From 24b3972931395c70358146b00fec809625a550f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Kopeck=C3=BD?= <themq37@gmail.com>
Date: Wed, 17 Sep 2025 11:51:37 +0200
Subject: [PATCH 1/2] fix: prevent streamable http wite after end from crashing
 the node process (#933)

---
 src/server/streamableHttp.ts | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/server/streamableHttp.ts b/src/server/streamableHttp.ts
index 3bf84e430..c0da91704 100644
--- a/src/server/streamableHttp.ts
+++ b/src/server/streamableHttp.ts
@@ -303,6 +303,11 @@ export class StreamableHTTPServerTransport implements Transport {
     res.on("close", () => {
       this._streamMapping.delete(this._standaloneSseStreamId);
     });
+
+    // Add error handler for standalone SSE stream
+    res.on("error", (error) => {
+      this.onerror?.(error as Error);
+    });
   }
 
   /**
@@ -334,6 +339,11 @@ export class StreamableHTTPServerTransport implements Transport {
         }
       });
       this._streamMapping.set(streamId, res);
+
+      // Add error handler for replay stream
+      res.on("error", (error) => {
+        this.onerror?.(error as Error);
+      });
     } catch (error) {
       this.onerror?.(error as Error);
     }
@@ -520,6 +530,11 @@ export class StreamableHTTPServerTransport implements Transport {
           this._streamMapping.delete(streamId);
         });
 
+        // Add error handler for stream write errors
+        res.on("error", (error) => {
+          this.onerror?.(error as Error);
+        });
+
         // handle each message
         for (const message of messages) {
           this.onmessage?.(message, { authInfo, requestInfo });

From c94ba4b43cd305e39d88985c73d6b9bc1153da84 Mon Sep 17 00:00:00 2001
From: Felix Weinberger <3823880+felixweinberger@users.noreply.github.com>
Date: Thu, 18 Sep 2025 14:27:58 +0100
Subject: [PATCH 2/2] chore: update version to 1.18.1 for weekly release (#950)

---
 package-lock.json | 4 ++--
 package.json      | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 14b3a9f35..002fe2088 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.18.0",
+  "version": "1.18.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@modelcontextprotocol/sdk",
-      "version": "1.18.0",
+      "version": "1.18.1",
       "license": "MIT",
       "dependencies": {
         "ajv": "^6.12.6",
diff --git a/package.json b/package.json
index fda002f99..bb36a6d98 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.18.0",
+  "version": "1.18.1",
   "description": "Model Context Protocol implementation for TypeScript",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",