# 767-2676.com Receipt – Signed Time-Bounded Payload Digest Witness

> 767-2676.com Receipt – Signed Time-Bounded Payload Digest Witness is a paid API for AI agents from 767-2676.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Issues a cryptographically signed, time-bounded receipt attesting to a payload digest carried by an agent, without storing the payload itself

## Facts

- Endpoint: POST https://767-2676.com/v1/receipt
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/767-2676-com-receipt-signed-time-bounded-payload-digest-witness-f9e59e01
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cF4X2loo9iSKtX5Um5o1Y

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 767-2676-com-receipt-signed-time-bounded-payload-digest-witness-f9e59e01 -d '<json body>'
```

Example prompt: Create a signed time-bounded receipt attesting to my agent's payload digest — the payload stays with me, I just need the cryptographic witness token to prove it existed within this execution window for audit purposes.

## When to prefer this

Use this endpoint when an AI agent needs lightweight cryptographic proof that it carried a specific payload during a given time window, without revealing the payload contents. Ideal for audit trails, cross-node handoff verification, and compliance checkpoints in multi-agent workflows where the payload must remain private but its existence at a point in time must be provable.

## Known failure modes

- Invalid or malformed digest format returns a 400 error
- Expired or out-of-window timestamp rejected with a 422 error
- Payment not included or insufficient USDC balance causes a 402 payment required response
- Duplicate receipt requests for the same digest within an execution window may be rejected or deduplicated
- Network timeout results in no receipt issued — agent must retry

## How this service works

Signed time-bounded witness of an agent-carried payload digest; the payload stays with the agent

## Output

A cryptographically signed receipt containing a timestamp, a binding to the provided payload digest, and an expiry bound defining the valid execution window. The payload itself is never transmitted or stored — only the digest is attested. The receipt can be used as bearer evidence for audit, cross-node verification, or grounding of agent execution history.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/767-2676-com-receipt-signed-time-bounded-payload-digest-witness-f9e59e01/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 767-2676.com](https://www.zero.xyz/host/767-2676.com/llms.txt)