diff --git a/modules/aggregations/build.gradle b/modules/aggregations/build.gradle
index ae639be3db4af..ab826456613c2 100644
--- a/modules/aggregations/build.gradle
+++ b/modules/aggregations/build.gradle
@@ -12,11 +12,12 @@ apply plugin: 'elasticsearch.internal-cluster-test'
 esplugin {
   description 'Adds "built in" aggregations to Elasticsearch.'
   classname 'org.elasticsearch.aggregations.AggregationsPlugin'
+  extendedPlugins = ['lang-painless']
 }
 
 restResources {
   restApi {
-    include '_common', 'indices', 'cluster', 'index', 'search', 'nodes', 'bulk'
+    include '_common', 'indices', 'cluster', 'index', 'search', 'nodes', 'bulk', 'scripts_painless_execute'
   }
   restTests {
     // Pulls in all aggregation tests from core AND the forwards v7's core for forwards compatibility
@@ -38,3 +39,11 @@ tasks.named("yamlRestTestV7CompatTransform").configure { task ->
 artifacts {
   restTests(new File(projectDir, "src/yamlRestTest/resources/rest-api-spec/test"))
 }
+
+testClusters.configureEach {
+  module ':modules:lang-painless'
+}
+
+dependencies {
+  compileOnly(project(':modules:lang-painless:spi'))
+}
diff --git a/modules/aggregations/src/main/java/module-info.java b/modules/aggregations/src/main/java/module-info.java
index a41affa5ba4b6..5c3acfcc3beeb 100644
--- a/modules/aggregations/src/main/java/module-info.java
+++ b/modules/aggregations/src/main/java/module-info.java
@@ -8,11 +8,16 @@
 
 module org.elasticsearch.aggs {
     requires org.elasticsearch.base;
+    requires org.elasticsearch.painless.spi;
     requires org.elasticsearch.server;
     requires org.elasticsearch.xcontent;
     requires org.apache.lucene.core;
 
     exports org.elasticsearch.aggregations.bucket.histogram;
     exports org.elasticsearch.aggregations.bucket.adjacency;
+    exports org.elasticsearch.aggregations.pipeline;
 
+    opens org.elasticsearch.aggregations to org.elasticsearch.painless.spi; // whitelist resource access
+
+    provides org.elasticsearch.painless.spi.PainlessExtension with org.elasticsearch.aggregations.AggregationsPainlessExtension;
 }
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPainlessExtension.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPainlessExtension.java
new file mode 100644
index 0000000000000..e181bb0018015
--- /dev/null
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPainlessExtension.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.aggregations;
+
+import org.elasticsearch.aggregations.pipeline.MovingFunctionScript;
+import org.elasticsearch.painless.spi.PainlessExtension;
+import org.elasticsearch.painless.spi.PainlessTestScript;
+import org.elasticsearch.painless.spi.Whitelist;
+import org.elasticsearch.painless.spi.WhitelistLoader;
+import org.elasticsearch.script.ScriptContext;
+import org.elasticsearch.search.aggregations.pipeline.MovingFunctions;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Extends the painless whitelist for the {@link MovingFunctionScript} to include {@link MovingFunctions}.
+ */
+public class AggregationsPainlessExtension implements PainlessExtension {
+    private static final Whitelist MOVING_FUNCTION_ALLOWLIST = WhitelistLoader.loadFromResourceFiles(
+        AggregationsPainlessExtension.class,
+        "moving_function_whitelist.txt"
+    );
+
+    @Override
+    public Map<ScriptContext<?>, List<Whitelist>> getContextWhitelists() {
+        return Map.ofEntries(
+            Map.entry(MovingFunctionScript.CONTEXT, List.of(MOVING_FUNCTION_ALLOWLIST)),
+            Map.entry(PainlessTestScript.CONTEXT, List.of(MOVING_FUNCTION_ALLOWLIST))
+        );
+    }
+}
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java
index d13cc20cb2d2d..1553470a47403 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java
@@ -12,13 +12,16 @@
 import org.elasticsearch.aggregations.bucket.adjacency.InternalAdjacencyMatrix;
 import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.aggregations.bucket.histogram.InternalAutoDateHistogram;
+import org.elasticsearch.aggregations.pipeline.MovFnPipelineAggregationBuilder;
+import org.elasticsearch.aggregations.pipeline.MovingFunctionScript;
 import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.plugins.ScriptPlugin;
 import org.elasticsearch.plugins.SearchPlugin;
+import org.elasticsearch.script.ScriptContext;
 
 import java.util.List;
 
