering.buttons[button]
-          ?.let { name ->
-            dialog.setButton(button.toId(), name) { _, _ ->
-              rendering.onEvent(ButtonClicked(button))
-            }
-          }
-          ?: run {
-            dialog.getButton(button.toId())
-                ?.visibility = View.INVISIBLE
+        ?.let { name ->
+          dialog.setButton(button.toId(), name) { _, _ ->
+            rendering.onEvent(ButtonClicked(button))
           }
+        }
+        ?: run {
+          dialog.getButton(button.toId())
+            ?.visibility = View.INVISIBLE
+        }
     }
 
     dialog.setMessage(rendering.message)
@@ -80,21 +82,22 @@ public class AlertContainer @JvmOverloads constructor(
 
   private class AlertContainerViewFactory(
     @StyleRes private val dialogThemeResId: Int = 0
-  ) : ViewFactory<AlertContainerScreen<*>> by BuilderViewFactory(
-      type = AlertContainerScreen::class,
-      viewConstructor = { initialRendering, initialEnv, context, _ ->
-        AlertContainer(context, dialogThemeResId = dialogThemeResId)
-            .apply {
-              id = R.id.workflow_alert_container
-              layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
-              bindShowRendering(initialRendering, initialEnv, ::update)
-            }
-      }
+  ) : ScreenViewFactory<AlertContainerScreen<*>> by ManualScreenViewFactory(
+    type = AlertContainerScreen::class,
+    viewConstructor = { initialRendering, initialEnv, context, _ ->
+      AlertContainer(context, dialogThemeResId = dialogThemeResId)
+        .apply {
+          id = R.id.workflow_alert_container
+          layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
+          bindShowRendering(initialRendering, initialEnv, ::update)
+        }
+    }
   )
 
-  public companion object : ViewFactory<AlertContainerScreen<*>> by AlertContainerViewFactory() {
+  public companion object : ScreenViewFactory<AlertContainerScreen<*>>
+  by AlertContainerViewFactory() {
     /**
-     * Creates a [ViewFactory] to show the [AlertScreen]s of an [AlertContainerScreen]
+     * Creates a [ScreenViewFactory] to show the [AlertScreen]s of an [AlertContainerScreen]
      * as Android `AlertDialog`s.
      *
      * @param dialogThemeResId the resource ID of the theme against which to inflate
@@ -102,6 +105,6 @@ public class AlertContainer @JvmOverloads constructor(
      */
     public fun customThemeBinding(
       @StyleRes dialogThemeResId: Int = 0
-    ): ViewFactory<AlertContainerScreen<*>> = AlertContainerViewFactory(dialogThemeResId)
+    ): ScreenViewFactory<AlertContainerScreen<*>> = AlertContainerViewFactory(dialogThemeResId)
   }
 }
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalContainer.kt
index 13ce2fadf5..23d0666061 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalContainer.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.modal
 
 import android.app.Dialog
@@ -17,11 +19,11 @@ import androidx.lifecycle.LifecycleObserver
 import androidx.lifecycle.OnLifecycleEvent
 import com.squareup.workflow1.ui.Compatible
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.backstack.withBackStackStateKeyPrefix
+import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
 import com.squareup.workflow1.ui.compatible
+import com.squareup.workflow1.ui.container.withBackStackStateKeyPrefix
 
 /**
  * Base class for containers that show [HasModals.modals] in [Dialog] windows.
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
index 6df9057e12..7246739a88 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
+++ b/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/modal/ModalViewContainer.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.modal
 
 import android.app.Dialog
@@ -10,10 +12,11 @@ import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.view.ViewGroup.LayoutParams.WRAP_CONTENT
 import androidx.annotation.IdRes
+import com.squareup.workflow1.ui.asScreen
 import com.squareup.workflow1.ui.BuilderViewFactory
-import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewRegistry
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.backPressedHandler
 import com.squareup.workflow1.ui.bindShowRendering
 import com.squareup.workflow1.ui.buildView
@@ -61,16 +64,11 @@ public open class ModalViewContainer @JvmOverloads constructor(
     initialModalRendering: Any,
     initialViewEnvironment: ViewEnvironment
   ): DialogRef<Any> {
-    val view = initialViewEnvironment[ViewRegistry]
-      // Notice that we don't pass a custom initializeView function to set the
-      // WorkflowLifecycleOwner here. ModalContainer will do that itself, on the parent of the view
-      // created here.
-      .buildView(
-        initialRendering = initialModalRendering,
-        initialViewEnvironment = initialViewEnvironment,
-        contextForNewView = this.context,
-        container = this
-      )
+    val view = asScreen(initialModalRendering).buildView(
+            viewEnvironment = initialViewEnvironment,
+            contextForNewView = this.context,
+            container = this
+    )
         .apply {
           // If the modal's root view has no backPressedHandler, add a no-op one to
           // ensure that the `onBackPressed` call below will not leak up to handlers
@@ -107,7 +105,9 @@ public open class ModalViewContainer @JvmOverloads constructor(
   }
 
   override fun updateDialog(dialogRef: DialogRef<Any>) {
-    with(dialogRef) { (extra as View).showRendering(modalRendering, viewEnvironment) }
+    with(dialogRef) {
+      (extra as View).showRendering(asScreen(modalRendering), viewEnvironment)
+    }
   }
 
   @PublishedApi
diff --git a/workflow-ui/container-android/src/main/res/values/ids.xml b/workflow-ui/container-android/src/main/res/values/ids.xml
index b58c7435bd..91877c61dc 100644
--- a/workflow-ui/container-android/src/main/res/values/ids.xml
+++ b/workflow-ui/container-android/src/main/res/values/ids.xml
@@ -1,14 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-  <!--
-  BackStackContainer restricts animation to child with this id, if there is one.
-  Otherwise animates its entire body.
-   -->
-  <item type="id" name="back_stack_body"/>
-  <!-- View Tag holding the BackStackScreen.Key associated with a view. -->
-  <item type="id" name="workflow_back_stack_key"/>
-  <!-- ID used by BackStackContainer to opt in to view persistence. -->
-  <item type="id" name="workflow_back_stack_container"/>
   <!-- ID used by AlertContainer to opt in to view persistence. -->
   <item type="id" name="workflow_alert_container"/>
+  <!-- ID used by BackStackContainer to opt in to view persistence. -->
+  <item type="id" name="workflow_back_stack_container"/>
 </resources>
diff --git a/workflow-ui/container-common/api/container-common.api b/workflow-ui/container-common/api/container-common.api
index 5b00621a33..41a10a1408 100644
--- a/workflow-ui/container-common/api/container-common.api
+++ b/workflow-ui/container-common/api/container-common.api
@@ -14,11 +14,12 @@ public final class com/squareup/workflow1/ui/backstack/BackStackScreen {
 }
 
 public final class com/squareup/workflow1/ui/backstack/BackStackScreenKt {
+	public static final fun asNonLegacy (Lcom/squareup/workflow1/ui/backstack/BackStackScreen;)Lcom/squareup/workflow1/ui/container/BackStackScreen;
 	public static final fun toBackStackScreen (Ljava/util/List;)Lcom/squareup/workflow1/ui/backstack/BackStackScreen;
 	public static final fun toBackStackScreenOrNull (Ljava/util/List;)Lcom/squareup/workflow1/ui/backstack/BackStackScreen;
 }
 
-public final class com/squareup/workflow1/ui/modal/AlertContainerScreen : com/squareup/workflow1/ui/modal/HasModals {
+public final class com/squareup/workflow1/ui/modal/AlertContainerScreen : com/squareup/workflow1/ui/Screen, com/squareup/workflow1/ui/modal/HasModals {
 	public fun <init> (Ljava/lang/Object;Lcom/squareup/workflow1/ui/modal/AlertScreen;)V
 	public fun <init> (Ljava/lang/Object;Ljava/util/List;)V
 	public synthetic fun <init> (Ljava/lang/Object;Ljava/util/List;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
diff --git a/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/backstack/BackStackScreen.kt b/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/backstack/BackStackScreen.kt
index c736b0fc92..01e416154a 100644
--- a/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/backstack/BackStackScreen.kt
+++ b/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/backstack/BackStackScreen.kt
@@ -1,23 +1,14 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.backstack
 
+import com.squareup.workflow1.ui.asScreen
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.container.BackStackScreen as NewBackStackScreen
 
-/**
- * Represents an active screen ([top]), and a set of previously visited screens to which we may
- * return ([backStack]). By rendering the entire history we allow the UI to do things like maintain
- * cached view state, implement drag-back gestures without waiting for the workflow, etc.
- *
- * Effectively a list that can never be empty.
- *
- * If multiple [BackStackScreen]s are used as sibling renderings within the same parent navigation
- * container (either the root activity or another [BackStackScreen]), then the siblings must be
- * distinguished by wrapping them in [Named][com.squareup.workflow1.ui.Named] renderings in order to
- * correctly support AndroidX `SavedStateRegistry`.
- *
- * @param bottom the bottom-most entry in the stack
- * @param rest the rest of the stack, empty by default
- */
 @WorkflowUiExperimentalApi
+@Deprecated("Use com.squareup.workflow1.ui.container.BackStackScreen")
 public class BackStackScreen<StackedT : Any>(
   bottom: StackedT,
   rest: List<StackedT>
@@ -51,12 +42,12 @@ public class BackStackScreen<StackedT : Any>(
 
   public fun <R : Any> map(transform: (StackedT) -> R): BackStackScreen<R> {
     return frames.map(transform)
-        .toBackStackScreen()
+      .toBackStackScreen()
   }
 
   public fun <R : Any> mapIndexed(transform: (index: Int, StackedT) -> R): BackStackScreen<R> {
     return frames.mapIndexed(transform)
-        .toBackStackScreen()
+      .toBackStackScreen()
   }
 
   override fun equals(other: Any?): Boolean {
@@ -83,3 +74,14 @@ public fun <T : Any> List<T>.toBackStackScreen(): BackStackScreen<T> {
   require(isNotEmpty())
   return BackStackScreen(first(), subList(1, size))
 }
+
+@WorkflowUiExperimentalApi
+public fun BackStackScreen<*>.asNonLegacy(): NewBackStackScreen<Screen> {
+  return NewBackStackScreen(
+    bottom = asScreen(frames.first()),
+    rest = when (frames.size) {
+      1 -> emptyList()
+      else -> frames.takeLast(frames.count() - 1).map { asScreen(it) }
+    }
+  )
+}
diff --git a/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/modal/AlertContainerScreen.kt b/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/modal/AlertContainerScreen.kt
index 6a029910e6..a315725e72 100644
--- a/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/modal/AlertContainerScreen.kt
+++ b/workflow-ui/container-common/src/main/java/com/squareup/workflow1/ui/modal/AlertContainerScreen.kt
@@ -1,5 +1,6 @@
 package com.squareup.workflow1.ui.modal
 
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 
 /**
@@ -11,7 +12,7 @@ import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 public data class AlertContainerScreen<B : Any>(
   override val beneathModals: B,
   override val modals: List<AlertScreen> = emptyList()
-) : HasModals<B, AlertScreen> {
+) : Screen, HasModals<B, AlertScreen> {
   public constructor(
     baseScreen: B,
     alert: AlertScreen
diff --git a/workflow-ui/container-common/src/test/java/com/squareup/workflow1/ui/backstack/BackStackScreenTest.kt b/workflow-ui/container-common/src/test/java/com/squareup/workflow1/ui/backstack/BackStackScreenTest.kt
index 1e48651b92..82591f9892 100644
--- a/workflow-ui/container-common/src/test/java/com/squareup/workflow1/ui/backstack/BackStackScreenTest.kt
+++ b/workflow-ui/container-common/src/test/java/com/squareup/workflow1/ui/backstack/BackStackScreenTest.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.backstack
 
 import com.google.common.truth.Truth.assertThat
@@ -6,7 +8,7 @@ import org.junit.Test
 import kotlin.test.assertFailsWith
 
 @OptIn(WorkflowUiExperimentalApi::class)
-class BackStackScreenTest {
+internal class BackStackScreenTest {
   @Test fun `top  is last`() {
     assertThat(BackStackScreen(1, 2, 3, 4).top).isEqualTo(4)
   }
diff --git a/workflow-ui/core-android/api/core-android.api b/workflow-ui/core-android/api/core-android.api
index 4cc208b366..f6e2eff984 100644
--- a/workflow-ui/core-android/api/core-android.api
+++ b/workflow-ui/core-android/api/core-android.api
@@ -7,6 +7,27 @@ public final class com/squareup/workflow1/ui/AndroidRenderWorkflowKt {
 	public static synthetic fun renderWorkflowIn$default (Lcom/squareup/workflow1/Workflow;Lkotlinx/coroutines/CoroutineScope;Lkotlinx/coroutines/flow/StateFlow;Landroidx/lifecycle/SavedStateHandle;Ljava/util/List;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)Lkotlinx/coroutines/flow/StateFlow;
 }
 
+public abstract interface class com/squareup/workflow1/ui/AndroidScreen : com/squareup/workflow1/ui/Screen {
+	public abstract fun getViewFactory ()Lcom/squareup/workflow1/ui/ScreenViewFactory;
+}
+
+public final class com/squareup/workflow1/ui/AndroidScreenKt {
+	public static final fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lkotlin/jvm/functions/Function1;)Landroid/view/View;
+	public static synthetic fun buildView$default (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Landroid/view/View;
+}
+
+public final class com/squareup/workflow1/ui/AndroidViewEnvironmentKt {
+	public static final fun getViewFactoryForRendering (Lcom/squareup/workflow1/ui/ViewEnvironment;Lcom/squareup/workflow1/ui/Screen;)Lcom/squareup/workflow1/ui/ScreenViewFactory;
+	public static final fun showFirstRendering (Landroid/view/View;)V
+}
+
+public final class com/squareup/workflow1/ui/AndroidViewRegistryKt {
+	public static final fun buildView (Lcom/squareup/workflow1/ui/ViewRegistry;Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lkotlin/jvm/functions/Function1;)Landroid/view/View;
+	public static synthetic fun buildView$default (Lcom/squareup/workflow1/ui/ViewRegistry;Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Landroid/view/View;
+	public static final fun getFactoryFor (Lcom/squareup/workflow1/ui/ViewRegistry;Lkotlin/reflect/KClass;)Lcom/squareup/workflow1/ui/ViewFactory;
+	public static final fun getFactoryForRendering (Lcom/squareup/workflow1/ui/ViewRegistry;Ljava/lang/Object;)Lcom/squareup/workflow1/ui/ViewFactory;
+}
+
 public abstract interface class com/squareup/workflow1/ui/AndroidViewRendering {
 	public abstract fun getViewFactory ()Lcom/squareup/workflow1/ui/ViewFactory;
 }
@@ -23,6 +44,15 @@ public final class com/squareup/workflow1/ui/BuilderViewFactory : com/squareup/w
 	public fun getType ()Lkotlin/reflect/KClass;
 }
 
+public final class com/squareup/workflow1/ui/DecorativeScreenViewFactory : com/squareup/workflow1/ui/ScreenViewFactory {
+	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function4;)V
+	public synthetic fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function4;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function2;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function4;)V
+	public synthetic fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function2;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function4;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
+	public fun getType ()Lkotlin/reflect/KClass;
+}
+
 public final class com/squareup/workflow1/ui/DecorativeViewFactory : com/squareup/workflow1/ui/ViewFactory {
 	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function4;)V
 	public synthetic fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function4;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
@@ -51,6 +81,34 @@ public final class com/squareup/workflow1/ui/LayoutRunnerViewFactory : com/squar
 	public fun getType ()Lkotlin/reflect/KClass;
 }
 
+public final class com/squareup/workflow1/ui/LayoutScreenViewFactory : com/squareup/workflow1/ui/ScreenViewFactory {
+	public fun <init> (Lkotlin/reflect/KClass;ILkotlin/jvm/functions/Function1;)V
+	public fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
+	public fun getType ()Lkotlin/reflect/KClass;
+}
+
+public final class com/squareup/workflow1/ui/ManualScreenViewFactory : com/squareup/workflow1/ui/ScreenViewFactory {
+	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function4;)V
+	public fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
+	public fun getType ()Lkotlin/reflect/KClass;
+}
+
+public abstract interface class com/squareup/workflow1/ui/ScreenViewFactory : com/squareup/workflow1/ui/ViewRegistry$Entry {
+	public abstract fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
+}
+
+public final class com/squareup/workflow1/ui/ScreenViewFactory$DefaultImpls {
+	public static synthetic fun buildView$default (Lcom/squareup/workflow1/ui/ScreenViewFactory;Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;ILjava/lang/Object;)Landroid/view/View;
+}
+
+public abstract interface class com/squareup/workflow1/ui/ScreenViewRunner {
+	public static final field Companion Lcom/squareup/workflow1/ui/ScreenViewRunner$Companion;
+	public abstract fun showRendering (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;)V
+}
+
+public final class com/squareup/workflow1/ui/ScreenViewRunner$Companion {
+}
+
 public final class com/squareup/workflow1/ui/ShowRenderingTag {
 	public fun <init> (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Lkotlin/jvm/functions/Function2;)V
 	public final fun component1 ()Ljava/lang/Object;
@@ -74,64 +132,26 @@ public final class com/squareup/workflow1/ui/TextControllerControlEditTextKt {
 	public static final fun control (Lcom/squareup/workflow1/ui/TextController;Landroid/widget/EditText;)V
 }
 
-public final class com/squareup/workflow1/ui/ViewBindingViewFactory : com/squareup/workflow1/ui/ViewFactory {
+public final class com/squareup/workflow1/ui/ViewBindingScreenViewFactory : com/squareup/workflow1/ui/ScreenViewFactory {
 	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function3;Lkotlin/jvm/functions/Function1;)V
-	public fun buildView (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
+	public fun buildView (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
 	public fun getType ()Lkotlin/reflect/KClass;
 }
 
-public final class com/squareup/workflow1/ui/ViewEnvironment {
-	public fun <init> ()V
-	public fun <init> (Ljava/util/Map;)V
-	public synthetic fun <init> (Ljava/util/Map;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public fun equals (Ljava/lang/Object;)Z
-	public final fun get (Lcom/squareup/workflow1/ui/ViewEnvironmentKey;)Ljava/lang/Object;
-	public final fun getMap ()Ljava/util/Map;
-	public fun hashCode ()I
-	public final fun plus (Lcom/squareup/workflow1/ui/ViewEnvironment;)Lcom/squareup/workflow1/ui/ViewEnvironment;
-	public final fun plus (Lkotlin/Pair;)Lcom/squareup/workflow1/ui/ViewEnvironment;
-	public fun toString ()Ljava/lang/String;
-}
-
-public abstract class com/squareup/workflow1/ui/ViewEnvironmentKey {
-	public fun <init> (Lkotlin/reflect/KClass;)V
-	public final fun equals (Ljava/lang/Object;)Z
-	public abstract fun getDefault ()Ljava/lang/Object;
-	public final fun hashCode ()I
-	public fun toString ()Ljava/lang/String;
+public final class com/squareup/workflow1/ui/ViewBindingViewFactory : com/squareup/workflow1/ui/ViewFactory {
+	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function3;Lkotlin/jvm/functions/Function1;)V
+	public fun buildView (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
+	public fun getType ()Lkotlin/reflect/KClass;
 }
 
-public abstract interface class com/squareup/workflow1/ui/ViewFactory {
+public abstract interface class com/squareup/workflow1/ui/ViewFactory : com/squareup/workflow1/ui/ViewRegistry$Entry {
 	public abstract fun buildView (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;)Landroid/view/View;
-	public abstract fun getType ()Lkotlin/reflect/KClass;
 }
 
 public final class com/squareup/workflow1/ui/ViewFactory$DefaultImpls {
 	public static synthetic fun buildView$default (Lcom/squareup/workflow1/ui/ViewFactory;Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;ILjava/lang/Object;)Landroid/view/View;
 }
 
-public abstract interface class com/squareup/workflow1/ui/ViewRegistry {
-	public static final field Companion Lcom/squareup/workflow1/ui/ViewRegistry$Companion;
-	public abstract fun getFactoryFor (Lkotlin/reflect/KClass;)Lcom/squareup/workflow1/ui/ViewFactory;
-	public abstract fun getKeys ()Ljava/util/Set;
-}
-
-public final class com/squareup/workflow1/ui/ViewRegistry$Companion : com/squareup/workflow1/ui/ViewEnvironmentKey {
-	public fun getDefault ()Lcom/squareup/workflow1/ui/ViewRegistry;
-	public synthetic fun getDefault ()Ljava/lang/Object;
-}
-
-public final class com/squareup/workflow1/ui/ViewRegistryKt {
-	public static final fun ViewRegistry ()Lcom/squareup/workflow1/ui/ViewRegistry;
-	public static final fun ViewRegistry ([Lcom/squareup/workflow1/ui/ViewFactory;)Lcom/squareup/workflow1/ui/ViewRegistry;
-	public static final fun buildView (Lcom/squareup/workflow1/ui/ViewRegistry;Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lkotlin/jvm/functions/Function1;)Landroid/view/View;
-	public static synthetic fun buildView$default (Lcom/squareup/workflow1/ui/ViewRegistry;Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Landroid/content/Context;Landroid/view/ViewGroup;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Landroid/view/View;
-	public static final fun getFactoryForRendering (Lcom/squareup/workflow1/ui/ViewRegistry;Ljava/lang/Object;)Lcom/squareup/workflow1/ui/ViewFactory;
-	public static final fun plus (Lcom/squareup/workflow1/ui/ViewRegistry;Lcom/squareup/workflow1/ui/ViewFactory;)Lcom/squareup/workflow1/ui/ViewRegistry;
-	public static final fun plus (Lcom/squareup/workflow1/ui/ViewRegistry;Lcom/squareup/workflow1/ui/ViewRegistry;)Lcom/squareup/workflow1/ui/ViewRegistry;
-	public static final fun showFirstRendering (Landroid/view/View;)V
-}
-
 public final class com/squareup/workflow1/ui/ViewShowRenderingKt {
 	public static final fun bindShowRendering (Landroid/view/View;Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;Lkotlin/jvm/functions/Function2;)V
 	public static final fun canShowRendering (Landroid/view/View;Ljava/lang/Object;)Z
@@ -147,6 +167,7 @@ public final class com/squareup/workflow1/ui/WorkflowLayout : android/widget/Fra
 	public final fun start (Lkotlinx/coroutines/flow/Flow;Lcom/squareup/workflow1/ui/ViewEnvironment;)V
 	public final fun start (Lkotlinx/coroutines/flow/Flow;Lcom/squareup/workflow1/ui/ViewRegistry;)V
 	public static synthetic fun start$default (Lcom/squareup/workflow1/ui/WorkflowLayout;Lkotlinx/coroutines/flow/Flow;Lcom/squareup/workflow1/ui/ViewEnvironment;ILjava/lang/Object;)V
+	public final fun take (Lkotlinx/coroutines/flow/Flow;)V
 }
 
 public final class com/squareup/workflow1/ui/WorkflowViewStub : android/view/View {
@@ -166,6 +187,7 @@ public final class com/squareup/workflow1/ui/WorkflowViewStub : android/view/Vie
 	public final fun setReplaceOldViewInParent (Lkotlin/jvm/functions/Function2;)V
 	public final fun setUpdatesVisibility (Z)V
 	public fun setVisibility (I)V
+	public final fun show (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;)Landroid/view/View;
 	public final fun update (Ljava/lang/Object;Lcom/squareup/workflow1/ui/ViewEnvironment;)Landroid/view/View;
 }
 
@@ -186,3 +208,69 @@ public final class com/squareup/workflow1/ui/androidx/WorkflowLifecycleOwner$Com
 	public static synthetic fun installOn$default (Lcom/squareup/workflow1/ui/androidx/WorkflowLifecycleOwner$Companion;Landroid/view/View;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 }
 
