# AOTrust Notarization API

> AOTrust Notarization API is a paid API for AI agents from api.aotrust.link, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Notarizes an agent payload by cryptographically signing it and returning a signed Payload Data Receipt (PDR)

## Facts

- Endpoint: POST https://api.aotrust.link/notarize
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/aotrust-notarization-api-73bcc119
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_31qLnpBeyTR7xHDUINqau

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 aotrust-notarization-api-73bcc119 -d '<json body>'
```

Example prompt: Notarize this agent payload for me and get back a signed PDR so I have a cryptographically verified receipt proving the content hasn't been tampered with.

## When to prefer this

Use this endpoint when you need a cryptographically signed, verifiable receipt for an agent payload — especially in multi-agent pipelines, compliance-sensitive workflows, or audit contexts where tamper-evidence and provenance matter. Prefer it over generic logging or storage when you specifically need a signed attestation (PDR) rather than just a record.

## Known failure modes

- Invalid or malformed payload body — 400 error returned
- Payment not attached or insufficient USDC — 402 payment required
- Signature generation failure due to internal key issues — 500 server error
- Network timeout if payload is too large
- Duplicate payload submission may return the same PDR or an error depending on deduplication logic

## How this service works

Notarize agent payload. Returns signed PDR.

## Output

A signed Payload Data Receipt (PDR) — a cryptographic attestation tied to the submitted agent payload, proving its contents at the time of submission and providing a verifiable, tamper-evident record.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aotrust-notarization-api-73bcc119/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.aotrust.link](https://www.zero.xyz/host/api.aotrust.link/llms.txt)