Universal OpenAPI MCP

A powerful Model Context Protocol (MCP) server that provides universal OpenAPI integration. One MCP installation that works with ANY OpenAPI specification - no more generating separate MCPs for each API!

🚀 Key Features

• 🌐 Universal Compatibility: Works with any valid OpenAPI 2.0/3.0/3.1 specification
• 🔧 Dynamic Operation: No pre-generation needed - parses and executes APIs in real-time
• 🔐 Authentication & Session Persistence: Secure handling of authentication and session persistence
• 🌍 Remote APIs: Support for both local files and remote OpenAPI URLs
• 📖 Rich Documentation: Detailed operation descriptions and usage examples

📦 Installation

npm install -g openapi-client-mcp

⚡ Quick Use

Once configured, simply tell your AI assistant what you want to do:

Example Conversations:

"My API is at https://petstore.swagger.io/v2/swagger.json OR "./schema.yml""

• The MCP will discover the OpenAPI spec and call the appropriate endpoint

"Call the POST /users endpoint with name 'John' and email '[email protected]'"

• Automatically finds the endpoint and formats the request

"List all available endpoints from my Stripe API"

• Discovers and shows all operations from the API specification

"Set up authentication for my API using API key 'sk-123...'"

• Configures authentication and remembers it for future calls

Natural Language → API Calls

Just describe what you want in plain English:

• ✅ "Get user by ID 123"
• ✅ "Create a new product with name and price"
• ✅ "Update customer email address"
• ✅ "Delete order 456"

No need to know exact endpoint names or parameter formats!

🔐 Smart Session Management

The MCP helps you authenticate and remembers your login even after restart:

• Login once: "Help me login to my API with OAuth/API key"
• Persistent sessions: Your authentication is safely stored
• Auto-reconnect: Sessions work across MCP restarts
• Multiple APIs: Manage sessions for different APIs simultaneously

⚙️ Installation

Add to your MCP client (e.g., Claude Desktop, Cursor, VS Code):

{
  "mcpServers": {
    "openapi-client-mcp": {
      "command": "openapi-client-mcp"
    }
  }
}

Alternative (no installation):

{
  "mcpServers": {
    "openapi-client-mcp": {
      "command": "npx",
      "args": ["openapi-client-mcp"]
    }
  }
}

🔍 Supported OpenAPI Features

• ✅ OpenAPI 2.0 (Swagger)
• ✅ OpenAPI 3.0.x
• ✅ OpenAPI 3.1.x
• ✅ JSON and YAML formats
• ✅ Path parameters
• ✅ Query parameters
• ✅ Header parameters
• ✅ Request bodies
• ✅ Multiple content types
• ✅ Response schemas
• ✅ Authentication schemes
• ✅ Tags and operation grouping
• ✅ Server definitions

🛡️ Security Features

• Input validation with Zod schemas
• Secure parameter handling
• No arbitrary code execution

🤝 Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

🔗 Links

• npm Package
• GitHub Repository
• Report Issues

📄 License

MIT License - see LICENSE file for details.

🆘 Troubleshooting

MCP Server Not Found:

• Ensure global install: npm install -g openapi-client-mcp
• Try npx instead: Use the npx configuration above
• Check Node.js >=18.0.0 is installed

OpenAPI File Not Detected:

• File must have .yaml, .yml, or .json extension
• File must contain valid OpenAPI specification

API Calls Failing:

• Check base URL in your OpenAPI spec
• Use manage_auth tool for authentication
• Verify required parameters are provided