-public class AggregationsPlugin extends Plugin implements SearchPlugin {
-
+public class AggregationsPlugin extends Plugin implements SearchPlugin, ScriptPlugin {
     @Override
     public List<AggregationSpec> getAggregations() {
         return List.of(
@@ -35,4 +38,20 @@ public List<AggregationSpec> getAggregations() {
                 .setAggregatorRegistrar(AutoDateHistogramAggregationBuilder::registerAggregators)
         );
     }
+
+    @Override
+    public List<PipelineAggregationSpec> getPipelineAggregations() {
+        return List.of(
+            new PipelineAggregationSpec(
+                MovFnPipelineAggregationBuilder.NAME,
+                MovFnPipelineAggregationBuilder::new,
+                MovFnPipelineAggregationBuilder.PARSER
+            )
+        );
+    }
+
+    @Override
+    public List<ScriptContext<?>> getContexts() {
+        return List.of(MovingFunctionScript.CONTEXT);
+    }
 }
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilder.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilder.java
similarity index 97%
rename from server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilder.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilder.java
index 1208e7661c81f..8c721ae2e1797 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilder.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilder.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.Version;
 import org.elasticsearch.common.Strings;
@@ -14,7 +14,9 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.search.DocValueFormat;
+import org.elasticsearch.search.aggregations.pipeline.AbstractPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 import org.elasticsearch.xcontent.ConstructingObjectParser;
 import org.elasticsearch.xcontent.ObjectParser;
 import org.elasticsearch.xcontent.ParseField;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregator.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregator.java
similarity index 95%
rename from server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregator.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregator.java
index f4995762cc789..7431e806d96e4 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregator.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregator.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.script.Script;
 import org.elasticsearch.search.DocValueFormat;
@@ -16,6 +16,9 @@
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.MultiBucketsAggregation;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramFactory;
+import org.elasticsearch.search.aggregations.pipeline.BucketHelpers;
+import org.elasticsearch.search.aggregations.pipeline.InternalSimpleValue;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 
 import java.util.ArrayList;
 import java.util.HashMap;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovingFunctionScript.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovingFunctionScript.java
similarity index 95%
rename from server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovingFunctionScript.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovingFunctionScript.java
index af9ef625e4808..2a6dc1107ad67 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovingFunctionScript.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovingFunctionScript.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.ScriptFactory;
diff --git a/modules/aggregations/src/main/resources/META-INF/services/org.elasticsearch.painless.spi.PainlessExtension b/modules/aggregations/src/main/resources/META-INF/services/org.elasticsearch.painless.spi.PainlessExtension
new file mode 100644
index 0000000000000..49fffefd631dc
--- /dev/null
+++ b/modules/aggregations/src/main/resources/META-INF/services/org.elasticsearch.painless.spi.PainlessExtension
@@ -0,0 +1,9 @@
+#
+# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+# or more contributor license agreements. Licensed under the Elastic License
+# 2.0 and the Server Side Public License, v 1; you may not use this file except
+# in compliance with, at your election, the Elastic License 2.0 or the Server
+# Side Public License, v 1.
+#
+
+org.elasticsearch.aggregations.AggregationsPainlessExtension
diff --git a/modules/lang-painless/src/main/resources/org/elasticsearch/painless/org.elasticsearch.script.moving_function.txt b/modules/aggregations/src/main/resources/org/elasticsearch/aggregations/moving_function_whitelist.txt
similarity index 89%
rename from modules/lang-painless/src/main/resources/org/elasticsearch/painless/org.elasticsearch.script.moving_function.txt
rename to modules/aggregations/src/main/resources/org/elasticsearch/aggregations/moving_function_whitelist.txt
index 634c47f738486..0575734988063 100644
--- a/modules/lang-painless/src/main/resources/org/elasticsearch/painless/org.elasticsearch.script.moving_function.txt
+++ b/modules/aggregations/src/main/resources/org/elasticsearch/aggregations/moving_function_whitelist.txt
@@ -6,7 +6,7 @@
 # Side Public License, v 1.
 #
 
