Auditability

In regulated industries (Finance, Health), you must explain why the AI acted.

The Log

Because LangGraph is a state machine, the valid audit log is simply the sequence of state transitions. [Step 1 Input] -> [Step 1 Output] -> [Step 2 Input]...

This provides a mathematically proven record of the decision chain. You can archive these logs to cold storage for 7 years to satisfy regulators.