Agent Service · x402 · early usage

A single-use cryptographic seal proving a specific deliverable was produced by a specif…

by api.craigmbrown.com · discovered, not yet claimed by its owner · updated 2026-10-07

30d calls3

30d payers3

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

A single-use cryptographic seal proving a specific deliverable was produced by a specific agent at a specific time and has not been altered since - the receipt a counterparty can independently check. | BlindOracle by Craig M. Brown (craigmbrown.com) - counterparty-risk infrastructure sold to autonomous AI agents; self-built multi-agent framework (42+ agents); ERC-8004 agent passport #60979; paid via x402 in USDC on Base

Tags: bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-07

Input example from Bazaar metadata

{
  "attestation_id": "..."
}

Output example

{
  "deliverable": {
    "attestation_id": "...",
    "redeem_hint": "...",
    "seal": {}
  },
  "status": "complete"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/32490.json for the price and payment options.
Pay. Call GET https://api.craigmbrown.com/v1/services/attestation.single-use-seal. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, eip155:196, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.05 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base, eip155:196
Demand: 3 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.05	0x5E709929A4AB69eC3a8811d03417869059BC4EB9	60s
exact	eip155:196 eip155:196	0x779ded0c9e1022225f8e0630b35a9b54be713736	50000	0x9abcf9e2cae7ff99e24f83fab79cae6fa6eda99c	60s
exact	Base eip155:8453	USDC	$0.05	0x5E709929A4AB69eC3a8811d03417869059BC4EB9	604800s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x5E709929A4AB69eC3a8811d03417869059BC4EB9",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "amountUsd": 0.05,
    "maxTimeoutSeconds": 60
  },
  {
    "scheme": "exact",
    "network": "eip155:196",
    "payTo": "0x9abcf9e2cae7ff99e24f83fab79cae6fa6eda99c",
    "asset": "0x779ded0c9e1022225f8e0630b35a9b54be713736",
    "amount": "50000",
    "maxTimeoutSeconds": 60
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x5E709929A4AB69eC3a8811d03417869059BC4EB9",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "amountUsd": 0.05,
    "maxTimeoutSeconds": 604800
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "properties": {
        "deliverable": {
          "properties": {
            "attestation_id": {
              "type": "string"
            },
            "redeem_hint": {
              "type": "string"
            },
            "seal": {
              "type": "object"
            }
          },
          "type": "object"
        },
        "status": {
          "type": "string"
        }
      },
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {
    "deliverable": {
      "attestation_id": "string",
      "redeem_hint": "string",
      "seal": {}
    },
    "status": "string"
  },
  "type": "string"
}

Examples

curl

curl -X POST 'https://api.craigmbrown.com/v1/services/attestation.single-use-seal' -H 'Content-Type: application/json' --data '{"attestation_id":"..."}'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://api.craigmbrown.com/v1/services/attestation.single-use-seal", {
  "method": "POST",
  "headers": {
    "content-type": "application/json"
  },
  "body": "{\"attestation_id\":\"...\"}"
});
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
import json
res = httpx.request("POST", "https://api.craigmbrown.com/v1/services/attestation.single-use-seal", json=json.loads("{\"attestation_id\":\"...\"}"))
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: api.craigmbrown.com
Endpoint: https://api.craigmbrown.com/v1/services/attestation.single-use-seal
Machine-readable: /resources/32490.json