> ## Documentation Index
> Fetch the complete documentation index at: https://docs.useharmonia.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Receipts and verification reference

> Immutable execution evidence, independent read-back, and replay lineage.

A `Receipt` records action identity, idempotency key, type, time, outcome, optional artifact evidence, provider detail, operation ID, and trace ID. It states what the executor reports happened.

A `VerificationResult` references the exact action and receipt, then records an independent `official_api_readback` or `artifact_digest_reread`, evidence, time, and result. It states what a separate observation found.

```text theme={"system"}
approved payload → effect command → claim → receipt → independent verification
                                           ↘ replay: already_applied
```

Verification must match receipt identity and artifact lineage. A receipt alone is not verification; a successful API response without a persisted receipt is not durable proof; a screenshot without identifiers is not replayable evidence.

The vertical-slice validator in `src/lib/verticalSliceEvidence.ts` checks approval, command, claim, receipt, verification, trace, digest, and replay consistency. See [Evidence runbook](/evidence-runbook).