Openapi To Mcpserver

🚀 OpenAPI to MCP Conversion Tool

Convert OpenAPI specification files into an MCP server for interacting with existing Web APIs described by OpenAPI specifications.

This enables AI agents or other MCP-aware clients to interact with existing Web APIs described by OpenAPI specifications.

🚀 Quick Start

The OpenAPI to MCP conversion tool allows you to transform OpenAPI specification files into an MCP server, facilitating interaction between MCP-aware clients and existing Web APIs described by OpenAPI specifications.

✨ Features

• Automatically convert OpenAPI operations to MCP tools.
• Support modern streaming HTTP and legacy SSE transports.
• Automatically detect the API base URL from the OpenAPI specification.
• Support OpenAPI/Swagger 2.0 and OpenAPI 3.x.
• Handle binary responses.
• Provide graceful shutdown handling.
• Offer detailed logging for debugging.

📦 Installation

Prerequisites

• Node.js (Recommended version v16 or higher).

Steps

1. Clone the repository (or ensure you have the openapi-to-mcp directory).
2. Navigate to the openapi-to-mcp directory:

   cd openapi-to-mcp
   

3. Install the dependencies:

   npm install
   

🛠️ Build

Compile the TypeScript code to JavaScript:

npm run build

This will create a dist directory in the project, containing the compiled JavaScript files.

💻 Usage Examples

Basic Usage

Use the start script to start the server and provide the path to the OpenAPI specification file using the -f or --file option:

# Example: Use a local petstore.yaml file
npm start -- serve -f ./path/to/your/openapi.json

# Example: Specify a different port and host
npm start -- serve --file ./specs/petstore.json --port 9090 --host 0.0.0.0

• Replace ./path/to/your/openapi.json with the actual path to your OpenAPI file.
• The server will parse the file, adapt API operations to MCP functions, and start listening.
• It will print out the endpoints for modern and legacy MCP connections.

Connecting as an MCP Client

Modern Connection (Recommended)

The server provides a modern streaming HTTP transport managed by the MCP SDK. This is the recommended way to connect.

Legacy SSE Connection

For compatibility with older versions, the server also supports SSE connections:

1. Connect to the SSE endpoint (e.g., http://localhost:8080/sse).
2. You will receive an mcp-hello event upon connection.
3. To call a function, send a POST request to the /messages endpoint with a sessionId query parameter that matches your SSE connection ID. Example: Send a POST request to /messages?sessionId=<your_session_id> Headers:

   Content-Type: application/json
   

   Body:

   {
     "type": "function_call",
     "id": "call-123",
     "function_name": "get_pets_by_status",
     "parameters": {
       "status": "available"
     }
   }
   

4. The server will execute the corresponding API call and send a function_return or error event via the established SSE connection.

🔧 Development

Run in development mode with automatic recompilation:

# Ensure to provide the path to the OpenAPI file
npm run dev -- -f ./path/to/your/openapi.yaml

📌 Current Limitations

• Authentication: Not yet implemented.
• Schema Validation: Although basic schema validation is in place, some complex OpenAPI schema features (such as discriminators and complex combinations) may not be fully supported.
• Testing: No automated tests are currently included.
• Documentation: The documentation for the individual tool can be improved with more examples and parameter descriptions.