OpenMCP

https://www.open-mcp.org

OpenMCP is both:

1. a standard for converting web APIs into MCP servers
2. an open source registry of servers which follow the standard

Each OpenMCP server gives MCP clients the ability to make requests to a particular web API. Together the servers in the registry represent a broad range of services, empowering the underlying client LLMs to fetch data and perform actions on behalf of their users across many domains.

Contents

• Creating a server
• Adding OpenMCP servers to MCP clients
• Converting web API -> OpenMCP

Creating a server

https://www.open-mcp.org/servers/creating

Adding OpenMCP servers to MCP clients

Remote hosting

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Local hosting

Requirements:

• Node.js v18 or later (includes npx and npm)

Claude desktop

npx @open-mcp/{server-id} add-to-client ~/Library/Application\ Support/Claude/claude_desktop_config.json

Cursor

Run this from the root of your project directory or, to add to all cursor projects, run it from your home directory ~.

npx @open-mcp/{server-id} add-to-client .cursor/mcp.json

Other clients

npx @open-mcp/{server-id} add-to-client /path/to/client/config.json

Alternatives

If you don't want to use the helper command add-to-client you can use npm to install the package manually, then add a node command to your client config with an absolute path to dist/index.js. See the individual server READMEs for more details.

Converting web API -> OpenMCP

REST openapi.yaml / openapi.json

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gRPC service.proto

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JSON-RPC openrpc.json

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GraphQL schema.gql

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SOAP service.wsdl

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PostgREST schema.sql

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