+public final class com/squareup/workflow1/ui/container/BackStackConfig : java/lang/Enum {
+	public static final field Companion Lcom/squareup/workflow1/ui/container/BackStackConfig$Companion;
+	public static final field First Lcom/squareup/workflow1/ui/container/BackStackConfig;
+	public static final field None Lcom/squareup/workflow1/ui/container/BackStackConfig;
+	public static final field Other Lcom/squareup/workflow1/ui/container/BackStackConfig;
+	public static fun valueOf (Ljava/lang/String;)Lcom/squareup/workflow1/ui/container/BackStackConfig;
+	public static fun values ()[Lcom/squareup/workflow1/ui/container/BackStackConfig;
+}
+
+public final class com/squareup/workflow1/ui/container/BackStackConfig$Companion : com/squareup/workflow1/ui/ViewEnvironmentKey {
+	public fun getDefault ()Lcom/squareup/workflow1/ui/container/BackStackConfig;
+	public synthetic fun getDefault ()Ljava/lang/Object;
+}
+
+public class com/squareup/workflow1/ui/container/BackStackContainer : android/widget/FrameLayout {
+	public fun <init> (Landroid/content/Context;)V
+	public fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;)V
+	public fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;I)V
+	public fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;II)V
+	public synthetic fun <init> (Landroid/content/Context;Landroid/util/AttributeSet;IIILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	protected fun onAttachedToWindow ()V
+	protected fun onDetachedFromWindow ()V
+	protected fun onRestoreInstanceState (Landroid/os/Parcelable;)V
+	protected fun onSaveInstanceState ()Landroid/os/Parcelable;
+	protected fun performTransition (Landroid/view/View;Landroid/view/View;Z)V
+	public final fun update (Lcom/squareup/workflow1/ui/container/BackStackScreen;Lcom/squareup/workflow1/ui/ViewEnvironment;)V
+}
+
+public final class com/squareup/workflow1/ui/container/BackStackStateKeyKt {
+	public static final fun withBackStackStateKeyPrefix (Lcom/squareup/workflow1/ui/ViewEnvironment;Ljava/lang/String;)Lcom/squareup/workflow1/ui/ViewEnvironment;
+}
+
+public final class com/squareup/workflow1/ui/container/ViewStateCache : android/os/Parcelable {
+	public static final field CREATOR Lcom/squareup/workflow1/ui/container/ViewStateCache$CREATOR;
+	public fun <init> ()V
+	public final fun attachToParentRegistry (Ljava/lang/String;Landroidx/savedstate/SavedStateRegistryOwner;)V
+	public fun describeContents ()I
+	public final fun detachFromParentRegistry ()V
+	public final fun prune (Ljava/util/Collection;)V
+	public final fun restore (Lcom/squareup/workflow1/ui/container/ViewStateCache;)V
+	public final fun update (Ljava/util/Collection;Landroid/view/View;Landroid/view/View;)V
+	public fun writeToParcel (Landroid/os/Parcel;I)V
+}
+
+public final class com/squareup/workflow1/ui/container/ViewStateCache$CREATOR : android/os/Parcelable$Creator {
+	public fun createFromParcel (Landroid/os/Parcel;)Lcom/squareup/workflow1/ui/container/ViewStateCache;
+	public synthetic fun createFromParcel (Landroid/os/Parcel;)Ljava/lang/Object;
+	public fun newArray (I)[Lcom/squareup/workflow1/ui/container/ViewStateCache;
+	public synthetic fun newArray (I)[Ljava/lang/Object;
+}
+
+public final class com/squareup/workflow1/ui/container/ViewStateCache$SavedState : android/view/View$BaseSavedState {
+	public static final field CREATOR Lcom/squareup/workflow1/ui/container/ViewStateCache$SavedState$CREATOR;
+	public fun <init> (Landroid/os/Parcel;)V
+	public fun <init> (Landroid/os/Parcelable;Lcom/squareup/workflow1/ui/container/ViewStateCache;)V
+	public final fun getViewStateCache ()Lcom/squareup/workflow1/ui/container/ViewStateCache;
+	public fun writeToParcel (Landroid/os/Parcel;I)V
+}
+
+public final class com/squareup/workflow1/ui/container/ViewStateCache$SavedState$CREATOR : android/os/Parcelable$Creator {
+	public fun createFromParcel (Landroid/os/Parcel;)Lcom/squareup/workflow1/ui/container/ViewStateCache$SavedState;
+	public synthetic fun createFromParcel (Landroid/os/Parcel;)Ljava/lang/Object;
+	public fun newArray (I)[Lcom/squareup/workflow1/ui/container/ViewStateCache$SavedState;
+	public synthetic fun newArray (I)[Ljava/lang/Object;
+}
+
diff --git a/workflow-ui/core-android/src/androidTest/AndroidManifest.xml b/workflow-ui/core-android/src/androidTest/AndroidManifest.xml
index f09bff9472..988bfbc7fc 100644
--- a/workflow-ui/core-android/src/androidTest/AndroidManifest.xml
+++ b/workflow-ui/core-android/src/androidTest/AndroidManifest.xml
@@ -5,5 +5,8 @@
     <activity
         android:name="com.squareup.workflow1.ui.WorkflowViewStubLifecycleActivity"
         android:theme="@style/Theme.AppCompat.NoActionBar"/>
+    <activity
+        android:name="com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity"
+        android:theme="@style/Theme.AppCompat.NoActionBar"/>
   </application>
 </manifest>
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
new file mode 100644
index 0000000000..70685b3770
--- /dev/null
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeScreenViewFactoryTest.kt
@@ -0,0 +1,153 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import androidx.test.platform.app.InstrumentationRegistry
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+@OptIn(WorkflowUiExperimentalApi::class)
+internal class DecorativeScreenViewFactoryTest {
+  private val instrumentation = InstrumentationRegistry.getInstrumentation()
+
+  @Test fun initializeView_is_only_call_to_showRendering() {
+    val events = mutableListOf<String>()
+
+    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
+      override val type = InnerRendering::class
+      override fun buildView(
+        initialRendering: InnerRendering,
+        initialViewEnvironment: ViewEnvironment,
+        contextForNewView: Context,
+        container: ViewGroup?
+      ): View = InnerView(contextForNewView).apply {
+        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
+          events += "inner showRendering $rendering"
+        }
+      }
+    }
+
+    val envString = object : ViewEnvironmentKey<String>(String::class) {
+      override val default: String get() = "Not set"
+    }
+
+    val outerViewFactory = DecorativeScreenViewFactory(
+      type = OuterRendering::class,
+      map = { outer, env ->
+        val enhancedEnv = env + (envString to "Updated environment")
+        Pair(outer.wrapped, enhancedEnv)
+      },
+      initializeView = {
+        val outerRendering = getRendering<OuterRendering>()
+        events += "initializeView $outerRendering ${environment!![envString]}"
+        showFirstRendering()
+        events += "exit initializeView"
+      }
+    )
+    val viewRegistry = ViewRegistry(innerViewFactory)
+    val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
+
+    outerViewFactory.buildView(
+      OuterRendering("outer", InnerRendering("inner")),
+      viewEnvironment,
+      instrumentation.context
+    )
+
+    assertThat(events).containsExactly(
+      "initializeView OuterRendering(outerData=outer, wrapped=InnerRendering(innerData=inner)) " +
+        "Updated environment",
+      "inner showRendering InnerRendering(innerData=inner)",
+      "exit initializeView"
+    )
+  }
+
+  @Test fun initial_doShowRendering_calls_wrapped_showRendering() {
+    val events = mutableListOf<String>()
+
+    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
+      override val type = InnerRendering::class
+      override fun buildView(
+        initialRendering: InnerRendering,
+        initialViewEnvironment: ViewEnvironment,
+        contextForNewView: Context,
+        container: ViewGroup?
+      ): View = InnerView(contextForNewView).apply {
+        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
+          events += "inner showRendering $rendering"
+        }
+      }
+    }
+    val outerViewFactory = DecorativeScreenViewFactory(
+      type = OuterRendering::class,
+      map = { outer -> outer.wrapped },
+      doShowRendering = { _, innerShowRendering, outerRendering, env ->
+        events += "doShowRendering $outerRendering"
+        innerShowRendering(outerRendering.wrapped, env)
+      }
+    )
+    val viewRegistry = ViewRegistry(innerViewFactory)
+    val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
+
+    outerViewFactory.buildView(
+      OuterRendering("outer", InnerRendering("inner")),
+      viewEnvironment,
+      instrumentation.context
+    )
+
+    assertThat(events).containsExactly(
+      "doShowRendering OuterRendering(outerData=outer, wrapped=InnerRendering(innerData=inner))",
+      "inner showRendering InnerRendering(innerData=inner)"
+    )
+  }
+
+  @Test fun subsequent_showRendering_calls_wrapped_showRendering() {
+    val events = mutableListOf<String>()
+
+    val innerViewFactory = object : ScreenViewFactory<InnerRendering> {
+      override val type = InnerRendering::class
+      override fun buildView(
+        initialRendering: InnerRendering,
+        initialViewEnvironment: ViewEnvironment,
+        contextForNewView: Context,
+        container: ViewGroup?
+      ): View = InnerView(contextForNewView).apply {
+        bindShowRendering(initialRendering, initialViewEnvironment) { rendering, _ ->
+          events += "inner showRendering $rendering"
+        }
+      }
+    }
+    val outerViewFactory = DecorativeScreenViewFactory(
+      type = OuterRendering::class,
+      map = { outer -> outer.wrapped },
+      doShowRendering = { _, innerShowRendering, outerRendering, env ->
+        events += "doShowRendering $outerRendering"
+        innerShowRendering(outerRendering.wrapped, env)
+      }
+    )
+    val viewRegistry = ViewRegistry(innerViewFactory)
+    val viewEnvironment = ViewEnvironment(mapOf(ViewRegistry to viewRegistry))
+
+    val view = outerViewFactory.buildView(
+      OuterRendering("out1", InnerRendering("in1")),
+      viewEnvironment,
+      instrumentation.context
+    )
+    events.clear()
+
+    view.showRendering(OuterRendering("out2", InnerRendering("in2")), viewEnvironment)
+
+    assertThat(events).containsExactly(
+      "doShowRendering OuterRendering(outerData=out2, wrapped=InnerRendering(innerData=in2))",
+      "inner showRendering InnerRendering(innerData=in2)"
+    )
+  }
+
+  private data class InnerRendering(val innerData: String) : Screen
+  private data class OuterRendering(
+    val outerData: String,
+    val wrapped: InnerRendering
+  ) : Screen
+
+  private class InnerView(context: Context) : View(context)
+}
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeViewFactoryTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeViewFactoryTest.kt
index 8220c1b6a4..3f02ef81d0 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeViewFactoryTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/DecorativeViewFactoryTest.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui
 
 import android.content.Context
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt
index d4bec1f911..9a1754bd2e 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleActivity.kt
@@ -8,19 +8,19 @@ import com.squareup.workflow1.ui.internal.test.AbstractLifecycleTestActivity
 @OptIn(WorkflowUiExperimentalApi::class)
 internal class WorkflowViewStubLifecycleActivity : AbstractLifecycleTestActivity() {
 
-  sealed class TestRendering {
+  sealed class TestRendering : Screen {
     data class LeafRendering(val name: String) : TestRendering(), Compatible {
       override val compatibilityKey: String get() = name
     }
 
     data class RecurseRendering(val wrapped: TestRendering) : TestRendering()
 
-    abstract class ViewRendering<T : ViewRendering<T>> : TestRendering(), AndroidViewRendering<T>
+    abstract class ViewRendering<T : ViewRendering<T>> : TestRendering(), AndroidScreen<T>
   }
 
   override val viewRegistry: ViewRegistry = ViewRegistry(
     leafViewBinding(LeafRendering::class, lifecycleLoggingViewObserver { it.name }),
-    BuilderViewFactory(RecurseRendering::class) { initialRendering,
+    ManualScreenViewFactory(RecurseRendering::class) { initialRendering,
       initialViewEnvironment,
       contextForNewView, _ ->
       FrameLayout(contextForNewView).also { container ->
@@ -30,7 +30,7 @@ internal class WorkflowViewStubLifecycleActivity : AbstractLifecycleTestActivity
           initialRendering,
           initialViewEnvironment
         ) { rendering, env ->
-          stub.update(rendering.wrapped, env)
+          stub.show(rendering.wrapped, env)
         }
       }
     },
diff --git a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt
index af76b8ab9c..e480065127 100644
--- a/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/WorkflowViewStubLifecycleTest.kt
@@ -255,7 +255,7 @@ internal class WorkflowViewStubLifecycleTest {
     }
 
     data class RegistrySetter(val wrapped: TestRendering) : ViewRendering<RegistrySetter>() {
-      override val viewFactory: ViewFactory<RegistrySetter> = BuilderViewFactory(
+      override val viewFactory: ScreenViewFactory<RegistrySetter> = ManualScreenViewFactory(
         RegistrySetter::class
       ) { initialRendering, initialViewEnvironment, context, _ ->
         val stub = WorkflowViewStub(context)
@@ -265,7 +265,7 @@ internal class WorkflowViewStubLifecycleTest {
           addView(stub)
 
           bindShowRendering(initialRendering, initialViewEnvironment) { r, e ->
-            stub.update(r.wrapped, e)
+            stub.show(r.wrapped, e)
           }
         }
       }
@@ -298,7 +298,7 @@ internal class WorkflowViewStubLifecycleTest {
       const val Tag = "counter"
     }
 
-    override val viewFactory: ViewFactory<CounterRendering> = BuilderViewFactory(
+    override val viewFactory: ScreenViewFactory<CounterRendering> = ManualScreenViewFactory(
       CounterRendering::class
     ) { initialRendering, initialViewEnvironment, context, _ ->
       var counter = 0
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/BackstackContainerTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/BackstackContainerTest.kt
similarity index 96%
rename from workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/BackstackContainerTest.kt
rename to workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/BackstackContainerTest.kt
index fed23dcc47..aaa1061d7b 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/BackstackContainerTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/BackstackContainerTest.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack.test
+package com.squareup.workflow1.ui.container
 
 import android.os.Build
 import android.view.View
@@ -9,11 +9,11 @@ import androidx.test.ext.junit.rules.ActivityScenarioRule
 import androidx.test.filters.SdkSuppress
 import com.google.common.truth.Truth.assertThat
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity
-import com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
-import com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity.TestRendering.RecurseRendering
-import com.squareup.workflow1.ui.backstack.test.fixtures.viewForScreen
-import com.squareup.workflow1.ui.backstack.test.fixtures.waitForScreen
+import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity
+import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
+import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.RecurseRendering
+import com.squareup.workflow1.ui.container.fixtures.viewForScreen
+import com.squareup.workflow1.ui.container.fixtures.waitForScreen
 import org.junit.Rule
 import org.junit.Test
 
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/ViewStateCacheTest.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/ViewStateCacheTest.kt
similarity index 87%
rename from workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/ViewStateCacheTest.kt
rename to workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/ViewStateCacheTest.kt
index 0483ccfbb4..090fe6f59f 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/ViewStateCacheTest.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/ViewStateCacheTest.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack.test
+package com.squareup.workflow1.ui.container
 
 import android.os.Parcel
 import android.os.Parcelable
@@ -7,14 +7,12 @@ import android.view.View
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry
 import com.google.common.truth.Truth.assertThat
-import com.squareup.workflow1.ui.Named
+import com.squareup.workflow1.ui.NamedScreen
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.KeyedStateRegistryOwner
-import com.squareup.workflow1.ui.backstack.ViewStateCache
-import com.squareup.workflow1.ui.backstack.ViewStateFrame
-import com.squareup.workflow1.ui.backstack.test.fixtures.ViewStateTestView
+import com.squareup.workflow1.ui.container.fixtures.ViewStateTestView
 import com.squareup.workflow1.ui.bindShowRendering
 import org.junit.Assert.fail
 import org.junit.Test
@@ -32,8 +30,10 @@ internal class ViewStateCacheTest {
   private val instrumentation = InstrumentationRegistry.getInstrumentation()
   private val viewEnvironment = ViewEnvironment()
 
+  private object AScreen : Screen
+
   @Test fun saves_and_restores_self() {
-    val rendering = Named(wrapped = Unit, name = "rendering")
+    val rendering = NamedScreen(wrapped = AScreen, name = "rendering")
     val childState = SparseArray<Parcelable>().apply {
       put(0, TestChildState("hello world"))
     }
@@ -57,8 +57,8 @@ internal class ViewStateCacheTest {
 
   @Test fun saves_and_restores_child_states_on_navigation() {
     val cache = ViewStateCache()
-    val firstRendering = Named(wrapped = Unit, name = "first")
-    val secondRendering = Named(wrapped = Unit, name = "second")
+    val firstRendering = NamedScreen(wrapped = AScreen, name = "first")
+    val secondRendering = NamedScreen(wrapped = AScreen, name = "second")
     // Android requires ID to be set for view hierarchy to be saved or restored.
     val firstView = createTestView(firstRendering, id = 1)
     val secondView = createTestView(secondRendering)
@@ -84,8 +84,8 @@ internal class ViewStateCacheTest {
 
   @Test fun doesnt_restore_state_when_restored_view_id_is_different() {
     val cache = ViewStateCache()
-    val firstRendering = Named(wrapped = Unit, name = "first")
-    val secondRendering = Named(wrapped = Unit, name = "second")
+    val firstRendering = NamedScreen(wrapped = AScreen, name = "first")
+    val secondRendering = NamedScreen(wrapped = AScreen, name = "second")
     // Android requires ID to be set for view hierarchy to be saved or restored.
     val firstView = createTestView(firstRendering, id = 1)
     val secondView = createTestView(secondRendering)
@@ -115,8 +115,8 @@ internal class ViewStateCacheTest {
 
   @Test fun doesnt_restore_state_when_view_id_not_set() {
     val cache = ViewStateCache()
-    val firstRendering = Named(wrapped = Unit, name = "first")
-    val secondRendering = Named(wrapped = Unit, name = "second")
+    val firstRendering = NamedScreen(wrapped = AScreen, name = "first")
+    val secondRendering = NamedScreen(wrapped = AScreen, name = "second")
     val firstView = createTestView(firstRendering)
     val secondView = createTestView(secondRendering)
 
@@ -141,20 +141,20 @@ internal class ViewStateCacheTest {
 
   @Test fun throws_when_view_not_bound() {
     val cache = ViewStateCache()
-    val rendering = Named(wrapped = Unit, name = "duplicate")
+    val rendering = NamedScreen(wrapped = AScreen, name = "duplicate")
     val view = View(instrumentation.context)
 
     try {
       cache.update(listOf(rendering, rendering), null, view)
       fail("Expected exception.")
     } catch (e: IllegalStateException) {
-      assertThat(e.message).contains("to be showing a Named<*> rendering, found null")
+      assertThat(e.message).contains("to be showing a NamedScreen<*> rendering, found null")
     }
   }
 
   @Test fun throws_on_duplicate_renderings() {
     val cache = ViewStateCache()
-    val rendering = Named(wrapped = Unit, name = "duplicate")
+    val rendering = NamedScreen(wrapped = AScreen, name = "duplicate")
     val view = createTestView(rendering)
 
     try {
@@ -166,7 +166,7 @@ internal class ViewStateCacheTest {
   }
 
   private fun createTestView(
-    firstRendering: Named<Unit>,
+    firstRendering: NamedScreen<*>,
     id: Int? = null
   ) = ViewStateTestView(instrumentation.context).also { view ->
     id?.let { view.id = id }
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/BackStackContainerLifecycleActivity.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
similarity index 86%
rename from workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/BackStackContainerLifecycleActivity.kt
rename to workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
index ca84e4bf15..524e138c87 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/BackStackContainerLifecycleActivity.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/BackStackContainerLifecycleActivity.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack.test.fixtures
+package com.squareup.workflow1.ui.container.fixtures
 
 import android.content.Context
 import android.view.View
@@ -8,17 +8,18 @@ import androidx.test.core.app.ActivityScenario
 import androidx.test.espresso.assertion.ViewAssertions.matches
 import androidx.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.withTagValue
-import com.squareup.workflow1.ui.BuilderViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
 import com.squareup.workflow1.ui.Compatible
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
-import com.squareup.workflow1.ui.backstack.BackStackScreen
-import com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
-import com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity.TestRendering.RecurseRendering
+import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
+import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.RecurseRendering
 import com.squareup.workflow1.ui.bindShowRendering
+import com.squareup.workflow1.ui.container.BackStackScreen
 import com.squareup.workflow1.ui.internal.test.AbstractLifecycleTestActivity
 import com.squareup.workflow1.ui.internal.test.inAnyView
 import org.hamcrest.Matcher
@@ -31,7 +32,7 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
   /**
    * Default rendering always shown in the backstack to simplify test configuration.
    */
-  object BaseRendering : ViewFactory<BaseRendering> {
+  object BaseRendering : Screen, ScreenViewFactory<BaseRendering> {
     override val type: KClass<in BaseRendering> = BaseRendering::class
     override fun buildView(
       initialRendering: BaseRendering,
@@ -43,7 +44,7 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
     }
   }
 
-  sealed class TestRendering {
+  sealed class TestRendering : Screen {
     data class LeafRendering(val name: String) : TestRendering(), Compatible {
       override val compatibilityKey: String get() = name
     }
@@ -108,7 +109,7 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
     NoTransitionBackStackContainer,
     BaseRendering,
     leafViewBinding(LeafRendering::class, viewObserver, viewConstructor = ::ViewStateTestView),
-    BuilderViewFactory(RecurseRendering::class) { initialRendering,
+    ManualScreenViewFactory(RecurseRendering::class) { initialRendering,
       initialViewEnvironment,
       contextForNewView, _ ->
       FrameLayout(contextForNewView).also { container ->
@@ -118,7 +119,7 @@ internal class BackStackContainerLifecycleActivity : AbstractLifecycleTestActivi
           initialRendering,
           initialViewEnvironment
         ) { rendering, env ->
-          stub.update(rendering.wrappedBackstack.toBackstackWithBase(), env)
+          stub.show(rendering.wrappedBackstack.toBackstackWithBase(), env)
         }
       }
     },
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/NoTransitionBackStackContainer.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt
similarity index 72%
rename from workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/NoTransitionBackStackContainer.kt
rename to workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt
index df2289c8b3..026848fd26 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/NoTransitionBackStackContainer.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/NoTransitionBackStackContainer.kt
@@ -1,15 +1,15 @@
-package com.squareup.workflow1.ui.backstack.test.fixtures
+package com.squareup.workflow1.ui.container.fixtures
 
 import android.content.Context
 import android.view.View
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
-import com.squareup.workflow1.ui.BuilderViewFactory
-import com.squareup.workflow1.ui.ViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.BackStackContainer
-import com.squareup.workflow1.ui.backstack.BackStackScreen
 import com.squareup.workflow1.ui.bindShowRendering
-import com.squareup.workflow1.ui.container.R
+import com.squareup.workflow1.ui.container.BackStackContainer
+import com.squareup.workflow1.ui.container.BackStackScreen
+import com.squareup.workflow1.ui.R
 
 /**
  * A subclass of [BackStackContainer] that disables transitions to make it simpler to test the
@@ -23,8 +23,8 @@ internal class NoTransitionBackStackContainer(context: Context) : BackStackConta
     addView(newView)
   }
 
-  companion object : ViewFactory<BackStackScreen<*>>
-  by BuilderViewFactory(
+  companion object : ScreenViewFactory<BackStackScreen<*>>
+  by ManualScreenViewFactory(
     type = BackStackScreen::class,
     viewConstructor = { initialRendering, initialEnv, context, _ ->
       NoTransitionBackStackContainer(context)
diff --git a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/ViewStateTestView.kt b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/ViewStateTestView.kt
similarity index 90%
rename from workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/ViewStateTestView.kt
rename to workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/ViewStateTestView.kt
index c4ba553c6a..f42a41b0f5 100644
--- a/workflow-ui/container-android/src/androidTest/java/com/squareup/workflow1/ui/backstack/test/fixtures/ViewStateTestView.kt
+++ b/workflow-ui/core-android/src/androidTest/java/com/squareup/workflow1/ui/container/fixtures/ViewStateTestView.kt
@@ -1,11 +1,11 @@
-package com.squareup.workflow1.ui.backstack.test.fixtures
+package com.squareup.workflow1.ui.container.fixtures
 
 import android.content.Context
 import android.os.Parcel
 import android.os.Parcelable
 import android.os.Parcelable.Creator
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.test.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
+import com.squareup.workflow1.ui.container.fixtures.BackStackContainerLifecycleActivity.TestRendering.LeafRendering
 import com.squareup.workflow1.ui.internal.test.AbstractLifecycleTestActivity.LeafView
 
