the tail
Every loop leaves a tail.
An AI audit trail is an append-only, cryptographically signed record of every decision an AI system makes and every change made to it — what was observed, how it was judged, what changed, who approved it, and what happened next. Looptail writes one automatically for every loop.
- 14:03:12 observe support-agent · ticket #4211 answered · outcome pending sig 9f3a…c2 ✓
- 14:03:14 evaluate rubric refund-policy-v3 scored 0.94 · pass sig 41bc…88 ✓
- 14:07:02 issue cluster #18 "partial refunds mis-quoted" +1 case sig 77e0…4d ✓
- 14:21:40 improve patch #91 proposed · prompt diff +12 −4 · replay 132/132 pass sig b8d1…09 ✓
- 14:29:05 approve patch #91 approved → canary 5% sig e42f…7a ✓
What a loop record holds
- Observation — inputs, retrieved context, tool calls, output, outcome signals.
- Judgment — which evaluator scored it, against which rubric version, and the result.
- Change — the patch that followed: prompt, policy, or routing diff, plus replay results.
- Approval — who or what promoted it, and through which gate.
- Outcome — what the canary and post-deploy evals showed.
Append-only and signed
Records are hash-chained and signed at write time. Nothing is edited in place; corrections append. You can verify the chain yourself from the CLI — you don't have to take our word for it.
npx @looptail/cli verify --app support-agent --since 30d
✔ 41,872 loop events
✔ chain intact · signatures validEvidence you can hand to someone
Export a dated, self-verifying evidence pack for an audit, an incident postmortem, or a customer's security review: the full chain, a manifest, and instructions the recipient can run without trusting you. This is the record the EU AI Act's record-keeping obligations expect you to have.
npx @looptail/cli export --app support-agent
✔ exported 41,872 loop events
✔ chain intact · signatures valid
→ looptail-evidence-support-agent-2026-07-11.zipYours, in an open format
Export works on every tier, including free. The trail format is an open, Apache-licensed spec — the archive is yours, and it should outlive any vendor, including us.