Responds to ping requests

MCP clients send ping requests to verify a server is alive before timing out a connection or showing an error to the user. A server that returns -32601 Method not found on ping tells the client it is disconnected, triggering reconnection logic or user-visible errors even when the server is running fine. A server that returns a non-standard value (e.g., the string "pong" instead of an empty object {}) breaks clients that validate response shape. Ping is cheap to implement correctly and expensive to get wrong.

The MCP SDK handles ping automatically — do not override it. For custom implementations, add a case for ping that returns an empty result object.

// src/transport/handler.ts — ping handler
if (message.method === 'ping') {
  return {
    jsonrpc: '2.0',
    id: message.id,
    result: {}  // empty object, not null, not 'pong'
  }
}

Verify the ping handler is working by sending { "jsonrpc": "2.0", "method": "ping", "id": 1 } directly to your server and confirming the response is { "jsonrpc": "2.0", "id": 1, "result": {} }.