-# This file contains a whitelist for the Moving Function pipeline aggregator in core
+# This file contains a allowlist for the Moving Function pipeline aggregator
 
 class org.elasticsearch.search.aggregations.pipeline.MovingFunctions {
   double max(double[])
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnAggrgatorTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnAggregatorTests.java
similarity index 78%
rename from server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnAggrgatorTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnAggregatorTests.java
index 6c673cd837e39..acb30ca23ec8d 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnAggrgatorTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnAggregatorTests.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.LongPoint;
@@ -24,10 +24,9 @@
 import org.elasticsearch.index.mapper.DateFieldMapper;
 import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.NumberFieldMapper;
-import org.elasticsearch.script.MockScriptEngine;
 import org.elasticsearch.script.Script;
+import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.ScriptEngine;
-import org.elasticsearch.script.ScriptModule;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.script.ScriptType;
 import org.elasticsearch.search.aggregations.AggregatorTestCase;
@@ -36,17 +35,20 @@
 import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalDateHistogram;
 import org.elasticsearch.search.aggregations.metrics.AvgAggregationBuilder;
+import org.elasticsearch.search.aggregations.pipeline.InternalSimpleValue;
+import org.elasticsearch.search.aggregations.pipeline.MovingFunctions;
 
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.function.Consumer;
 
 import static org.hamcrest.Matchers.equalTo;
 
-public class MovFnAggrgatorTests extends AggregatorTestCase {
+public class MovFnAggregatorTests extends AggregatorTestCase {
 
     private static final String DATE_FIELD = "date";
     private static final String INSTANT_FIELD = "instant";
@@ -69,14 +71,44 @@ public class MovFnAggrgatorTests extends AggregatorTestCase {
 
     @Override
     protected ScriptService getMockScriptService() {
-        MockScriptEngine scriptEngine = new MockScriptEngine(
-            MockScriptEngine.NAME,
-            Collections.singletonMap("test", script -> MovingFunctions.max((double[]) script.get("_values"))),
-            Collections.emptyMap()
-        );
+        ScriptEngine scriptEngine = new ScriptEngine() {
+            @Override
+            public String getType() {
+                return "test";
+            }
+
+            @Override
+            public <FactoryType> FactoryType compile(
+                String name,
+                String code,
+                ScriptContext<FactoryType> context,
+                Map<String, String> params
+            ) {
+                if (getSupportedContexts().contains(context) == false) {
+                    return null;
+                }
+                MovingFunctionScript.Factory factory = () -> new MovingFunctionScript() {
+                    @Override
+                    public double execute(Map<String, Object> params, double[] values) {
+                        return MovingFunctions.max(values);
+                    }
+                };
+                return context.factoryClazz.cast(factory);
+            }
+
+            @Override
+            public Set<ScriptContext<?>> getSupportedContexts() {
+                return Set.of(MovingFunctionScript.CONTEXT);
+            }
+        };
         Map<String, ScriptEngine> engines = Collections.singletonMap(scriptEngine.getType(), scriptEngine);
 
-        return new ScriptService(Settings.EMPTY, engines, ScriptModule.CORE_CONTEXTS, () -> 1L);
+        return new ScriptService(
+            Settings.EMPTY,
+            engines,
+            Map.of(MovingFunctionScript.CONTEXT.name, MovingFunctionScript.CONTEXT),
+            () -> 1L
+        );
     }
 
     public void testMatchAllDocs() throws IOException {
@@ -94,7 +126,7 @@ public void testWideWindow() throws IOException {
     }
 
     private void check(int shift, int window, List<Double> expected) throws IOException {
-        Script script = new Script(ScriptType.INLINE, MockScriptEngine.NAME, "test", Collections.emptyMap());
+        Script script = new Script(ScriptType.INLINE, "test", "test", Collections.emptyMap());
         MovFnPipelineAggregationBuilder builder = new MovFnPipelineAggregationBuilder("mov_fn", "avg", script, window);
         builder.setShift(shift);
 
diff --git a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
index 5149570d1f7af..88c8a54232310 100644
--- a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
@@ -8,14 +8,16 @@
 
 package org.elasticsearch.aggregations.pipeline;
 
