Merge branch 'main' into dhodun/add-streamable-http-comments

Author: dhodun

README.md

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.12.0",
+  "version": "1.12.3",
   "description": "Model Context Protocol implementation for TypeScript",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",

package.json

@@ -14,6 +14,7 @@ import {
   ListToolsRequestSchema,
   CallToolRequestSchema,
   CreateMessageRequestSchema,
+  ElicitRequestSchema,
   ListRootsRequestSchema,
   ErrorCode,
 } from "../types.js";
@@ -597,6 +598,43 @@ test("should only allow setRequestHandler for declared capabilities", () => {
   }).toThrow("Client does not support roots capability");
 });
 
+test("should allow setRequestHandler for declared elicitation capability", () => {
+  const client = new Client(
+    {
+      name: "test-client",
+      version: "1.0.0",
+    },
+    {
+      capabilities: {
+        elicitation: {},
+      },
+    },
+  );
+
+  // This should work because elicitation is a declared capability
+  expect(() => {
+    client.setRequestHandler(ElicitRequestSchema, () => ({
+      action: "accept",
+      content: {
+        username: "test-user",
+        confirmed: true,
+      },
+    }));
+  }).not.toThrow();
+
+  // This should throw because sampling is not a declared capability
+  expect(() => {
+    client.setRequestHandler(CreateMessageRequestSchema, () => ({
+      model: "test-model",
+      role: "assistant",
+      content: {
+        type: "text",
+        text: "Test response",
+      },
+    }));
+  }).toThrow("Client does not support sampling capability");
+});
+
 /***
  * Test: Type Checking
  * Test that custom request/notification/result schemas can be used with the Client class.

src/client/index.test.ts

@@ -165,6 +165,10 @@ export class Client<
 
       this._serverCapabilities = result.capabilities;
       this._serverVersion = result.serverInfo;
+      // HTTP transports must set the protocol version in each header after initialization.
+      if (transport.setProtocolVersion) {
+        transport.setProtocolVersion(result.protocolVersion);
+      }
 
       this._instructions = result.instructions;
 
@@ -303,6 +307,14 @@ export class Client<
         }
         break;
 
+      case "elicitation/create":
+        if (!this._capabilities.elicitation) {
+          throw new Error(
+            `Client does not support elicitation capability (required for ${method})`,
+          );
+        }
+        break;
+
       case "roots/list":
         if (!this._capabilities.roots) {
           throw new Error(

src/client/index.ts

@@ -62,6 +62,7 @@ export class SSEClientTransport implements Transport {
   private _eventSourceInit?: EventSourceInit;
   private _requestInit?: RequestInit;
   private _authProvider?: OAuthClientProvider;
+  private _protocolVersion?: string;
 
   onclose?: () => void;
   onerror?: (error: Error) => void;
@@ -99,13 +100,18 @@ export class SSEClientTransport implements Transport {
   }
 
   private async _commonHeaders(): Promise<HeadersInit> {
-    const headers: HeadersInit = {};
+    const headers = {
+      ...this._requestInit?.headers,
+    } as HeadersInit & Record<string, string>;
     if (this._authProvider) {
       const tokens = await this._authProvider.tokens();
       if (tokens) {
         headers["Authorization"] = `Bearer ${tokens.access_token}`;
       }
     }
+    if (this._protocolVersion) {
+      headers["mcp-protocol-version"] = this._protocolVersion;
+    }
 
     return headers;
   }
@@ -214,7 +220,7 @@ export class SSEClientTransport implements Transport {
 
     try {
       const commonHeaders = await this._commonHeaders();
-      const headers = new Headers({ ...commonHeaders, ...this._requestInit?.headers });
+      const headers = new Headers(commonHeaders);
       headers.set("content-type", "application/json");
       const init = {
         ...this._requestInit,
@@ -249,4 +255,8 @@ export class SSEClientTransport implements Transport {
       throw error;
     }
   }
+
+  setProtocolVersion(version: string): void {
+    this._protocolVersion = version;
+  }
 }

src/client/sse.ts

@@ -124,6 +124,7 @@ export class StreamableHTTPClientTransport implements Transport {
   private _authProvider?: OAuthClientProvider;
   private _sessionId?: string;
   private _reconnectionOptions: StreamableHTTPReconnectionOptions;
+  private _protocolVersion?: string;
 
   onclose?: () => void;
   onerror?: (error: Error) => void;
@@ -162,7 +163,7 @@ export class StreamableHTTPClientTransport implements Transport {
   }
 
   private async _commonHeaders(): Promise<Headers> {
-    const headers: HeadersInit = {};
+    const headers: HeadersInit & Record<string, string> = {};
     if (this._authProvider) {
       const tokens = await this._authProvider.tokens();
       if (tokens) {
@@ -173,6 +174,9 @@ export class StreamableHTTPClientTransport implements Transport {
     if (this._sessionId) {
       headers["mcp-session-id"] = this._sessionId;
     }
+    if (this._protocolVersion) {
+      headers["mcp-protocol-version"] = this._protocolVersion;
+    }
 
     return new Headers(
       { ...headers, ...this._requestInit?.headers }
@@ -516,4 +520,11 @@ export class StreamableHTTPClientTransport implements Transport {
       throw error;
     }
   }
+
+  setProtocolVersion(version: string): void {
+    this._protocolVersion = version;
+  }
+  get protocolVersion(): string | undefined {
+    return this._protocolVersion;
+  }
 }