 /**
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
new file mode 100644
index 0000000000..13a65d05ba
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidScreen.kt
@@ -0,0 +1,95 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+
+/**
+ * Interface implemented by a rendering class to allow it to drive an Android UI
+ * via an appropriate [ScreenViewFactory] implementation.
+ *
+ * You will rarely, if ever, write a [ScreenViewFactory] yourself.  Instead
+ * use [ScreenViewRunner.bind] to work with XML layout resources, or
+ * [BuilderViewFactory] to create views from code.  See [ScreenViewRunner] for more
+ * details.
+ *
+ *     @OptIn(WorkflowUiExperimentalApi::class)
+ *     data class HelloScreen(
+ *       val message: String,
+ *       val onClick: () -> Unit
+ *     ) : AndroidScreen<HelloScreen> {
+ *       override val viewFactory =
+ *         ScreenViewRunner.bind(HelloGoodbyeLayoutBinding::inflate) { screen, _ ->
+ *           helloMessage.text = screen.message
+ *           helloMessage.setOnClickListener { screen.onClick() }
+ *         }
+ *     }
+ *
+ * This is the simplest way to bridge the gap between your workflows and the UI,
+ * but using it requires your workflows code to reside in Android modules, instead
+ * of pure Kotlin. If this is a problem, or you need more flexibility for any other
+ * reason, you can use [ViewRegistry] to bind your renderings to [ScreenViewFactory]
+ * implementations at runtime. Also note that a [ViewRegistry] entry will override
+ * the [viewFactory] returned by an [AndroidScreen].
+ */
+@WorkflowUiExperimentalApi
+public interface AndroidScreen<V : AndroidScreen<V>> : Screen {
+  /**
+   * Used to build instances of [android.view.View] as needed to
+   * display renderings of this type.
+   */
+  public val viewFactory: ScreenViewFactory<V>
+}
+
+/**
+ * It is usually more convenient to use [WorkflowViewStub] or [DecorativeScreenViewFactory]
+ * than to call this method directly.
+ *
+ * Finds a [ScreenViewFactory] to create a [View] to display [this@buildView]. The new view
+ * can be updated via calls to [View.showRendering] -- that is, it is guaranteed that
+ * [bindShowRendering] has been called on this view.
+ *
+ * The returned view will have a
+ * [WorkflowLifecycleOwner][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner]
+ * set on it. The returned view must EITHER:
+ *
+ * 1. Be attached at least once to ensure that the lifecycle eventually gets destroyed (because its
+ *    parent is destroyed), or
+ * 2. Have its
+ *    [WorkflowLifecycleOwner.destroyOnDetach][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner.destroyOnDetach]
+ *    called, which will either schedule the
+ *    lifecycle to be destroyed if the view is attached, or destroy it immediately if it's detached.
+ *
+ * [WorkflowViewStub] takes care of this chore itself.
+ *
+ * @param initializeView Optional function invoked immediately after the [View] is
+ * created (that is, immediately after the call to [ScreenViewFactory.buildView]).
+ * [showRendering], [getRendering] and [environment] are all available when this is called.
+ * Defaults to a call to [View.showFirstRendering].
+ *
+ * @throws IllegalArgumentException if no builder can be find for type [ScreenT]
+ *
+ * @throws IllegalStateException if the matching [ScreenViewFactory] fails to call
+ * [View.bindShowRendering] when constructing the view
+ */
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen> ScreenT.buildView(
+  viewEnvironment: ViewEnvironment,
+  contextForNewView: Context,
+  container: ViewGroup? = null,
+  initializeView: View.() -> Unit = { showFirstRendering() }
+): View {
+  val entry = viewEnvironment.getViewFactoryForRendering(this)
+  val viewFactory = (entry as? ScreenViewFactory<ScreenT>)
+    ?: error("Require a ScreenViewFactory for $this, found $entry")
+
+  return viewFactory.buildView(
+    this, viewEnvironment, contextForNewView, container
+  ).also { view ->
+    checkNotNull(view.showRenderingTag) {
+      "View.bindShowRendering should have been called for $view, typically by the " +
+        "${ScreenViewFactory::class.java.name} that created it."
+    }
+    initializeView.invoke(view)
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewEnvironment.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewEnvironment.kt
new file mode 100644
index 0000000000..1b07a68778
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewEnvironment.kt
@@ -0,0 +1,62 @@
+package com.squareup.workflow1.ui
+
+import android.view.View
+import com.squareup.workflow1.ui.container.BackStackScreen
+import com.squareup.workflow1.ui.container.BackStackScreenViewFactory
+import com.squareup.workflow1.ui.container.WithEnvironmentViewFactory
+import com.squareup.workflow1.ui.container.WithEnvironment
+
+/**
+ * It is usually more convenient to use [WorkflowViewStub] or [DecorativeScreenViewFactory]
+ * than to call this method directly.
+ *
+ * Returns the [ScreenViewFactory] that builds [View] instances suitable to display the given [rendering],
+ * via subsequent calls to [View.showRendering].
+ *
+ * Prefers factories found via [ViewRegistry.getEntryFor]. If that returns null, falls
+ * back to the builder provided by the rendering's implementation of
+ * [AndroidScreen.viewFactory], if there is one. Note that this means that a
+ * compile time [AndroidScreen.viewFactory] binding can be overridden at runtime.
+ *
+ * The returned view will have a
+ * [WorkflowLifecycleOwner][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner]
+ * set on it. The returned view must EITHER:
+ *
+ * 1. Be attached at least once to ensure that the lifecycle eventually gets destroyed (because its
+ *    parent is destroyed), or
+ * 2. Have its
+ *    [WorkflowLifecycleOwner.destroyOnDetach][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner.destroyOnDetach]
+ *    called, which will either schedule the
+ *    lifecycle to be destroyed if the view is attached, or destroy it immediately if it's detached.
+ *
+ * @throws IllegalArgumentException if no builder can be find for type [ScreenT]
+ */
+@WorkflowUiExperimentalApi
+public fun <ScreenT : Screen>
+  ViewEnvironment.getViewFactoryForRendering(rendering: ScreenT): ScreenViewFactory<ScreenT> {
+  @Suppress("UNCHECKED_CAST", "DEPRECATION")
+  return (get(ViewRegistry).getEntryFor(rendering::class) as? ScreenViewFactory<ScreenT>)
+    ?: (rendering as? AndroidScreen<*>)?.viewFactory as? ScreenViewFactory<ScreenT>
+    ?: (rendering as? AsScreen<*>)?.let { AsScreenViewFactory as ScreenViewFactory<ScreenT> }
+    ?: (rendering as? BackStackScreen<*>)?.let {
+      BackStackScreenViewFactory as ScreenViewFactory<ScreenT>
+    }
+    ?: (rendering as? NamedScreen<*>)?.let { NamedScreenViewFactory as ScreenViewFactory<ScreenT> }
+    ?: (rendering as? WithEnvironment<*>)?.let {
+      WithEnvironmentViewFactory as ScreenViewFactory<ScreenT>
+    }
+    ?: throw IllegalArgumentException(
+      "A ScreenViewFactory should have been registered to display $rendering, " +
+        "or that class should implement AndroidScreen."
+    )
+}
+
+/**
+ * Default implementation for the `initializeView` argument of [Screen.buildView],
+ * and for [DecorativeScreenViewFactory.initializeView]. Calls [showRendering] against
+ * [getRendering] and [environment].
+ */
+@WorkflowUiExperimentalApi
+public fun View.showFirstRendering() {
+  showRendering(getRendering()!!, environment!!)
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt
new file mode 100644
index 0000000000..631a14328e
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRegistry.kt
@@ -0,0 +1,56 @@
+@file:Suppress("DEPRECATION")
+
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import com.squareup.workflow1.ui.container.BackStackScreen
+import kotlin.reflect.KClass
+
+@Deprecated("Use ViewEnvironment.getViewFactoryForRendering()")
+@WorkflowUiExperimentalApi
+public fun <RenderingT : Any>
+  ViewRegistry.getFactoryForRendering(rendering: RenderingT): ViewFactory<RenderingT> {
+  @Suppress("UNCHECKED_CAST")
+  return getFactoryFor(rendering::class)
+    ?: (rendering as? AndroidViewRendering<*>)?.viewFactory as? ViewFactory<RenderingT>
+    ?: (rendering as? AsScreen<*>)?.let { AsScreenLegacyViewFactory as ViewFactory<RenderingT> }
+    ?: (rendering as? BackStackScreen<*>)?.let {
+      BackStackScreenLegacyViewFactory as ViewFactory<RenderingT>
+    }
+    ?: (rendering as? Named<*>)?.let { NamedViewFactory as ViewFactory<RenderingT> }
+    ?: throw IllegalArgumentException(
+      "A ViewFactory should have been registered to display $rendering, " +
+        "or that class should implement AndroidViewRendering."
+    )
+}
+
+@Deprecated("Use getEntryFor()")
+@WorkflowUiExperimentalApi
+public fun <RenderingT : Any> ViewRegistry.getFactoryFor(
+  renderingType: KClass<out RenderingT>
+): ViewFactory<RenderingT>? {
+  return getEntryFor(renderingType) as? ViewFactory<RenderingT>
+}
+
+@Suppress("DEPRECATION")
+@Deprecated("Use ViewEnvironment.buildview")
+@WorkflowUiExperimentalApi
+public fun <RenderingT : Any> ViewRegistry.buildView(
+  initialRendering: RenderingT,
+  initialViewEnvironment: ViewEnvironment,
+  contextForNewView: Context,
+  container: ViewGroup? = null,
+  initializeView: View.() -> Unit = { showFirstRendering() }
+): View {
+  return getFactoryForRendering(initialRendering).buildView(
+    initialRendering, initialViewEnvironment, contextForNewView, container
+  ).also { view ->
+    checkNotNull(view.showRenderingTag) {
+      "View.bindShowRendering should have been called for $view, typically by the " +
+        "${ViewFactory::class.java.name} that created it."
+    }
+    initializeView.invoke(view)
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRendering.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRendering.kt
index 35e551fe81..775c506faa 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRendering.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AndroidViewRendering.kt
@@ -1,32 +1,7 @@
 package com.squareup.workflow1.ui
 
-/**
- * Interface implemented by a rendering class to allow it to drive an Android UI
- * via an appropriate [ViewFactory] implementation.
- *
- * You will rarely, if ever, write a [ViewFactory] yourself.  Instead
- * use [LayoutRunner.bind] to work with XML layout resources, or
- * [BuilderViewFactory] to create views from code.  See [LayoutRunner] for more
- * details.
- *
- *     @OptIn(WorkflowUiExperimentalApi::class)
- *     data class HelloView(
- *       val message: String,
- *       val onClick: () -> Unit
- *     ) : AndroidViewRendering<HelloView> {
- *       override val viewFactory: ViewFactory<HelloView> =
- *         LayoutRunner.bind(HelloGoodbyeLayoutBinding::inflate) { r, _ ->
- *           helloMessage.text = r.message
- *           helloMessage.setOnClickListener { r.onClick() }
- *         }
- *     }
- *
- * This is the simplest way to bridge the gap between your workflows and the UI,
- * but using it requires your workflows code to reside in Android modules, instead
- * of pure Kotlin. If this is a problem, or you need more flexibility for any other
- * reason, you can use [ViewRegistry] to bind your renderings to [ViewFactory]
- * implementations at runtime.
- */
+@Suppress("DEPRECATION")
+@Deprecated("Use AndroidScreen")
 @WorkflowUiExperimentalApi
 public interface AndroidViewRendering<V : AndroidViewRendering<V>> {
   /**
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenLegacyViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenLegacyViewFactory.kt
new file mode 100644
index 0000000000..2951307656
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenLegacyViewFactory.kt
@@ -0,0 +1,6 @@
+package com.squareup.workflow1.ui
+
+@Suppress("DEPRECATION")
+@WorkflowUiExperimentalApi
+internal object AsScreenLegacyViewFactory : ViewFactory<AsScreen<*>>
+by DecorativeViewFactory(AsScreen::class, { asScreen -> asScreen.rendering })
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt
new file mode 100644
index 0000000000..2363518a66
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/AsScreenViewFactory.kt
@@ -0,0 +1,28 @@
+package com.squareup.workflow1.ui
+
+@WorkflowUiExperimentalApi
+@Suppress("DEPRECATION")
+internal object AsScreenViewFactory : ScreenViewFactory<AsScreen<*>>
+by ManualScreenViewFactory(
+  type = AsScreen::class,
+  viewConstructor = { initialRendering, initialViewEnvironment, context, container ->
+    initialViewEnvironment[ViewRegistry]
+      .buildView(
+        initialRendering.rendering,
+        initialViewEnvironment,
+        context,
+        container,
+        // Don't call showRendering yet, we need to wrap the function first.
+        initializeView = { }
+      ).also { view ->
+        val legacyShowRendering = view.getShowRendering<Any>()!!
+
+        view.bindShowRendering(
+          initialRendering,
+          initialViewEnvironment
+        ) { rendering, env -> legacyShowRendering(rendering.rendering, env) }
+
+        view.showFirstRendering()
+      }
+  }
+)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BackStackScreenLegacyViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BackStackScreenLegacyViewFactory.kt
new file mode 100644
index 0000000000..c60da654bc
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BackStackScreenLegacyViewFactory.kt
@@ -0,0 +1,21 @@
+package com.squareup.workflow1.ui
+
+import android.view.ViewGroup.LayoutParams
+import android.view.ViewGroup.LayoutParams.MATCH_PARENT
+import com.squareup.workflow1.ui.container.BackStackContainer
+import com.squareup.workflow1.ui.container.BackStackScreen
+
+@Suppress("DEPRECATION")
+@WorkflowUiExperimentalApi
+internal object BackStackScreenLegacyViewFactory : ViewFactory<BackStackScreen<*>>
+by BuilderViewFactory(
+  type = BackStackScreen::class,
+  viewConstructor = { initialRendering, initialEnv, context, _ ->
+    BackStackContainer(context)
+      .apply {
+        id = R.id.workflow_back_stack_container
+        layoutParams = (LayoutParams(MATCH_PARENT, MATCH_PARENT))
+        bindShowRendering(initialRendering, initialEnv, ::update)
+      }
+  }
+)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt
index c3f24accc8..e18aa37185 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/BuilderViewFactory.kt
@@ -5,25 +5,8 @@ import android.view.View
 import android.view.ViewGroup
 import kotlin.reflect.KClass
 
-/**
- * A [ViewFactory] that creates [View]s that need to be generated from code.
- * (Use [LayoutRunner] to work with XML layout resources.)
- *
- *    data class MyView(): AndroidViewRendering<MyView> {
- *      val viewFactory = BuilderViewFactory(
- *          type = MyScreen::class,
- *          viewConstructor = { initialRendering, _, context, _ ->
- *            MyFrame(context).apply {
- *              layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
- *              bindShowRendering(initialRendering, ::update)
- *            }
- *      )
- *    }
- *
- *    private class MyFrame(context: Context) : FrameLayout(context, attributeSet) {
- *      private fun update(rendering:  MyView) { ... }
- *    }
- */
+@Suppress("DEPRECATION")
+@Deprecated("Use ManualScreenViewFactory")
 @WorkflowUiExperimentalApi
 public class BuilderViewFactory<RenderingT : Any>(
   override val type: KClass<RenderingT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
new file mode 100644
index 0000000000..de2b3334cf
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeScreenViewFactory.kt
@@ -0,0 +1,185 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import kotlin.reflect.KClass
+
+/**
+ * A [ScreenViewFactory] for [OuterT] that delegates view construction responsibilities
+ * to the factory registered for [InnerT]. Makes it convenient for [OuterT] to wrap
+ * instances of [InnerT] to add information or behavior, without requiring wasteful wrapping
+ * in the view system.
+ *
+ * One general note: when creating a wrapper rendering, you're very likely to want it
+ * to implement [Compatible], to ensure that checks made to update or replace a view
+ * are based on the wrapped item. Each wrapper example below illustrates this.
+ *
+ * ## Examples
+ *
+ * To make one rendering type an "alias" for another -- that is, to use the same [ScreenViewFactory]
+ * to display it -- provide nothing but a single-arg mapping function:
+ *
+ *    class OriginalRendering(val data: String) : AndroidScreen<OriginalRendering> {
+ *      ...
+ *    }
+ *    class AliasRendering(val similarData: String)
+ *
+ *    object DecorativeScreenViewFactory : ScreenViewFactory<AliasRendering>
+ *    by DecorativeScreenViewFactory(
+ *      type = AliasRendering::class, map = { alias ->
+ *        OriginalRendering(alias.similarData)
+ *      }
+ *    )
+ *
+ * To make a wrapper that adds information to the [ViewEnvironment]:
+ *
+ *    class NeutronFlowPolarity(val reversed: Boolean) : Screen {
+ *      companion object : ViewEnvironmentKey<NeutronFlowPolarity>(
+ *        NeutronFlowPolarity::class
+ *      ) {
+ *        override val default: NeutronFlowPolarity =
+ *          NeutronFlowPolarity(reversed = false)
+ *      }
+ *    }
+ *
+ *    class NeutronFlowPolarityOverride<W : Screen>(
+ *      val wrapped: W,
+ *      val polarity: NeutronFlowPolarity
+ *    ) : Screen, Compatible {
+ *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
+ *    }
+ *
+ *    object NeutronFlowPolarityViewFactory :
+ *      ScreenViewFactory<NeutronFlowPolarityOverride<*>>
+ *    by DecorativeScreenViewFactory(
+ *        type = NeutronFlowPolarityOverride::class,
+ *        map = { override, env ->
+ *          Pair(override.wrapped, env + (NeutronFlowPolarity to override.polarity))
+ *        }
+ *    )
+ *
+ * To make a wrapper that customizes [View] initialization:
+ *
+ *    class WithTutorialTips<W : Screen>(val wrapped: W) : Screen, Compatible {
+ *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
+ *    }
+ *
+ *    object WithTutorialTipsViewFactory : ScreenViewFactory<WithTutorialTips<*>>
+ *    by DecorativeScreenViewFactory(
+ *      type = WithTutorialTips::class,
+ *      map = { withTips -> withTips.wrapped },
+ *      initializeView = {
+ *        TutorialTipRunner.run(this)
+ *        showFirstRendering<WithTutorialTips<*>>()
+ *      }
+ *    )
+ *
+ * To make a wrapper that adds pre- or post-processing to [View] updates:
+ *
+ *    class BackButtonScreen<W : Screen>(
+ *       val wrapped: W,
+ *       val override: Boolean = false,
+ *       val onBackPressed: (() -> Unit)? = null
+ *    ) : Screen, Compatible {
+ *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
+ *    }
+ *
+ *    object BackButtonViewFactory : ScreenViewFactory<BackButtonScreen<*>>
+ *    by DecorativeScreenViewFactory(
+ *      type = BackButtonScreen::class,
+ *      map = { outer -> outer.wrapped },
+ *      doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
+ *        if (!outerRendering.override) {
+ *          // Place our handler before invoking innerShowRendering, so that
+ *          // its later calls to view.backPressedHandler will take precedence
+ *          // over ours.
+ *          view.backPressedHandler = outerRendering.onBackPressed
+ *        }
+ *
+ *        innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
+ *
+ *        if (outerRendering.override) {
+ *          // Place our handler after invoking innerShowRendering, so that ours wins.
+ *          view.backPressedHandler = outerRendering.onBackPressed
+ *        }
+ *      }
+ *    )
+ *
+ * @param map called to convert instances of [OuterT] to [InnerT], and to
+ * allow [ViewEnvironment] to be transformed.
+ *
+ * @param initializeView Optional function invoked immediately after the [View] is
+ * created (that is, immediately after the call to [ScreenViewFactory.buildView]).
+ * [showRendering], [getRendering] and [environment] are all available when this is called.
+ * Defaults to a call to [View.showFirstRendering].
+ *
+ * @param doShowRendering called to apply the [ViewShowRendering] function for
+ * [InnerT], allowing pre- and post-processing. Default implementation simply
+ * uses [map] to extract the [InnerT] instance from [OuterT] and makes the function call.
+ */
+@WorkflowUiExperimentalApi
+public class DecorativeScreenViewFactory<OuterT : Screen, InnerT : Screen>(
+  override val type: KClass<OuterT>,
+  private val map: (OuterT, ViewEnvironment) -> Pair<InnerT, ViewEnvironment>,
+  private val initializeView: View.() -> Unit = { showFirstRendering() },
+  private val doShowRendering: (
+    view: View,
+    innerShowRendering: ViewShowRendering<InnerT>,
+    outerRendering: OuterT,
+    env: ViewEnvironment
+  ) -> Unit = { _, innerShowRendering, outerRendering, viewEnvironment ->
+    val (innerRendering, processedEnv) = map(outerRendering, viewEnvironment)
+    innerShowRendering(innerRendering, processedEnv)
+  }
+) : ScreenViewFactory<OuterT> {
+
+  /**
+   * Convenience constructor for cases requiring no changes to the [ViewEnvironment].
+   */
+  public constructor(
+    type: KClass<OuterT>,
+    map: (OuterT) -> InnerT,
+    initializeView: View.() -> Unit = { showFirstRendering() },
+    doShowRendering: (
+      view: View,
+      innerShowRendering: ViewShowRendering<InnerT>,
+      outerRendering: OuterT,
+      env: ViewEnvironment
+    ) -> Unit = { _, innerShowRendering, outerRendering, viewEnvironment ->
+      innerShowRendering(map(outerRendering), viewEnvironment)
+    }
+  ) : this(
+    type,
+    map = { outer, viewEnvironment -> Pair(map(outer), viewEnvironment) },
+    initializeView = initializeView,
+    doShowRendering = doShowRendering
+  )
+
+  override fun buildView(
+    initialRendering: OuterT,
+    initialViewEnvironment: ViewEnvironment,
+    contextForNewView: Context,
+    container: ViewGroup?
+  ): View {
+    val (innerInitialRendering, processedInitialEnv) = map(initialRendering, initialViewEnvironment)
+
+    return innerInitialRendering.buildView(
+      processedInitialEnv,
+      contextForNewView,
+      container,
+      // Don't call showRendering yet, we need to wrap the function first.
+      initializeView = { }
+    )
+      .also { view ->
+        val innerShowRendering: ViewShowRendering<InnerT> = view.getShowRendering()!!
+
+        view.bindShowRendering(
+          initialRendering,
+          processedInitialEnv
+        ) { rendering, env -> doShowRendering(view, innerShowRendering, rendering, env) }
+
+        view.initializeView()
+      }
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
index 346b708b59..dcd11eeba7 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/DecorativeViewFactory.kt
@@ -5,112 +5,8 @@ import android.view.View
 import android.view.ViewGroup
 import kotlin.reflect.KClass
 
-/**
- * A [ViewFactory] for [OuterT] that delegates view construction responsibilities
- * to the factory registered for [InnerT]. Makes it convenient for [OuterT] to wrap
- * instances of [InnerT] to add information or behavior, without requiring wasteful wrapping
- * in the view system.
- *
- * One general note: when creating a wrapper rendering, you're very likely to want it
- * to implement [Compatible], to ensure that checks made to update or replace a view
- * are based on the wrapped item. Each example below illustrates this.
- *
- * ## Examples
- *
- * To make one rendering type an "alias" for another -- that is, to use the same [ViewFactory]
- * to display it -- provide nothing but a single-arg mapping function:
- *
- *    class OriginalRendering(val data: String)
- *    class AliasRendering(val similarData: String) : Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object DecorativeViewFactory : ViewFactory<AliasRendering>
- *    by DecorativeViewFactory(
- *      type = AliasRendering::class, map = { alias -> OriginalRendering(alias.similarData) }
- *    )
- *
- * To make a decorator type that adds information to the [ViewEnvironment]:
- *
- *    class NeutronFlowPolarity(val reversed: Boolean) {
- *      companion object : ViewEnvironmentKey<NeutronFlowPolarity>(NeutronFlowPolarity::class) {
- *        override val default: NeutronFlowPolarity = NeutronFlowPolarity(reversed = false)
- *      }
- *    }
- *
- *    class NeutronFlowPolarityOverride<W>(
- *      val wrapped: W,
- *      val polarity: NeutronFlowPolarity
- *    ) : Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object NeutronFlowPolarityViewFactory : ViewFactory<NeutronFlowPolarityOverride<*>>
- *    by DecorativeViewFactory(
- *        type = NeutronFlowPolarityOverride::class,
- *        map = { override, env ->
- *          Pair(override.wrapped, env + (NeutronFlowPolarity to override.polarity))
- *        }
- *    )
- *
- * To make a decorator type that customizes [View] initialization:
- *
- *    class WithTutorialTips<W>(val wrapped: W) : Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object WithTutorialTipsViewFactory : ViewFactory<WithTutorialTips<*>>
- *    by DecorativeViewFactory(
- *        type = WithTutorialTips::class,
- *        map = { withTips -> withTips.wrapped },
- *        initializeView = {
- *          TutorialTipRunner.run(this)
- *          showFirstRendering<WithTutorialTips<*>>()
- *        }
- *    )
- *
- * To make a decorator type that adds pre- or post-processing to [View] updates:
- *
- *    class BackButtonScreen<W : Any>(
- *       val wrapped: W,
- *       val override: Boolean = false,
- *       val onBackPressed: (() -> Unit)? = null
- *    ) : Compatible {
- *      override val compatibilityKey: String = Compatible.keyFor(wrapped)
- *    }
- *
- *    object BackButtonViewFactory : ViewFactory<BackButtonScreen<*>>
- *    by DecorativeViewFactory(
- *        type = BackButtonScreen::class,
- *        map = { outer -> outer.wrapped },
- *        doShowRendering = { view, innerShowRendering, outerRendering, viewEnvironment ->
- *          if (!outerRendering.override) {
- *            // Place our handler before invoking innerShowRendering, so that
- *            // its later calls to view.backPressedHandler will take precedence
- *            // over ours.
- *            view.backPressedHandler = outerRendering.onBackPressed
- *          }
- *
- *          innerShowRendering.invoke(outerRendering.wrapped, viewEnvironment)
- *
- *          if (outerRendering.override) {
- *            // Place our handler after invoking innerShowRendering, so that ours wins.
- *            view.backPressedHandler = outerRendering.onBackPressed
- *          }
- *        })
- *
- * @param map called to convert instances of [OuterT] to [InnerT], and to
- * allow [ViewEnvironment] to be transformed.
- *
- * @param initializeView Optional function invoked immediately after the [View] is
- * created (that is, immediately after the call to [ViewFactory.buildView]).
- * [showRendering], [getRendering] and [environment] are all available when this is called.
- * Defaults to a call to [View.showFirstRendering].
- *
- * @param doShowRendering called to apply the [ViewShowRendering] function for
- * [InnerT], allowing pre- and post-processing. Default implementation simply
- * uses [map] to extract the [InnerT] instance from [OuterT] and makes the function call.
- */
+@Suppress("DEPRECATION")
+@Deprecated("Use DecorativeScreenViewFactory")
 @WorkflowUiExperimentalApi
 public class DecorativeViewFactory<OuterT : Any, InnerT : Any>(
   override val type: KClass<OuterT>,
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt
index a39f1b0281..0300b09b43 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunner.kt
@@ -1,24 +1,11 @@
 package com.squareup.workflow1.ui
 
