Overview
What is OpenAPI MCP Server?
A command-line tool that transforms any OpenAPI service into a Model Context Protocol (MCP) server, enabling seamless integration with AI agents and tools that support the MCP specification. It automatically generates an MCP server from an OpenAPI spec and proxies requests between MCP clients and the original REST API.
How to use OpenAPI MCP Server?
Install globally via npm install -g openapi-mcp-proxy, then run with npx openapi-mcp-proxy --spec <path> --target <url> --port <number>. The --spec option is required; target and port default to http://localhost:8080 and 3000 respectively. The server exposes endpoints on the given port under the /mcp path.
Key features of OpenAPI MCP Server
- Transforms any OpenAPI spec into an MCP server
- Proxies requests between MCP and REST conventions
- No modifications required to the original service
- Supports JSON and YAML OpenAPI specs
- Configurable target URL, port, and spec path
Use cases of OpenAPI MCP Server
- Make existing REST APIs accessible to AI agents via MCP
- Rapidly prototype AI integrations with any OpenAPI‑compliant service
- Use with VS Code’s agent mode for natural language API interactions
- Test and inspect MCP endpoints using the official MCP Inspector
FAQ from OpenAPI MCP Server
What is Model Context Protocol (MCP)?
MCP is a standardized protocol for AI agents to interact with external tools and services, providing a consistent way for AI models to discover and use capabilities through a unified interface.
What is OpenAPI?
OpenAPI (formerly Swagger) is a specification for machine-readable interface files that describe, produce, consume, and visualize RESTful web services without needing source code access.
How do I install and run OpenAPI MCP Server?
Install globally: npm install -g openapi-mcp-proxy. Then run npx openapi-mcp-proxy --spec ./openapi.yml --target http://your-api.com --port 3000. The --spec argument is required; --target and --port are optional.
How can I test the MCP server?
Use the MCP Inspector via npx @modelcontextprotocol/inspector and navigate to http://localhost:3000/mcp. Alternatively, add the server URL to VS Code’s agent mode (Cmd/Ctrl+Shift+P, “MCP: add Server”) and interact through Copilot.
What are the required and optional parameters?
--spec (or env OMP_OPENAPI_SPEC_FILE) is required. --target (env OMP_TARGET_BASE_URL, default http://localhost:8080), --port (env PORT, default 3000), --version, and --help are optional.
