Audit trail (evidence-first)
An audit trail is a record of what happened, when it happened, and which policy governed the decision. In an AI gateway, the audit trail is designed to be reviewable without storing unnecessary raw content.
Evidence-first vs full-content logging
Many teams assume they must store full prompts and outputs. In practice, that can increase risk and make reviews harder. Evidence-first logging focuses on decision metadata, which is usually enough for audit discussions and incident timelines.
The goal is to preserve the story of the decision while keeping the data surface small. If a pilot requires deeper retention, it should be defined explicitly in scope and data handling agreements.
Core fields to log
- Request ID - unique identifier for the action.
- Decision - allow, deny, or approval_required.
- Policy reference - the version or hash of the policy evaluated.
- Timestamp - when the decision was made.
- Reviewer metadata - if approval was required (optional).
These fields support traceability and can be mapped to a policy version during reviews. They are also easy to share with procurement or compliance stakeholders because they avoid sensitive content.
Minimum viable evidence bundle
A compact evidence bundle is often enough for a pilot review. It can include the request id, decision, policy reference, timestamps, and any approval metadata. This keeps the audit surface small while still allowing stakeholders to reconstruct the decision path.
If the pilot requires additional fields, add them explicitly and document why they are needed. Avoid adding raw prompt or output content unless the pilot scope requires it.
Where audit trails fit in a pilot
A pilot should prove that audit metadata is generated for every gated decision. This shows that policy checks happened before execution and that approvals are recorded. It also gives the team an evidence packet for review.
Retention and access rules should be defined in the pilot scope. If the pilot requires longer retention, document the duration and storage location before go-live.
Retention and access
Retention rules should be defined with the pilot scope. Some pilots require short retention windows for operational review, while others need longer retention for governance reporting. Access should be limited to approved operators and documented in the pilot plan.
Operational tips
- Keep the audit trail consistent across tools and use cases.
- Store only what you need to explain the decision.
- Use policy references so reviewers can trace outcomes to rules.
- Define retention as part of the pilot scope, not as an afterthought.
How to run an audit review
Start with a small sample of decisions, verify that each record has a policy reference, and confirm that approvals were recorded when required. This is usually enough to validate that the control layer is working.
If inconsistencies appear, refine the policy rules or the approval workflow before expanding the pilot scope.
FAQ
Do you store prompts by default?
By default, the gateway is designed to store decision metadata rather than raw prompts. Any content retention is defined in pilot scope.
Is evidence metadata enough for audits?
For many reviews, yes. It ties decisions to policy versions and timestamps. If deeper context is required, define it explicitly and document how it will be handled.
What about redaction?
Redaction practices depend on the pilot scope. Some pilots use summaries instead of full content to reduce exposure while keeping decisions reviewable.
What if we need deeper retention?
Deeper retention can be configured if required, but it should be defined explicitly in pilot scope along with access controls and retention duration.