Echo MCP Server

A minimal MCP (Model Context Protocol) server implementation for Smithery.

Features

• Echo Tool: Returns the message provided
• Ping Tool: Returns "pong" when called
• Version Tool: Returns the server version "0.0.1"
• Implements the MCP Streamable HTTP Transport
• No external APIs, auth, or database dependencies

Installation

npm install

Running the Server

Start the server on port 8000:

npm start

The server will be available at http://localhost:8000/mcp.

Testing

Using MCP Inspector

1. Install MCP Inspector:

   npm install -g @modelcontextprotocol/inspector
   

2. Start the MCP Inspector:

   npx @modelcontextprotocol/inspector streamable-http http://localhost:8000/mcp
   

3. Open the Inspector UI at http://127.0.0.1:6274

   • Set Transport Type to "Streamable HTTP"
   • Set URL to "http://localhost:8000/mcp"
   • Click Connect

Using cURL

Initialize a session:

curl -v -X POST -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" \
     -d '{"jsonrpc":"2.0","method":"initialize","params":{"protocolVersion":"2025-03-26","capabilities":{},"clientInfo":{"name":"curl-client","version":"1.0.0"}},"id":1}' \
     http://localhost:8000/mcp

Send "initialized" notification (using the session ID from the response headers):

curl -X POST -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" \
     -H "mcp-session-id: YOUR_SESSION_ID" \
     -d '{"jsonrpc":"2.0","method":"initialized","params":{}}' \
     http://localhost:8000/mcp

List available tools:

curl -X POST -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" \
     -H "mcp-session-id: YOUR_SESSION_ID" \
     -d '{"jsonrpc":"2.0","method":"tools/list","params":{},"id":2}' \
     http://localhost:8000/mcp

Call the echo tool:

curl -X POST -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" \
     -H "mcp-session-id: YOUR_SESSION_ID" \
     -d '{"jsonrpc":"2.0","method":"tools/call","params":{"name":"echo","input":{"message":"hello"}},"id":3}' \
     http://localhost:8000/mcp

License

ISC