n8n-MCP

# n8n MCP HTTP Streamable Configuration Guide ## Overview This guide shows how to configure the n8n-nodes-mcp community node to connect to n8n-mcp using the **recommended HTTP Streamable transport**. ## Prerequisites 1. Install n8n-nodes-mcp community node: - Go to n8n Settings → Community Nodes - Install: `n8n-nodes-mcp` - Restart n8n if prompted 2. Ensure environment variable is set: ```bash N8N_COMMUNITY_PACKAGES_ALLOW_TOOL_USAGE=true ``` ## Quick Start ### Step 1: Start Services ```bash # Stop any existing containers docker stop n8n n8n-mcp && docker rm n8n n8n-mcp # Start with HTTP Streamable configuration docker-compose -f docker-compose.n8n.yml up -d # Services will be available at: # - n8n: http://localhost:5678 # - n8n-mcp: http://localhost:3000 ``` ### Step 2: Create MCP Credentials in n8n 1. Open n8n at http://localhost:5678 2. Go to Credentials → Add credential 3. Search for "MCP" and select "MCP API" 4. Configure the fields as follows: - **Credential Name**: `n8n MCP Server` - **HTTP Stream URL**: ` - **Messages Post Endpoint**: (leave empty) - **Additional Headers**: ```json { "Authorization": "Bearer test-secure-token-123456789" } ``` 5. Save the credential ### Step 3: Configure MCP Client Node Add an MCP Client node to your workflow with these settings: - **Connection Type**: `HTTP Streamable` - **HTTP Streamable URL**: `http://n8n-mcp:3000/mcp` - **Authentication**: `Bearer Auth` - **Credentials**: Select the credential you created - **Operation**: Choose your operation (e.g., "List Tools", "Call Tool") ### Step 4: Test the Connection 1. Execute the workflow 2. The MCP Client should successfully connect and return results ## Available Operations ### List Tools Shows all available MCP tools: - `tools_documentation` - `list_nodes` - `get_node_info` - `search_nodes` - `get_node_essentials` - `validate_node_config` - And many more... ### Call Tool Execute specific tools with arguments: **Example: Get Node Info** - Tool Name: `get_node_info` - Arguments: `{ "nodeType": "n8n-nodes-base.httpRequest" }` **Example: Search Nodes** - Tool Name: `search_nodes` - Arguments: `{ "query": "webhook", "limit": 5 }` ## Import Example Workflow Import the pre-configured workflow: 1. Go to Workflows → Add workflow → Import from File 2. Select: `examples/n8n-mcp-streamable-workflow.json` 3. Update the credentials with your bearer token ## Troubleshooting ### Connection Refused - Verify services are running: `docker ps` - Check logs: `docker logs n8n-mcp` - Ensure you're using `http://n8n-mcp:3000/mcp` (container name) not `localhost` ### Authentication Failed - Verify bearer token matches exactly - Check CORS settings allow n8n origin ### Test Endpoint Manually ```bash # Test health check curl http://localhost:3000/health # Test MCP endpoint (should return error without proper JSON-RPC body) curl -X POST http://localhost:3000/mcp \ -H "Authorization: Bearer test-secure-token-123456789" \ -H "Content-Type: application/json" ``` ## Architecture Notes - **Transport**: HTTP Streamable (StreamableHTTPServerTransport) - **Protocol**: JSON-RPC 2.0 over HTTP POST - **Authentication**: Bearer token in Authorization header - **Endpoint**: Single `/mcp` endpoint handles all operations - **Stateless**: Each request creates a new MCP server instance ## Why HTTP Streamable? 1. **Recommended by MCP**: The official recommended transport method 2. **Better Performance**: More efficient than SSE 3. **Simpler Implementation**: Single POST endpoint 4. **Future Proof**: SSE is deprecated in MCP spec