mirrored listing x402 eip155:8453

Anchor an AI agent decision or audit record to Base mainnet

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.

20000 (raw units)

price

calls / 30d

unique payers

2026-09-16

updated

Provider

x402.fairseal.io · discovered, not yet claimed by its owner

Payment (x402 accepts[])

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xBd5eB5559f5Ac14475AC0C81b6735A4d9106ce28",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "batch-settlement",
    "network": "eip155:8453",
    "payTo": "0xBd5eB5559f5Ac14475AC0C81b6735A4d9106ce28",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "maxTimeoutSeconds": 300
  }
]

Output schema

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "metadata": {
            "agent_id": "my-agent-v1",
            "decided_at": "2026-09-12T10:00:00Z",
            "decision_hash": "b94f6f125c79e3a5ffaa826f584c10d52ada669e6762051b826b55776d05a3d7",
            "input_hash": "a665a45920422f9d417e4867efdc4fb8a04a1f3fff1fa07e998e86f7f7a27ae3"
          },
          "payload_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
          "schema": "agent_decision"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      }
    },
    "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"
    }
  }
}

Use it

curl

curl "https://x402.fairseal.io/v1/notarize"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://x402.fairseal.io/v1/notarize");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://x402.fairseal.io/v1/notarize")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Machine-readable

Everything on this page is also available as clean JSON at /resources/13436.json, and this resource appears in /discovery/resources and /discovery/search.