-import android.content.Context
-import android.view.LayoutInflater
 import android.view.View
-import android.view.ViewGroup
 import androidx.annotation.LayoutRes
 import androidx.viewbinding.ViewBinding
 
-@WorkflowUiExperimentalApi
-public typealias ViewBindingInflater<BindingT> = (LayoutInflater, ViewGroup?, Boolean) -> BindingT
-
-/**
- * A delegate that implements a [showRendering] method to be called when a workflow rendering
- * of type [RenderingT] is ready to be displayed in a view inflated from a layout resource
- * by a [ViewRegistry]. (Use [BuilderViewFactory] if you want to build views from code rather
- * than layouts.)
- *
- * If you're using [AndroidX ViewBinding][ViewBinding] you likely won't need to
- * implement this interface at all. For details, see the three overloads of [LayoutRunner.bind].
- */
+@Suppress("DEPRECATION")
+@Deprecated("Use ScreenViewRunner")
 @WorkflowUiExperimentalApi
 public fun interface LayoutRunner<RenderingT : Any> {
   public fun showRendering(
@@ -98,7 +85,3 @@ public fun interface LayoutRunner<RenderingT : Any> {
     ): ViewFactory<RenderingT> = bind(layoutId) { LayoutRunner { _, _ -> } }
   }
 }
-
-internal fun Context.viewBindingLayoutInflater(container: ViewGroup?) =
-  LayoutInflater.from(container?.context ?: this)
-      .cloneInContext(this)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunnerViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunnerViewFactory.kt
index 2a25ad5fc6..e471e19956 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunnerViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutRunnerViewFactory.kt
@@ -11,6 +11,7 @@ import kotlin.reflect.KClass
  * [LayoutRunner factory][runnerConstructor] function. See [LayoutRunner] for
  * details.
  */
+@Suppress("DEPRECATION")
 @WorkflowUiExperimentalApi
 @PublishedApi
 internal class LayoutRunnerViewFactory<RenderingT : Any>(
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
new file mode 100644
index 0000000000..49a117406b
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/LayoutScreenViewFactory.kt
@@ -0,0 +1,36 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import androidx.annotation.LayoutRes
+import kotlin.reflect.KClass
+
+/**
+ * A [ScreenViewFactory] that ties a [layout resource][layoutId] to a
+ * [ViewRunner factory][runnerConstructor] function. See [ScreenViewRunner] for
+ * details.
+ */
+@WorkflowUiExperimentalApi
+@PublishedApi
+internal class LayoutScreenViewFactory<RenderingT : Screen>(
+  override val type: KClass<RenderingT>,
+  @LayoutRes private val layoutId: Int,
+  private val runnerConstructor: (View) -> ScreenViewRunner<RenderingT>
+) : ScreenViewFactory<RenderingT> {
+  override fun buildView(
+    initialRendering: RenderingT,
+    initialViewEnvironment: ViewEnvironment,
+    contextForNewView: Context,
+    container: ViewGroup?
+  ): View {
+    return contextForNewView.viewBindingLayoutInflater(container)
+      .inflate(layoutId, container, false)
+      .also { view ->
+        val runner = runnerConstructor(view)
+        view.bindShowRendering(initialRendering, initialViewEnvironment) { rendering, environment ->
+          runner.showRendering(rendering, environment)
+        }
+      }
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
new file mode 100644
index 0000000000..97147b970e
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ManualScreenViewFactory.kt
@@ -0,0 +1,43 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import kotlin.reflect.KClass
+
+/**
+ * A [ScreenViewFactory] that creates [View]s that need to be generated from code.
+ * (Use [ScreenViewRunner] to work with XML layout resources.)
+ *
+ *    data class MyScreen(): AndroidScreen<MyView> {
+ *      val viewFactory = ManualScreenViewFactory(
+ *          type = MyScreen::class,
+ *          viewConstructor = { initialRendering, _, context, _ ->
+ *            MyFrame(context).apply {
+ *              layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)
+ *              bindShowRendering(initialRendering, ::update)
+ *            }
+ *      )
+ *    }
+ *
+ *    private class MyFrame(context: Context) : FrameLayout(context, attributeSet) {
+ *      private fun update(rendering:  MyScreen) { ... }
+ *    }
+ */
+@WorkflowUiExperimentalApi
+public class ManualScreenViewFactory<RenderingT : Screen>(
+  override val type: KClass<RenderingT>,
+  private val viewConstructor: (
+    initialRendering: RenderingT,
+    initialViewEnvironment: ViewEnvironment,
+    contextForNewView: Context,
+    container: ViewGroup?
+  ) -> View
+) : ScreenViewFactory<RenderingT> {
+  override fun buildView(
+    initialRendering: RenderingT,
+    initialViewEnvironment: ViewEnvironment,
+    contextForNewView: Context,
+    container: ViewGroup?
+  ): View = viewConstructor(initialRendering, initialViewEnvironment, contextForNewView, container)
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
new file mode 100644
index 0000000000..ddff8051a3
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedScreenViewFactory.kt
@@ -0,0 +1,9 @@
+package com.squareup.workflow1.ui
+
+/**
+ * [ScreenViewFactory] that allows views to display instances of [NamedScreen]. Delegates
+ * to the factory for [NamedScreen.wrapped].
+ */
+@WorkflowUiExperimentalApi
+internal object NamedScreenViewFactory : ScreenViewFactory<NamedScreen<*>>
+by DecorativeScreenViewFactory(NamedScreen::class, { named -> named.wrapped })
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedViewFactory.kt
index 7b98144de0..3349140614 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/NamedViewFactory.kt
@@ -4,6 +4,7 @@ package com.squareup.workflow1.ui
  * [ViewFactory] that allows views to display instances of [Named]. Delegates
  * to the factory for [Named.wrapped].
  */
+@Suppress("DEPRECATION")
 @WorkflowUiExperimentalApi
 internal object NamedViewFactory : ViewFactory<Named<*>>
 by DecorativeViewFactory(Named::class, { named -> named.wrapped })
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
new file mode 100644
index 0000000000..507658c0ca
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewFactory.kt
@@ -0,0 +1,33 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+
+/**
+ * Factory for [View] instances that can show renderings of type [RenderingT] : [Screen].
+ *
+ * Two concrete [ScreenViewFactory] implementations are provided:
+ *
+ *  - The various [bind][ScreenViewRunner.bind] methods on [ScreenViewRunner] allow easy use of
+ *    Android XML layout resources and [AndroidX ViewBinding][androidx.viewbinding.ViewBinding].
+ *
+ *  - [ManualScreenViewFactory] allows views to be built from code.
+ *
+ * It's simplest to have your rendering classes implement [AndroidScreen] to associate
+ * them with appropriate an appropriate [ScreenViewFactory]. For more flexibility, and to
+ * avoid coupling your workflow directly to the Android runtime, see [ViewRegistry].
+ */
+@WorkflowUiExperimentalApi
+public interface ScreenViewFactory<in RenderingT : Screen> : ViewRegistry.Entry<RenderingT> {
+  /**
+   * Returns a View ready to display [initialRendering] (and any succeeding values)
+   * via [View.showRendering].
+   */
+  public fun buildView(
+    initialRendering: RenderingT,
+    initialViewEnvironment: ViewEnvironment,
+    contextForNewView: Context,
+    container: ViewGroup? = null
+  ): View
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewRunner.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewRunner.kt
new file mode 100644
index 0000000000..52e51238fa
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ScreenViewRunner.kt
@@ -0,0 +1,105 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.annotation.LayoutRes
+import androidx.viewbinding.ViewBinding
+
+@WorkflowUiExperimentalApi
+public typealias ViewBindingInflater<BindingT> = (LayoutInflater, ViewGroup?, Boolean) -> BindingT
+
+/**
+ * A delegate that implements a [showRendering] method to be called when a workflow
+ * rendering of type [RenderingT] : [Screen] is ready to be displayed in a view created
+ * by a [ScreenViewFactory].
+ *
+ * If you're using [AndroidX ViewBinding][ViewBinding] you likely won't need to
+ * implement this interface at all. For details, see the three overloads of [ScreenViewRunner.bind].
+ */
+@WorkflowUiExperimentalApi
+public fun interface ScreenViewRunner<RenderingT : Screen> {
+  public fun showRendering(
+    rendering: RenderingT,
+    viewEnvironment: ViewEnvironment
+  )
+
+  public companion object {
+    /**
+     * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
+     * to show renderings of type [RenderingT] : [Screen], using [a lambda][showRendering].
+     *
+     *    val HelloViewFactory: ScreenViewFactory<HelloScreen> =
+     *      ScreenViewRunner.bind(HelloGoodbyeViewBinding::inflate) { rendering, viewEnvironment ->
+     *        helloMessage.text = rendering.message
+     *        helloMessage.setOnClickListener { rendering.onClick(Unit) }
+     *      }
+     *
+     * If you need to initialize your view before [showRendering] is called,
+     * implement [ScreenViewRunner] and create a binding using the `bind` variant
+     * that accepts a `(ViewBinding) -> ScreenViewRunner` function, below.
+     */
+    public inline fun <BindingT : ViewBinding, reified RenderingT : Screen> bind(
+      noinline bindingInflater: ViewBindingInflater<BindingT>,
+      crossinline showRendering: BindingT.(RenderingT, ViewEnvironment) -> Unit
+    ): ScreenViewFactory<RenderingT> = bind(bindingInflater) { binding ->
+      ScreenViewRunner { rendering, viewEnvironment ->
+        binding.showRendering(rendering, viewEnvironment)
+      }
+    }
+
+    /**
+     * Creates a [ScreenViewFactory] that [inflates][bindingInflater] a [ViewBinding] ([BindingT])
+     * to show renderings of type [RenderingT] : [Screen], using a [ScreenViewRunner]
+     * created by [constructor]. Handy if you need to perform some set up before
+     * [showRendering] is called.
+     *
+     *   class HelloScreenRunner(
+     *     private val binding: HelloGoodbyeViewBinding
+     *   ) : ScreenViewRunner<HelloScreen> {
+     *
+     *     override fun showRendering(rendering: HelloScreen) {
+     *       binding.messageView.text = rendering.message
+     *       binding.messageView.setOnClickListener { rendering.onClick(Unit) }
+     *     }
+     *
+     *     companion object : ScreenViewFactory<HelloScreen> by bind(
+     *       HelloGoodbyeViewBinding::inflate, ::HelloScreenRunner
+     *     )
+     *   }
+     *
+     * If the view doesn't need to be initialized before [showRendering] is called,
+     * use the variant above which just takes a lambda.
+     */
+    public inline fun <BindingT : ViewBinding, reified RenderingT : Screen> bind(
+      noinline bindingInflater: ViewBindingInflater<BindingT>,
+      noinline constructor: (BindingT) -> ScreenViewRunner<RenderingT>
+    ): ScreenViewFactory<RenderingT> =
+      ViewBindingScreenViewFactory(RenderingT::class, bindingInflater, constructor)
+
+    /**
+     * Creates a [ScreenViewFactory] that inflates [layoutId] to show renderings of
+     * type [RenderingT]  : [Screen], using a [ScreenViewRunner] created by [constructor].
+     * Avoids any use of [AndroidX ViewBinding][ViewBinding].
+     */
+    public inline fun <reified RenderingT : Screen> bind(
+      @LayoutRes layoutId: Int,
+      noinline constructor: (View) -> ScreenViewRunner<RenderingT>
+    ): ScreenViewFactory<RenderingT> =
+      LayoutScreenViewFactory(RenderingT::class, layoutId, constructor)
+
+    /**
+     * Creates a [ScreenViewFactory] that inflates [layoutId] to "show" renderings of type [RenderingT],
+     * with a no-op [ScreenViewRunner]. Handy for showing static views, e.g. when prototyping.
+     */
+    @Suppress("unused")
+    public inline fun <reified RenderingT : Screen> bindNoRunner(
+      @LayoutRes layoutId: Int
+    ): ScreenViewFactory<RenderingT> = bind(layoutId) { ScreenViewRunner { _, _ -> } }
+  }
+}
+
+internal fun Context.viewBindingLayoutInflater(container: ViewGroup?) =
+  LayoutInflater.from(container?.context ?: this)
+      .cloneInContext(this)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
new file mode 100644
index 0000000000..ab8d0b072a
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingScreenViewFactory.kt
@@ -0,0 +1,33 @@
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import androidx.viewbinding.ViewBinding
+import kotlin.reflect.KClass
+
+@WorkflowUiExperimentalApi
+@PublishedApi
+internal class ViewBindingScreenViewFactory<BindingT : ViewBinding, RenderingT : Screen>(
+  override val type: KClass<RenderingT>,
+  private val bindingInflater: ViewBindingInflater<BindingT>,
+  private val runnerConstructor: (BindingT) -> ScreenViewRunner<RenderingT>
+) : ScreenViewFactory<RenderingT> {
+  override fun buildView(
+    initialRendering: RenderingT,
+    initialViewEnvironment: ViewEnvironment,
+    contextForNewView: Context,
+    container: ViewGroup?
+  ): View =
+    bindingInflater(contextForNewView.viewBindingLayoutInflater(container), container, false)
+      .also { binding ->
+        val runner = runnerConstructor(binding)
+        binding.root.bindShowRendering(
+          initialRendering,
+          initialViewEnvironment
+        ) { rendering, environment ->
+          runner.showRendering(rendering, environment)
+        }
+      }
+      .root
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingViewFactory.kt
index 4b1f215e13..94c62f177c 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewBindingViewFactory.kt
@@ -6,6 +6,7 @@ import android.view.ViewGroup
 import androidx.viewbinding.ViewBinding
 import kotlin.reflect.KClass
 
+@Suppress("DEPRECATION")
 @WorkflowUiExperimentalApi
 @PublishedApi
 internal class ViewBindingViewFactory<BindingT : ViewBinding, RenderingT : Any>(
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewFactory.kt
index 6a19e89035..ca7bb3c3c6 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewFactory.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewFactory.kt
@@ -3,26 +3,10 @@ package com.squareup.workflow1.ui
 import android.content.Context
 import android.view.View
 import android.view.ViewGroup
-import kotlin.reflect.KClass
 
-/**
- * Factory for [View] instances that can show renderings of type[RenderingT].
- *
- * Two concrete [ViewFactory] implementations are provided:
- *
- *  - The various [bind][LayoutRunner.bind] methods on [LayoutRunner] allow easy use of
- *    Android XML layout resources and [AndroidX ViewBinding][androidx.viewbinding.ViewBinding].
- *
- *  - [BuilderViewFactory] allows views to be built from code.
- *
- * It's simplest to have your rendering classes implement [AndroidViewRendering] to associate
- * them with appropriate an appropriate [ViewFactory]. For more flexibility, and to
- * avoid coupling your workflow directly to the Android runtime, see [ViewRegistry].
- */
+@Deprecated("Use ScreenViewFactory")
 @WorkflowUiExperimentalApi
-public interface ViewFactory<in RenderingT : Any> {
-  public val type: KClass<in RenderingT>
-
+public interface ViewFactory<in RenderingT : Any> : ViewRegistry.Entry<RenderingT> {
   /**
    * Returns a View ready to display [initialRendering] (and any succeeding values)
    * via [View.showRendering].
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewRegistry.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewRegistry.kt
deleted file mode 100644
index 6fd84cf762..0000000000
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewRegistry.kt
+++ /dev/null
@@ -1,206 +0,0 @@
-@file:Suppress("FunctionName")
-
-package com.squareup.workflow1.ui
-
-import android.content.Context
-import android.view.View
-import android.view.ViewGroup
-import kotlin.reflect.KClass
-
-/**
- * The [ViewEnvironment] service that can be used to display the stream of renderings
- * from a workflow tree as [View] instances. This is the engine behind [AndroidViewRendering],
- * [WorkflowViewStub] and [ViewFactory]. Most apps can ignore [ViewRegistry] as an implementation
- * detail, by using [AndroidViewRendering] to tie their rendering classes to view code.
- *
- * To avoid that coupling between workflow code and the Android runtime, registries can
- * be loaded with [ViewFactory] instances at runtime, and provided as an optional parameter to
- * [WorkflowLayout.start].
- *
- * For example:
- *
- *     val AuthViewFactories = ViewRegistry(
- *       AuthorizingLayoutRunner, LoginLayoutRunner, SecondFactorLayoutRunner
- *     )
- *
- *     val TicTacToeViewFactories = ViewRegistry(
- *       NewGameLayoutRunner, GamePlayLayoutRunner, GameOverLayoutRunner
- *     )
- *
- *     val ApplicationViewFactories = ViewRegistry(ApplicationLayoutRunner) +
- *       AuthViewFactories + TicTacToeViewFactories
- *
- *     override fun onCreate(savedInstanceState: Bundle?) {
- *       super.onCreate(savedInstanceState)
- *
- *       val model: MyViewModel by viewModels()
- *       setContentView(
- *         WorkflowLayout(this).apply { start(model.renderings, ApplicationViewFactories) }
- *       )
- *     }
- *
- *     /** As always, use an androidx ViewModel for state that survives config change. */
- *     class MyViewModel(savedState: SavedStateHandle) : ViewModel() {
- *       val renderings: StateFlow<Any> by lazy {
- *         renderWorkflowIn(
- *           workflow = rootWorkflow,
- *           scope = viewModelScope,
- *           savedStateHandle = savedState
- *         )
- *       }
- *     }
- *
- * In the above example, it is assumed that the `companion object`s of the various
- * decoupled [LayoutRunner] classes honor a convention of implementing [ViewFactory], in
- * aid of this kind of assembly.
- *
- *     class GamePlayLayoutRunner(view: View) : LayoutRunner<GameRendering> {
- *
- *       // ...
- *
- *       companion object : ViewFactory<GameRendering> by LayoutRunner.bind(
- *         R.layout.game_layout, ::GameLayoutRunner
- *       )
- *     }
- */
-@WorkflowUiExperimentalApi
-public interface ViewRegistry {
-  /**
-   * The set of unique keys which this registry can derive from the renderings passed to [buildView]
-   * and for which it knows how to create views.
-   *
-   * Used to ensure that duplicate bindings are never registered.
-   */
-  public val keys: Set<KClass<*>>
-
-  /**
-   * This method is not for general use, use [WorkflowViewStub] instead.
-   *
-   * Returns the [ViewFactory] that was registered for the given [renderingType], or null
-   * if none was found.
-   */
-  public fun <RenderingT : Any> getFactoryFor(
-    renderingType: KClass<out RenderingT>
-  ): ViewFactory<RenderingT>?
-
-  public companion object : ViewEnvironmentKey<ViewRegistry>(ViewRegistry::class) {
-    override val default: ViewRegistry get() = ViewRegistry()
-  }
-}
-
-@WorkflowUiExperimentalApi
-public fun ViewRegistry(vararg bindings: ViewFactory<*>): ViewRegistry =
-  TypedViewRegistry(*bindings)
-
-/**
- * Returns a [ViewRegistry] that contains no bindings.
- *
- * Exists as a separate overload from the other two functions to disambiguate between them.
- */
-@WorkflowUiExperimentalApi
-public fun ViewRegistry(): ViewRegistry = TypedViewRegistry()
-
-/**
- * It is usually more convenient to use [WorkflowViewStub] or [DecorativeViewFactory]
- * than to call this method directly.
- *
- * Returns the [ViewFactory] that builds [View] instances suitable to display the given [rendering],
- * via subsequent calls to [View.showRendering].
- *
- * Prefers factories found via [ViewRegistry.getFactoryFor]. If that returns null, falls
- * back to the factory provided by the rendering's implementation of
- * [AndroidViewRendering.viewFactory], if there is one. Note that this means that a
- * compile time [AndroidViewRendering.viewFactory] binding can be overridden at runtime.
- *
- * The returned view will have a
- * [WorkflowLifecycleOwner][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner]
- * set on it. The returned view must EITHER:
- *
- * 1. Be attached at least once to ensure that the lifecycle eventually gets destroyed (because its
- *    parent is destroyed), or
- * 2. Have its
- *    [WorkflowLifecycleOwner.destroyOnDetach][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner.destroyOnDetach]
- *    called, which will either schedule the
- *    lifecycle to be destroyed if the view is attached, or destroy it immediately if it's detached.
- *
- * @throws IllegalArgumentException if no factory can be find for type [RenderingT]
- */
-@WorkflowUiExperimentalApi
-public fun <RenderingT : Any>
-  ViewRegistry.getFactoryForRendering(rendering: RenderingT): ViewFactory<RenderingT> {
-  @Suppress("UNCHECKED_CAST")
-  return getFactoryFor(rendering::class)
-    ?: (rendering as? AndroidViewRendering<*>)?.viewFactory as? ViewFactory<RenderingT>
-    ?: (rendering as? Named<*>)?.let { NamedViewFactory as ViewFactory<RenderingT> }
-    ?: throw IllegalArgumentException(
-      "A ${ViewFactory::class.qualifiedName} should have been registered to display " +
-        "${rendering::class.qualifiedName} instances, or that class should implement " +
-        "${AndroidViewRendering::class.simpleName}<${rendering::class.simpleName}>."
-    )
-}
-
-/**
- * It is usually more convenient to use [WorkflowViewStub] or [DecorativeViewFactory]
- * than to call this method directly.
- *
- * Finds a [ViewFactory] to create a [View] to display [initialRendering]. The new view
- * can be updated via calls to [View.showRendering] -- that is, it is guaranteed that
- * [bindShowRendering] has been called on this view.
- *
- * The returned view will have a
- * [WorkflowLifecycleOwner][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner]
- * set on it. The returned view must EITHER:
- *
- * 1. Be attached at least once to ensure that the lifecycle eventually gets destroyed (because its
- *    parent is destroyed), or
- * 2. Have its
- *    [WorkflowLifecycleOwner.destroyOnDetach][com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner.destroyOnDetach]
- *    called, which will either schedule the
- *    lifecycle to be destroyed if the view is attached, or destroy it immediately if it's detached.
- *
- * @param initializeView Optional function invoked immediately after the [View] is
- * created (that is, immediately after the call to [ViewFactory.buildView]).
- * [showRendering], [getRendering] and [environment] are all available when this is called.
- * Defaults to a call to [View.showFirstRendering].
- *
- * @throws IllegalArgumentException if no factory can be find for type [RenderingT]
- *
- * @throws IllegalStateException if the matching [ViewFactory] fails to call
- * [View.bindShowRendering] when constructing the view
- */
-@WorkflowUiExperimentalApi
-public fun <RenderingT : Any> ViewRegistry.buildView(
-  initialRendering: RenderingT,
-  initialViewEnvironment: ViewEnvironment,
-  contextForNewView: Context,
-  container: ViewGroup? = null,
-  initializeView: View.() -> Unit = { showFirstRendering() }
-): View {
-  return getFactoryForRendering(initialRendering).buildView(
-    initialRendering, initialViewEnvironment, contextForNewView, container
-  ).also { view ->
-    checkNotNull(view.showRenderingTag) {
-      "View.bindShowRendering should have been called for $view, typically by the " +
-        "${ViewFactory::class.java.name} that created it."
-    }
-    initializeView.invoke(view)
-  }
-}
-
-@WorkflowUiExperimentalApi
-public operator fun ViewRegistry.plus(binding: ViewFactory<*>): ViewRegistry =
-  this + ViewRegistry(binding)
-
-@WorkflowUiExperimentalApi
-public operator fun ViewRegistry.plus(other: ViewRegistry): ViewRegistry =
-  CompositeViewRegistry(this, other)
-
-/**
- * Default implementation for the `initializeView` argument of [ViewRegistry.buildView],
- * and for [DecorativeViewFactory.initializeView]. Calls [showRendering] against
- * [getRendering] and [environment].
- */
-@WorkflowUiExperimentalApi
-public fun View.showFirstRendering() {
-  showRendering(getRendering()!!, environment!!)
-}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt
index bb84966898..9d21324903 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewShowRendering.kt
@@ -2,10 +2,6 @@ package com.squareup.workflow1.ui
 
 import android.view.View
 
-/**
- * Function attached to a view created by [ViewFactory], to allow it
- * to respond to [View.showRendering].
- */
 @WorkflowUiExperimentalApi
 public typealias ViewShowRendering<RenderingT> =
   (@UnsafeVariance RenderingT, ViewEnvironment) -> Unit
@@ -87,7 +83,7 @@ public fun <RenderingT : Any> View.showRendering(
     }
     ?: error(
       "Expected $this to have a showRendering function to show $rendering. " +
-        "Perhaps it was not built by a ${ViewFactory::class.java.simpleName}, " +
+        "Perhaps it was not built by a ScreenViewFactory, " +
         "or perhaps the factory did not call View.bindShowRendering."
     )
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt
index 071a0a105f..2f49c9893b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowLayout.kt
@@ -10,16 +10,19 @@ import android.view.View
 import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import android.widget.FrameLayout
+import com.squareup.workflow1.ui.container.WithEnvironment
+import com.squareup.workflow1.ui.container.withEnvironment
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
 
