MCP Link

What automation-ai-labs/mcp-link MCP server does

The automation-ai-labs/mcp-link MCP server turns an OpenAPI V3 document into an MCP-compatible interface. It maps the operations described by the specification to tools that AI agents can invoke, allowing an existing REST API to participate in MCP-based workflows without changes to the API implementation.

The repository lists examples including Brave Search, DuckDuckGo, Figma, GitHub, Home Assistant, Notion, Slack, Stripe, TMDB, and YouTube.

How it works

MCP Link runs as a Go application that serves an MCP endpoint. A request identifies the OpenAPI specification with s= and the target API base URL with u=. The service reads the API definition, constructs the corresponding MCP tool interface, and sends calls to the configured API.

Authentication can be supplied through h= using the format header-name:value-prefix. This supports configurations such as API keys, API tokens, and bearer tokens when they can be represented by an HTTP header.

Endpoint selection is controlled with f= path filters. A filter can include or exclude a path, select an HTTP method, or combine multiple rules with semicolons. Single-segment and multi-segment wildcards are supported, so a deployment can expose only the required portion of an API.

Setup and configuration

Clone the repository, enter the project directory, and download its Go dependencies with go mod download. Start the service with go run main.go serve, optionally providing --port and --host, for example port 8080 and host 0.0.0.0.

Configure an MCP client with a URL shaped like:

http://localhost:8080/sse?s=[OpenAPI-Spec-URL]&u=[API-Base-URL]&h=[Auth-Header]:[Value-Prefix]

Replace the bracketed values with URL-encoded configuration for the specification, API endpoint, and authentication header. Add f= when endpoint filtering is needed. A hosted version is also available at mcp-link.vercel.app for converting and testing APIs without a local installation.

Tools and capabilities

The automation-ai-labs/mcp-link MCP server provides capabilities derived from the selected OpenAPI schema rather than a fixed catalog of tools. Its supported functions include:

• Converting OpenAPI V3 operations into MCP tools
• Forwarding agent calls to a configured REST API
• Passing authentication headers to the target API
• Including or excluding endpoints with path and method filters
• Serving the resulting interface over an MCP connection

Limitations and notes

The generated tool surface depends on the completeness and compatibility of the OpenAPI specification. The project describes OAuth support for the MCP protocol, resource handling, and broader MIME-type support as future development items, so these should not be assumed to be available.

The configuration examples use SSE and require the API specification URL, target base URL, and any needed authentication details. Review the selected endpoints and credentials before exposing the service to an agent. The project is listed in the Developer Tools category and is most relevant when an existing API already has an OpenAPI V3 schema.