mcp-protocol-version-a-remote-mcp-server-built-with-the-typescript-sdk--0fee9f42

THEN Add protocol version negotiation and support for the older SSE-based transport (e.g., responding to GET /sse) in addition to the new streamable HTTP transport. Modify the server to detect and fall back to the previous MCP protocol version (pre‑2025-03-26) when the client does not support the latest version. This can be done by implementing a simple version check during initialization and routing requests accordingly.

// Paraphrased from MIT-licensed TypeScript SDK example.
// Add a handler for the legacy SSE endpoint:
app.get('/sse', async (req, res) => {
  // Set up SSE stream and respond using the older protocol format
  res.writeHead(200, { 'Content-Type': 'text/event-stream' });
  // Listen for client messages and forward via the transport
});