 /**
- * A view that can be driven by a stream of renderings (and an optional [ViewRegistry])
- * passed to its [start] method.
+ * A view that can be driven by a stream of [Screen] renderings passed to its [take] method.
+ * To configure the [ViewEnvironment] in play, use [WithEnvironment] as your root rendering type.
  *
  * [id][setId] defaults to [R.id.workflow_layout], as a convenience to ensure that
  * view persistence will work without requiring authors to be immersed in Android arcana.
@@ -44,34 +47,63 @@ public class WorkflowLayout(
   private var restoredChildState: SparseArray<Parcelable>? = null
 
   /**
-   * Subscribes to [renderings], and uses [registry] to
-   * [build a new view][ViewRegistry.buildView] each time a new type of rendering is received,
-   * making that view the only child of this one.
+   * While this view is attached to a window, subscribes to [renderings] and display its values.
+   *
+   * To configure the [ViewEnvironment], use [WithEnvironment] as your rendering type.
+   * For example, to customize the UI via [ViewRegistry] entries:
+   *
+   *     val registry = ViewRegistry(MuchBetterViewForFooScreen)
+   *     val renderings: Flow<WithEnvironment<*>> = renderWorkflowIn(...).map {
+   *       it.withRegistry(registry)
+   *     }
+   *     workflowLayout.take(renderings)
    */
+  public fun take(renderings: Flow<Screen>) {
+    takeWhileAttached(renderings.map { it.withEnvironment() }) { show(it) }
+  }
+
+  @Deprecated(
+    "Use take()",
+    ReplaceWith(
+      "take(renderings.map { asScreen(it).withRegistry(registry) })",
+      "com.squareup.workflow1.ui.ViewEnvironment",
+      "com.squareup.workflow1.ui.ViewRegistry",
+      "com.squareup.workflow1.ui.asScreen",
+      "com.squareup.workflow1.ui.container.withRegistry",
+      "kotlinx.coroutines.flow.map"
+    )
+  )
   public fun start(
     renderings: Flow<Any>,
     registry: ViewRegistry
   ) {
+    @Suppress("DEPRECATION")
     start(renderings, ViewEnvironment(mapOf(ViewRegistry to registry)))
   }
 
-  /**
-   * Subscribes to [renderings], and uses the [ViewRegistry] in the given [environment] to
-   * [build a new view][ViewRegistry.buildView] each time a new type of rendering is received,
-   * making that view the only child of this one.
-   */
+  @Deprecated(
+    "Use take()",
+    ReplaceWith(
+      "take(renderings.map { asScreen(it).withEnvironment(environment) })",
+      "com.squareup.workflow1.ui.ViewEnvironment",
+      "com.squareup.workflow1.ui.ViewRegistry",
+      "com.squareup.workflow1.ui.asScreen",
+      "com.squareup.workflow1.ui.container.withEnvironment",
+      "kotlinx.coroutines.flow.map"
+    )
+  )
   public fun start(
     renderings: Flow<Any>,
     environment: ViewEnvironment = ViewEnvironment()
   ) {
-    takeWhileAttached(renderings) { show(it, environment) }
+    takeWhileAttached(renderings) {
+      @Suppress("DEPRECATION")
+      show(asScreen(it).withEnvironment(environment))
+    }
   }
 
-  private fun show(
-    newRendering: Any,
-    environment: ViewEnvironment
-  ) {
-    showing.update(newRendering, environment)
+  private fun show(rootScreen: WithEnvironment<*>) {
+    showing.show(rootScreen.screen, rootScreen.viewEnvironment)
     restoredChildState?.let { restoredState ->
       restoredChildState = null
       showing.actual.restoreHierarchyState(restoredState)
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
index a290e2149b..06fb08405a 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/WorkflowViewStub.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui
 
 import android.content.Context
@@ -168,6 +170,15 @@ public class WorkflowViewStub @JvmOverloads constructor(
     }
   }
 
+  @Deprecated("Use show()", ReplaceWith("show(rendering, viewEnvironment)"))
+  public fun update(
+    rendering: Any,
+    viewEnvironment: ViewEnvironment
+  ): View {
+    @Suppress("DEPRECATION")
+    return show(asScreen(rendering), viewEnvironment)
+  }
+
   /**
    * Replaces this view with one that can display [rendering]. If the receiver
    * has already been replaced, updates the replacement if it [canShowRendering].
@@ -192,8 +203,8 @@ public class WorkflowViewStub @JvmOverloads constructor(
    * [View.bindShowRendering][com.squareup.workflow1.ui.bindShowRendering]
    * when constructing the view
    */
-  public fun update(
-    rendering: Any,
+  public fun show(
+    rendering: Screen,
     viewEnvironment: ViewEnvironment
   ): View {
     actual.takeIf { it.canShowRendering(rendering) }
@@ -219,17 +230,15 @@ public class WorkflowViewStub @JvmOverloads constructor(
       WorkflowLifecycleOwner.get(actual)?.destroyOnDetach()
     }
 
-    return viewEnvironment[ViewRegistry]
-      .buildView(
-        rendering,
-        viewEnvironment,
-        parent.context,
-        parent,
-        initializeView = {
-          WorkflowLifecycleOwner.installOn(this)
-          showFirstRendering()
-        }
-      )
+    return rendering.buildView(
+      viewEnvironment,
+      parent.context,
+      parent,
+      initializeView = {
+        WorkflowLifecycleOwner.installOn(this)
+        showFirstRendering()
+      }
+    )
       .also { newView ->
         if (inflatedId != NO_ID) newView.id = inflatedId
         if (updatesVisibility) newView.visibility = visibility
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/androidx/WorkflowLifecycleOwner.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/androidx/WorkflowLifecycleOwner.kt
index 3187f0a685..fefa4bccb9 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/androidx/WorkflowLifecycleOwner.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/androidx/WorkflowLifecycleOwner.kt
@@ -27,7 +27,7 @@ import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner.Companion.insta
  * This type is meant to help integrate with [ViewTreeLifecycleOwner] by allowing the creation of a
  * tree of [LifecycleOwner]s that mirrors the view tree.
  *
- * Custom container views that use [ViewRegistry.buildView][com.squareup.workflow1.ui.buildView]
+ * Custom container views that use [Screen.buildView][com.squareup.workflow1.ui.buildView]
  * to create their children _must_ ensure
  * they call [destroyOnDetach] on the outgoing view before they replace children with new views.
  * If this is not done, then certain processes that are started by that view's subtree may continue
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackConfig.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackConfig.kt
similarity index 83%
rename from workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackConfig.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackConfig.kt
index 5887cc52dd..53aa5f5652 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackConfig.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackConfig.kt
@@ -1,9 +1,9 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.ViewEnvironmentKey
-import com.squareup.workflow1.ui.backstack.BackStackConfig.First
-import com.squareup.workflow1.ui.backstack.BackStackConfig.Other
+import com.squareup.workflow1.ui.container.BackStackConfig.First
+import com.squareup.workflow1.ui.container.BackStackConfig.Other
 
 /**
  * Informs views whether they're children of a [BackStackContainer],
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
new file mode 100644
index 0000000000..83f1b745a2
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackContainer.kt
@@ -0,0 +1,233 @@
+package com.squareup.workflow1.ui.container
+
+import android.content.Context
+import android.os.Parcelable
+import android.util.AttributeSet
+import android.util.Log
+import android.view.Gravity
+import android.view.View
+import android.view.animation.AccelerateDecelerateInterpolator
+import android.widget.FrameLayout
+import androidx.savedstate.SavedStateRegistry
+import androidx.savedstate.ViewTreeSavedStateRegistryOwner
+import androidx.transition.Scene
+import androidx.transition.Slide
+import androidx.transition.TransitionManager
+import androidx.transition.TransitionSet
+import com.squareup.workflow1.ui.NamedScreen
+import com.squareup.workflow1.ui.R
+import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.androidx.WorkflowAndroidXSupport.stateRegistryOwnerFromViewTreeOrContext
+import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
+import com.squareup.workflow1.ui.buildView
+import com.squareup.workflow1.ui.canShowRendering
+import com.squareup.workflow1.ui.compatible
+import com.squareup.workflow1.ui.container.BackStackConfig.First
+import com.squareup.workflow1.ui.container.BackStackConfig.Other
+import com.squareup.workflow1.ui.container.ViewStateCache.SavedState
+import com.squareup.workflow1.ui.showFirstRendering
+import com.squareup.workflow1.ui.showRendering
+
+/**
+ * A container view that can display a stream of [BackStackScreen] instances.
+ *
+ * This container supports saving and restoring the view state of each of its subviews corresponding
+ * to the renderings in its [BackStackScreen]. It supports two distinct state mechanisms:
+ *  1. Classic view hierarchy state ([View.onSaveInstanceState]/[View.onRestoreInstanceState])
+ *  2. AndroidX [SavedStateRegistry] via [ViewTreeSavedStateRegistryOwner].
+ *
+ * ## A note about `SavedStateRegistry` support.
+ *
+ * The [SavedStateRegistry] API involves defining string keys to associate with state bundles. These
+ * keys must be unique relative to the instance of the registry they are saved in. To support this
+ * requirement, [BackStackContainer] tries to generate a best-effort unique key by combining its
+ * fully-qualified class name with both its [view ID][View.getId] and the
+ * [compatibility key][com.squareup.workflow1.ui.Compatible.compatibilityKey] of its rendering.
+ *
+ * This method isn't guaranteed to give a unique registry key, but it should be good enough: If you
+ * need to nest multiple [BackStackContainer]s under the same `SavedStateRegistry`, just wrap each
+ * [BackStackScreen] with a [NamedScreen], or give each [BackStackContainer] a unique view ID. If that
+ * heuristic fails you, use [ViewEnvironment.withBackStackStateKeyPrefix] to add unique names to
+ * the [ViewEnvironment] used to show each [BackStackScreen].
+ *
+ * There's a potential issue here where if our ID is changed to something else, then another
+ * [BackStackContainer] is added with our old ID, that container will overwrite our state. Since
+ * they'd both be using the same key, [SavedStateRegistry] would throw an exception. As long as this
+ * container is detached before its ID is changed, it shouldn't be a problem.
+ */
+@WorkflowUiExperimentalApi
+public open class BackStackContainer @JvmOverloads constructor(
+  context: Context,
+  attributeSet: AttributeSet? = null,
+  defStyle: Int = 0,
+  defStyleRes: Int = 0
+) : FrameLayout(context, attributeSet, defStyle, defStyleRes) {
+
+  private val viewStateCache = ViewStateCache()
+
+  private val currentView: View? get() = if (childCount > 0) getChildAt(0) else null
+  private var currentRendering: BackStackScreen<NamedScreen<*>>? = null
+  private var stateRegistryKey: String? = null
+
+  public fun update(
+    newRendering: BackStackScreen<*>,
+    newViewEnvironment: ViewEnvironment
+  ) {
+    updateStateRegistryKey(newViewEnvironment)
+
+    val config = if (newRendering.backStack.isEmpty()) First else Other
+    val environment = newViewEnvironment + (BackStackConfig to config)
+
+    val named: BackStackScreen<NamedScreen<*>> = newRendering
+      // ViewStateCache requires that everything be Named.
+      // It's fine if client code is already using Named for its own purposes, recursion works.
+      .map { NamedScreen(it, "backstack") }
+
+    val oldViewMaybe = currentView
+
+    // If existing view is compatible, just update it.
+    oldViewMaybe
+      ?.takeIf { it.canShowRendering(named.top) }
+      ?.let {
+        viewStateCache.prune(named.frames)
+        it.showRendering(named.top, environment)
+        return
+      }
+
+    val newView = named.top.buildView(
+            viewEnvironment = environment,
+            contextForNewView = this.context,
+            container = this,
+            initializeView = {
+                WorkflowLifecycleOwner.installOn(this)
+                showFirstRendering()
+            }
+    )
+    viewStateCache.update(named.backStack, oldViewMaybe, newView)
+
+    val popped = currentRendering?.backStack?.any { compatible(it, named.top) } == true
+
+    performTransition(oldViewMaybe, newView, popped)
+    // Notify the view we're about to replace that it's going away.
+    oldViewMaybe?.let(WorkflowLifecycleOwner::get)?.destroyOnDetach()
+
+    currentRendering = named
+  }
+
+  /**
+   * Called from [View.showRendering] to swap between views.
+   * Subclasses can override to customize visual effects. There is no need to call super.
+   * Note that views are showing renderings of type [NamedScreen]`<BackStackScreen<*>>`.
+   *
+   * @param oldViewMaybe the outgoing view, or null if this is the initial rendering.
+   * @param newView the view that should replace [oldViewMaybe] (if it exists), and become
+   * this view's only child
+   * @param popped true if we should give the appearance of popping "back" to a previous rendering,
+   * false if a new rendering is being "pushed". Should be ignored if [oldViewMaybe] is null.
+   */
+  protected open fun performTransition(
+    oldViewMaybe: View?,
+    newView: View,
+    popped: Boolean
+  ) {
+    // Showing something already, transition with push or pop effect.
+    oldViewMaybe
+      ?.let { oldView ->
+        val oldBody: View? = oldView.findViewById(R.id.back_stack_body)
+        val newBody: View? = newView.findViewById(R.id.back_stack_body)
+
+        val oldTarget: View
+        val newTarget: View
+        if (oldBody != null && newBody != null) {
+          oldTarget = oldBody
+          newTarget = newBody
+        } else {
+          oldTarget = oldView
+          newTarget = newView
+        }
+
+        val (outEdge, inEdge) = when (popped) {
+          false -> Gravity.START to Gravity.END
+          true -> Gravity.END to Gravity.START
+        }
+
+        val transition = TransitionSet()
+          .addTransition(Slide(outEdge).addTarget(oldTarget))
+          .addTransition(Slide(inEdge).addTarget(newTarget))
+          .setInterpolator(AccelerateDecelerateInterpolator())
+
+        TransitionManager.go(Scene(this, newView), transition)
+        return
+      }
+
+    // This is the first view, just show it.
+    addView(newView)
+  }
+
+  override fun onSaveInstanceState(): Parcelable {
+    return SavedState(super.onSaveInstanceState(), viewStateCache)
+  }
+
+  override fun onRestoreInstanceState(state: Parcelable) {
+    (state as? SavedState)
+      ?.let {
+        viewStateCache.restore(it.viewStateCache)
+        super.onRestoreInstanceState(state.superState)
+      }
+      ?: super.onRestoreInstanceState(super.onSaveInstanceState())
+    // Some other class wrote state, but we're not allowed to skip
+    // the call to super. Make a no-op call.
+  }
+
+  override fun onAttachedToWindow() {
+    super.onAttachedToWindow()
+
+    // Wire up our viewStateCache to our parent SavedStateRegistry.
+    val parentRegistryOwner = stateRegistryOwnerFromViewTreeOrContext(this)!!
+    val key = checkNotNull(stateRegistryKey) {
+      "Expected stateRegistryKey to have been set – the view seems to be getting attached before " +
+        "its first update: $this"
+    }
+
+    viewStateCache.attachToParentRegistry(key, parentRegistryOwner)
+  }
+
+  override fun onDetachedFromWindow() {
+    // Disconnect our state cache from our parent SavedStateRegistry so that it doesn't get asked
+    // to save state anymore.
+    viewStateCache.detachFromParentRegistry()
+    super.onDetachedFromWindow()
+  }
+
+  /**
+   * In order to save our state with a unique ID in our parent's registry, we use a combination
+   * of this class name, our [compatibility key][NamedScreen.compatibilityKey] if specified,
+   * and our view ID if specified.
+   *
+   * This method isn't guaranteed to give a unique registry key, but it should be
+   * good enough: If you need to nest multiple [BackStackContainer]s under the same
+   * `SavedStateRegistry`, just wrap each [BackStackScreen] with a [NamedScreen], or give each
+   * [BackStackContainer] a unique view ID.
+   *
+   * There's a potential issue here where if our ID is changed to something else, then another
+   * BackStackContainer is added with our old ID, that container will overwrite our state. Since
+   * they'd both be using the same key, SavedStateRegistry would throw an exception. That's a
+   * pretty unlikely situation though I think. And as long as this container is detached before
+   * its ID is changed, it won't be a problem.
+   */
+  private fun updateStateRegistryKey(environment: ViewEnvironment) {
+    val idSuffix = if (id == NO_ID) "" else "-$id"
+    val keyPrefix = environment.getBackStackStateKeyPrefix
+    val newKey = keyPrefix + BackStackContainer::class.java.name + idSuffix
+
+    if (stateRegistryKey != null && stateRegistryKey != newKey) {
+      Log.wtf(
+        "workflow1",
+        "BackStackContainer state registry key changed – view state may be lost:" +
+          " from $stateRegistryKey to $newKey"
+      )
+    }
+    stateRegistryKey = newKey
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt
new file mode 100644
index 0000000000..6708071272
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackScreenViewFactory.kt
@@ -0,0 +1,23 @@
+package com.squareup.workflow1.ui.container
+
+import android.view.ViewGroup.LayoutParams
+import android.view.ViewGroup.LayoutParams.MATCH_PARENT
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.R
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.bindShowRendering
+
+@WorkflowUiExperimentalApi
+internal object BackStackScreenViewFactory : ScreenViewFactory<BackStackScreen<*>>
+by ManualScreenViewFactory(
+  type = BackStackScreen::class,
+  viewConstructor = { initialRendering, initialEnv, context, _ ->
+    BackStackContainer(context)
+      .apply {
+        id = R.id.workflow_back_stack_container
+        layoutParams = (LayoutParams(MATCH_PARENT, MATCH_PARENT))
+        bindShowRendering(initialRendering, initialEnv, ::update)
+      }
+  }
+)
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackStateKey.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackStateKey.kt
similarity index 96%
rename from workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackStateKey.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackStateKey.kt
index b8d4be6177..dfbe933139 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/BackStackStateKey.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/BackStackStateKey.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.ViewEnvironmentKey
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/KeyedStateRegistryOwner.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/KeyedStateRegistryOwner.kt
similarity index 95%
rename from workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/KeyedStateRegistryOwner.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/KeyedStateRegistryOwner.kt
index bdd5bf0508..1da4503123 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/KeyedStateRegistryOwner.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/KeyedStateRegistryOwner.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import android.view.View
 import androidx.lifecycle.LifecycleOwner
@@ -8,7 +8,7 @@ import androidx.savedstate.SavedStateRegistryOwner
 import androidx.savedstate.ViewTreeSavedStateRegistryOwner
 import com.squareup.workflow1.ui.androidx.WorkflowLifecycleOwner
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.KeyedStateRegistryOwner.Companion.installAsSavedStateRegistryOwnerOn
+import com.squareup.workflow1.ui.container.KeyedStateRegistryOwner.Companion.installAsSavedStateRegistryOwnerOn
 
 /**
  * The implementation of [SavedStateRegistryOwner] that is installed on every immediate child view
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/StateRegistryAggregator.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/StateRegistryAggregator.kt
similarity index 99%
rename from workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/StateRegistryAggregator.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/StateRegistryAggregator.kt
index c8467ae2b0..6683397cec 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/StateRegistryAggregator.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/StateRegistryAggregator.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import android.os.Bundle
 import androidx.lifecycle.Lifecycle.Event
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/ViewStateCache.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ViewStateCache.kt
similarity index 93%
rename from workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/ViewStateCache.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ViewStateCache.kt
index 0cbddc48de..7a46064515 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/ViewStateCache.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ViewStateCache.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import android.os.Parcel
 import android.os.Parcelable
@@ -10,13 +10,13 @@ import androidx.annotation.VisibleForTesting
 import androidx.annotation.VisibleForTesting.PRIVATE
 import androidx.savedstate.SavedStateRegistryOwner
 import androidx.savedstate.ViewTreeSavedStateRegistryOwner
-import com.squareup.workflow1.ui.Named
+import com.squareup.workflow1.ui.NamedScreen
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
-import com.squareup.workflow1.ui.backstack.ViewStateCache.SavedState
+import com.squareup.workflow1.ui.container.ViewStateCache.SavedState
 import com.squareup.workflow1.ui.getRendering
 
 /**
- * Handles persistence chores for container views that manage a set of [Named] renderings,
+ * Handles persistence chores for container views that manage a set of [NamedScreen] renderings,
  * showing a view for one at a time -- think back stacks or tab sets.
  *
  * This class implements [Parcelable] so that it can be preserved from
@@ -61,7 +61,7 @@ internal constructor(
    * the same. Any cached view state held for renderings that are not
    * [compatible][com.squareup.workflow1.ui.compatible] those in [retaining] will be dropped.
    */
-  public fun prune(retaining: Collection<Named<*>>) {
+  public fun prune(retaining: Collection<NamedScreen<*>>) {
     pruneKeys(retaining.map { it.compatibilityKey })
   }
 
@@ -77,18 +77,18 @@ internal constructor(
    * on a succeeding call to his method. Any other cached view state will be dropped.
    *
    * @param oldViewMaybe the view that is being removed, if any, which is expected to be showing
-   * a [Named] rendering. If that rendering is
+   * a [NamedScreen] rendering. If that rendering is
    * [compatible with][com.squareup.workflow1.ui.compatible] a member of
    * [retainedRenderings], its state will be [saved][View.saveHierarchyState].
    *
    * @param newView the view that is about to be displayed, which must be showing a
-   * [Named] rendering. If [compatible][com.squareup.workflow1.ui.compatible]
+   * [NamedScreen] rendering. If [compatible][com.squareup.workflow1.ui.compatible]
    * view state is found in the cache, it is [restored][View.restoreHierarchyState].
    *
    * @return true if [newView] has been restored.
    */
   public fun update(
-    retainedRenderings: Collection<Named<*>>,
+    retainedRenderings: Collection<NamedScreen<*>>,
     oldViewMaybe: View?,
     newView: View
   ) {
@@ -237,9 +237,9 @@ internal constructor(
 @WorkflowUiExperimentalApi
 private val View.namedKey: String
   get() {
-    val rendering = getRendering<Named<*>>()
+    val rendering = getRendering<NamedScreen<*>>()
     return checkNotNull(rendering?.compatibilityKey) {
-      "Expected $this to be showing a ${Named::class.java.simpleName}<*> rendering, " +
+      "Expected $this to be showing a ${NamedScreen::class.java.simpleName}<*> rendering, " +
           "found $rendering"
     }
   }
diff --git a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/ViewStateFrame.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ViewStateFrame.kt
similarity index 96%
rename from workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/ViewStateFrame.kt
rename to workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ViewStateFrame.kt
index b20ab6f253..f25b0d84f8 100644
--- a/workflow-ui/container-android/src/main/java/com/squareup/workflow1/ui/backstack/ViewStateFrame.kt
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/ViewStateFrame.kt
@@ -1,4 +1,4 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import android.os.Parcel
 import android.os.Parcelable
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/WithEnvironmentViewFactory.kt b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/WithEnvironmentViewFactory.kt
new file mode 100644
index 0000000000..032b7874ef
--- /dev/null
+++ b/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/WithEnvironmentViewFactory.kt
@@ -0,0 +1,18 @@
+package com.squareup.workflow1.ui.container
+
+import com.squareup.workflow1.ui.DecorativeScreenViewFactory
+import com.squareup.workflow1.ui.ScreenViewFactory
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.updateFrom
+
+@WorkflowUiExperimentalApi
+internal object WithEnvironmentViewFactory : ScreenViewFactory<WithEnvironment<*>>
+by DecorativeScreenViewFactory(
+  type = WithEnvironment::class,
+  map = { withEnvironment, inheritedEnvironment ->
+    Pair(
+      withEnvironment.screen,
+      inheritedEnvironment.updateFrom(withEnvironment.viewEnvironment)
+    )
+  }
+)
diff --git a/workflow-ui/container-android/src/main/res/layout/view_stack_layout.xml b/workflow-ui/core-android/src/main/res/layout/view_stack_layout.xml
similarity index 63%
rename from workflow-ui/container-android/src/main/res/layout/view_stack_layout.xml
rename to workflow-ui/core-android/src/main/res/layout/view_stack_layout.xml
index 92150e5e30..99c295d23f 100644
--- a/workflow-ui/container-android/src/main/res/layout/view_stack_layout.xml
+++ b/workflow-ui/core-android/src/main/res/layout/view_stack_layout.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
-<com.squareup.workflow1.ui.backstack.BackStackContainer xmlns:android="http://schemas.android.com/apk/res/android"
+<com.squareup.workflow1.ui.container.BackStackContainer xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/view_stack"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     >
 
