mcp-openapi

# MCP-OpenAPI A [Model Context Protocol][mcp] server that exposes HTTP methods from an OpenAPI spec as tools. > [!WARNING] > This is a proof of concept, yet to be fully tested and documented. ## Usage Each MCP-OpenAPI server exposes operations from a single OpenAPI spec. You could run multiple instances to expose multiple specs. This package is available on PyPI @ [`mcp-openapi`][pypi]. You can start a server with `uvx mcp-openapi --openapi-url https://httpbin.org/spec.json (sse | stdio)`. An example Claude config (while running `fastapi dev tests/todos.py` with port 8000): ```json { "mcpServers": { "todos": { "command": "uvx", "args": [ "mcp-openapi", "--openapi-url=http://localhost:8000/openapi.json", "stdio" ] } } } ``` The OpenAPI url can also be passed as an environment variable, `MCP_OPENAPI_URL`. When running as SSE, you can configure the server with: - `--fastmcp-sse-host` - the host to serve the MCP server on - `--fastmcp-sse-port` - the port to serve the MCP server on There are additional global options: - `--fastmcp-debug` - enable debug mode for the MCP server - `--fastmcp-log-level` - the log level for the MCP server These can also be configured via environment variables using the `FASTMCP_` prefix, e.g. `FASTMCP_LOG_LEVEL=DEBUG`. ### How it works 1. The MCP-OpenAPI server is initialised with an OpenAPI spec URL. 2. The server fetches and parses the OpenAPI spec, and registers each path-operation as a tool. 3. A FastMCP server is started with the registered tools. 4. When a client requests a tool, the MCP server makes a HTTP request to the API and returns the response. ### Supported OpenAPI/Swagger versions | Swagger 2.0 | OpenAPI 3.0 | OpenAPI 3.1 | |-------------|-------------|-------------| | :x: | :heavy_check_mark: | :heavy_check_mark: | This package supports OpenAPI 3.0 and 3.1 specs, in JSON and YAML formats. We're using [openapi-parser][openapi-parser] under the hood, which se…