openapi-mcp-generator

What it does

This tool converts OpenAPI specifications into complete, production-ready MCP servers. Given an OpenAPI 3.0+ spec, it generates a TypeScript project that proxies requests to your actual REST API while adding MCP protocol handling, runtime input validation via Zod schemas, and support for multiple transport modes—stdio for local integration, SSE for web clients, and StreamableHTTP for broader deployment. The generated server handles authentication (API keys, Bearer tokens, Basic auth, OAuth2) via environment variables and includes a browser-based test client for web transports.

Who it's for

Backend engineers and platform teams maintaining REST APIs who want to expose them as MCP tools for Claude and other AI agents. Organizations deploying agent infrastructure that needs seamless integration with documented APIs. Developers building API gateways or multi-agent orchestration systems where consistent tool interfaces across APIs are essential.

Common use cases

• Expose a documented REST API as an MCP tool without writing server code
• Enable Claude Code and AI agents to call your API with structured, validated inputs
• Generate proxy servers for legacy or third-party APIs without modifying the original
• Deploy API access across stdio, HTTP, and SSE transports from a single OpenAPI spec
• Validate API request payloads against the OpenAPI schema before forwarding

Setup pitfalls

• Requires a complete OpenAPI spec (YAML or JSON); missing or inaccurate schema definitions will be reflected in generated validation
• Marked as high-risk due to filesystem writes and network call capabilities—review generated servers and validate that the OpenAPI spec is trusted before production use
• API credentials and secrets must be injected via environment variables at runtime; ensure .env files are properly gitignored and access-controlled
• The generated project is TypeScript; requires Node.js and a build step before deployment