+import org.elasticsearch.aggregations.AggregationsPlugin;
+import org.elasticsearch.plugins.SearchPlugin;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
-import org.elasticsearch.search.aggregations.pipeline.MovFnPipelineAggregationBuilder;
 
 import java.io.IOException;
 import java.util.Collections;
+import java.util.List;
 
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
@@ -23,6 +25,11 @@
 import static org.hamcrest.Matchers.nullValue;
 
 public class MovFnPipelineAggregationBuilderSerializationTests extends BasePipelineAggregationTestCase<MovFnPipelineAggregationBuilder> {
+    @Override
+    protected List<SearchPlugin> plugins() {
+        return List.of(new AggregationsPlugin());
+    }
+
     @Override
     protected MovFnPipelineAggregationBuilder createTestAggregatorFactory() {
         MovFnPipelineAggregationBuilder builder = new MovFnPipelineAggregationBuilder(
diff --git a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java
index 71f2ec284f8c2..94ad4e4bc657a 100644
--- a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java
@@ -134,7 +134,7 @@ public static double calculateMetric(double[] values, ValuesSourceAggregationBui
         return 0.0;
     }
 
-    static AggregationBuilder getRandomSequentiallyOrderedParentAgg() throws IOException {
+    public static AggregationBuilder getRandomSequentiallyOrderedParentAgg() throws IOException {
         @SuppressWarnings("unchecked")
         Function<String, AggregationBuilder> builder = randomFrom(
             HistogramAggregationBuilder::new,
diff --git a/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/70_adjacency_matrix.yml b/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/adjacency_matrix.yml
similarity index 100%
rename from modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/70_adjacency_matrix.yml
rename to modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/adjacency_matrix.yml
diff --git a/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/70_moving_fn_agg.yml b/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/moving_fn.yml
similarity index 95%
rename from modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/70_moving_fn_agg.yml
rename to modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/moving_fn.yml
index d2ff73ab16b1c..177bafaa07adf 100644
--- a/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/70_moving_fn_agg.yml
+++ b/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/moving_fn.yml
@@ -765,3 +765,50 @@ bad path:
                     buckets_path: "missing"
                     window: 2
                     script: "MovingFunctions.min(values)"
+
+---
+"Bad window":
+
+  - skip:
+      version: " - 7.1.99"
+      reason:  "calendar_interval added in 7.2"
+
+  - do:
+      catch: /\[window\] must be a positive, non-zero integer\./
+      search:
+        rest_total_hits_as_int: true
+        body:
+          size: 0
+          aggs:
+            the_histo:
+              date_histogram:
+                field: "date"
+                calendar_interval: "1d"
+              aggs:
+                the_avg:
+                  avg:
+                    field: "value_field"
+                the_mov_fn:
+                  moving_fn:
+                    buckets_path: "the_avg"
+                    window: -1
+                    script: "MovingFunctions.max(values)"
+
+---
+"Not under date_histo":
+
+  - do:
+      catch: /moving_fn aggregation \[the_mov_fn\] must have a histogram, date_histogram or auto_date_histogram as parent but doesn't have a parent/
+      search:
+        rest_total_hits_as_int: true
+        body:
+          size: 0
+          aggs:
+            the_avg:
+              avg:
+                field: "value_field"
+            the_mov_fn:
+              moving_fn:
+                buckets_path: "the_avg"
+                window: 1
+                script: "MovingFunctions.max(values)"
diff --git a/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/painless_execute.yml b/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/painless_execute.yml
new file mode 100644
index 0000000000000..9ee544f7a10fb
--- /dev/null
+++ b/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/painless_execute.yml
@@ -0,0 +1,8 @@
+---
+MovingFunctions are available in the default context:
+  - do:
+      scripts_painless_execute:
+        body:
+          script:
+            source: "MovingFunctions.max(new double[] {1.0, 2.0, -1234})"
+  - match: { result: "2.0" }
diff --git a/modules/lang-painless/build.gradle b/modules/lang-painless/build.gradle
index 31c2955c38751..17e43a755bedd 100644
--- a/modules/lang-painless/build.gradle
+++ b/modules/lang-painless/build.gradle
@@ -96,7 +96,8 @@ tasks.named("yamlRestTestV7CompatTest").configure {
             'painless/40_fields_api/script fields api for dates',
             'painless/70_execute_painless_scripts/Execute with double field context (multi-value, fields api)',
             'painless/40_fields_api/filter script fields api',
-            'painless/40_fields_api/script score fields api'
+            'painless/40_fields_api/script score fields api',
+            'painless/70_mov_fn_agg/*' // Agg moved to a module.
     ].join(',')
 }
 