-</com.squareup.workflow1.ui.backstack.BackStackContainer>
+</com.squareup.workflow1.ui.container.BackStackContainer>
diff --git a/workflow-ui/core-android/src/main/res/values/ids.xml b/workflow-ui/core-android/src/main/res/values/ids.xml
index 1e13c033cf..996b3b662e 100644
--- a/workflow-ui/core-android/src/main/res/values/ids.xml
+++ b/workflow-ui/core-android/src/main/res/values/ids.xml
@@ -1,5 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+  <!--
+  BackStackContainer restricts animation to child with this id, if there is one.
+  Otherwise animates its entire body.
+   -->
+  <item type="id" name="back_stack_body"/>
+  <!-- View Tag holding the BackStackScreen.Key associated with a view. -->
+  <item type="id" name="workflow_back_stack_key"/>
+  <!-- ID used by BackStackContainer to opt in to view persistence. -->
+  <item type="id" name="workflow_back_stack_container"/>
   <!-- View Tag that holds the function to update a view created via ViewRegistry. -->
   <item name="view_show_rendering_function" type="id"/>
   <!-- View Tag used for back button handlers. -->
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/AndroidViewEnvironmentTest.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/AndroidViewEnvironmentTest.kt
new file mode 100644
index 0000000000..c5b5b49e05
--- /dev/null
+++ b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/AndroidViewEnvironmentTest.kt
@@ -0,0 +1,87 @@
+@file:OptIn(WorkflowUiExperimentalApi::class)
+
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.ViewRegistry.Entry
+import org.junit.Test
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.eq
+import org.mockito.kotlin.mock
+import kotlin.reflect.KClass
+import kotlin.test.assertFailsWith
+
+internal class AndroidViewEnvironmentTest {
+
+  @OptIn(WorkflowUiExperimentalApi::class)
+  @Test fun missingBindingMessage_isUseful() {
+    val emptyReg = object : ViewRegistry {
+      override val keys: Set<KClass<*>> = emptySet()
+      override fun <RenderingT : Any> getEntryFor(
+        renderingType: KClass<out RenderingT>
+      ): Entry<RenderingT>? = null
+    }
+    val env = ViewEnvironment(mapOf(ViewRegistry to emptyReg))
+
+    val fooScreen = object : Screen {
+      override fun toString() = "FooScreen"
+    }
+
+    val error = assertFailsWith<IllegalArgumentException> {
+      fooScreen.buildView(env, mock())
+    }
+    assertThat(error.message).isEqualTo(
+      "A ScreenViewFactory should have been registered to display " +
+        "FooScreen, or that class should implement AndroidScreen."
+    )
+  }
+
+  @Test fun `buildView honors AndroidScreen`() {
+    val registry = ViewRegistry()
+    val env = ViewEnvironment(mapOf(ViewRegistry to registry))
+    val screen = MyAndroidScreen()
+
+    screen.buildView(env, mock())
+    assertThat(screen.viewFactory.called).isTrue()
+  }
+
+  @Test fun `buildView prefers registry entries to AndroidViewRendering`() {
+    val registry = ViewRegistry(overrideViewRenderingFactory)
+    val env = ViewEnvironment(mapOf(ViewRegistry to registry))
+
+    val screen = MyAndroidScreen()
+    screen.buildView(env, mock())
+    assertThat(screen.viewFactory.called).isFalse()
+    assertThat(overrideViewRenderingFactory.called).isTrue()
+  }
+
+  private class TestViewFactory<T : Screen>(
+    override val type: KClass<in T>
+  ) : ScreenViewFactory<T> {
+    var called = false
+
+    override fun buildView(
+      initialRendering: T,
+      initialViewEnvironment: ViewEnvironment,
+      contextForNewView: Context,
+      container: ViewGroup?
+    ): View {
+      called = true
+
+      return mock {
+        on {
+          getTag(eq(R.id.view_show_rendering_function))
+        } doReturn (ShowRenderingTag(initialRendering, initialViewEnvironment, { _, _ -> }))
+      }
+    }
+  }
+
+  private class MyAndroidScreen : AndroidScreen<MyAndroidScreen> {
+    override val viewFactory = TestViewFactory(MyAndroidScreen::class)
+  }
+
+  private val overrideViewRenderingFactory = TestViewFactory(MyAndroidScreen::class)
+}
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/LegacyAndroidViewRegistryTest.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/LegacyAndroidViewRegistryTest.kt
new file mode 100644
index 0000000000..3ce5c3d5a8
--- /dev/null
+++ b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/LegacyAndroidViewRegistryTest.kt
@@ -0,0 +1,174 @@
+@file:Suppress("DEPRECATION")
+
+package com.squareup.workflow1.ui
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.ViewRegistry.Entry
+import org.junit.Test
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.eq
+import org.mockito.kotlin.mock
+import kotlin.reflect.KClass
+import kotlin.test.assertFailsWith
+import kotlin.test.assertTrue
+
+@OptIn(WorkflowUiExperimentalApi::class)
+internal class LegacyAndroidViewRegistryTest {
+
+  @OptIn(WorkflowUiExperimentalApi::class)
+  @Test fun missingBindingMessage_isUseful() {
+    val emptyReg = object : ViewRegistry {
+      override val keys: Set<KClass<*>> = emptySet()
+      override fun <RenderingT : Any> getEntryFor(
+        renderingType: KClass<out RenderingT>
+      ): Entry<RenderingT>? = null
+    }
+
+    val error = assertFailsWith<IllegalArgumentException> {
+      emptyReg.buildView("render this, bud")
+    }
+    assertThat(error.message).isEqualTo(
+      "A ViewFactory should have been registered to display " +
+        "render this, bud, or that class should implement AndroidViewRendering.")
+  }
+
+  @Test fun `getFactoryFor delegates to composite registries`() {
+    val fooFactory = TestViewFactory(FooRendering::class)
+    val barFactory = TestViewFactory(BarRendering::class)
+    val bazFactory = TestViewFactory(BazRendering::class)
+    val fooBarRegistry = TestRegistry(
+      mapOf(
+        FooRendering::class to fooFactory,
+        BarRendering::class to barFactory
+      )
+    )
+    val bazRegistry = TestRegistry(factories = mapOf(BazRendering::class to bazFactory))
+    val registry = fooBarRegistry + bazRegistry
+
+    assertThat(registry.getEntryFor(FooRendering::class))
+      .isSameInstanceAs(fooFactory)
+    assertThat(registry.getEntryFor(BarRendering::class))
+      .isSameInstanceAs(barFactory)
+    assertThat(registry.getEntryFor(BazRendering::class))
+      .isSameInstanceAs(bazFactory)
+  }
+
+  @Test fun `getFactoryFor returns null on missing registry`() {
+    val fooRegistry = TestRegistry(setOf(FooRendering::class))
+    val registry = ViewRegistry() + fooRegistry
+
+    assertThat(registry.getEntryFor(BarRendering::class)).isNull()
+  }
+
+  @Test fun `keys includes all composite registries' keys`() {
+    val fooBarRegistry = TestRegistry(setOf(FooRendering::class, BarRendering::class))
+    val bazRegistry = TestRegistry(setOf(BazRendering::class))
+    val registry = fooBarRegistry + bazRegistry
+
+    assertThat(registry.keys).containsExactly(
+      FooRendering::class,
+      BarRendering::class,
+      BazRendering::class
+    )
+  }
+
+  @Test fun `keys from bindings`() {
+    val factory1 = TestViewFactory(FooRendering::class)
+    val factory2 = TestViewFactory(BarRendering::class)
+    val registry = ViewRegistry(factory1, factory2)
+
+    assertThat(registry.keys).containsExactly(factory1.type, factory2.type)
+  }
+
+  @Test fun `constructor throws on duplicates`() {
+    val factory1 = TestViewFactory(FooRendering::class)
+    val factory2 = TestViewFactory(FooRendering::class)
+
+    val error = assertFailsWith<IllegalStateException> {
+      ViewRegistry(factory1, factory2)
+    }
+    assertThat(error).hasMessageThat()
+      .endsWith("must not have duplicate entries.")
+    assertThat(error).hasMessageThat()
+      .contains(FooRendering::class.java.name)
+  }
+
+  @Test fun `getFactoryFor works`() {
+    val fooFactory = TestViewFactory(FooRendering::class)
+    val registry = ViewRegistry(fooFactory)
+
+    val factory = registry.getEntryFor(FooRendering::class)
+    assertThat(factory).isSameInstanceAs(fooFactory)
+  }
+
+  @Test fun `getFactoryFor returns null on missing binding`() {
+    val fooFactory = TestViewFactory(FooRendering::class)
+    val registry = ViewRegistry(fooFactory)
+
+    assertThat(registry.getEntryFor(BarRendering::class)).isNull()
+  }
+
+  @Test fun `buildView honors AndroidViewRendering`() {
+    val registry = ViewRegistry()
+    registry.buildView(ViewRendering)
+    assertThat(ViewRendering.viewFactory.called).isTrue()
+  }
+
+  @Test fun `buildView prefers registry entries to AndroidViewRendering`() {
+    val registry = ViewRegistry(overrideViewRenderingFactory)
+    registry.buildView(ViewRendering)
+    assertThat(ViewRendering.viewFactory.called).isFalse()
+    assertThat(overrideViewRenderingFactory.called).isTrue()
+  }
+
+  @Test fun `ViewRegistry with no arguments infers type`() {
+    val registry = ViewRegistry()
+    assertTrue(registry.keys.isEmpty())
+  }
+
+  private object FooRendering
+  private object BarRendering
+  private object BazRendering
+
+  private object ViewRendering : AndroidViewRendering<ViewRendering> {
+    override val viewFactory: TestViewFactory<ViewRendering> = TestViewFactory(ViewRendering::class)
+  }
+  private val overrideViewRenderingFactory = TestViewFactory(ViewRendering::class)
+
+  private class TestRegistry(private val factories: Map<KClass<*>, ViewFactory<*>>) : ViewRegistry {
+    constructor(keys: Set<KClass<*>>) : this(keys.associateWith { TestViewFactory(it) })
+
+    override val keys: Set<KClass<*>> get() = factories.keys
+
+    @Suppress("UNCHECKED_CAST")
+    override fun <RenderingT : Any> getEntryFor(
+      renderingType: KClass<out RenderingT>
+    ): Entry<RenderingT> = factories.getValue(renderingType) as Entry<RenderingT>
+  }
+
+  @OptIn(WorkflowUiExperimentalApi::class)
+  private fun <R : Any> ViewRegistry.buildView(rendering: R): View =
+    buildView(rendering, ViewEnvironment(mapOf(ViewRegistry to this)), mock())
+
+  @OptIn(WorkflowUiExperimentalApi::class)
+  private class TestViewFactory<R : Any>(override val type: KClass<R>) : ViewFactory<R> {
+    var called = false
+
+    override fun buildView(
+      initialRendering: R,
+      initialViewEnvironment: ViewEnvironment,
+      contextForNewView: Context,
+      container: ViewGroup?
+    ): View {
+      called = true
+      return mock {
+        on {
+          getTag(eq(com.squareup.workflow1.ui.R.id.view_show_rendering_function))
+        } doReturn (ShowRenderingTag(initialRendering, initialViewEnvironment, { _, _ -> }))
+      }
+    }
+  }
+}
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/TestViewFactory.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/TestViewFactory.kt
deleted file mode 100644
index a718275c8c..0000000000
--- a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/TestViewFactory.kt
+++ /dev/null
@@ -1,32 +0,0 @@
-package com.squareup.workflow1.ui
-
-import android.content.Context
-import android.view.View
-import android.view.ViewGroup
-import org.mockito.kotlin.doReturn
-import org.mockito.kotlin.eq
-import org.mockito.kotlin.mock
-import kotlin.reflect.KClass
-
-@OptIn(WorkflowUiExperimentalApi::class)
-internal fun <R : Any> ViewRegistry.buildView(rendering: R): View =
-  buildView(rendering, ViewEnvironment(mapOf(ViewRegistry to this)), mock<Context>())
-
-@OptIn(WorkflowUiExperimentalApi::class)
-internal class TestViewFactory<R : Any>(override val type: KClass<R>) : ViewFactory<R> {
-  var called = false
-
-  override fun buildView(
-    initialRendering: R,
-    initialViewEnvironment: ViewEnvironment,
-    contextForNewView: Context,
-    container: ViewGroup?
-  ): View {
-    called = true
-    return mock {
-      on {
-        getTag(eq(com.squareup.workflow1.ui.R.id.view_show_rendering_function))
-      } doReturn (ShowRenderingTag(initialRendering, initialViewEnvironment, { _, _ -> }))
-    }
-  }
-}
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/TypedViewRegistryTest.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/TypedViewRegistryTest.kt
deleted file mode 100644
index 88d5fa21da..0000000000
--- a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/TypedViewRegistryTest.kt
+++ /dev/null
@@ -1,72 +0,0 @@
-package com.squareup.workflow1.ui
-
-import com.google.common.truth.Truth.assertThat
-import org.junit.Test
-import kotlin.test.assertFailsWith
-import kotlin.test.assertTrue
-
-@OptIn(WorkflowUiExperimentalApi::class)
-class TypedViewRegistryTest {
-
-  @Test fun `keys from bindings`() {
-    val factory1 = TestViewFactory(FooRendering::class)
-    val factory2 = TestViewFactory(BarRendering::class)
-    val registry = TypedViewRegistry(factory1, factory2)
-
-    assertThat(registry.keys).containsExactly(factory1.type, factory2.type)
-  }
-
-  @Test fun `constructor throws on duplicates`() {
-    val factory1 = TestViewFactory(FooRendering::class)
-    val factory2 = TestViewFactory(FooRendering::class)
-
-    val error = assertFailsWith<IllegalStateException> {
-      TypedViewRegistry(factory1, factory2)
-    }
-    assertThat(error).hasMessageThat()
-      .endsWith("must not have duplicate entries.")
-    assertThat(error).hasMessageThat()
-      .contains(FooRendering::class.java.name)
-  }
-
-  @Test fun `getFactoryFor works`() {
-    val fooFactory = TestViewFactory(FooRendering::class)
-    val registry = TypedViewRegistry(fooFactory)
-
-    val factory = registry.getFactoryFor(FooRendering::class)
-    assertThat(factory).isSameInstanceAs(fooFactory)
-  }
-
-  @Test fun `getFactoryFor returns null on missing binding`() {
-    val fooFactory = TestViewFactory(FooRendering::class)
-    val registry = TypedViewRegistry(fooFactory)
-
-    assertThat(registry.getFactoryFor(BarRendering::class)).isNull()
-  }
-
-  @Test fun `buildView honors AndroidViewRendering`() {
-    val registry = TypedViewRegistry()
-    registry.buildView(ViewRendering)
-    assertThat(ViewRendering.viewFactory.called).isTrue()
-  }
-
-  @Test fun `buildView prefers registry entries to AndroidViewRendering`() {
-    val registry = TypedViewRegistry(overrideViewRenderingFactory)
-    registry.buildView(ViewRendering)
-    assertThat(ViewRendering.viewFactory.called).isFalse()
-    assertThat(overrideViewRenderingFactory.called).isTrue()
-  }
-
-  @Test fun `ViewRegistry with no arguments infers type`() {
-    val registry = ViewRegistry()
-    assertTrue(registry.keys.isEmpty())
-  }
-
-  private object FooRendering
-  private object BarRendering
-
-  private object ViewRendering : AndroidViewRendering<ViewRendering> {
-    override val viewFactory: TestViewFactory<ViewRendering> = TestViewFactory(ViewRendering::class)
-  }
-  private val overrideViewRenderingFactory = TestViewFactory(ViewRendering::class)
-}
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ViewRegistryTest.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ViewRegistryTest.kt
deleted file mode 100644
index bec88b9d86..0000000000
--- a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ViewRegistryTest.kt
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.squareup.workflow1.ui
-
-import com.google.common.truth.Truth.assertThat
-import org.junit.Test
-import kotlin.reflect.KClass
-import kotlin.test.assertFailsWith
-
-@OptIn(WorkflowUiExperimentalApi::class)
-internal class ViewRegistryTest {
-
-  @OptIn(WorkflowUiExperimentalApi::class)
-  @Test fun missingBindingMessage_isUseful() {
-    val emptyReg = object : ViewRegistry {
-      override val keys: Set<KClass<*>> = emptySet()
-      override fun <RenderingT : Any> getFactoryFor(
-        renderingType: KClass<out RenderingT>
-      ): ViewFactory<RenderingT>? = null
-    }
-
-    val error = assertFailsWith<IllegalArgumentException> {
-      emptyReg.buildView("render this, bud")
-    }
-    assertThat(error.message).isEqualTo(
-      "A com.squareup.workflow1.ui.ViewFactory should have been registered to display " +
-        "kotlin.String instances, or that class should implement AndroidViewRendering<String>.")
-  }
-}
diff --git a/workflow-ui/container-android/src/test/java/com/squareup/workflow1/ui/backstack/StateRegistryAggregatorTest.kt b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/container/StateRegistryAggregatorTest.kt
similarity index 71%
rename from workflow-ui/container-android/src/test/java/com/squareup/workflow1/ui/backstack/StateRegistryAggregatorTest.kt
rename to workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/container/StateRegistryAggregatorTest.kt
index 7da5708f45..4c27791bf7 100644
--- a/workflow-ui/container-android/src/test/java/com/squareup/workflow1/ui/backstack/StateRegistryAggregatorTest.kt
+++ b/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/container/StateRegistryAggregatorTest.kt
@@ -1,59 +1,60 @@
-package com.squareup.workflow1.ui.backstack
+package com.squareup.workflow1.ui.container
 
 import android.os.Bundle
 import androidx.lifecycle.Lifecycle
-import androidx.lifecycle.Lifecycle.Event.ON_CREATE
-import androidx.lifecycle.Lifecycle.State.RESUMED
 import androidx.lifecycle.LifecycleRegistry
 import androidx.savedstate.SavedStateRegistry
 import androidx.savedstate.SavedStateRegistryController
 import androidx.savedstate.SavedStateRegistryOwner
-import com.google.common.truth.Truth.assertThat
+import com.google.common.truth.Truth
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
 import kotlin.test.assertFailsWith
 
 @RunWith(RobolectricTestRunner::class)
-class StateRegistryAggregatorTest {
+internal class StateRegistryAggregatorTest {
 
-  @Test fun `attach stops observing previous parent when called multiple times without detach`() {
+  @Test
+  fun `attach stops observing previous parent when called multiple times without detach`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent1 = SimpleStateRegistry()
     val parent2 = SimpleStateRegistry()
 
     aggregator.attachToParentRegistry("key", parent1)
-    assertThat(parent1.lifecycleRegistry.observerCount).isEqualTo(1)
+    Truth.assertThat(parent1.lifecycleRegistry.observerCount).isEqualTo(1)
 
     aggregator.attachToParentRegistry("key", parent2)
-    assertThat(parent1.lifecycleRegistry.observerCount).isEqualTo(0)
+    Truth.assertThat(parent1.lifecycleRegistry.observerCount).isEqualTo(0)
   }
 
-  @Test fun `attach throws more helpful exception when key already registered`() {
+  @Test
+  fun `attach throws more helpful exception when key already registered`() {
     val key = "fizzbuz"
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       stateRegistryController.savedStateRegistry.registerSavedStateProvider(key) { Bundle() }
     }
 
     val error = assertFailsWith<IllegalArgumentException> {
-      aggregator.attachToParentRegistry(key, parent)
+        aggregator.attachToParentRegistry(key, parent)
     }
 
-    assertThat(error).hasMessageThat()
+    Truth.assertThat(error).hasMessageThat()
       .contains("Error registering StateRegistryHolder as SavedStateProvider with key \"$key\"")
   }
 
-  @Test fun `attach observes parent lifecycle`() {
+  @Test
+  fun `attach observes parent lifecycle`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       stateRegistryController.performRestore(null)
@@ -63,13 +64,14 @@ class StateRegistryAggregatorTest {
 
     // The androidx internals add 2 additional observers. This test could break if that changes, but
     // unfortunately there's no other public API to check.
-    assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(3)
+    Truth.assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(3)
   }
 
-  @Test fun `attach doesn't observe parent when already restored`() {
+  @Test
+  fun `attach doesn't observe parent when already restored`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       stateRegistryController.performRestore(null)
@@ -77,7 +79,7 @@ class StateRegistryAggregatorTest {
 
     // Restore the aggregator.
     aggregator.attachToParentRegistry("key", parent)
-    parent.lifecycleRegistry.currentState = RESUMED
+    parent.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
 
     // Re-attach it.
     aggregator.detachFromParentRegistry()
@@ -85,13 +87,14 @@ class StateRegistryAggregatorTest {
 
     // The androidx internals add 2 additional observers. This test could break if that changes, but
     // unfortunately there's no other public API to check.
-    assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(1)
+    Truth.assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(1)
   }
 
-  @Test fun `stops observing parent after ON_CREATED`() {
+  @Test
+  fun `stops observing parent after ON_CREATED`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       // Must restore parent in order to advance lifecycle.
@@ -99,30 +102,32 @@ class StateRegistryAggregatorTest {
     }
 
     aggregator.attachToParentRegistry("key", parent)
-    parent.lifecycleRegistry.handleLifecycleEvent(ON_CREATE)
+    parent.lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE)
 
     // The androidx internals add 1 additional observer. This test could break if that changes, but
     // unfortunately there's no other public API to check.
-    assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(1)
+    Truth.assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(1)
   }
 
-  @Test fun `detach stops observing parent lifecycle`() {
+  @Test
+  fun `detach stops observing parent lifecycle`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry()
 
     aggregator.attachToParentRegistry("key", parent)
     aggregator.detachFromParentRegistry()
 
-    assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(0)
+    Truth.assertThat(parent.lifecycleRegistry.observerCount).isEqualTo(0)
   }
 
-  @Test fun `saveRegistryController saves when parent is restored`() {
+  @Test
+  fun `saveRegistryController saves when parent is restored`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       // Must restore the parent controller in order to initialize the aggregator.
@@ -132,22 +137,23 @@ class StateRegistryAggregatorTest {
     val child = SimpleStateRegistry().apply {
       savedStateRegistry.registerSavedStateProvider("key") {
         childSaveCount++
-        Bundle()
+          Bundle()
       }
     }
     aggregator.attachToParentRegistry("parentKey", parent)
     // Advancing the lifecycle triggers restoration.
-    parent.lifecycleRegistry.currentState = RESUMED
+    parent.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
 
     aggregator.saveRegistryController("childKey", child.stateRegistryController)
 
-    assertThat(childSaveCount).isEqualTo(1)
+    Truth.assertThat(childSaveCount).isEqualTo(1)
   }
 
-  @Test fun `saveRegistryController doesn't save if not restored`() {
+  @Test
+  fun `saveRegistryController doesn't save if not restored`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       stateRegistryController.performRestore(null)
@@ -156,7 +162,7 @@ class StateRegistryAggregatorTest {
     val child = SimpleStateRegistry().apply {
       savedStateRegistry.registerSavedStateProvider("key") {
         childSaveCount++
-        Bundle()
+          Bundle()
       }
     }
     aggregator.attachToParentRegistry("parentKey", parent)
@@ -164,13 +170,14 @@ class StateRegistryAggregatorTest {
 
     aggregator.saveRegistryController("childKey", child.stateRegistryController)
 
-    assertThat(childSaveCount).isEqualTo(0)
+    Truth.assertThat(childSaveCount).isEqualTo(0)
   }
 
-  @Test fun `restoreRegistryControllerIfReady restores when parent is restored`() {
+  @Test
+  fun `restoreRegistryControllerIfReady restores when parent is restored`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       stateRegistryController.performRestore(null)
@@ -178,17 +185,18 @@ class StateRegistryAggregatorTest {
     val child = SimpleStateRegistry()
     aggregator.attachToParentRegistry("parentKey", parent)
     // Advancing the lifecycle triggers restoration.
-    parent.lifecycleRegistry.currentState = RESUMED
+    parent.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
 
     aggregator.restoreRegistryControllerIfReady("childKey", child.stateRegistryController)
 
-    assertThat(child.savedStateRegistry.isRestored).isTrue()
+    Truth.assertThat(child.savedStateRegistry.isRestored).isTrue()
   }
 
-  @Test fun `restoreRegistryControllerIfReady doesn't restore if not restored`() {
+  @Test
+  fun `restoreRegistryControllerIfReady doesn't restore if not restored`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       stateRegistryController.performRestore(null)
@@ -199,21 +207,22 @@ class StateRegistryAggregatorTest {
 
     aggregator.restoreRegistryControllerIfReady("childKey", child.stateRegistryController)
 
-    assertThat(child.savedStateRegistry.isRestored).isFalse()
+    Truth.assertThat(child.savedStateRegistry.isRestored).isFalse()
   }
 
   // This is really more of an integration test.
-  @Test fun `saves and restores child state controller`() {
+  @Test
+  fun `saves and restores child state controller`() {
     val holderToSave = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parentToSave = SimpleStateRegistry().apply {
       // Need to call restore before moving lifecycle state past INITIALIZED.
       stateRegistryController.performRestore(null)
     }
     holderToSave.attachToParentRegistry("parentKey", parentToSave)
-    parentToSave.lifecycleRegistry.currentState = RESUMED
+    parentToSave.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
 
     // Store some data in the system.
     val childToSave = stateRegistryOf("key" to bundleOf("data" to "value"))
@@ -224,14 +233,14 @@ class StateRegistryAggregatorTest {
 
     // Create a whole new tree, restored from our bundle.
     val holderToRestore = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parentToRestore = SimpleStateRegistry().apply {
       stateRegistryController.performRestore(parentSavedBundle)
     }
     holderToRestore.attachToParentRegistry("parentKey", parentToRestore)
-    parentToRestore.lifecycleRegistry.currentState = RESUMED
+    parentToRestore.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
     val childToRestore = SimpleStateRegistry()
     holderToRestore.restoreRegistryControllerIfReady(
       "childKey",
@@ -240,13 +249,14 @@ class StateRegistryAggregatorTest {
     val restoredChildContent = childToRestore.savedStateRegistry.consumeRestoredStateForKey("key")!!
 
