@modelcontextprotocol/sdk - npm Package Compare versions

Comparing version 1.3.2 to 1.4.0

dist/cjs/cli.js

@@ -6,7 +6,4 @@ "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-const eventsource_1 = __importDefault(require("eventsource"));
 const ws_1 = __importDefault(require("ws"));
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-global.EventSource = eventsource_1.default;
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 global.WebSocket = ws_1.default;
@@ -13,0 +10,0 @@ const express_1 = __importDefault(require("express"));

dist/cjs/client/index.d.ts

@@ -40,2 +40,3 @@ import { Protocol, ProtocolOptions, RequestOptions } from "../shared/protocol.js";
     private _capabilities;
+    private _instructions?;
     /**
@@ -61,2 +62,6 @@ * Initializes this client with the given name and version information.
     getServerVersion(): Implementation | undefined;
+    /**
+     * After initialization has completed, this may be populated with information about the server's instructions.
+     */
+    getInstructions(): string | undefined;
     protected assertCapabilityForMethod(method: RequestT["method"]): void;
@@ -63,0 +68,0 @@ protected assertNotificationCapability(method: NotificationT["method"]): void;

dist/cjs/client/index.js

@@ -77,2 +77,3 @@ "use strict";
             this._serverVersion = result.serverInfo;
+            this._instructions = result.instructions;
             await this.notification({
@@ -100,2 +101,8 @@ method: "notifications/initialized",
     }
+    /**
+     * After initialization has completed, this may be populated with information about the server's instructions.
+     */
+    getInstructions() {
+        return this._instructions;
+    }
     assertCapabilityForMethod(method) {
@@ -102,0 +109,0 @@ var _a, _b, _c, _d, _e;

dist/cjs/client/sse.d.ts

 import { Transport } from "../shared/transport.js";
 import { JSONRPCMessage } from "../types.js";
+import { type EventSourceInit } from "eventsource";
 /**
  * Client transport for SSE: this will connect to a server using Server-Sent Events for receiving
  * messages and make separate POST requests for sending messages.
- *
- * This uses the EventSource API in browsers. You can install the `eventsource` package for Node.js.
  */
@@ -9,0 +8,0 @@ export declare class SSEClientTransport implements Transport {

dist/cjs/client/sse.js

@@ -5,7 +5,6 @@ "use strict";
 const types_js_1 = require("../types.js");
+const eventsource_1 = require("eventsource");
 /**
  * Client transport for SSE: this will connect to a server using Server-Sent Events for receiving
  * messages and make separate POST requests for sending messages.
- *
- * This uses the EventSource API in browsers. You can install the `eventsource` package for Node.js.
  */
@@ -23,3 +22,3 @@ class SSEClientTransport {
         return new Promise((resolve, reject) => {
-            this._eventSource = new EventSource(this._url.href, this._eventSourceInit);
+            this._eventSource = new eventsource_1.EventSource(this._url.href, this._eventSourceInit);
             this._abortController = new AbortController();
@@ -86,3 +85,3 @@ this._eventSource.onerror = (event) => {
                 body: JSON.stringify(message),
-                signal: (_b = this._abortController) === null || _b === void 0 ? void 0 : _b.signal
+                signal: (_b = this._abortController) === null || _b === void 0 ? void 0 : _b.signal,
             };
@@ -89,0 +88,0 @@ const response = await fetch(this._endpoint, init);

dist/cjs/types.js

@@ -276,2 +276,8 @@ "use strict";
     serverInfo: exports.ImplementationSchema,
+    /**
+     * Instructions describing how to use the server and its features.
+     *
+     * This can be used by clients to improve the LLM's understanding of available tools, resources, etc. It can be thought of like a "hint" to the model. For example, this information MAY be added to the system prompt.
+     */
+    instructions: zod_1.z.optional(zod_1.z.string()),
 });
@@ -278,0 +284,0 @@ /**

dist/esm/cli.js

@@ -1,6 +0,3 @@
-import EventSource from "eventsource";
 import WebSocket from "ws";
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-global.EventSource = EventSource;
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 global.WebSocket = WebSocket;
@@ -7,0 +4,0 @@ import express from "express";

dist/esm/client/index.d.ts

@@ -40,2 +40,3 @@ import { Protocol, ProtocolOptions, RequestOptions } from "../shared/protocol.js";
     private _capabilities;
+    private _instructions?;
     /**
@@ -61,2 +62,6 @@ * Initializes this client with the given name and version information.
     getServerVersion(): Implementation | undefined;
+    /**
+     * After initialization has completed, this may be populated with information about the server's instructions.
+     */
+    getInstructions(): string | undefined;
     protected assertCapabilityForMethod(method: RequestT["method"]): void;
@@ -63,0 +68,0 @@ protected assertNotificationCapability(method: NotificationT["method"]): void;

dist/esm/client/index.js

@@ -74,2 +74,3 @@ import { mergeCapabilities, Protocol, } from "../shared/protocol.js";
             this._serverVersion = result.serverInfo;
+            this._instructions = result.instructions;
             await this.notification({
@@ -97,2 +98,8 @@ method: "notifications/initialized",
     }
+    /**
+     * After initialization has completed, this may be populated with information about the server's instructions.
+     */
+    getInstructions() {
+        return this._instructions;
+    }
     assertCapabilityForMethod(method) {
@@ -99,0 +106,0 @@ var _a, _b, _c, _d, _e;

