# ForgeMesh AI Notarization & Proof

> ForgeMesh AI Notarization & Proof is a paid API for AI agents from notary-solana.forgemesh.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-11).

Cryptographically notarizes an AI model's prompt-response pair and returns an ed25519-signed attestation receipt with a content hash, enabling third parties to verify authenticity.

## Facts

- Endpoint: POST https://notary-solana.forgemesh.io/api/notarize?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/forgemesh-ai-notarization-proof-b36391ca
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_og_YrxlFEsaa8RB9REHnC

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 forgemesh-ai-notarization-proof-b36391ca -d '<json body>'
```

Example prompt: Notarize this AI response for me — the model was openai/gpt-5, the prompt was 'Summarize the risks of climate change in three sentences', and the response was 'Climate change poses risks including rising sea levels, extreme weather events, and ecosystem collapse. These threaten food security and human health globally. Urgent action is needed to limit warming to 1.5°C.' Generate a cryptographic receipt I can use to prove it's authentic.

## When to prefer this

Choose this endpoint when you need a cryptographically verifiable, tamper-evident proof that a specific AI model produced a specific response to a specific prompt — especially for legal, compliance, audit, or publishing contexts where authenticity must be demonstrable to third parties. Prefer this over simple logging when you need non-repudiation (ed25519 signature) rather than just a database record, and when the $0.001 USDC cost per attestation is acceptable. Less suitable if you need batch notarization of thousands of responses at once or if you require on-chain finality before proceeding.

## Known failure modes

- Payment not included or insufficient — 402 Payment Required with x402 challenge
- Missing required fields (prompt or response) — 400 Bad Request
- Invalid model_id format — 400 validation error
- Malformed client_timestamp (non-ISO-8601) — 400 Bad Request
- Service unavailable or Solana anchor backend down — 503 with retry-after
- Receipt token lost — cannot re-retrieve private token after initial response

## How this service works

Paid AI output notarization via x402. Prove any AI response is authentic with cryptographic receipts.

## Output

Returns a JSON object containing: a base64-encoded ed25519 signature over the content hash, the SHA-256 content hash of the prompt+response+timestamp, the signer's ed25519 public key, a unique attestation ID (e.g. att_0123...), a receipt URL for public verification, a private receipt token for the caller, the notarized timestamp, the model ID, the blockchain anchor status (pending/confirmed), and a flag indicating whether payload was stored server-side.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "prompt": {
   "type": "string",
   "description": "Exact prompt/input sent to the model"
  },
  "metadata": {
   "type": "object",
   "description": "Optional caller metadata, <= 4 KB — accepted but NOT persisted or hashed (reserved for future opt-in retention)"
  },
  "model_id": {
   "type": "string",
   "description": "Model identifier, e.g. openai/gpt-5 or claude-fable-5"
  },
  "response": {
   "type": "string",
   "description": "Exact model output being notarized"
  },
  "client_timestamp": {
   "type": "string",
   "description": "ISO-8601 time the inference ran (optional; included in the content hash)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "anchor": {
   "status": "pending"
  },
  "model_id": "openai/gpt-5",
  "algorithm": "ed25519",
  "signature": "base64-ed25519-signature",
  "receipt_url": "https://notary.forgemesh.io/api/receipt/att_0123456789abcdef01234567",
  "content_hash": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
  "notarized_at": "2026-07-03T12:00:01.000Z",
  "receipt_token": "private-receipt-token",
  "signer_pubkey": "base64-ed25519-public-key",
  "attestation_id": "att_0123456789abcdef01234567",
  "payload_stored": false,
  "client_timestamp": "2026-07-03T12:00:00Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/forgemesh-ai-notarization-proof-b36391ca/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from notary-solana.forgemesh.io](https://www.zero.xyz/host/notary-solana.forgemesh.io/llms.txt)