MCP servers

Step 1: Start the MCP test server

Run the open source server-everything MCP test server with the streamable HTTP transport.

PORT=3005 npx -y @modelcontextprotocol/server-everything streamableHttp

Step 2: Start agentgateway

You add the MCP server from the UI in the next steps, so you can start agentgateway without a config file. When you run agentgateway without specifying a config, it bootstraps a basic config at ~/.config/agentgateway/config.yaml and uses it automatically.

agentgateway

Example output:

info  app  serving UI at http://localhost:4000/ui

Step 3: Enable MCP

The first time that you run the UI, the Welcome to Agentgateway wizard walks you through enabling LLM configuration. If you already did this, you can skip to the next step.

1. Open the agentgateway UI.

2. From the welcome wizard, click Enable MCP and then click Continue.

   

   

The Gateway Overview home page opens, with the MCP row enabled.

Step 4: Add the MCP server

1. In the MCP section of the navigation menu, click Servers, and then click Add server.
2. For the Server name, enter server-everything.
3. Keep the Streamable HTTP transport. For the URL, enter http://localhost:3005/mcp.
4. Click Save server.

Step 5: Try a tool in the playground

1. In the MCP section, click Tool Playground.

2. If you see a Browser access is not allowed notice, click Apply CORS so the playground can call the MCP listener from the UI.

3. Click Initialize to open an MCP session. The playground lists the tools that the server exposes, such as echo and various get commands.

   

   

4. From the Tool dropdown list, select the echo tool.

5. In the Message field, enter a string, such as This is my first agentgateway setup, and click Call tool.

6. Verify that the Result card shows an HTTP 200 response with your message echoed back.