Merge branch 'main' into justin/simplified-api

Author: jspahrsummers

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.1.0",
+  "version": "1.1.1",
   "description": "Model Context Protocol implementation for TypeScript",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",
@@ -19,21 +19,26 @@
     "mcp"
   ],
   "exports": {
-    "./*": "./dist/*"
+    "./*": {
+      "import": "./dist/esm/*",
+      "require": "./dist/cjs/*"
+    }
   },
   "typesVersions": {
     "*": {
       "*": [
-        "./dist/*"
+        "./dist/esm/*"
       ]
     }
   },
   "files": [
     "dist"
   ],
   "scripts": {
-    "build": "tsc -p tsconfig.prod.json",
-    "prepack": "tsc -p tsconfig.prod.json",
+    "build": "npm run build:esm && npm run build:cjs",
+    "build:esm": "tsc -p tsconfig.prod.json && echo '{\"type\": \"module\"}' > dist/esm/package.json",
+    "build:cjs": "tsc -p tsconfig.cjs.json && echo '{\"type\": \"commonjs\"}' > dist/cjs/package.json",
+    "prepack": "npm run build:esm && npm run build:cjs",
     "lint": "eslint src/",
     "test": "jest",
     "start": "npm run server",

src/integration-tests/process-cleanup.test.ts

@@ -0,0 +1,28 @@
+import { Server } from "../server/index.js";
+import { StdioServerTransport } from "../server/stdio.js";
+
+describe("Process cleanup", () => {
+  jest.setTimeout(5000); // 5 second timeout
+
+  it("should exit cleanly after closing transport", async () => {
+    const server = new Server(
+      {
+        name: "test-server",
+        version: "1.0.0",
+      },
+      {
+        capabilities: {},
+      }
+    );
+
+    const transport = new StdioServerTransport();
+    await server.connect(transport);
+
+    // Close the transport
+    await transport.close();
+
+    // If we reach here without hanging, the test passes
+    // The test runner will fail if the process hangs
+    expect(true).toBe(true);
+  });
+});

src/server/index.test.ts

@@ -38,6 +38,7 @@ test("should accept latest protocol version", async () => {
             name: "test server",
             version: "1.0",
           },
+          instructions: "Test instructions",
         });
         sendPromiseResolve(undefined);
       }
@@ -57,6 +58,7 @@ test("should accept latest protocol version", async () => {
         tools: {},
         logging: {},
       },
+      instructions: "Test instructions",
     },
   );
 

src/server/index.ts

@@ -34,6 +34,11 @@ export type ServerOptions = ProtocolOptions & {
    * Capabilities to advertise as being supported by this server.
    */
   capabilities?: ServerCapabilities;
+
+  /**
+   * Optional instructions describing how to use the server and its features.
+   */
+  instructions?: string;
 };
 
 /**
@@ -73,6 +78,7 @@ export class Server<
   private _clientCapabilities?: ClientCapabilities;
   private _clientVersion?: Implementation;
   private _capabilities: ServerCapabilities;
+  private _instructions?: string;
 
   /**
    * Callback for when initialization has fully completed (i.e., the client has sent an `initialized` notification).
@@ -88,6 +94,7 @@ export class Server<
   ) {
     super(options);
     this._capabilities = options?.capabilities ?? {};
+    this._instructions = options?.instructions;
 
     this.setRequestHandler(InitializeRequestSchema, (request) =>
       this._oninitialize(request),
@@ -250,6 +257,7 @@ export class Server<
         : LATEST_PROTOCOL_VERSION,
       capabilities: this.getCapabilities(),
       serverInfo: this._serverInfo,
+      ...(this._instructions && { instructions: this._instructions }),
     };
   }
 

src/server/stdio.ts

@@ -62,8 +62,19 @@ export class StdioServerTransport implements Transport {
   }
 
   async close(): Promise<void> {
+    // Remove our event listeners first
     this._stdin.off("data", this._ondata);
     this._stdin.off("error", this._onerror);
+
+    // Check if we were the only data listener
+    const remainingDataListeners = this._stdin.listenerCount('data');
+    if (remainingDataListeners === 0) {
+      // Only pause stdin if we were the only listener
+      // This prevents interfering with other parts of the application that might be using stdin
+      this._stdin.pause();
+    }
+    
+    // Clear the buffer and notify closure
     this._readBuffer.clear();
     this.onclose?.();
   }

tsconfig.cjs.json

@@ -0,0 +1,9 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "outDir": "./dist/cjs"
+  },
+  "exclude": ["**/*.test.ts"]
+}

tsconfig.prod.json

@@ -1,6 +1,7 @@
 {
   "extends": "./tsconfig.json",
-  "exclude": [
-    "**/*.test.ts",
-  ]
+  "compilerOptions": {
+    "outDir": "./dist/esm"
+  },
+  "exclude": ["**/*.test.ts"]
 }