openapi-mcp-generator

OpenAPI to MCP Generator

A command-line tool that generates Model Context Protocol (MCP) server code from OpenAPI specifications. This tool helps you quickly create an MCP server that acts as a bridge between LLMs (Large Language Models) and your API.

Features

• Automatic Tool Generation: Converts each API endpoint in your OpenAPI spec into an MCP tool
• Multiple Transport Options: Supports stdio, WebSocket, and HTTP transport methods
• Complete Project Setup: Generates all necessary files to run an MCP server
• TypeScript Support: Includes TypeScript definitions and configuration
• Easy Configuration: Simple environment-based configuration for the generated server

Installation

# Install globally from npm
npm install -g openapi-mcp-generator

# Or with yarn
yarn global add openapi-mcp-generator

# Or with pnpm
pnpm add -g openapi-mcp-generator

Usage

Generate an MCP server from an OpenAPI specification:

openapi-mcp-generator --openapi path/to/openapi.json --output /Path/to/output

Command Line Options

Option	Alias	Description	Default
--openapi	-o	Path or URL to OpenAPI specification	(required)
--output	-d	Output directory for generated files	./mcp-server
--name	-n	Name for the MCP server	openapi-mcp-server
--version	-v	Version for the MCP server	1.0.0
--transport	-t	Transport mechanism (stdio, websocket, http)	stdio
--port	-p	Port for websocket or HTTP server	3000
--help	-h	Show help information

Examples

Generate from a local OpenAPI file:

openapi-mcp-generator --openapi ./specs/petstore.json --output ./petstore-mcp

Generate from a remote OpenAPI URL:

openapi-mcp-generator --openapi https://petstore3.swagger.io/api/v3/openapi.json --output ./petstore-mcp

Specify a WebSocket transport:

openapi-mcp-generator --openapi ./specs/petstore.json --transport websocket --port 8080

Generated Files

The tool generates the following files in the output directory:

• server.js - The main MCP server implementation
• package.json - Dependencies and scripts
• README.md - Documentation for the generated server
• .env.example - Template for environment variables
• types.d.ts - TypeScript type definitions for the API
• tsconfig.json - TypeScript configuration

Using the Generated Server

After generating your MCP server:

1. Navigate to the generated directory:

   cd my-mcp-server

2. Install dependencies:

   npm install

3. Create an environment file:

   cp .env.example .env

4. Edit .env to set your API base URL and any required headers:

   API_BASE_URL=https://api.example.com
   API_HEADERS=Authorization:Bearer your-token-here
   

5. Start the server:

   npm start

Programmatic Usage

You can also use the package programmatically in your Node.js projects:

const { generateMcpServer } = require('openapi-mcp-generator');

// Using async/await
async function generate() {
  try {
    const result = await generateMcpServer({
      openapi: './specs/petstore.json',
      output: './petstore-mcp',
      transport: 'http',
      port: 3000
    });
    console.log(`MCP server generated at: ${result.outputPath}`);
  } catch (error) {
    console.error('Generation failed:', error);
  }
}

generate();

Requirements

• Node.js 16.x or higher
• npm 7.x or higher

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

MIT