swagger-mcp-toolkit

An MCP server for Swagger/OpenAPI definitions: connects to a Swagger spec and helps AI/clients quickly explore endpoints/models and generate MCP tool definition code.

This project is adapted from the upstream project: https://github.com/Vizioz/Swagger-MCP

Changes in this fork

• Enhanced Swagger 2.0 definition support (while retaining the original swagger-mcp capabilities)
• Added Knife4j / KnifeHeader handling: supports custom headers, plus gatewayHeader / gatewayCode passthrough
• Added swagger-resources support: new listSwaggerResources and saveSwaggerResources tools

Features

• Downloads a Swagger specification and stores it locally for faster reference.
• Fetches Knife4j swagger-resources and supports saving them locally for module selection.
• Returns a list of all the endpoints and their HTTP Methods and descriptions
• Returns a list of all the models
• Returns a model
• Returns service to connect to the end point
• Returns MCP function definitions
• Generates complete MCP tool definitions with full schema information
• Includes AI-specific instructions in tool descriptions

Prerequisites

• Node.js (v14 or higher)
• npm or yarn

Installation

1. Clone the repository:

git clone https://github.com/ZTrainWilliams/swagger-mcp-toolkit.git
cd swagger-mcp-toolkit

1. Install dependencies:

npm install

1. Create a .env file based on the .env.example file:

cp .env.example .env

1. Update the .env file.

Configuration

Edit the .env file to configure the application:

• PORT: The port on which the server will run (default: 3000)
• NODE_ENV: The environment (development, production, test)
• LOG_LEVEL: Logging level (info, error, debug)

Usage

Building the application

Build the application:

npm run build

This will compile the TypeScript code ready to be used as an MCP Server

Running as an MCP Server

To run as an MCP server for integration with Cursor and other applications:

node build/index.js

You can also provide a Swagger URL via CLI argument:

node build/index.js --swagger-url="https://petstore.swagger.io/v2/swagger.json"

Or using the alternative format:

node build/index.js --swaggerUrl="https://petstore.swagger.io/v2/swagger.json"

Note: The CLI --swagger-url argument takes priority over the swaggerFilePath parameter in tool calls. If both are provided, the CLI argument will be used.

Running via npm (npx)

If you publish this project as an npm package named swagger-mcp-toolkit, you can run it without cloning:

npx -y swagger-mcp-toolkit@latest --swagger-url="https://petstore.swagger.io/v2/swagger.json"

Using the MCP Inspector

To run the MCP inspector for debugging:

npm run inspector

Adding to Cursor

To add this MCP server to Cursor:

1. Open Cursor Settings > Features > MCP
2. Click "+ Add New MCP Server"
3. Enter a name for the server (e.g., "Swagger MCP Toolkit")
4. Select "stdio" as the transport type
5. Enter the command to run the server:
   • Basic: node path/to/swagger-mcp-toolkit/build/index.js
   • With Swagger URL: node path/to/swagger-mcp-toolkit/build/index.js --swagger-url="https://your-api-url/swagger.json"
6. Click "Add"

The Swagger MCP tools will now be available to the Cursor Agent in Composer.

Tip: If you provide the --swagger-url CLI argument when configuring the server, you won't need to provide swaggerFilePath in tool calls, making the tools easier to use.

Custom MCP config examples

Local build usage:

{
  "mcpServers": {
    "get-swagger": {
      "command": "node",
      "args": [
        "C:/projects/swagger-mcp-toolkit/build/index.js",
        "--swagger-url=http://xxx.xx.xx.xx:xxxxxx"
      ],
      "env": {}
    }
  }
}

npm (npx) usage:

{
  "mcpServers": {
    "get-swagger": {
      "command": "npx",
      "args": [
        "-y",
        "swagger-mcp-toolkit@latest",
        "--swagger-url=http://xxx.xx.xx.xx:xxxxxx"
      ],
      "env": {}
    }
  }
}

Available Swagger MCP Tools

The following tools are available through the MCP server:

• getSwaggerDefinition: Downloads a Swagger definition from a URL
• listSwaggerResources: Fetches Knife4j swagger-resources for module selection
• saveSwaggerResources: Fetches Knife4j swagger-resources and saves them as a JSON file
• listEndpoints: Lists all endpoints from the Swagger definition (optional swaggerFilePath)
• listEndpointModels: Lists all models used by a specific endpoint (optional swaggerFilePath)
• generateModelCode: Generates TypeScript code for a model (optional swaggerFilePath)
• generateEndpointToolCode: Generates TypeScript code for an MCP tool definition (optional swaggerFilePath)

Swagger Definition Priority: The tools determine which Swagger definition to use based on this priority:

1. CLI --swagger-url argument (if provided when starting the server)
2. swaggerFilePath parameter (if provided in the tool call)
3. Error if neither is available

If you start the server with --swagger-url, you can omit the swaggerFilePath parameter in tool calls for convenience.

License

This project is licensed under the MIT License - see the LICENSE file for details.

MCP Prompts for AI Assistants

To help AI assistants use the Swagger MCP tools effectively, we've created a collection of prompts that guide them through common tasks. These prompts provide step-by-step instructions for processes like adding new endpoints, using generated models, and more.

Check out the PROMPTS.md file for the full collection of prompts.

Example use case: When asking an AI assistant to add a new endpoint to your project, you can reference the "Adding a New Endpoint" prompt to ensure the assistant follows the correct process in the right order.