diff --git a/modules/lang-painless/spi/src/main/java/org/elasticsearch/painless/spi/PainlessTestScript.java b/modules/lang-painless/spi/src/main/java/org/elasticsearch/painless/spi/PainlessTestScript.java
new file mode 100644
index 0000000000000..6f2f49233242f
--- /dev/null
+++ b/modules/lang-painless/spi/src/main/java/org/elasticsearch/painless/spi/PainlessTestScript.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.painless.spi;
+
+import org.elasticsearch.script.ScriptContext;
+
+import java.util.Map;
+
+/**
+ * Generic "test" context used by the painless execute REST API
+ * for testing painless scripts.
+ */
+public abstract class PainlessTestScript {
+    private final Map<String, Object> params;
+
+    public PainlessTestScript(Map<String, Object> params) {
+        this.params = params;
+    }
+
+    /** Return the parameters for this script. */
+    public Map<String, Object> getParams() {
+        return params;
+    }
+
+    public abstract Object execute();
+
+    public interface Factory {
+        PainlessTestScript newInstance(Map<String, Object> params);
+    }
+
+    public static final String[] PARAMETERS = {};
+    public static final ScriptContext<Factory> CONTEXT = new ScriptContext<>("painless_test", Factory.class);
+}
diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/PainlessPlugin.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/PainlessPlugin.java
index 490d3899962f8..dfb547cbff0c4 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/PainlessPlugin.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/PainlessPlugin.java
@@ -27,6 +27,7 @@
 import org.elasticsearch.painless.action.PainlessContextAction;
 import org.elasticsearch.painless.action.PainlessExecuteAction;
 import org.elasticsearch.painless.spi.PainlessExtension;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 import org.elasticsearch.painless.spi.Whitelist;
 import org.elasticsearch.painless.spi.WhitelistLoader;
 import org.elasticsearch.painless.spi.annotation.WhitelistAnnotationParser;
@@ -111,7 +112,7 @@ public final class PainlessPlugin extends Plugin implements ScriptPlugin, Extens
             }
         }
         testWhitelists.add(WhitelistLoader.loadFromResourceFiles(PainlessPlugin.class, "org.elasticsearch.json.txt"));
-        whitelists.put(PainlessExecuteAction.PainlessTestScript.CONTEXT, testWhitelists);
+        whitelists.put(PainlessTestScript.CONTEXT, testWhitelists);
     }
 
     private final SetOnce<PainlessScriptEngine> painlessScriptEngine = new SetOnce<>();
@@ -171,7 +172,7 @@ public void loadExtensions(ExtensionLoader loader) {
 
     @Override
     public List<ScriptContext<?>> getContexts() {
-        return Collections.singletonList(PainlessExecuteAction.PainlessTestScript.CONTEXT);
+        return Collections.singletonList(PainlessTestScript.CONTEXT);
     }
 
     @Override
diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java
index e2468506b4013..6a3d54e734975 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java
@@ -56,6 +56,7 @@
 import org.elasticsearch.index.query.SearchExecutionContext;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.indices.IndicesService;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.action.RestToXContentListener;
@@ -433,32 +434,6 @@ public int hashCode() {
         }
     }
 
-    public abstract static class PainlessTestScript {
-
-        private final Map<String, Object> params;
-
-        public PainlessTestScript(Map<String, Object> params) {
-            this.params = params;
-        }
-
-        /** Return the parameters for this script. */
-        public Map<String, Object> getParams() {
-            return params;
-        }
-
-        public abstract Object execute();
-
-        public interface Factory {
-
-            PainlessTestScript newInstance(Map<String, Object> params);
-
-        }
-
-        public static final String[] PARAMETERS = {};
-        public static final ScriptContext<Factory> CONTEXT = new ScriptContext<>("painless_test", Factory.class);
-
-    }
-
     public static class TransportAction extends TransportSingleShardAction<Request, Response> {
 
         private final ScriptService scriptService;
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/AliasTests.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/AliasTests.java
index 0825fb98c2c4e..f9d87f5ce46b8 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/AliasTests.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/AliasTests.java
@@ -8,8 +8,8 @@
 
 package org.elasticsearch.painless;
 
