Payments · x402 · early usage

Payment receipt and settlement proof for x402 and agent payments, by Liquid Logic X

Name: Payment receipt and settlement proof for x402 and agent payments, by Liquid Logic X
Price: 0.02 USD
Availability: InStock

by audit.liquidlogicx.com · discovered, not yet claimed by its owner · updated 2026-10-06

30d calls1

30d payers1

MethodGET

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

Payment receipt and settlement proof for x402 and agent payments, by Liquid Logic X. Input: a Base USDC tx hash (optional memo). Output: JSON proof recorded onchain on Arc mainnet (proofId, from/to/amount, Arc tx, refId) plus a public verify link anyone can check. $0.02 USDC on Base, charged only when a proof is returned. Your paying wallet must be the tx sender or recipient. Liquid Logic X also records proofs on Tempo mainnet. Site: https://liquidlogicx.com

Tags: payment-receipt · settlement-proof · verify · x402 · usdc · bazaar · builder-code · eip2612GasSponsoring · erc20ApprovalGasSponsoring

Call contract

Method: GET
Input: query parameters
Output: json
Last paid call: 2026-10-06

Input example from Bazaar metadata

{
  "memo": "invoice-42",
  "txHash": "0x93a15735c5b82fb8c9fdc0f7db5d56916a14f6ee4ef343000a29fd55c4bcaf4c"
}

Output example

{
  "arc": {
    "chain": "eip155:5042",
    "contract": "0x1de52cbc4490a7873ef007e51cb91a5b374facb1",
    "txHash": "0x2bb316073c034140d74d73ca67ad2b71bfaaa9dea531d69290a16efdd0f10bbe"
  },
  "memo": "llx-self-test-0.001",
  "proofId": 1,
  "recordedAt": "2026-09-22T15:32:28.000Z",
  "refId": "0xe6db5a86740c0e40943c06268bda4e09b45ac0a45fd6c5d7b7f2550e19e0c50e",
  "source": {
    "amountUsdc": "0.001",
    "chain": "eip155:8453",
    "from": "0xEA24bafbBAF6d7Ba58bE860EE906f0Fe533d167D",
    "timestamp": "2026-09-15T20:38:57.000Z",
    "to": "0x147991A1c25e78f6D9225d2dBA61eD93A6158c7b",
    "txHash": "0x93a15735c5b82fb8c9fdc0f7db5d56916a14f6ee4ef343000a29fd55c4bcaf4c"
  },
  "status": "recorded",
  "verifyUrl": "https://proofs.liquidlogicx.com/proofs?q=0xe6db5a86740c0e40943c06268bda4e09b45ac0a45fd6c5d7b7f2550e19e0c50e"
}

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/36642.json for the price and payment options.
Pay. Call GET https://audit.liquidlogicx.com/api/prove. 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, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.02 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 1 calls · 1 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.02	0x147991A1c25e78f6D9225d2dBA61eD93A6158c7b	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x147991A1c25e78f6D9225d2dBA61eD93A6158c7b",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "amountUsd": 0.02,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "properties": {
        "arc": {
          "properties": {
            "chain": {
              "const": "eip155:5042",
              "type": "string"
            },
            "contract": {
              "const": "0x1de52cbc4490a7873ef007e51cb91a5b374facb1",
              "type": "string"
            },
            "txHash": {
              "description": "Arc tx that recorded the proof",
              "pattern": "^0x[0-9a-fA-F]{64}$",
              "type": [
                "string",
                "null"
              ]
            }
          },
          "required": [
            "chain",
            "contract",
            "txHash"
          ],
          "type": "object"
        },
        "memo": {
          "type": "string"
        },
        "proofId": {
          "description": "1-based position in the SettlementProofs registry on Arc",
          "type": [
            "integer",
            "null"
          ]
        },
        "recordedAt": {
          "type": "string"
        },
        "refId": {
          "description": "Settlement ID on Arc = keccak256(srcTxHash, payee, amountUSDC)",
          "pattern": "^0x[0-9a-fA-F]{64}$",
          "type": "string"
        },
        "source": {
          "properties": {
            "amountUsdc": {
              "description": "Decimal USDC, e.g. \"0.05\"",
              "type": "string"
            },
            "chain": {
              "const": "eip155:8453",
              "type": "string"
            },
            "from": {
              "pattern": "^0x[0-9a-fA-F]{40}$",
              "type": "string"
            },
            "timestamp": {
              "description": "Base block time (UTC)",
              "type": "string"
            },
            "to": {
              "pattern": "^0x[0-9a-fA-F]{40}$",
              "type": "string"
            },
            "txHash": {
              "pattern": "^0x[0-9a-fA-F]{64}$",
              "type": "string"
            }
          },
          "required": [
            "chain",
            "txHash",
            "from",
            "to",
            "amountUsdc",
            "timestamp"
          ],
          "type": "object"
        },
        "status": {
          "enum": [
            "recorded",
            "existing"
          ],
          "type": "string"
        },
        "verifyUrl": {
          "description": "Public verifier page on proofs.liquidlogicx.com",
          "type": "string"
        }
      },
      "required": [
        "proofId",
        "status",
        "source",
        "arc",
        "verifyUrl",
        "recordedAt"
      ],
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

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

{
  "example": {
    "arc": {
      "chain": "string",
      "contract": "string",
      "txHash": "string"
    },
    "memo": "string",
    "proofId": 0,
    "recordedAt": "string",
    "refId": "string",
    "source": {
      "amountUsdc": "string",
      "chain": "string",
      "from": "string",
      "timestamp": "string",
      "to": "string",
      "txHash": "string"
    },
    "status": "recorded",
    "verifyUrl": "string"
  },
  "type": "string"
}

Examples

curl

curl "https://audit.liquidlogicx.com/api/prove"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://audit.liquidlogicx.com/api/prove");
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://audit.liquidlogicx.com/api/prove")
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: audit.liquidlogicx.com
Endpoint: https://audit.liquidlogicx.com/api/prove
Machine-readable: /resources/36642.json