Use eventsource package

package-lock.json

@@ -1,15 +1,16 @@
 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.3.1",
+  "version": "1.3.2",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@modelcontextprotocol/sdk",
-      "version": "1.3.1",
+      "version": "1.3.2",
       "license": "MIT",
       "dependencies": {
         "content-type": "^1.0.5",
+        "eventsource": "^3.0.2",
         "raw-body": "^3.0.0",
         "zod": "^3.23.8",
         "zod-to-json-schema": "^3.24.1"
@@ -24,7 +25,6 @@
         "@types/node": "^22.0.2",
         "@types/ws": "^8.5.12",
         "eslint": "^9.8.0",
-        "eventsource": "^2.0.2",
         "express": "^4.19.2",
         "jest": "^29.7.0",
         "ts-jest": "^29.2.4",
@@ -3066,12 +3066,24 @@
       }
     },
     "node_modules/eventsource": {
-      "version": "2.0.2",
-      "resolved": "https://registry.npmjs.org/eventsource/-/eventsource-2.0.2.tgz",
-      "integrity": "sha512-IzUmBGPR3+oUG9dUeXynyNmf91/3zUSJg1lCktzKw47OXuhco54U3r9B7O4XX+Rb1Itm9OZ2b0RkTs10bICOxA==",
-      "dev": true,
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/eventsource/-/eventsource-3.0.2.tgz",
+      "integrity": "sha512-YolzkJNxsTL3tCJMWFxpxtG2sCjbZ4LQUBUrkdaJK0ub0p6lmJt+2+1SwhKjLc652lpH9L/79Ptez972H9tphw==",
+      "license": "MIT",
+      "dependencies": {
+        "eventsource-parser": "^3.0.0"
+      },
       "engines": {
-        "node": ">=12.0.0"
+        "node": ">=18.0.0"
+      }
+    },
+    "node_modules/eventsource-parser": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/eventsource-parser/-/eventsource-parser-3.0.0.tgz",
+      "integrity": "sha512-T1C0XCUimhxVQzW4zFipdx0SficT651NnkR0ZSH3yQwh+mFMdLfgjABVi4YtMTtaL4s168593DaoaRLMqryavA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18.0.0"
       }
     },
     "node_modules/execa": {

package.json

@@ -47,6 +47,7 @@
   },
   "dependencies": {
     "content-type": "^1.0.5",
+    "eventsource": "^3.0.2",
     "raw-body": "^3.0.0",
     "zod": "^3.23.8",
     "zod-to-json-schema": "^3.24.1"
@@ -61,7 +62,6 @@
     "@types/node": "^22.0.2",
     "@types/ws": "^8.5.12",
     "eslint": "^9.8.0",
-    "eventsource": "^2.0.2",
     "express": "^4.19.2",
     "jest": "^29.7.0",
     "ts-jest": "^29.2.4",

src/cli.ts

@@ -1,8 +1,5 @@
-import EventSource from "eventsource";
 import WebSocket from "ws";
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-(global as any).EventSource = EventSource;
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 (global as any).WebSocket = WebSocket;
 

src/client/sse.ts

@@ -1,11 +1,10 @@
 import { Transport } from "../shared/transport.js";
 import { JSONRPCMessage, JSONRPCMessageSchema } from "../types.js";
+import { EventSource, 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.
  */
 export class SSEClientTransport implements Transport {
   private _eventSource?: EventSource;
@@ -19,7 +18,10 @@ export class SSEClientTransport implements Transport {
   onerror?: (error: Error) => void;
   onmessage?: (message: JSONRPCMessage) => void;
 
-  constructor(url: URL, opts?: { eventSourceInit?: EventSourceInit, requestInit?: RequestInit }) {
+  constructor(
+    url: URL,
+    opts?: { eventSourceInit?: EventSourceInit; requestInit?: RequestInit },
+  ) {
     this._url = url;
     this._eventSourceInit = opts?.eventSourceInit;
     this._requestInit = opts?.requestInit;
@@ -33,7 +35,10 @@ export class SSEClientTransport implements Transport {
     }
 
     return new Promise((resolve, reject) => {
-      this._eventSource = new EventSource(this._url.href, this._eventSourceInit);
+      this._eventSource = new EventSource(
+        this._url.href,
+        this._eventSourceInit,
+      );
       this._abortController = new AbortController();
 
       this._eventSource.onerror = (event) => {
@@ -101,7 +106,7 @@ export class SSEClientTransport implements Transport {
         method: "POST",
         headers,
         body: JSON.stringify(message),
-        signal: this._abortController?.signal
+        signal: this._abortController?.signal,
       };
 
       const response = await fetch(this._endpoint, init);