getdatanaut/openmcp

npx -y openmcp install <url-or-file-path-to-openapi-spec> --client <chat client>

Usage

• •Install creates an openmcp.json and registers the server in your client's MCP config (e.g. npx -y openmcp install https://api.weather.gov/openapi.json --client cursor)
• •openmcp.json mixes openapi servers and stdio servers (e.g. @modelcontextprotocol/server-postgres)
• •Restrict exposed tools per server with the 'tools' allowlist by operationId; configure auth via headers/query referencing configs or environment variables
• •Run manually with npx -y openmcp run --config <path to openmcp.json>

Key features

• ✓OpenAPI-to-MCP conversion from a URL or local file
• ✓Compose multiple MCP servers into one with per-server tool allowlists
• ✓Config values fall back to environment variables when unset
• ✓stdio and sse transports

Best for

Quickly exposing any OpenAPI-backed API to MCP chat clients and composing existing MCP servers under a single config

Caveats

• ⚠Requires the target API to expose an OpenAPI specification
• ⚠Auth support is limited to static headers/query params from config or env