Détail du package

n8n-nodes-mcp-client

KyanBergeron4Runr303.9kMIT0.2.12

4Runr's custom MCP Client node for n8n — connects to a self-hosted MCP server via SSE and streams tool definitions to n8n AI Agents.

n8n, 4Runr, mcp, automation

readme

n8n-nodes-mcp-client

Built by 4Runr, this is a custom n8n node that connects to a self-hosted MCP Server via Server-Sent Events (SSE). It streams tool definitions to n8n AI Agents in real time, enabling flexible, dynamic automation at scale.

Features

  • Listens to an sseUrl endpoint for incoming tools events.
  • Emits tool definitions for use in the n8n AI Agent ecosystem.
  • Allows dynamic tool selection and parameter input.
  • Executes tools by POSTing to /mcp/message with the correct payload and headers.
  • Logs events, handles errors, and filters events automatically.
  • Optimized for 4Runr's AI automation infrastructure and MCP server systems.

Usage

  1. Configure Credentials

    • Set up a credential of type 4Runr MCP Access with:
      • SSE URL (required): Your MCP server's SSE endpoint (e.g., https://mcp-server/mcp-events)
      • SSE Connection Timeout (optional): Timeout in ms (default: 60000)
      • Messages POST Endpoint (required): Your MCP server's message endpoint (e.g., https://mcp-server/mcp/message)
      • Additional Headers (optional): JSON for API keys, etc. (e.g., { "X-API-Key": "Test12345" })

  2. Add the Node to Your Workflow

    • Use the "4Runr MCP Client" node as a tool source in your AI Agent configuration.
    • The node will dynamically display available tools as they arrive from the SSE stream.
    • You can select a tool and input parameters (as JSON) to execute it.

  3. Tool Execution

    • When a tool is executed, the node will POST to the configured message endpoint with the payload:
      {
  "toolCall": {
    "toolName": "check_availability",
    "parameters": { ... }
  }
}
    • The X-API-Key header (if provided) will be included in all POST requests.

  4. Error Handling

    • The node provides robust error handling for SSE, JSON parsing, and HTTP errors.
    • Errors are logged and displayed in the n8n UI.

Assumptions

  • Tool names are accepted as sent by the server (namespacing/aliasing is optional).
  • All tool parameters and required/optional flags are respected as sent by the server.
  • The node expects the MCP server to emit a tools event with a tools array in the data payload.

Advanced/Optional

  • Tool name mapping/aliasing is supported via the Tool Name Mapping (Optional) property.
  • Future enhancements may include caching, custom parameter UI, and more.

Maintainer

Developed and maintained by 4Runr — Montreal's AI infrastructure company transforming how businesses run with intelligent systems.