fix(tests): close existing connection before reconnecting in MCP protocol tests

MCP SDK 1.27+ enforces single-connection per Server instance, throwing
"Already connected to a transport" when connect() is called twice.
Updated test helper to close existing connections before reconnecting.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/dependency-check.yml

@@ -77,15 +77,15 @@ jobs:
           echo "Zod version: $ZOD_VERSION"
           echo ""
 
-          # Check MCP SDK version - must be exactly 1.20.1
+          # Check MCP SDK version - must be exactly 1.27.1
           if [[ "$SDK_VERSION" == "not found" ]]; then
             echo "❌ FAILED: Could not determine MCP SDK version!"
             echo "   The dependency may not have been installed correctly."
             exit 1
           fi
-          if [[ "$SDK_VERSION" != "1.20.1" ]]; then
+          if [[ "$SDK_VERSION" != "1.27.1" ]]; then
             echo "❌ FAILED: MCP SDK version mismatch!"
-            echo "   Expected: 1.20.1"
+            echo "   Expected: 1.27.1"
             echo "   Got: $SDK_VERSION"
             echo ""
             echo "This can cause runtime errors. See issues #440, #444, #446, #447, #450"
@@ -100,7 +100,7 @@ jobs:
             exit 1
           fi
           if [[ "$ZOD_VERSION" =~ ^4\. ]]; then
-            echo "❌ FAILED: Zod v4 detected - incompatible with MCP SDK 1.20.1!"
+            echo "❌ FAILED: Zod v4 detected - incompatible with MCP SDK 1.27.1!"
             echo "   Expected: 3.x"
             echo "   Got: $ZOD_VERSION"
             echo ""

CHANGELOG.md

@@ -7,6 +7,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.36.2] - 2026-03-14
+
+### Changed
+
+- **Updated n8n dependencies**: n8n 2.10.3 → 2.11.4, n8n-core 2.10.1 → 2.11.1, n8n-workflow 2.10.1 → 2.11.1, @n8n/n8n-nodes-langchain 2.10.1 → 2.11.2
+- **Updated @modelcontextprotocol/sdk**: 1.20.1 → 1.27.1 (fixes critical cross-client data leak vulnerability CVE GHSA-345p-7cg4-v4c7)
+- Rebuilt node database with 1,239 nodes (809 core + 430 community preserved)
+- Updated README badge with new n8n version and node counts
+
+Conceived by Romuald Czlonkowski - https://www.aiadvisors.pl/en
+
 ## [2.36.1] - 2026-03-08
 
 ### Added

README.md

@@ -5,11 +5,11 @@
 [![npm version](https://img.shields.io/npm/v/n8n-mcp.svg)](https://www.npmjs.com/package/n8n-mcp)
 [![codecov](https://codecov.io/gh/czlonkowski/n8n-mcp/graph/badge.svg?token=YOUR_TOKEN)](https://codecov.io/gh/czlonkowski/n8n-mcp)
 [![Tests](https://img.shields.io/badge/tests-3336%20passing-brightgreen.svg)](https://github.com/czlonkowski/n8n-mcp/actions)
-[![n8n version](https://img.shields.io/badge/n8n-2.10.3-orange.svg)](https://github.com/n8n-io/n8n)
+[![n8n version](https://img.shields.io/badge/n8n-2.11.4-orange.svg)](https://github.com/n8n-io/n8n)
 [![Docker](https://img.shields.io/badge/docker-ghcr.io%2Fczlonkowski%2Fn8n--mcp-green.svg)](https://github.com/czlonkowski/n8n-mcp/pkgs/container/n8n-mcp)
 [![Deploy on Railway](https://railway.com/button.svg)](https://railway.com/deploy/n8n-mcp?referralCode=n8n-mcp)
 
-A Model Context Protocol (MCP) server that provides AI assistants with comprehensive access to n8n node documentation, properties, and operations. Deploy in minutes to give Claude and other AI assistants deep knowledge about n8n's 1,236 workflow automation nodes (806 core + 430 community).
+A Model Context Protocol (MCP) server that provides AI assistants with comprehensive access to n8n node documentation, properties, and operations. Deploy in minutes to give Claude and other AI assistants deep knowledge about n8n's 1,239 workflow automation nodes (809 core + 430 community).
 
 ## Overview
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.36.1",
+  "version": "2.36.2",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -152,17 +152,17 @@
     "vitest": "^3.2.4"
   },
   "dependencies": {
-    "@modelcontextprotocol/sdk": "1.20.1",
-    "@n8n/n8n-nodes-langchain": "^2.10.1",
+    "@modelcontextprotocol/sdk": "^1.27.1",
+    "@n8n/n8n-nodes-langchain": "^2.11.2",
     "@supabase/supabase-js": "^2.57.4",
     "dotenv": "^16.5.0",
     "express": "^5.1.0",
     "express-rate-limit": "^7.1.5",
     "form-data": "^4.0.5",
     "lru-cache": "^11.2.1",
-    "n8n": "^2.10.3",
-    "n8n-core": "^2.10.1",
-    "n8n-workflow": "^2.10.1",
+    "n8n": "^2.11.4",
+    "n8n-core": "^2.11.1",
+    "n8n-workflow": "^2.11.1",
     "openai": "^4.77.0",
     "sql.js": "^1.13.0",
     "tslib": "^2.6.2",

tests/integration/mcp-protocol/test-helpers.ts

@@ -134,9 +134,22 @@ export class TestableN8NMCPServer {
       }
     }
     
+    // MCP SDK 1.27+ enforces single-connection per Server instance.
+    // Close existing connections before connecting a new transport.
+    for (const conn of this.connections) {
+      try {
+        if (conn && typeof conn.close === 'function') {
+          await conn.close();
+        }
+      } catch {
+        // Ignore errors during cleanup
+      }
+    }
+    this.connections.clear();
+
     // Track this transport for cleanup
     this.transports.add(transport);
-    
+
     const connection = await this.server.connect(transport);
     this.connections.add(connection);
   }