-import org.elasticsearch.painless.action.PainlessExecuteAction.PainlessTestScript;
 import org.elasticsearch.painless.lookup.PainlessLookupBuilder;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 import org.elasticsearch.painless.spi.Whitelist;
 import org.elasticsearch.painless.spi.WhitelistLoader;
 import org.elasticsearch.script.ScriptContext;
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/Debugger.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/Debugger.java
index d20ac3cf31bea..04577d8ca9d81 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/Debugger.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/Debugger.java
@@ -8,10 +8,10 @@
 
 package org.elasticsearch.painless;
 
-import org.elasticsearch.painless.action.PainlessExecuteAction.PainlessTestScript;
 import org.elasticsearch.painless.lookup.PainlessLookupBuilder;
 import org.elasticsearch.painless.phase.IRTreeVisitor;
 import org.elasticsearch.painless.phase.UserTreeVisitor;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 import org.elasticsearch.painless.spi.Whitelist;
 import org.elasticsearch.painless.symbol.ScriptScope;
 import org.elasticsearch.painless.symbol.WriteScope;
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/DynamicTypeTests.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/DynamicTypeTests.java
index cdeea943782fe..ffbb7a17137d9 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/DynamicTypeTests.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/DynamicTypeTests.java
@@ -8,7 +8,7 @@
 
 package org.elasticsearch.painless;
 
-import org.elasticsearch.painless.action.PainlessExecuteAction.PainlessTestScript;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 import org.elasticsearch.painless.spi.Whitelist;
 import org.elasticsearch.painless.spi.WhitelistLoader;
 import org.elasticsearch.script.ScriptContext;
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/ScriptTestCase.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/ScriptTestCase.java
index 0cab58ae95504..ec5973a2d8371 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/ScriptTestCase.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/ScriptTestCase.java
@@ -12,6 +12,7 @@
 
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.painless.antlr.Walker;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 import org.elasticsearch.painless.spi.Whitelist;
 import org.elasticsearch.painless.spi.WhitelistLoader;
 import org.elasticsearch.script.ScriptContext;
@@ -25,7 +26,6 @@
 import java.util.List;
 import java.util.Map;
 
-import static org.elasticsearch.painless.action.PainlessExecuteAction.PainlessTestScript;
 import static org.hamcrest.Matchers.hasSize;
 
 /**
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/PainlessExecuteApiTests.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/PainlessExecuteApiTests.java
index f0cd8fbf60b44..63eb067a7a103 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/PainlessExecuteApiTests.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/PainlessExecuteApiTests.java
@@ -390,11 +390,6 @@ public void testContextWhitelists() throws IOException {
         response = innerShardOperation(request, scriptService, null);
         assertEquals("0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33", response.getResult());
 
-        // movfn
-        request = new Request(new Script("MovingFunctions.max(new double[]{1, 3, 2})"), null, null);
-        response = innerShardOperation(request, scriptService, null);
-        assertEquals(3.0, Double.parseDouble((String) response.getResult()), .1);
-
         // json
         request = new Request(new Script("Json.load('{\"a\": 1, \"b\": 2}')['b']"), null, null);
         response = innerShardOperation(request, scriptService, null);
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/SuggestTests.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/SuggestTests.java
index c930d38675a26..f3e10ac0d1162 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/SuggestTests.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/action/SuggestTests.java
@@ -11,9 +11,9 @@
 import org.antlr.v4.runtime.ANTLRInputStream;
 import org.antlr.v4.runtime.Token;
 import org.elasticsearch.painless.ScriptTestCase;
-import org.elasticsearch.painless.action.PainlessExecuteAction.PainlessTestScript;
 import org.elasticsearch.painless.antlr.EnhancedSuggestLexer;
 import org.elasticsearch.painless.antlr.SuggestLexer;
+import org.elasticsearch.painless.spi.PainlessTestScript;
 
 import java.util.List;
 