     // Verify that our leaf data was restored.
-    assertThat(restoredChildContent.getString("data")).isEqualTo("value")
+    Truth.assertThat(restoredChildContent.getString("data")).isEqualTo("value")
   }
 
-  @Test fun `restores child state controller`() {
+  @Test
+  fun `restores child state controller`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
     val parent = stateRegistryOf(
       "parentKey" to bundleOf(
@@ -261,29 +271,31 @@ class StateRegistryAggregatorTest {
     )
 
     aggregator.attachToParentRegistry("parentKey", parent)
-    parent.lifecycleRegistry.handleLifecycleEvent(ON_CREATE)
+    parent.lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE)
 
     val child = SimpleStateRegistry()
     aggregator.restoreRegistryControllerIfReady("childKey", child.stateRegistryController)
 
     val childState = child.savedStateRegistry.consumeRestoredStateForKey("key")!!
-    assertThat(childState.getString("data")).isEqualTo("value")
+    Truth.assertThat(childState.getString("data")).isEqualTo("value")
   }
 
-  @Test fun `detach doesn't throws when called without attach`() {
+  @Test
+  fun `detach doesn't throws when called without attach`() {
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = {}
+        onWillSave = {},
+        onRestored = {}
     )
 
     aggregator.detachFromParentRegistry()
   }
 
-  @Test fun `save callback is invoked`() {
+  @Test
+  fun `save callback is invoked`() {
     var saveCount = 0
     val aggregator = StateRegistryAggregator(
-      onWillSave = { saveCount++ },
-      onRestored = {}
+        onWillSave = { saveCount++ },
+        onRestored = {}
     )
     val parent = SimpleStateRegistry().apply {
       // Must restore the parent controller in order to initialize the aggregator.
@@ -291,18 +303,19 @@ class StateRegistryAggregatorTest {
     }
     aggregator.attachToParentRegistry("parentKey", parent)
     // Advancing the lifecycle triggers restoration.
-    parent.lifecycleRegistry.currentState = RESUMED
+    parent.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
 
     parent.saveToBundle()
 
-    assertThat(saveCount).isEqualTo(1)
+    Truth.assertThat(saveCount).isEqualTo(1)
   }
 
-  @Test fun `restore callback is invoked when restored`() {
+  @Test
+  fun `restore callback is invoked when restored`() {
     var restoreCount = 0
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = { restoreCount++ }
+        onWillSave = {},
+        onRestored = { restoreCount++ }
     )
     val parent = SimpleStateRegistry().apply {
       // Must restore the parent controller in order to initialize the aggregator.
@@ -310,16 +323,17 @@ class StateRegistryAggregatorTest {
     }
     aggregator.attachToParentRegistry("parentKey", parent)
     // Advancing the lifecycle triggers restoration.
-    parent.lifecycleRegistry.currentState = RESUMED
+    parent.lifecycleRegistry.currentState = Lifecycle.State.RESUMED
 
-    assertThat(restoreCount).isEqualTo(1)
+    Truth.assertThat(restoreCount).isEqualTo(1)
   }
 
-  @Test fun `restore callback is not invoked when attached`() {
+  @Test
+  fun `restore callback is not invoked when attached`() {
     var restoreCount = 0
     val aggregator = StateRegistryAggregator(
-      onWillSave = {},
-      onRestored = { restoreCount++ }
+        onWillSave = {},
+        onRestored = { restoreCount++ }
     )
     val parent = SimpleStateRegistry().apply {
       // Must restore the parent controller in order to initialize the aggregator.
@@ -327,7 +341,7 @@ class StateRegistryAggregatorTest {
     }
     aggregator.attachToParentRegistry("parentKey", parent)
 
-    assertThat(restoreCount).isEqualTo(0)
+    Truth.assertThat(restoreCount).isEqualTo(0)
   }
 
   /**
diff --git a/workflow-ui/core-common/api/core-common.api b/workflow-ui/core-common/api/core-common.api
index 0dcc88401c..68fa18bcb5 100644
--- a/workflow-ui/core-common/api/core-common.api
+++ b/workflow-ui/core-common/api/core-common.api
@@ -1,3 +1,13 @@
+public final class com/squareup/workflow1/ui/AsScreen : com/squareup/workflow1/ui/Compatible, com/squareup/workflow1/ui/Screen {
+	public fun <init> (Ljava/lang/Object;)V
+	public fun getCompatibilityKey ()Ljava/lang/String;
+	public final fun getRendering ()Ljava/lang/Object;
+}
+
+public final class com/squareup/workflow1/ui/AsScreenKt {
+	public static final fun asScreen (Ljava/lang/Object;)Lcom/squareup/workflow1/ui/Screen;
+}
+
 public abstract interface class com/squareup/workflow1/ui/Compatible {
 	public static final field Companion Lcom/squareup/workflow1/ui/Compatible$Companion;
 	public abstract fun getCompatibilityKey ()Ljava/lang/String;
@@ -26,6 +36,23 @@ public final class com/squareup/workflow1/ui/Named : com/squareup/workflow1/ui/C
 	public fun toString ()Ljava/lang/String;
 }
 
+public final class com/squareup/workflow1/ui/NamedScreen : com/squareup/workflow1/ui/Compatible, com/squareup/workflow1/ui/Screen {
+	public fun <init> (Lcom/squareup/workflow1/ui/Screen;Ljava/lang/String;)V
+	public final fun component1 ()Lcom/squareup/workflow1/ui/Screen;
+	public final fun component2 ()Ljava/lang/String;
+	public final fun copy (Lcom/squareup/workflow1/ui/Screen;Ljava/lang/String;)Lcom/squareup/workflow1/ui/NamedScreen;
+	public static synthetic fun copy$default (Lcom/squareup/workflow1/ui/NamedScreen;Lcom/squareup/workflow1/ui/Screen;Ljava/lang/String;ILjava/lang/Object;)Lcom/squareup/workflow1/ui/NamedScreen;
+	public fun equals (Ljava/lang/Object;)Z
+	public fun getCompatibilityKey ()Ljava/lang/String;
+	public final fun getName ()Ljava/lang/String;
+	public final fun getWrapped ()Lcom/squareup/workflow1/ui/Screen;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public abstract interface class com/squareup/workflow1/ui/Screen {
+}
+
 public final class com/squareup/workflow1/ui/TextController {
 	public fun <init> ()V
 	public fun <init> (Ljava/lang/String;)V
@@ -35,6 +62,86 @@ public final class com/squareup/workflow1/ui/TextController {
 	public final fun setTextValue (Ljava/lang/String;)V
 }
 
+public final class com/squareup/workflow1/ui/ViewEnvironment {
+	public fun <init> ()V
+	public fun <init> (Ljava/util/Map;)V
+	public synthetic fun <init> (Ljava/util/Map;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun get (Lcom/squareup/workflow1/ui/ViewEnvironmentKey;)Ljava/lang/Object;
+	public final fun getMap ()Ljava/util/Map;
+	public fun hashCode ()I
+	public final fun plus (Lcom/squareup/workflow1/ui/ViewEnvironment;)Lcom/squareup/workflow1/ui/ViewEnvironment;
+	public final fun plus (Lkotlin/Pair;)Lcom/squareup/workflow1/ui/ViewEnvironment;
+	public fun toString ()Ljava/lang/String;
+}
+
+public abstract class com/squareup/workflow1/ui/ViewEnvironmentKey {
+	public fun <init> (Lkotlin/reflect/KClass;)V
+	public final fun equals (Ljava/lang/Object;)Z
+	public abstract fun getDefault ()Ljava/lang/Object;
+	public final fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public final class com/squareup/workflow1/ui/ViewEnvironmentKt {
+	public static final fun updateFrom (Lcom/squareup/workflow1/ui/ViewEnvironment;Lcom/squareup/workflow1/ui/ViewEnvironment;)Lcom/squareup/workflow1/ui/ViewEnvironment;
+}
+
+public abstract interface class com/squareup/workflow1/ui/ViewRegistry {
+	public static final field Companion Lcom/squareup/workflow1/ui/ViewRegistry$Companion;
+	public abstract fun getEntryFor (Lkotlin/reflect/KClass;)Lcom/squareup/workflow1/ui/ViewRegistry$Entry;
+	public abstract fun getKeys ()Ljava/util/Set;
+}
+
+public final class com/squareup/workflow1/ui/ViewRegistry$Companion : com/squareup/workflow1/ui/ViewEnvironmentKey {
+	public fun getDefault ()Lcom/squareup/workflow1/ui/ViewRegistry;
+	public synthetic fun getDefault ()Ljava/lang/Object;
+}
+
+public abstract interface class com/squareup/workflow1/ui/ViewRegistry$Entry {
+	public abstract fun getType ()Lkotlin/reflect/KClass;
+}
+
+public final class com/squareup/workflow1/ui/ViewRegistryKt {
+	public static final fun ViewRegistry ()Lcom/squareup/workflow1/ui/ViewRegistry;
+	public static final fun ViewRegistry ([Lcom/squareup/workflow1/ui/ViewRegistry$Entry;)Lcom/squareup/workflow1/ui/ViewRegistry;
+	public static final fun plus (Lcom/squareup/workflow1/ui/ViewRegistry;Lcom/squareup/workflow1/ui/ViewRegistry$Entry;)Lcom/squareup/workflow1/ui/ViewRegistry;
+	public static final fun plus (Lcom/squareup/workflow1/ui/ViewRegistry;Lcom/squareup/workflow1/ui/ViewRegistry;)Lcom/squareup/workflow1/ui/ViewRegistry;
+}
+
 public abstract interface annotation class com/squareup/workflow1/ui/WorkflowUiExperimentalApi : java/lang/annotation/Annotation {
 }
 
+public final class com/squareup/workflow1/ui/container/BackStackScreen : com/squareup/workflow1/ui/Screen {
+	public fun <init> (Lcom/squareup/workflow1/ui/Screen;Ljava/util/List;)V
+	public fun <init> (Lcom/squareup/workflow1/ui/Screen;[Lcom/squareup/workflow1/ui/Screen;)V
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun get (I)Lcom/squareup/workflow1/ui/Screen;
+	public final fun getBackStack ()Ljava/util/List;
+	public final fun getFrames ()Ljava/util/List;
+	public final fun getTop ()Lcom/squareup/workflow1/ui/Screen;
+	public fun hashCode ()I
+	public final fun map (Lkotlin/jvm/functions/Function1;)Lcom/squareup/workflow1/ui/container/BackStackScreen;
+	public final fun mapIndexed (Lkotlin/jvm/functions/Function2;)Lcom/squareup/workflow1/ui/container/BackStackScreen;
+	public final fun plus (Lcom/squareup/workflow1/ui/container/BackStackScreen;)Lcom/squareup/workflow1/ui/container/BackStackScreen;
+	public fun toString ()Ljava/lang/String;
+}
+
+public final class com/squareup/workflow1/ui/container/BackStackScreenKt {
+	public static final fun toBackStackScreen (Ljava/util/List;)Lcom/squareup/workflow1/ui/container/BackStackScreen;
+	public static final fun toBackStackScreenOrNull (Ljava/util/List;)Lcom/squareup/workflow1/ui/container/BackStackScreen;
+}
+
+public final class com/squareup/workflow1/ui/container/WithEnvironment : com/squareup/workflow1/ui/Compatible, com/squareup/workflow1/ui/Screen {
+	public fun getCompatibilityKey ()Ljava/lang/String;
+	public final fun getScreen ()Lcom/squareup/workflow1/ui/Screen;
+	public final fun getViewEnvironment ()Lcom/squareup/workflow1/ui/ViewEnvironment;
+}
+
+public final class com/squareup/workflow1/ui/container/WithEnvironmentKt {
+	public static final fun plus (Lcom/squareup/workflow1/ui/container/WithEnvironment;Lcom/squareup/workflow1/ui/ViewEnvironment;)Lcom/squareup/workflow1/ui/container/WithEnvironment;
+	public static final fun withEnvironment (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;)Lcom/squareup/workflow1/ui/container/WithEnvironment;
+	public static synthetic fun withEnvironment$default (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewEnvironment;ILjava/lang/Object;)Lcom/squareup/workflow1/ui/container/WithEnvironment;
+	public static final fun withRegistry (Lcom/squareup/workflow1/ui/Screen;Lcom/squareup/workflow1/ui/ViewRegistry;)Lcom/squareup/workflow1/ui/container/WithEnvironment;
+}
+
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/AsScreen.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/AsScreen.kt
new file mode 100644
index 0000000000..6d69d8b637
--- /dev/null
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/AsScreen.kt
@@ -0,0 +1,35 @@
+@file:Suppress("DEPRECATION")
+
+package com.squareup.workflow1.ui
+
+/**
+ * Provides backward compatibility for legacy non-[Screen] renderings based on
+ * `ViewFactory` and `AndroidViewRendering`. Should be used only as a stop gap
+ * until the wrapped [rendering] can be updated to implement [Screen].
+ */
+@Deprecated("Implement Screen directly.")
+@WorkflowUiExperimentalApi
+public class AsScreen<W : Any>(
+  public val rendering: W
+) : Screen, Compatible {
+  init {
+    check(rendering !is Screen) {
+      "AsScreen is for converting non-Screen renderings, it should not wrap Screen $rendering."
+    }
+  }
+
+  override val compatibilityKey: String
+    get() = Compatible.keyFor(rendering)
+}
+
+/**
+ * Ensures [rendering] implements [Screen], wrapping it in an [AsScreen] if necessary.
+ */
+@Deprecated("Implement Screen directly.")
+@WorkflowUiExperimentalApi
+public fun asScreen(rendering: Any): Screen {
+  return when (rendering) {
+    is Screen -> rendering
+    else -> AsScreen(rendering)
+  }
+}
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/CompositeViewRegistry.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/CompositeViewRegistry.kt
similarity index 83%
rename from workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/CompositeViewRegistry.kt
rename to workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/CompositeViewRegistry.kt
index e4b1424209..1a387cf51b 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/CompositeViewRegistry.kt
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/CompositeViewRegistry.kt
@@ -1,16 +1,18 @@
 package com.squareup.workflow1.ui
 
+import com.squareup.workflow1.ui.ViewRegistry.Entry
 import kotlin.reflect.KClass
 
 /**
- * A [ViewRegistry] that contains only other registries and delegates to their [buildView] methods.
+ * A [ViewRegistry] that contains only other registries and delegates to their [getEntryFor]
+ * methods.
  *
  * Whenever any registries are combined using the [ViewRegistry] factory functions or `plus`
  * operators, an instance of this class is returned. All registries' keys are checked at
  * construction to ensure that no duplicate keys exist.
  *
- * The implementation of [buildView] consists of a single layer of indirection – the responsible
- * [ViewRegistry] is looked up in a map by key, and then that registry's [buildView] is called.
+ * The implementation of [getEntryFor] consists of a single layer of indirection – the responsible
+ * [ViewRegistry] is looked up in a map by key, and then that registry's [getEntryFor] is called.
  *
  * When multiple [CompositeViewRegistry]s are combined, they are flattened, so that there is never
  * more than one layer of indirection. In other words, a [CompositeViewRegistry] will never contain
@@ -25,9 +27,9 @@ internal class CompositeViewRegistry private constructor(
 
   override val keys: Set<KClass<*>> get() = registriesByKey.keys
 
-  override fun <RenderingT : Any> getFactoryFor(
+  override fun <RenderingT : Any> getEntryFor(
     renderingType: KClass<out RenderingT>
-  ): ViewFactory<RenderingT>? = registriesByKey[renderingType]?.getFactoryFor(renderingType)
+  ): Entry<RenderingT>? = registriesByKey[renderingType]?.getEntryFor(renderingType)
 
   companion object {
     private fun mergeRegistries(vararg registries: ViewRegistry): Map<KClass<*>, ViewRegistry> {
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/NamedScreen.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/NamedScreen.kt
new file mode 100644
index 0000000000..c4767072e6
--- /dev/null
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/NamedScreen.kt
@@ -0,0 +1,22 @@
+package com.squareup.workflow1.ui
+
+/**
+ * Allows [Screen] renderings that do not implement [Compatible] themselves to be distinguished
+ * by more than just their type. Instances are [compatible] if they have the same name
+ * and have [compatible] [wrapped] fields.
+ */
+@WorkflowUiExperimentalApi
+public data class NamedScreen<W : Screen>(
+  val wrapped: W,
+  val name: String
+) : Screen, Compatible {
+  init {
+    require(name.isNotBlank()) { "name must not be blank." }
+  }
+
+  override val compatibilityKey: String = Compatible.keyFor(wrapped, name)
+
+  override fun toString(): String {
+    return "${super.toString()}: $compatibilityKey"
+  }
+}
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt
new file mode 100644
index 0000000000..37b586e8aa
--- /dev/null
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/Screen.kt
@@ -0,0 +1,7 @@
+package com.squareup.workflow1.ui
+
+/**
+ * Marker interface implemented by renderings that map to a UI system's 2d view class.
+ */
+@WorkflowUiExperimentalApi
+public interface Screen
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/TypedViewRegistry.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/TypedViewRegistry.kt
similarity index 66%
rename from workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/TypedViewRegistry.kt
rename to workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/TypedViewRegistry.kt
index cb864873a8..3bddf1a244 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/TypedViewRegistry.kt
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/TypedViewRegistry.kt
@@ -1,5 +1,6 @@
 package com.squareup.workflow1.ui
 
+import com.squareup.workflow1.ui.ViewRegistry.Entry
 import kotlin.reflect.KClass
 
 /**
@@ -8,25 +9,25 @@ import kotlin.reflect.KClass
  */
 @WorkflowUiExperimentalApi
 internal class TypedViewRegistry private constructor(
-  private val bindings: Map<KClass<*>, ViewFactory<*>>
+  private val bindings: Map<KClass<*>, Entry<*>>
 ) : ViewRegistry {
 
-  constructor(vararg bindings: ViewFactory<*>) : this(
+  constructor(vararg bindings: Entry<*>) : this(
       bindings.map { it.type to it }
           .toMap()
           .apply {
             check(keys.size == bindings.size) {
               "${bindings.map { it.type }} must not have duplicate entries."
             }
-          } as Map<KClass<*>, ViewFactory<*>>
+          } as Map<KClass<*>, Entry<*>>
   )
 
   override val keys: Set<KClass<*>> get() = bindings.keys
 
-  override fun <RenderingT : Any> getFactoryFor(
+  override fun <RenderingT : Any> getEntryFor(
     renderingType: KClass<out RenderingT>
-  ): ViewFactory<RenderingT>? {
+  ): Entry<RenderingT>? {
     @Suppress("UNCHECKED_CAST")
-    return bindings[renderingType] as? ViewFactory<RenderingT>
+    return bindings[renderingType] as? Entry<RenderingT>
   }
 }
diff --git a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewEnvironment.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/ViewEnvironment.kt
similarity index 62%
rename from workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewEnvironment.kt
rename to workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/ViewEnvironment.kt
index a363548e83..77315afa5a 100644
--- a/workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/ViewEnvironment.kt
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/ViewEnvironment.kt
@@ -4,9 +4,11 @@ import kotlin.reflect.KClass
 
 /**
  * Immutable, append-only map of values that a parent view can pass down to
- * its children via [View.showRendering][android.view.View.showRendering] et al.
- * Allows container views to give descendants information about the context in which
- * they're drawing.
+ * its children. Allows containers to give descendants information about
+ * the context in which they're drawing.
+ *
+ * Calling [Screen.withEnvironment][com.squareup.workflow1.ui.container.withEnvironment]
+ * is the easiest way to customize its environment.
  */
 @WorkflowUiExperimentalApi
 public class ViewEnvironment(
@@ -51,3 +53,24 @@ public abstract class ViewEnvironmentKey<T : Any>(
     return "ViewEnvironmentKey($type)-${super.toString()}"
   }
 }
+
+/**
+ * Combines the receiving [ViewEnvironment] with [other], taking care to merge
+ * their [ViewRegistry] entries. Duplicate values in [other] replace those
+ * in the receiver.
+ */
+@WorkflowUiExperimentalApi
+public fun ViewEnvironment.updateFrom(other: ViewEnvironment): ViewEnvironment {
+  if (other.map.isEmpty()) return this
+
+  val myReg = this[ViewRegistry]
+  val yourReg = other[ViewRegistry]
+
+  val union = (myReg.keys + yourReg.keys).asSequence()
+    .map { yourReg.getEntryFor(it) ?: myReg.getEntryFor(it)!! }
+    .toList()
+    .toTypedArray()
+
+  val unionRegistry = ViewRegistry(*union)
+  return this + other + (ViewRegistry to unionRegistry)
+}
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/ViewRegistry.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/ViewRegistry.kt
new file mode 100644
index 0000000000..cf74263c50
--- /dev/null
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/ViewRegistry.kt
@@ -0,0 +1,111 @@
+@file:Suppress("FunctionName")
+
+package com.squareup.workflow1.ui
+
+import com.squareup.workflow1.ui.ViewRegistry.Entry
+import kotlin.reflect.KClass
+
+/**
+ * The [ViewEnvironment] service that can be used to display the stream of renderings
+ * from a workflow tree as [View] instances. This is the engine behind [AndroidViewRendering],
+ * [WorkflowViewStub] and [ViewFactory]. Most apps can ignore [ViewRegistry] as an implementation
+ * detail, by using [AndroidViewRendering] to tie their rendering classes to view code.
+ *
+ * To avoid that coupling between workflow code and the Android runtime, registries can
+ * be loaded with [ViewFactory] instances at runtime, and provided as an optional parameter to
+ * [WorkflowLayout.start].
+ *
+ * For example:
+ *
+ *     val AuthViewFactories = ViewRegistry(
+ *       AuthorizingLayoutRunner, LoginLayoutRunner, SecondFactorLayoutRunner
+ *     )
+ *
+ *     val TicTacToeViewFactories = ViewRegistry(
+ *       NewGameLayoutRunner, GamePlayLayoutRunner, GameOverLayoutRunner
+ *     )
+ *
+ *     val ApplicationViewFactories = ViewRegistry(ApplicationLayoutRunner) +
+ *       AuthViewFactories + TicTacToeViewFactories
+ *
+ *     override fun onCreate(savedInstanceState: Bundle?) {
+ *       super.onCreate(savedInstanceState)
+ *
+ *       val model: MyViewModel by viewModels()
+ *       setContentView(
+ *         WorkflowLayout(this).apply { start(model.renderings, ApplicationViewFactories) }
+ *       )
+ *     }
+ *
+ *     /** As always, use an androidx ViewModel for state that survives config change. */
+ *     class MyViewModel(savedState: SavedStateHandle) : ViewModel() {
+ *       val renderings: StateFlow<Any> by lazy {
+ *         renderWorkflowIn(
+ *           workflow = rootWorkflow,
+ *           scope = viewModelScope,
+ *           savedStateHandle = savedState
+ *         )
+ *       }
+ *     }
+ *
+ * In the above example, it is assumed that the `companion object`s of the various
+ * decoupled [LayoutRunner] classes honor a convention of implementing [ViewFactory], in
+ * aid of this kind of assembly.
+ *
+ *     class GamePlayLayoutRunner(view: View) : LayoutRunner<GameRendering> {
+ *
+ *       // ...
+ *
+ *       companion object : ViewFactory<GameRendering> by LayoutRunner.bind(
+ *         R.layout.game_layout, ::GameLayoutRunner
+ *       )
+ *     }
+ */
+@WorkflowUiExperimentalApi
+public interface ViewRegistry {
+  public interface Entry<in RenderingT : Any> {
+    public val type: KClass<in RenderingT>
+  }
+
+  /**
+   * The set of unique keys which this registry can derive from the renderings passed to
+   * [getEntryFor] and for which it knows how to create views.
+   *
+   * Used to ensure that duplicate bindings are never registered.
+   */
+  public val keys: Set<KClass<*>>
+
+  /**
+   * This method is not for general use, use [WorkflowViewStub] instead.
+   *
+   * Returns the [ViewFactory] that was registered for the given [renderingType], or null
+   * if none was found.
+   */
+  public fun <RenderingT : Any> getEntryFor(
+    renderingType: KClass<out RenderingT>
+  ): Entry<RenderingT>?
+
+  public companion object : ViewEnvironmentKey<ViewRegistry>(ViewRegistry::class) {
+    override val default: ViewRegistry get() = ViewRegistry()
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun ViewRegistry(vararg bindings: Entry<*>): ViewRegistry =
+  TypedViewRegistry(*bindings)
+
+/**
+ * Returns a [ViewRegistry] that contains no bindings.
+ *
+ * Exists as a separate overload from the other two functions to disambiguate between them.
+ */
+@WorkflowUiExperimentalApi
+public fun ViewRegistry(): ViewRegistry = TypedViewRegistry()
+
+@WorkflowUiExperimentalApi
+public operator fun ViewRegistry.plus(binding: Entry<*>): ViewRegistry =
+  this + ViewRegistry(binding)
+
+@WorkflowUiExperimentalApi
+public operator fun ViewRegistry.plus(other: ViewRegistry): ViewRegistry =
+  CompositeViewRegistry(this, other)
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/container/BackStackScreen.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/container/BackStackScreen.kt
new file mode 100644
index 0000000000..8cd82a1073
--- /dev/null
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/container/BackStackScreen.kt
@@ -0,0 +1,81 @@
+package com.squareup.workflow1.ui.container
+
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+
+/**
+ * Represents an active screen ([top]), and a set of previously visited screens to which we may
+ * return ([backStack]). By rendering the entire history we allow the UI to do things like maintain
+ * cached view state, implement drag-back gestures without waiting for the workflow, etc.
+ *
+ * Effectively a list that can never be empty.
+ *
+ * @param bottom the bottom-most entry in the stack
+ * @param rest the rest of the stack, empty by default
+ */
+@WorkflowUiExperimentalApi
+public class BackStackScreen<StackedT : Screen>(
+  bottom: StackedT,
+  rest: List<StackedT>
+) : Screen {
+  /**
+   * Creates a screen with elements listed from the [bottom] to the top.
+   */
+  public constructor(
+    bottom: StackedT,
+    vararg rest: StackedT
+  ) : this(bottom, rest.toList())
+
+  public val frames: List<StackedT> = listOf(bottom) + rest
+
+  /**
+   * The active screen.
+   */
+  public val top: StackedT = frames.last()
+
+  /**
+   * Screens to which we may return.
+   */
+  public val backStack: List<StackedT> = frames.subList(0, frames.size - 1)
+
+  public operator fun get(index: Int): StackedT = frames[index]
+
+  public operator fun plus(other: BackStackScreen<StackedT>?): BackStackScreen<StackedT> {
+    return if (other == null) this
+    else BackStackScreen(frames[0], frames.subList(1, frames.size) + other.frames)
+  }
+
+  public fun <R : Screen> map(transform: (StackedT) -> R): BackStackScreen<R> {
+    return frames.map(transform)
+      .toBackStackScreen()
+  }
+
+  public fun <R : Screen> mapIndexed(transform: (index: Int, StackedT) -> R): BackStackScreen<R> {
+    return frames.mapIndexed(transform)
+      .toBackStackScreen()
+  }
+
+  override fun equals(other: Any?): Boolean {
+    return (other as? BackStackScreen<*>)?.frames == frames
+  }
+
+  override fun hashCode(): Int {
+    return frames.hashCode()
+  }
+
+  override fun toString(): String {
+    return "${this::class.java.simpleName}($frames)"
+  }
+}
+
+@WorkflowUiExperimentalApi
+public fun <T : Screen> List<T>.toBackStackScreenOrNull(): BackStackScreen<T>? = when {
+  isEmpty() -> null
+  else -> toBackStackScreen()
+}
+
+@WorkflowUiExperimentalApi
+public fun <T : Screen> List<T>.toBackStackScreen(): BackStackScreen<T> {
+  require(isNotEmpty())
+  return BackStackScreen(first(), subList(1, size))
+}
diff --git a/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/container/WithEnvironment.kt b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/container/WithEnvironment.kt
new file mode 100644
index 0000000000..698bef7a6c
--- /dev/null
+++ b/workflow-ui/core-common/src/main/java/com/squareup/workflow1/ui/container/WithEnvironment.kt
@@ -0,0 +1,61 @@
+package com.squareup.workflow1.ui.container
+
+import com.squareup.workflow1.ui.Compatible
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.ViewEnvironment
+import com.squareup.workflow1.ui.ViewRegistry
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import com.squareup.workflow1.ui.updateFrom
+
+/**
+ * Pairs a [screen] rendering with a [viewEnvironment] to support its display.
+ * Typically the rendering type (`RenderingT`) of the root of a UI workflow,
+ * but can be used at any point to modify the [ViewEnvironment] received from
+ * a parent view.
+ *
+ * Use [withEnvironment] or [withRegistry] to create or update instances.
+ */
+@WorkflowUiExperimentalApi
+public class WithEnvironment<V : Screen> internal constructor(
+  public val screen: V,
+  public val viewEnvironment: ViewEnvironment = ViewEnvironment()
+) : Compatible, Screen {
+  /**
+   * Ensures that we make the decision to update or replace the root view based on
+   * the wrapped [screen].
+   */
+  override val compatibilityKey: String = Compatible.keyFor(screen, "WithEnvironment")
+}
+
+@WorkflowUiExperimentalApi
+public operator fun <T : Screen> WithEnvironment<T>.plus(
+  environment: ViewEnvironment
+): WithEnvironment<T> {
+  return when {
+    environment.map.isEmpty() -> this
+    else -> WithEnvironment(screen, viewEnvironment.updateFrom(environment))
+  }
+}
+
+/**
+ * Returns a [WithEnvironment] derived from the receiver, whose [ViewEnvironment]
+ * includes a [ViewRegistry] updated from the given [viewRegistry].
+ */
+@WorkflowUiExperimentalApi
+public fun Screen.withRegistry(viewRegistry: ViewRegistry): WithEnvironment<*> {
+  return withEnvironment(ViewEnvironment(mapOf(ViewRegistry to viewRegistry)))
+}
+
+/**
+ * Returns a [WithEnvironment] derived from the receiver, whose [ViewEnvironment]
+ * is [updated][updateFrom] the given [viewEnvironment].
+ */
+@WorkflowUiExperimentalApi
+public fun Screen.withEnvironment(
+  viewEnvironment: ViewEnvironment = ViewEnvironment()
+): WithEnvironment<*> {
+  return when (this) {
+    is WithEnvironment<*> -> this + viewEnvironment
+    else -> WithEnvironment(this, viewEnvironment)
+  }
+}
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/CompositeViewRegistryTest.kt b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/CompositeViewRegistryTest.kt
similarity index 53%
rename from workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/CompositeViewRegistryTest.kt
rename to workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/CompositeViewRegistryTest.kt
index 2f4a605cfc..026b4245d7 100644
--- a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/CompositeViewRegistryTest.kt
+++ b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/CompositeViewRegistryTest.kt
@@ -1,78 +1,84 @@
 package com.squareup.workflow1.ui
 
