n8n-nodes-openapi-mcp-server

This is an n8n node that acts as a trigger, running an MCP (Machine-readable Capability Protocol) server inside n8n. It dynamically generates tools from an OpenAPI specification URL and makes them available via a webhook.

Installation

To install this node, follow these steps:

1. Go to your n8n instance.
2. Go to Settings > Community Nodes.
3. Click Install and enter n8n-nodes-openapi-mcp-server.
4. Click Install again.

Alternatively, you can use npm in your n8n's custom nodes directory:

npm install n8n-nodes-openapi-mcp-server

Configuration

The node has the following properties:

• Path: The path for the webhook URL. Defaults to mcp.
• OpenAPI URL: The URL of the openapi.json file to generate tools from.
• Default Filter: An optional tag to filter the tools from the OpenAPI specification.
• Available Tools: A read-only list of the tools that have been successfully loaded from the OpenAPI URL. This list refreshes automatically when you open the node.

Credentials

This node requires credentials to authenticate with the target API.

• Base URL: The base URL of the API (e.g., https://api.example.com).
• Bearer Token: The Bearer token for authentication.

Usage

This node functions as a webhook trigger. Once activated, it will provide a webhook URL. You can send MCP requests to this URL to interact with the tools generated from the OpenAPI specification.

The node handles the following MCP methods:

• initialize: Initializes the connection.
• tools/list: Lists all the available tools.
• tools/call: Executes a specific tool with the given arguments.
• ping: A simple ping to check the connection.

When a tools/call request is received, the node will make an HTTP request to the corresponding API endpoint defined in the OpenAPI specification, using the provided credentials.

Example

Here is an example of how to call the tools/list method using curl. Replace YOUR_N8N_WEBHOOK_URL with the actual webhook URL provided by the node.

curl -X POST YOUR_N8N_WEBHOOK_URL \
-H "Content-Type: application/json" \
-d '{
    "jsonrpc": "2.0",
    "id": "123",
    "method": "tools/list",
    "params": {}
}'

Development

Contributions are welcome. Please open an issue or a pull request on the project's repository.

License

This project is licensed under the ISC License.