How do I troubleshoot a LangGraph agent that hangs on Catalyst?

First, check Catalyst's execution logs for state transitions and tool call timeouts. Use the replay feature to step through the agent's workflow from the last persisted state. Verify that your LangGraph graph does not have infinite loops or unhandled errors. Ensure external tools are reachable and idempotent. The platform provides a timeline of all durable steps to isolate the hang point.