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Human-in-the-loop · May 15, 2026

Designing human review checkpoints for AI agents

A practical model for Placet-style review checkpoints: intent, evidence, side effects, credential scope, audit trail, and resumable follow-up.

HITLPlacetApprovals

Designing human review checkpoints for AI agents

Useful autonomy starts with a clear handoff between agent work and human ownership. Facio treats that handoff as runtime behavior: the agent can keep context, use tools, route through Placet, and continue after interruptions, but authority boundaries remain visible to the operator.

Teams often begin with a single approval prompt. That is fine for a prototype. In production, the stronger pattern is a chain of reviewable checkpoints connected to durable state, audit records, scoped credentials, and internal guidance like agent audit trails or agent rollout planning.

What belongs in a checkpoint

A review prompt should answer four questions before asking for a decision:

  • What is the agent trying to accomplish?
  • Which data, file, page, or tool result did it use?
  • What system will change after approval?
  • How can a human pause, reject, or resume the work later?

When those answers are visible, review becomes an operating primitive instead of a compliance afterthought. The same structure also helps operators debug later: a checkpoint should point back to the request, the evidence, the tool path, the approval decision, and the resumed outcome.

Approval data model

The exact schema can stay compact. A checkpoint record needs stable identifiers, a human-readable summary, and enough structured detail to rebuild the decision trail.

type ReviewCheckpoint = {
  id: string;
  runId: string;
  action: 'send_message' | 'export_file' | 'change_system';
  summary: string;
  evidence: Array<{ label: string; value: string }>;
  requiresCredential?: string;
  approvedBy?: string;
  approvedAt?: string;
};

Operating shape

LayerWhat the human seesWhy it matters
IntentAgent goal and requested actionPrevents blind approvals
EvidenceSource links, browser state, retrieved contextMakes review explainable
Side effectThe system or customer-facing changeKeeps risk concrete
CredentialPlaceholder or scope, never raw secret textKeeps approval separate from secret exposure
Audit trailDecision, actor, time, and resultSupports later debugging

Relative review quality

Relative review quality
No review18
Single prompt42
Structured checkpoint74
Checkpoint + audit91

The practical test is simple: after reading a checkpoint, a team should know what changes, who approved it, and which adjacent record helps them investigate later.