dist/esm/client/sse.d.ts

 import { Transport } from "../shared/transport.js";
 import { JSONRPCMessage } from "../types.js";
+import { type EventSourceInit } from "eventsource";
 /**
  * Client transport for SSE: this will connect to a server using Server-Sent Events for receiving
  * messages and make separate POST requests for sending messages.
- *
- * This uses the EventSource API in browsers. You can install the `eventsource` package for Node.js.
  */
@@ -9,0 +8,0 @@ export declare class SSEClientTransport implements Transport {

dist/esm/client/sse.js

 import { JSONRPCMessageSchema } from "../types.js";
+import { EventSource } from "eventsource";
 /**
  * Client transport for SSE: this will connect to a server using Server-Sent Events for receiving
  * messages and make separate POST requests for sending messages.
- *
- * This uses the EventSource API in browsers. You can install the `eventsource` package for Node.js.
  */
@@ -81,3 +80,3 @@ export class SSEClientTransport {
                 body: JSON.stringify(message),
-                signal: (_b = this._abortController) === null || _b === void 0 ? void 0 : _b.signal
+                signal: (_b = this._abortController) === null || _b === void 0 ? void 0 : _b.signal,
             };
@@ -84,0 +83,0 @@ const response = await fetch(this._endpoint, init);

dist/esm/types.js

@@ -272,2 +272,8 @@ import { z } from "zod";
     serverInfo: ImplementationSchema,
+    /**
+     * Instructions describing how to use the server and its features.
+     *
+     * This can be used by clients to improve the LLM's understanding of available tools, resources, etc. It can be thought of like a "hint" to the model. For example, this information MAY be added to the system prompt.
+     */
+    instructions: z.optional(z.string()),
 });
@@ -274,0 +280,0 @@ /**

package.json

 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.3.2",
+  "version": "1.4.0",
   "description": "Model Context Protocol implementation for TypeScript",
@@ -50,2 +50,3 @@ "license": "MIT",
     "content-type": "^1.0.5",
+    "eventsource": "^3.0.2",
     "raw-body": "^3.0.0",
@@ -65,3 +66,2 @@ "zod": "^3.23.8",
     "eslint": "^9.8.0",
-    "eventsource": "^2.0.2",
     "express": "^4.19.2",
@@ -68,0 +68,0 @@ "jest": "^29.7.0",

README.md

@@ -14,5 +14,5 @@ # MCP TypeScript SDK ![NPM Version](https://img.shields.io/npm/v/%40modelcontextprotocol%2Fsdk) ![MIT licensed](https://img.shields.io/npm/l/%40modelcontextprotocol%2Fsdk)
 - [Running Your Server](#running-your-server)
-  - [Development Mode](#development-mode)
-  - [Claude Desktop Integration](#claude-desktop-integration)
-  - [Direct Execution](#direct-execution)
+  - [stdio](#stdio)
+  - [HTTP with SSE](#http-with-sse)
+  - [Testing and Debugging](#testing-and-debugging)
 - [Examples](#examples)
@@ -47,2 +47,3 @@ - [Echo Server](#echo-server)
 import { McpServer, ResourceTemplate } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import { z } from "zod";
@@ -75,2 +76,6 @@
 );
+
+// Start receiving messages on stdin and sending messages on stdout
+const transport = new StdioServerTransport();
+await server.connect(transport);
 ```
@@ -184,2 +189,62 @@
 
+## Running Your Server
+
+MCP servers in TypeScript need to be connected to a transport to communicate with clients. How you start the server depends on the choice of transport:
+
+### stdio
+
+For command-line tools and direct integrations:
+
+```typescript
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
+
+const server = new McpServer({
+  name: "example-server",
+  version: "1.0.0"
+});
+
+// ... set up server resources, tools, and prompts ...
+
+const transport = new StdioServerTransport();
+await server.connect(transport);
+```
+
+### HTTP with SSE
+
+For remote servers, start a web server with a Server-Sent Events (SSE) endpoint, and a separate endpoint for the client to send its messages to:
+
+```typescript
+import express from "express";
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js";
+
+const server = new McpServer({
+  name: "example-server",
+  version: "1.0.0"
+});
+
+// ... set up server resources, tools, and prompts ...
+
+const app = express();
+
+app.get("/mcp", async (req, res) => {
+  const transport = new SSEServerTransport("/messages", res);
+  await server.connect(transport);
+});
+
+app.post("/messages", async (req, res) => {
+  // Note: to support multiple simultaneous connections, these messages will
+  // need to be routed to a specific matching transport. (This logic isn't
+  // implemented here, for simplicity.)
+  await transport.handlePostMessage(req, res);
+});
+
+app.listen(3000);
+```
+
+### Testing and Debugging
+
+To test your server, you can use the [MCP Inspector](https://github.com/modelcontextprotocol/inspector). See its README for more information.
+
 ## Examples
@@ -186,0 +251,0 @@

No alert changes

Improved metrics

Total package byte prevSize

3351429

increased by0.24%

Dev dependency count

16

decreased by-5.88%

Lines of code

63647

increased by0.15%

Number of lines in readme file

491

increased by15.26%

Worsened metrics

Dependency count

5

increased by25%

Dependency changes

• + Addedeventsource@^3.0.2

• + Addedeventsource@3.0.5(transitive)

• + Addedeventsource-parser@3.0.0(transitive)