OpenMCP

OpenMCP is a dual-purpose framework: a standard for converting web APIs into MCP servers and an open-source registry of servers that follow that standard. Each OpenMCP server exposes a token-efficient MCP interface that enables MCP clients to make requests to a target web API on behalf of users. Together, the servers in the registry enable client LLMs to fetch data and perform actions across a broad set of domains, providing a scalable, interoperable way to integrate external services with MCP clients. The documentation guides you through creating a server, adding it to MCP clients, and converting various web API formats into OpenMCP-compatible servers, covering REST, gRPC, JSON-RPC, GraphQL, SOAP, and PostgREST variants.