You have been asked to build an agent workflow that can pause before a sensitive action, wait for a human decision, and then continue safely.

At first glance, the flow looks simple:

agent proposes an action
→ human reviews it
→ approve, edit, reject, or request revision
→ workflow continues

The backend challenge is making that flow durable.

A review may take hours or days. Services may restart. New code may be deployed while the workflow is waiting. The same approval may be submitted twice. The external action may succeed even if the worker times out.