Notarize AI output
Notarize AI output: a signed Ed25519 attestation of the model response plus sha256 content hash, receipt token, and Merkle anchor status for one AI inference — a cryptographic receipt for inference that lets you prove an AI said X and verify model output authenticity, checkable free by anyone, anytime.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
834 msmedian answer time
$0.001listed price per call
$0.001price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://notary.forgemesh.io/api/notarize
| Category | Market data |
|---|---|
| Provider host | notary.forgemesh.io |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 8 from 5 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.001 | 834 ms |
Example input (from the provider)
{
"body": {
"client_timestamp": "2026-07-03T12:00:00Z",
"model_id": "openai/gpt-5",
"prompt": "What is 2+2?",
"response": "4"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"client_timestamp": {
"description": "ISO-8601 time the inference ran (optional; included in the content hash)",
"type": "string"
},
"metadata": {
"description": "Optional caller metadata, <= 4 KB \u2014 accepted but NOT persisted or hashed (reserved for future opt-in retention)",
"type": "object"
},
"model_id": {
"description": "Model identifier, e.g. openai/gpt-5 or claude-fable-5",
"type": "string"
},
"prompt": {
"description": "Exact prompt/input sent to the model",
"type": "string"
},
"response": {
"description": "Exact model output being notarized",
"type": "string"
}
},
"required": [
"prompt",
"response",
"model_id"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"algorithm": {
"type": "string"
},
"anchor": {
"properties": {
"status": {
"type": "string"
}
},
"type": "object"
},
"attestation_id": {
"type": "string"
},
"client_timestamp": {
"type": [
"string",
"null"
]
},
"content_hash": {
"description": "sha256 hex over canonical {prompt, response, model_id, client_timestamp}",
"type": "string"
},
"model_id": {
"type": "string"
},
"notarized_at": {
"type": "string"
},
"payload_stored": {
"description": "false by default: prompt/response/metadata are not persisted",
"type": "boolean"
},
"receipt_token": {
"description": "Private receipt token; payload is not stored by default",
"type": "string"
},
"receipt_url": {
"type": "string"
},
"signature": {
"description": "base64 Ed25519 signature by the notary key",
"type": "string"
},
"signer_pubkey": {
"description": "base64 raw Ed25519 public key",
"type": "string"
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}