mcp-sse-client-url-parsi-domexception-syntaxerror-an-invalid-or-illegal-str-c0d6a5df

THEN Wrap the SSE URL string in a new URL() object before passing it to SSEClientTransport. Example: const transport = new SSEClientTransport(new URL(sseUrl)); This ensures the EventSource constructor receives a valid URL object rather than a bare string.

const baseUrl = new URL(sseUrl);
const transport = new SSEClientTransport(baseUrl);