OpenAPI Proxy MCP server

The OpenAPI MCP Server enables searching and exploring OpenAPI specifications through oapis.org for Claude and Cursor. It works by identifying the OpenAPI you need, requesting a simplified summary, and determining which endpoints you need with clear explanations of how they work.

Installation Options

Installing via Smithery

To automatically install the OpenAPI MCP server for Claude Desktop using Smithery:

npx -y @smithery/cli install @janwilmake/openapi-mcp-server --client claude

Installing via npx

Run the following command and follow the provided instructions:

npx openapi-mcp-server@latest init

Using with Claude

After installation, you can start using the OpenAPI MCP server by asking Claude questions about APIs:

• "Find information about the Stripe API"
• "Explain how to use the GitHub API's repository endpoints"

When you ask these questions, Claude will use the MCP server to:

1. Get an overview of the requested API
2. Retrieve specific operation details as needed

Features

The OpenAPI MCP Server provides several key capabilities:

• Comprehensive overviews of any OpenAPI specification
• Detailed information about specific API operations
• Support for both JSON and YAML format specifications
• Compatibility with Claude Desktop and Cursor

Requirements

Before installing, ensure you have:

• Node.js version 16.17.0 or higher
• Claude Desktop, Cursor, or another MCP client

Important Notes

The current version (v2) focuses on API exploration and providing context rather than executing endpoints directly. It's particularly useful for code generation but doesn't include authentication features for direct endpoint execution.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "openapi-mcp-server" '{"command":"npx","args":["openapi-mcp-server@latest"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "openapi-mcp-server": {
            "command": "npx",
            "args": [
                "openapi-mcp-server@latest"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "openapi-mcp-server": {
            "command": "npx",
            "args": [
                "openapi-mcp-server@latest"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect