Why AI Agent Logs Are Not Reliable Evidence Without Cryptographic Verification

Agent audit logs only record what a process claims happened and cannot on their own prove that events are complete, correctly ordered, or unaltered. A timestamped JSON file is vulnerable if workers can overwrite it, multiple processes share sequence numbers, or a restart silently drops events. Engineers are advised to attach a verification contract to each log event, incorporating monotonic sequence numbers, hash links to prior events, and cryptographic signatures generated outside the agent process. A separate verifier service should independently check sequence integrity, event transitions, and signatures rather than letting the agent validate its own history. Signed checkpoints at regular intervals offer efficient integrity boundaries without requiring full re-verification of every event on each query.