An audit trail is a complete, chronological, and immutable record of what happened in an AI-driven process: what data was read, what decisions were made, what actions were taken, and when each happened. Once logged, it cannot be altered.
A banking AI agent that processes a wire transfer should record the request received, the identity verification check, the fraud screening result, the approval trigger, and the final transaction submission — with timestamps and agent version at each step. When a regulator asks, this record is the evidence that the system operated as intended. Without it, organizations cannot defend or explain what their AI did.
