# Verify a retained decision record

Compare retained evidence with independent policy and wallet records; distinguish receipts from anchors.

Canonical: https://402signal.com/developers/evidence

## Check what the buyer actually submitted

Use this when an agent's summary, a bill and your own expectations disagree. A private observation record helps establish what 402Signal checked, not every action the agent took.

Keep the verification record: retain the original route request and complete paid response, including `pq_trust.transparency.receipt` and `pq_trust.transparency.reveal`. Store it securely and do not put it in public logs. Public commitments are not a backup. Private replay outcomes support bounded recovery, not a long-term evidence backup.

```
import { verifyReceipt } from '@402signal/route-guard';
const result = verifyReceipt({
  routeResponseJson,
  routeRequestJson,
  trustedLogVkey
});
```

For a supported v4 record, this verifies historical signature/inclusion without calling a signer. Use independently trusted key configuration and retain raw input. Historical integrity verification does not extend expiry or authorize a new purchase. The [offline checks](/developers/test-buyer) include an altered saved-policy refusal.

### Compare three records

Compare the operator-approved policy, the request and offer in the verified observation, and the wallet/execution record. A receipt for a submitted $0.20 limit does not prove that the operator approved $0.20. The log cannot reveal bypassed purchases or reconstruct deleted private evidence.

### What later anchoring adds

Immediate checkpoints use Ed25519. Later cumulative checkpoints use Falcon-1024 authorization on Algorand MainNet. The route call does not wait for chain confirmation. A pending anchor is not confirmed evidence.

The historical receipt function does not verify that later anchor. Retain evidence, trusted key history and verification tools for long-term review. Post-quantum checkpoint authorization is an added integrity control, not a blanket claim that all receipt formats and payments are quantum secure. It does not authorize or secure the seller payment.

[Trust overview](/how#trust) · [Public checkpoint status](/transparency) · [Evidence guide as Markdown](https://github.com/402signalhq/402signal/blob/main/docs/customer/evidence.md).

Give this task to your coding agent

```
Inspect a retained 402Signal record using https://402signal.com/developers/evidence. Preserve raw input and independent key trust. Compare the verified submitted rules with separately retained operator policy and wallet records. Do not infer human approval, delivery, payment settlement or unobserved agent actions. Receipt verification and later Falcon anchor verification are distinct. Do not upload private evidence to public tools.
```

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