OpenAPI MCP Server

What is OpenAPI MCP Server about?

The project offers a Model Context Protocol (MCP) server that lets Claude, Cursor and other MCP‑compatible clients fetch high‑level overviews and detailed, plain‑language explanations of any OpenAPI specification hosted on oapis.org.

How to use OpenAPI MCP Server?

1. Install the server via npx:

   npx openapi-mcp-server@latest init
   

2. Once the server is running, ask your Claude or Cursor client to “find information about the Stripe API” or any other API.
3. The client will call the MCP server, which first returns a simple summary of the API and then provides operation‑level details on demand.

Key features of OpenAPI MCP Server

• Retrieves a concise, natural‑language overview of any OpenAPI spec (JSON or YAML).
• Supplies plain‑language descriptions of individual endpoints and their parameters.
• Works with Claude Desktop, Cursor, and any MCP‑compatible client.
• Supports both JSON and YAML formats.
• Designed for code generation use‑cases rather than direct endpoint execution.

Use cases of OpenAPI MCP Server

• AI‑assisted documentation: Let large language models explain third‑party APIs to users in everyday language.
• Rapid prototyping: Developers can quickly understand required request structures before writing code.
• Code generation assistance: Feed the plain‑language summaries into code generators to scaffold client libraries.
• Education & onboarding: Teach newcomers how REST APIs are structured without exposing raw OpenAPI files.

FAQ from the OpenAPI MCP Server

• Can the server execute API calls? No. Authentication and execution are not handled; the server only provides contextual information.
• Is there a stable version? v2 is a work‑in‑progress; earlier v1.x versions are still accessible via the legacy README.
• What Node.js version is required? Node.js ≥ 16.17.0.
• How do I contribute? Open a pull request on GitHub or DM the maintainer on X.
• Is the server open‑source? Yes, it is released under the MIT license.

OpenAPI MCP Server

A Model Context Protocol (MCP) server for Claude/Cursor that enables searching and exploring OpenAPI specifications through oapis.org.

• Demo: https://x.com/janwilmake/status/1903497808134496583
• HN Thread: https://news.ycombinator.com/item?id=43447278
• OpenAPISearch: https://github.com/janwilmake/openapisearch
• OAPIS: https://github.com/janwilmake/oapis

The MCP works by applying a 3 step process:

1. It figures out the openapi identifier you need
2. It requests a summary of that in simple language
3. It determines which endpoints you need, and checks out how exactly they work (again, in simple language)

Features

• Get an overview of any OpenAPI specification
• Retrieve details about specific API operations
• Support for both JSON and YAML formats
• Tested with Claude Desktop and Cursor

Installation

For other clients, use MCP URL: https://openapi-mcp.openapisearch.com/mcp

Local testing

First run the server

wrangler dev

Then run the mcp inspector:

npx @modelcontextprotocol/inspector