 import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.ViewRegistry.Entry
 import org.junit.Test
 import kotlin.reflect.KClass
 import kotlin.test.assertFailsWith
 
 @OptIn(WorkflowUiExperimentalApi::class)
-class CompositeViewRegistryTest {
+internal class CompositeViewRegistryTest {
 
   @Test fun `constructor throws on duplicates`() {
     val fooBarRegistry = TestRegistry(setOf(FooRendering::class, BarRendering::class))
     val barBazRegistry = TestRegistry(setOf(BarRendering::class, BazRendering::class))
 
     val error = assertFailsWith<IllegalStateException> {
-      CompositeViewRegistry(fooBarRegistry, barBazRegistry)
+      fooBarRegistry + barBazRegistry
     }
     assertThat(error).hasMessageThat()
-        .startsWith("Must not have duplicate entries: ")
+      .startsWith("Must not have duplicate entries: ")
     assertThat(error).hasMessageThat()
-        .contains(BarRendering::class.java.name)
+      .contains(BarRendering::class.java.name)
   }
 
   @Test fun `getFactoryFor delegates to composite registries`() {
-    val fooFactory = TestViewFactory(FooRendering::class)
-    val barFactory = TestViewFactory(BarRendering::class)
-    val bazFactory = TestViewFactory(BazRendering::class)
+    val fooFactory = TestEntry(FooRendering::class)
+    val barFactory = TestEntry(BarRendering::class)
+    val bazFactory = TestEntry(BazRendering::class)
     val fooBarRegistry = TestRegistry(
-        mapOf(
-            FooRendering::class to fooFactory,
-            BarRendering::class to barFactory
-        )
+      mapOf(
+        FooRendering::class to fooFactory,
+        BarRendering::class to barFactory
+      )
     )
     val bazRegistry = TestRegistry(factories = mapOf(BazRendering::class to bazFactory))
-    val registry = CompositeViewRegistry(fooBarRegistry, bazRegistry)
+    val registry = fooBarRegistry + bazRegistry
 
-    assertThat(registry.getFactoryFor(FooRendering::class))
-        .isSameInstanceAs(fooFactory)
-    assertThat(registry.getFactoryFor(BarRendering::class))
-        .isSameInstanceAs(barFactory)
-    assertThat(registry.getFactoryFor(BazRendering::class))
-        .isSameInstanceAs(bazFactory)
+    assertThat(registry.getEntryFor(FooRendering::class))
+      .isSameInstanceAs(fooFactory)
+    assertThat(registry.getEntryFor(BarRendering::class))
+      .isSameInstanceAs(barFactory)
+    assertThat(registry.getEntryFor(BazRendering::class))
+      .isSameInstanceAs(bazFactory)
   }
 
   @Test fun `getFactoryFor returns null on missing registry`() {
     val fooRegistry = TestRegistry(setOf(FooRendering::class))
-    val registry = CompositeViewRegistry(fooRegistry)
+    val registry = ViewRegistry() + fooRegistry
 
-    assertThat(registry.getFactoryFor(BarRendering::class)).isNull()
+    assertThat(registry.getEntryFor(BarRendering::class)).isNull()
   }
 
   @Test fun `keys includes all composite registries' keys`() {
     val fooBarRegistry = TestRegistry(setOf(FooRendering::class, BarRendering::class))
     val bazRegistry = TestRegistry(setOf(BazRendering::class))
-    val registry = CompositeViewRegistry(fooBarRegistry, bazRegistry)
+    val registry = fooBarRegistry + bazRegistry
 
     assertThat(registry.keys).containsExactly(
-        FooRendering::class,
-        BarRendering::class,
-        BazRendering::class
+      FooRendering::class,
+      BarRendering::class,
+      BazRendering::class
     )
   }
 
+  private class TestEntry<T : Any>(
+    override val type: KClass<in T>
+  ) : Entry<T>
+
   private object FooRendering
   private object BarRendering
   private object BazRendering
 
-  private class TestRegistry(private val factories: Map<KClass<*>, ViewFactory<*>>) : ViewRegistry {
-    constructor(keys: Set<KClass<*>>) : this(keys.associateWith { TestViewFactory(it) })
+  @Suppress("DEPRECATION")
+  private class TestRegistry(private val factories: Map<KClass<*>, Entry<*>>) : ViewRegistry {
+    constructor(keys: Set<KClass<*>>) : this(keys.associateWith { TestEntry(it) })
 
     override val keys: Set<KClass<*>> get() = factories.keys
 
     @Suppress("UNCHECKED_CAST")
-    override fun <RenderingT : Any> getFactoryFor(
+    override fun <RenderingT : Any> getEntryFor(
       renderingType: KClass<out RenderingT>
-    ): ViewFactory<RenderingT> = factories.getValue(renderingType) as ViewFactory<RenderingT>
+    ): Entry<RenderingT> = factories.getValue(renderingType) as Entry<RenderingT>
   }
 }
diff --git a/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/TypedViewRegistryTest.kt b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/TypedViewRegistryTest.kt
new file mode 100644
index 0000000000..1c23bbf077
--- /dev/null
+++ b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/TypedViewRegistryTest.kt
@@ -0,0 +1,60 @@
+package com.squareup.workflow1.ui
+
+import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.ViewRegistry.Entry
+import org.junit.Test
+import kotlin.reflect.KClass
+import kotlin.test.assertFailsWith
+import kotlin.test.assertTrue
+
+@OptIn(WorkflowUiExperimentalApi::class)
+internal class TypedViewRegistryTest {
+
+  @Test fun `keys from bindings`() {
+    val factory1 = TestEntry(FooRendering::class)
+    val factory2 = TestEntry(BarRendering::class)
+    val registry = ViewRegistry(factory1, factory2)
+
+    assertThat(registry.keys).containsExactly(factory1.type, factory2.type)
+  }
+
+  @Test fun `constructor throws on duplicates`() {
+    val factory1 = TestEntry(FooRendering::class)
+    val factory2 = TestEntry(FooRendering::class)
+
+    val error = assertFailsWith<IllegalStateException> {
+      ViewRegistry(factory1, factory2)
+    }
+    assertThat(error).hasMessageThat()
+      .endsWith("must not have duplicate entries.")
+    assertThat(error).hasMessageThat()
+      .contains(FooRendering::class.java.name)
+  }
+
+  @Test fun `getFactoryFor works`() {
+    val fooFactory = TestEntry(FooRendering::class)
+    val registry = ViewRegistry(fooFactory)
+
+    val factory = registry.getEntryFor(FooRendering::class)
+    assertThat(factory).isSameInstanceAs(fooFactory)
+  }
+
+  @Test fun `getFactoryFor returns null on missing binding`() {
+    val fooFactory = TestEntry(FooRendering::class)
+    val registry = ViewRegistry(fooFactory)
+
+    assertThat(registry.getEntryFor(BarRendering::class)).isNull()
+  }
+
+  @Test fun `ViewRegistry with no arguments infers type`() {
+    val registry = ViewRegistry()
+    assertTrue(registry.keys.isEmpty())
+  }
+
+  private class TestEntry<T : Any>(
+    override val type: KClass<in T>
+  ) : Entry<T>
+
+  private object FooRendering
+  private object BarRendering
+}
diff --git a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ViewEnvironmentTest.kt b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/ViewEnvironmentTest.kt
similarity index 95%
rename from workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ViewEnvironmentTest.kt
rename to workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/ViewEnvironmentTest.kt
index 1569d0bfac..540931e8fe 100644
--- a/workflow-ui/core-android/src/test/java/com/squareup/workflow1/ui/ViewEnvironmentTest.kt
+++ b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/ViewEnvironmentTest.kt
@@ -4,7 +4,7 @@ import com.google.common.truth.Truth.assertThat
 import org.junit.Test
 
 @OptIn(WorkflowUiExperimentalApi::class)
-class ViewEnvironmentTest {
+internal class ViewEnvironmentTest {
   private object StringHint : ViewEnvironmentKey<String>(String::class) {
     override val default = ""
   }
@@ -22,7 +22,7 @@ class ViewEnvironmentTest {
     }
   }
 
-  private val emptyEnv = ViewEnvironment(mapOf(ViewRegistry to ViewRegistry()))
+  private val emptyEnv = ViewEnvironment()
 
   @Test fun defaults() {
     assertThat(emptyEnv[DataHint]).isEqualTo(DataHint())
diff --git a/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/container/BackStackScreenTest.kt b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/container/BackStackScreenTest.kt
new file mode 100644
index 0000000000..936f1fb171
--- /dev/null
+++ b/workflow-ui/core-common/src/test/java/com/squareup/workflow1/ui/container/BackStackScreenTest.kt
@@ -0,0 +1,90 @@
+package com.squareup.workflow1.ui.container
+
+import com.google.common.truth.Truth.assertThat
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
+import org.junit.Test
+import kotlin.test.assertFailsWith
+
+@OptIn(WorkflowUiExperimentalApi::class)
+internal class BackStackScreenTest {
+  data class S<T>(val value: T) : Screen
+
+  @Test fun `top  is last`() {
+    assertThat(BackStackScreen(S(1), S(2), S(3), S(4)).top).isEqualTo(S(4))
+  }
+
+  @Test fun `backstack is all but top`() {
+    assertThat(BackStackScreen(S(1), S(2), S(3), S(4)).backStack)
+      .isEqualTo(listOf(S(1), S(2), S(3)))
+  }
+
+  @Test fun `get works`() {
+    assertThat(BackStackScreen(S("able"), S("baker"), S("charlie"))[1]).isEqualTo(S("baker"))
+  }
+
+  @Test fun `plus another stack`() {
+    assertThat(BackStackScreen(S(1), S(2), S(3)) + BackStackScreen(S(8), S(9), S(0)))
+      .isEqualTo(BackStackScreen(S(1), S(2), S(3), S(8), S(9), S(0)))
+  }
+
+  @Test fun `unequal by order`() {
+    assertThat(BackStackScreen(S(1), S(2), S(3)))
+      .isNotEqualTo(BackStackScreen(S(3), S(2), S(1)))
+  }
+
+  @Test fun `equal have matching hash`() {
+    assertThat(BackStackScreen(S(1), S(2), S(3)).hashCode())
+      .isEqualTo(BackStackScreen(S(1), S(2), S(3)).hashCode())
+  }
+
+  @Test fun `unequal have mismatching hash`() {
+    assertThat(BackStackScreen(S(1), S(2)).hashCode())
+      .isNotEqualTo(BackStackScreen(S(1), S(2), S(3)).hashCode())
+  }
+
+  @Test fun `bottom and rest`() {
+    assertThat(
+      BackStackScreen(
+        bottom = S(1),
+        rest = listOf(S(2), S(3), S(4))
+      )
+    ).isEqualTo(BackStackScreen(S(1), S(2), S(3), S(4)))
+  }
+
+  @Test fun singleton() {
+    val stack = BackStackScreen(S("hi"))
+    assertThat(stack.top).isEqualTo(S("hi"))
+    assertThat(stack.frames).isEqualTo(listOf(S("hi")))
+    assertThat(stack).isEqualTo(BackStackScreen(S("hi")))
+  }
+
+  @Test fun map() {
+    assertThat(BackStackScreen(S(1), S(2), S(3)).map { S(it.value * 2) })
+      .isEqualTo(BackStackScreen(S(2), S(4), S(6)))
+  }
+
+  @Test fun mapIndexed() {
+    val source = BackStackScreen(S("able"), S("baker"), S("charlie"))
+    assertThat(source.mapIndexed { index, frame -> S("$index: ${frame.value}") })
+      .isEqualTo(BackStackScreen(S("0: able"), S("1: baker"), S("2: charlie")))
+  }
+
+  @Test fun nullFromEmptyList() {
+    assertThat(emptyList<S<*>>().toBackStackScreenOrNull()).isNull()
+  }
+
+  @Test fun throwFromEmptyList() {
+    assertFailsWith<IllegalArgumentException> { emptyList<S<*>>().toBackStackScreen() }
+  }
+
+  @Test fun fromList() {
+    assertThat(listOf(S(1), S(2), S(3)).toBackStackScreen())
+      .isEqualTo(BackStackScreen(S(1), S(2), S(3)))
+  }
+
+  @Test fun fromListOrNull() {
+    assertThat(listOf(S(1), S(2), S(3)).toBackStackScreenOrNull())
+      .isEqualTo(BackStackScreen(S(1), S(2), S(3)))
+  }
+}
diff --git a/workflow-ui/internal-testing-android/api/internal-testing-android.api b/workflow-ui/internal-testing-android/api/internal-testing-android.api
index d820aa7654..df8d45249e 100644
--- a/workflow-ui/internal-testing-android/api/internal-testing-android.api
+++ b/workflow-ui/internal-testing-android/api/internal-testing-android.api
@@ -2,8 +2,8 @@ public abstract class com/squareup/workflow1/ui/internal/test/AbstractLifecycleT
 	public fun <init> ()V
 	public final fun consumeLifecycleEvents ()Ljava/util/List;
 	protected abstract fun getViewRegistry ()Lcom/squareup/workflow1/ui/ViewRegistry;
-	protected final fun leafViewBinding (Lkotlin/reflect/KClass;Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity$ViewObserver;Lkotlin/jvm/functions/Function1;)Lcom/squareup/workflow1/ui/ViewFactory;
-	public static synthetic fun leafViewBinding$default (Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity;Lkotlin/reflect/KClass;Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity$ViewObserver;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcom/squareup/workflow1/ui/ViewFactory;
+	protected final fun leafViewBinding (Lkotlin/reflect/KClass;Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity$ViewObserver;Lkotlin/jvm/functions/Function1;)Lcom/squareup/workflow1/ui/ScreenViewFactory;
+	public static synthetic fun leafViewBinding$default (Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity;Lkotlin/reflect/KClass;Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity$ViewObserver;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcom/squareup/workflow1/ui/ScreenViewFactory;
 	protected final fun lifecycleLoggingViewObserver (Lkotlin/jvm/functions/Function1;)Lcom/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity$ViewObserver;
 	protected final fun logEvent (Ljava/lang/String;)V
 	protected fun onCreate (Landroid/os/Bundle;)V
@@ -63,7 +63,7 @@ public class com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity : an
 	protected fun onCreate (Landroid/os/Bundle;)V
 	public final fun onRetainCustomNonConfigurationInstance ()Ljava/lang/Object;
 	public final fun recreateViewsOnNextRendering ()V
-	public final fun setRendering (Ljava/lang/Object;)Landroid/view/View;
+	public final fun setRendering (Lcom/squareup/workflow1/ui/Screen;)Landroid/view/View;
 	public final fun setRestoreRenderingAfterConfigChange (Z)V
 	public final fun setViewEnvironment (Lcom/squareup/workflow1/ui/ViewEnvironment;)V
 }
diff --git a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt
index 891ad87b79..5e7115d128 100644
--- a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt
+++ b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/AbstractLifecycleTestActivity.kt
@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.internal.test
 
 import android.content.Context
@@ -9,9 +11,10 @@ import androidx.lifecycle.Lifecycle.Event
 import androidx.lifecycle.LifecycleEventObserver
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.ViewTreeLifecycleOwner
-import com.squareup.workflow1.ui.BuilderViewFactory
+import com.squareup.workflow1.ui.ManualScreenViewFactory
+import com.squareup.workflow1.ui.Screen
+import com.squareup.workflow1.ui.ScreenViewFactory
 import com.squareup.workflow1.ui.ViewEnvironment
-import com.squareup.workflow1.ui.ViewFactory
 import com.squareup.workflow1.ui.ViewRegistry
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -26,8 +29,8 @@ import kotlin.reflect.KClass
  * test wants to use. Then call [consumeLifecycleEvents] to get a list of strings back that describe
  * what lifecycle-related events occurred since the last call.
  *
- * Subclasses must override [viewRegistry] to specify the [ViewFactory]s they require. All views
- * will be hosted inside a [WorkflowViewStub].
+ * Subclasses must override [viewRegistry] to specify the [ScreenViewFactory]s they require.
+ * All views will be hosted inside a [WorkflowViewStub].
  */
 @WorkflowUiExperimentalApi
 public abstract class AbstractLifecycleTestActivity : WorkflowUiTestActivity() {
@@ -86,13 +89,13 @@ public abstract class AbstractLifecycleTestActivity : WorkflowUiTestActivity() {
     lifecycleEvents += message
   }
 
-  protected fun <R : Any> leafViewBinding(
+  protected fun <R : Screen> leafViewBinding(
     type: KClass<R>,
     viewObserver: ViewObserver<R>,
     viewConstructor: (Context) -> LeafView<R> = ::LeafView
-  ): ViewFactory<R> =
-    BuilderViewFactory(type) { initialRendering, initialViewEnvironment, contextForNewView, _ ->
-      viewConstructor(contextForNewView).apply {
+  ): ScreenViewFactory<R> =
+    ManualScreenViewFactory(type) { initialRendering, initialViewEnvironment, context, _ ->
+      viewConstructor(context).apply {
         this.viewObserver = viewObserver
         viewObserver.onViewCreated(this, initialRendering)
 
diff --git a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt
index 71bd552c6d..70676137ae 100644
--- a/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt
+++ b/workflow-ui/internal-testing-android/src/main/java/com/squareup/workflow1/ui/internal/test/WorkflowUiTestActivity.kt
@@ -1,9 +1,12 @@
+@file:Suppress("DEPRECATION")
+
 package com.squareup.workflow1.ui.internal.test
 
 import android.os.Bundle
 import android.view.View
 import androidx.appcompat.app.AppCompatActivity
-import com.squareup.workflow1.ui.Named
+import com.squareup.workflow1.ui.NamedScreen
+import com.squareup.workflow1.ui.Screen
 import com.squareup.workflow1.ui.ViewEnvironment
 import com.squareup.workflow1.ui.WorkflowUiExperimentalApi
 import com.squareup.workflow1.ui.WorkflowViewStub
@@ -30,7 +33,7 @@ public open class WorkflowUiTestActivity : AppCompatActivity() {
 
   private val rootStub by lazy { WorkflowViewStub(this) }
   private var renderingCounter = 0
-  private lateinit var lastRendering: Any
+  private lateinit var lastRendering: Screen
 
   /**
    * The [ViewEnvironment] used to create views for renderings passed to [setRendering].
@@ -72,7 +75,6 @@ public open class WorkflowUiTestActivity : AppCompatActivity() {
     super.onCreate(savedInstanceState)
     setContentView(rootStub)
 
-    @Suppress("DEPRECATION")
     (lastCustomNonConfigurationInstance as NonConfigurationData?)?.let { data ->
       viewEnvironment = data.viewEnvironment
       customNonConfigurationData.apply {
@@ -96,18 +98,18 @@ public open class WorkflowUiTestActivity : AppCompatActivity() {
    * If [recreateViewsOnNextRendering] was previously called, the old view tree will be torn down
    * and re-created from scratch.
    */
-  public fun setRendering(rendering: Any): View {
+  public fun setRendering(rendering: Screen): View {
     lastRendering = rendering
-    val named = Named(
+    val named = NamedScreen(
       wrapped = rendering,
       name = renderingCounter.toString()
     )
-    return rootStub.update(named, viewEnvironment)
+    return rootStub.show(named, viewEnvironment)
   }
 
   private class NonConfigurationData(
     val viewEnvironment: ViewEnvironment,
-    val lastRendering: Any?,
+    val lastRendering: Screen?,
     val customData: MutableMap<String, Any?>,
   )
 }