swagger-mcp

Overview

`swagger-mcp` is a tool that reads a Swagger 2.0 or OpenAPI 3.0 specification and dynamically generates MCP tools at runtime — one tool per API endpoint. These tools can be used by any MCP client for LLM-driven API interaction.

Supported spec formats:

• Swagger 2.0 (`swagger: "2.0"`) — path/query/header parameters and `in: body` request bodies
• OpenAPI 3.0 (`openapi: "3.0.x"`) — path/query/header parameters and `requestBody` with inline or `$ref` schemas

Required and optional fields are read from the schema's `required` array and honoured in the generated tool definitions.

📽️ Demo Video

Check out demo video showcasing the project in action:

🙌 Support

If you find this project valuable, please support me on LinkedIn by:

• 👍 Liking and sharing our demo post
• 💬 Leaving your thoughts and feedback in the comments
• 🔗 Connecting with me for future updates

Your support on LinkedIn will help me reach more people and improve the project!

Prerequisites

To use `swagger-mcp`, ensure you have the following dependencies:

1. LLM Model API Key / Local LLM: Requires access to OpenAI, Claude, or Ollama models.

2. Any MCP Client: (Used mark3labs - mcphost)

Installation and Setup

go install github.com/danishjsheikh/swagger-mcp@latest

Run Configuration

Stdio mode (default)

swagger-mcp --specUrl=https://your_swagger_api_docs.json

SSE mode

swagger-mcp --specUrl=https://your_swagger_api_docs.json --sse --sseAddr=:8080

StreamableHTTP mode

swagger-mcp --specUrl=https://your_swagger_api_docs.json --http --httpAddr=:8080

All flags

Xquik OpenAPI Example

Xquik publishes a remote OpenAPI document for its X/Twitter automation API.

Because it uses an API key header, pass the key with `--security=apiKey` and

`--apiKeyAuth`:

export XQUIK_API_KEY="your-xquik-api-key"

swagger-mcp \
  --specUrl=https://xquik.com/openapi.json \
  --baseUrl=https://xquik.com \
  --security=apiKey \
  --apiKeyAuth=header:x-api-key=$XQUIK_API_KEY

The same arguments can be used in an MCP client config:

{
  "mcpServers": {
    "xquik": {
      "command": "swagger-mcp",
      "args": [
        "--specUrl=https://xquik.com/openapi.json",
        "--baseUrl=https://xquik.com",
        "--security=apiKey",
        "--apiKeyAuth=header:x-api-key="
      ]
    }
  }
}

MCP Configuration

To integrate with `mcphost`, include the following configuration in `.mcp.json`:

{
    "mcpServers": {
        "swagger_loader": {
            "command": "swagger-mcp",
            "args": ["--specUrl="]
        }
    }
}

With bearer auth and path filtering:

{
    "mcpServers": {
        "swagger_loader": {
            "command": "swagger-mcp",
            "args": [
                "--specUrl=https://api.example.com/openapi.json",
                "--security=bearer",
                "--bearerAuth=your-token-here",
                "--includeMethods=GET,POST"
            ]
        }
    }
}

Request Body Support

Both Swagger 2.0 and OpenAPI 3.0 request bodies are supported:

• Swagger 2.0: `parameters` with `in: body` and a `$ref` or inline schema under `definitions`
• OpenAPI 3.0: `requestBody.content..schema` — resolved from `components/schemas` if a `$ref`, or used inline if an object schema

Fields listed in the schema's `required` array are marked as required in the MCP tool. All other fields are optional and are omitted from the request if not provided.

Demo Flow

1. Some Backend:

go install github.com/danishjsheikh/go-backend-demo@latest 
    go-backend-demo

2. Ollama

ollama run llama3.2

3. MCP Client

go install github.com/mark3labs/mcphost@latest
    mcphost -m ollama:llama3.2 --config

Flow Diagram

🛠️ Need Help

I am working on improving tool definitions to enhance:

✅ Better error handling for more accurate responses

✅ LLM behavior control to ensure it relies only on API responses and does not use its own memory

✅ Preventing hallucinations and random data generation by enforcing strict data retrieval from APIs

If you have insights or suggestions on improving these aspects, please contribute by:

• Sharing your experience with similar implementations
• Suggesting modifications to tool definitions
• Providing feedback on current limitations

Your input will be invaluable in making this tool more reliable and effective! 🚀