diff --git a/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.aggregation/250_moving_fn.yml b/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.aggregation/250_moving_fn.yml
deleted file mode 100644
index 4e977468927f9..0000000000000
--- a/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.aggregation/250_moving_fn.yml
+++ /dev/null
@@ -1,47 +0,0 @@
-# There are many more tests under modules/lang-painless/...moving_fn.yml so they can use painless
----
-"Bad window":
-
-  - skip:
-      version: " - 7.1.99"
-      reason:  "calendar_interval added in 7.2"
-
-  - do:
-      catch: /\[window\] must be a positive, non-zero integer\./
-      search:
-        rest_total_hits_as_int: true
-        body:
-          size: 0
-          aggs:
-            the_histo:
-              date_histogram:
-                field: "date"
-                calendar_interval: "1d"
-              aggs:
-                the_avg:
-                  avg:
-                    field: "value_field"
-                the_mov_fn:
-                  moving_fn:
-                    buckets_path: "the_avg"
-                    window: -1
-                    script: "MovingFunctions.max(values)"
-
----
-"Not under date_histo":
-
-  - do:
-      catch: /moving_fn aggregation \[the_mov_fn\] must have a histogram, date_histogram or auto_date_histogram as parent but doesn't have a parent/
-      search:
-        rest_total_hits_as_int: true
-        body:
-          size: 0
-          aggs:
-            the_avg:
-              avg:
-                field: "value_field"
-            the_mov_fn:
-              moving_fn:
-                buckets_path: "the_avg"
-                window: 1
-                script: "MovingFunctions.max(values)"
diff --git a/server/src/main/java/org/elasticsearch/script/ScriptModule.java b/server/src/main/java/org/elasticsearch/script/ScriptModule.java
index 996d6815aa433..85afb96225254 100644
--- a/server/src/main/java/org/elasticsearch/script/ScriptModule.java
+++ b/server/src/main/java/org/elasticsearch/script/ScriptModule.java
@@ -12,7 +12,6 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.query.IntervalFilterScript;
 import org.elasticsearch.plugins.ScriptPlugin;
-import org.elasticsearch.search.aggregations.pipeline.MovingFunctionScript;
 
 import java.util.Collections;
 import java.util.HashMap;
@@ -63,7 +62,6 @@ public class ScriptModule {
                 SimilarityWeightScript.CONTEXT,
                 TemplateScript.CONTEXT,
                 TemplateScript.INGEST_CONTEXT,
-                MovingFunctionScript.CONTEXT,
                 ScriptedMetricAggContexts.InitScript.CONTEXT,
                 ScriptedMetricAggContexts.MapScript.CONTEXT,
                 ScriptedMetricAggContexts.CombineScript.CONTEXT,
diff --git a/server/src/main/java/org/elasticsearch/search/SearchModule.java b/server/src/main/java/org/elasticsearch/search/SearchModule.java
index 11e903ba989d1..628ff8fbe1b52 100644
--- a/server/src/main/java/org/elasticsearch/search/SearchModule.java
+++ b/server/src/main/java/org/elasticsearch/search/SearchModule.java
@@ -204,7 +204,6 @@
 import org.elasticsearch.search.aggregations.pipeline.MaxBucketPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.MinBucketPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.MovAvgPipelineAggregationBuilder;
-import org.elasticsearch.search.aggregations.pipeline.MovFnPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.PercentilesBucketPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.SerialDiffPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.StatsBucketPipelineAggregationBuilder;
@@ -791,13 +790,6 @@ private void registerPipelineAggregations(List<SearchPlugin> plugins) {
                 SerialDiffPipelineAggregationBuilder::parse
             )
         );
-        registerPipelineAggregation(
-            new PipelineAggregationSpec(
-                MovFnPipelineAggregationBuilder.NAME,
-                MovFnPipelineAggregationBuilder::new,
-                MovFnPipelineAggregationBuilder.PARSER
-            )
-        );
         if (RestApiVersion.minimumSupported() == RestApiVersion.V_7) {
             registerPipelineAggregation(
                 new PipelineAggregationSpec(
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/PipelineAggregatorBuilders.java b/server/src/main/java/org/elasticsearch/search/aggregations/PipelineAggregatorBuilders.java
index 1409ec94009a5..e5988ced78516 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/PipelineAggregatorBuilders.java
+++ b/server/src/main/java/org/elasticsearch/search/aggregations/PipelineAggregatorBuilders.java
@@ -18,7 +18,6 @@
 import org.elasticsearch.search.aggregations.pipeline.ExtendedStatsBucketPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.MaxBucketPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.MinBucketPipelineAggregationBuilder;
-import org.elasticsearch.search.aggregations.pipeline.MovFnPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.PercentilesBucketPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.SerialDiffPipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.StatsBucketPipelineAggregationBuilder;
@@ -91,8 +90,4 @@ public static CumulativeSumPipelineAggregationBuilder cumulativeSum(String name,
     public static SerialDiffPipelineAggregationBuilder diff(String name, String bucketsPath) {
         return new SerialDiffPipelineAggregationBuilder(name, bucketsPath);
     }
-
-    public static MovFnPipelineAggregationBuilder movingFunction(String name, Script script, String bucketsPaths, int window) {
-        return new MovFnPipelineAggregationBuilder(name, bucketsPaths, script, window);
-    }
 }
diff --git a/server/src/test/java/org/elasticsearch/script/ScriptLanguagesInfoTests.java b/server/src/test/java/org/elasticsearch/script/ScriptLanguagesInfoTests.java
index 22cf6d5aef36a..ca6d8930eb7b9 100644
--- a/server/src/test/java/org/elasticsearch/script/ScriptLanguagesInfoTests.java
+++ b/server/src/test/java/org/elasticsearch/script/ScriptLanguagesInfoTests.java
@@ -106,7 +106,7 @@ public void testContextsAllowedSettingRespected() {
             .collect(Collectors.toMap(c -> c.name, Function.identity()));
 
