Calibre MCP Server

""" Manual connectivity test for the Calibre MCP Server WebSocket transport. 1. Check raw TCP connectivity to the given host:port. 2. Optionally perform a WebSocket handshake using the 'websockets' package. Use this script while the Calibre MCP server is running (e.g. via the Calibre GUI plugin or `python -m calibre_mcp_server.main`). """ import asyncio import socket from urllib.parse import urlparse try: import websockets # type: ignore except ImportError: websockets = None # type: ignore[assignment] WEBSOCKET_URL = "ws://127.0.0.1:8765" CONNECT_TIMEOUT_SECONDS = 3.0 def test_tcp_connectivity(url: str) -> bool: """Check whether a TCP connection to the WebSocket host:port is possible.""" parsed = urlparse(url) host = parsed.hostname or "127.0.0.1" if parsed.port is not None: port = parsed.port elif parsed.scheme == "wss": port = 443 else: port = 80 print("=== TCP connectivity check ===") print("Target host:", host) print("Target port:", port) sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(CONNECT_TIMEOUT_SECONDS) try: sock.connect((host, port)) except OSError as exc: print() print("TCP connect failed:", repr(exc)) print() print("Most likely causes:") print(" - MCP server process is not running") print(" - MCP server is listening on a different host or port") print(" - Local firewall or security tool blocks the connection") return False else: print("TCP connect successful – port is open.") return True finally: try: sock.close() except OSError: # Ignore errors while closing the socket pass async def test_websocket_handshake(url: str) -> None: """Try to perform a WebSocket handshake and exchange a small message.""" if websockets is None: print() print("WebSocket handshake test skipped:") print(" 'websockets' package is not available in this environment.") print(" Install it with: python -m pip install websockets") return print() print("=== WebSocket handshake test ===") print("Target URL:", url) try: async with websockets.connect(url) as ws: # type: ignore[attr-defined] print("WebSocket handshake successful.") print("Send test message 'ping'...") await ws.send("ping") reply = await ws.recv() print("Received frame from server:", repr(reply)) except Exception as exc: print("WebSocket handshake failed:", repr(exc)) print() print("Possible reasons:") print(" - MCP server is not a WebSocket server on this port") print(" - TLS/URL mismatch (ws:// vs wss://)") print(" - Reverse proxy or middleware closes the connection") def main() -> None: """Run both TCP and optional WebSocket connectivity checks.""" print("Manual WebSocket connectivity test for Calibre MCP Server") print("Target URL:", WEBSOCKET_URL) print("=" * 60) tcp_ok = test_tcp_connectivity(WEBSOCKET_URL) if not tcp_ok: # If TCP fails, a WebSocket handshake cannot succeed return print("=" * 60) asyncio.run(test_websocket_handshake(WEBSOCKET_URL)) if __name__ == "__main__": main()