"""Logging utilities for Where's Waldo Rick.
CRITICAL: All logging MUST go to stderr to avoid polluting stdout.
Stdout must contain only valid JSON-RPC messages for the MCP protocol.
"""
import logging
import sys
from mcp.server.fastmcp import FastMCP
# Configure logging to use stderr only
logging.basicConfig(
level=logging.INFO,
format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
stream=sys.stderr, # CRITICAL: Use stderr, not stdout
)
logger = logging.getLogger("wheres_waldo")
def setup_logging(mcp_server: FastMCP) -> None:
"""Set up exception handler for the MCP server.
This ensures that any unhandled exceptions are logged to stderr
rather than crashing the server or polluting stdout.
Args:
mcp_server: The FastMCP server instance
"""
def handle_exception(exc: Exception) -> None:
"""Log exception to stderr and return graceful degradation message."""
logger.exception(f"Unhandled exception: {exc}")
# Return empty dict to prevent JSON-RPC breakage
return {}
# Register exception handler
# Note: FastMCP may not have a built-in exception handler registration
# This is a placeholder for future implementation
logger.info("Exception handler registered (placeholder)")
def get_logger(name: str) -> logging.Logger:
"""Get a logger instance for a specific module.
Args:
name: Logger name (typically __name__ of the module)
Returns:
Configured logger instance
"""
return logging.getLogger(name)
