MCP Kit Local Relay

What is MCP Kit Local Relay?

MCP Kit Local Relay is a command-line tool that bridges local MCP clients using standard input/output (stdio)—such as Claude Desktop—with remote MCP Servers configured through the MCP Kit Web App. It proxies requests to one target server at a time, making its tools and resources available locally.

How to use MCP Kit Local Relay?

Clone the repository, run npm install, create a .env file with your MCP Kit API key and an mcpconfig.json with the target server ID, then build with npm run build. Configure Claude Desktop to run node pointing to the absolute path of dist/index.js, restart Claude, and verify the hammer icon shows the server’s tools. You can also run manually with npm start or use npm run dev for development with hot reloading.

Key features of MCP Kit Local Relay

• Bridges stdio clients to one remote MCP server
• Uses MCP Kit Web App for server configuration
• Works with Claude Desktop out of the box
• Generates a debug log for troubleshooting
• Supports Node.js v18 or later
• Development mode with automatic restarts

Use cases of MCP Kit Local Relay

• Connect Claude Desktop to a remote MCP server hosted on MCP Kit
• Test a custom MCP server locally before deploying
• Integrate any stdio-based MCP client with a remote server

FAQ from MCP Kit Local Relay

What does MCP Kit Local Relay do that direct server connection does not?

It enables local stdio-only MCP clients (like Claude Desktop) to reach MCP servers hosted remotely via the MCP Kit platform, without requiring the client to support network transports.

What runtime and dependencies are required?

Node.js v18 or later, Git, and npm. The relay is installed from the GitHub repository and built with standard JavaScript tooling.

Where is configuration stored and how is authentication handled?

Configuration lives in two files inside the local-relay folder: .env holds the MCP Kit API key, and mcpconfig.json specifies the target server ID. The API key is generated from the MCP Kit Web App.

How can I debug connection errors?

Check the local-relay-debug.log file in the relay directory for detailed error messages. Also verify that .env and mcpconfig.json are present with valid values, and that npm run build completed without errors.

Can the relay connect to multiple MCP servers at once?

No. It proxies requests to a single target server at a time. To connect to multiple servers, you would need to run separate relay instances for each.