         List<String> allContexts = new ArrayList<>(mockContexts.keySet());
-        List<String> allowed = allContexts.subList(0, allContexts.size() / 2);
+        List<String> allowed = new ArrayList<>(allContexts.subList(0, allContexts.size() / 2));
         String miscContext = "misc_context";
         allowed.add(miscContext);
         // check that allowing more than available doesn't pollute the returned contexts
diff --git a/test/framework/src/main/java/org/elasticsearch/script/MockScriptEngine.java b/test/framework/src/main/java/org/elasticsearch/script/MockScriptEngine.java
index b1cc863835314..ea02011459784 100644
--- a/test/framework/src/main/java/org/elasticsearch/script/MockScriptEngine.java
+++ b/test/framework/src/main/java/org/elasticsearch/script/MockScriptEngine.java
@@ -20,7 +20,6 @@
 import org.elasticsearch.index.similarity.ScriptedSimilarity.Field;
 import org.elasticsearch.index.similarity.ScriptedSimilarity.Query;
 import org.elasticsearch.index.similarity.ScriptedSimilarity.Term;
-import org.elasticsearch.search.aggregations.pipeline.MovingFunctionScript;
 import org.elasticsearch.search.lookup.SearchLookup;
 
 import java.io.IOException;
@@ -251,15 +250,6 @@ public String execute() {
         } else if (context.instanceClazz.equals(SimilarityWeightScript.class)) {
             SimilarityWeightScript.Factory factory = mockCompiled::createSimilarityWeightScript;
             return context.factoryClazz.cast(factory);
-        } else if (context.instanceClazz.equals(MovingFunctionScript.class)) {
-            MovingFunctionScript.Factory factory = () -> new MovingFunctionScript() {
-                @Override
-                public double execute(Map<String, Object> params1, double[] values) {
-                    params1.put("_values", values);
-                    return (double) script.apply(params1);
-                }
-            };
-            return context.factoryClazz.cast(factory);
         } else if (context.instanceClazz.equals(ScoreScript.class)) {
             ScoreScript.Factory factory = new MockScoreScript(script);
             return context.factoryClazz.cast(factory);
@@ -372,7 +362,6 @@ public Set<ScriptContext<?>> getSupportedContexts() {
             FilterScript.CONTEXT,
             SimilarityScript.CONTEXT,
             SimilarityWeightScript.CONTEXT,
-            MovingFunctionScript.CONTEXT,
             ScoreScript.CONTEXT,
             ScriptedMetricAggContexts.InitScript.CONTEXT,
             ScriptedMetricAggContexts.MapScript.CONTEXT,