Index onlineMerchant portal
Api Endpoint

api.fairseal.io

Notarize an AI agent decision, audit record, or any payload to Base mainnet. Submit SHA-256 hash + metadata; get a tamper-proof verifiable receipt immediately. Merkle proof and on-chain anchor_tx available free after batch (~120s). Use Idempotency-Key to prevent double-charges on retry.

Open interactive test console

Offering

Provider
api.fairseal.io
Method
POST
Offering type
Api Endpoint
Transport type
http
Category
Blockchain And Crypto
Delivery
Not provided
Pricing model
Not provided
x402 version
2

Endpoint context

URL
https://api.fairseal.io/v1/notarize
MIME type
Not provided
First seen
2026-10-16T01:54:06.400Z
Last seen
Tags
None supplied

Website

Payment pricing

x402 payment terms are the authoritative price for calling this endpoint.

Payment option 1
0.05 USDC
Atomic price: 50000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Payment option 2
0.05 USDC
Atomic price: 50000 · Network: eip155:8453 · Asset: USDC · Scheme: batch-settlement
Raw x402 terms
[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "payTo": "0xBd5eB5559f5Ac14475AC0C81b6735A4d9106ce28"
  },
  {
    "scheme": "batch-settlement",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "payTo": "0xBd5eB5559f5Ac14475AC0C81b6735A4d9106ce28"
  }
]

Observed health

Status
Healthy
Latest latency
325 ms
Average latency
686 ms
HTTP status
204
Last checked
Reachability
100% over 14 checks

Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.

Input schema

{
  "additionalProperties": false,
  "properties": {
    "body": {
      "properties": {
        "metadata": {
          "description": "Schema-specific metadata. agent_decision requires {agent_id, decided_at, input_hash, decision_hash}",
          "type": "object"
        },
        "payload_hash": {
          "description": "SHA-256 hex of full payload (64 lowercase hex chars)",
          "pattern": "^[0-9a-f]{64}$",
          "type": "string"
        },
        "schema": {
          "enum": [
            "agent_decision",
            "audit_evidence",
            "probe_record"
          ],
          "type": "string"
        }
      },
      "required": [
        "schema",
        "payload_hash",
        "metadata"
      ],
      "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 schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "properties": {
            "metadata": {
              "description": "Schema-specific metadata. agent_decision requires {agent_id, decided_at, input_hash, decision_hash}",
              "type": "object"
            },
            "payload_hash": {
              "description": "SHA-256 hex of full payload (64 lowercase hex chars)",
              "pattern": "^[0-9a-f]{64}$",
              "type": "string"
            },
            "schema": {
              "enum": [
                "agent_decision",
                "audit_evidence",
                "probe_record"
              ],
              "type": "string"
            }
          },
          "required": [
            "schema",
            "payload_hash",
            "metadata"
          ],
          "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"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}