Api Endpoint

x402.fairseal.io

Anchor an AI agent decision or audit record to Base mainnet. Submit {schema, payload_hash (SHA-256 hex, 64 chars), metadata}; service queues into a Merkle batch and returns a receipt with pending_anchor status immediately. Full Merkle proof and on-chain anchor_tx available via free GET /v1/notarize/:receipt_id after batch anchors (within batch_threshold receipts or 120s). Include Idempotency-Key header to prevent double-charges on retry.

Open interactive test console

Offering

Provider: x402.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://x402.fairseal.io/v1/notarize
MIME type: Not provided
First seen: 2026-10-16T01:58:03.323Z
Last seen: 2026-11-01T15:23:28.507Z
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: 348 ms
Average latency: 845 ms
HTTP status: 204
Last checked: 2026-11-02T17:00:57.777Z
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"
}