{"uid":"cap_Rm8kiULvIemoe3kLofnaZ","slug":"liquid-logic-audit-usdc-payment-proof-on-arc-1d2b4c14","name":"Liquid Logic Audit — USDC Payment Proof on Arc","description":"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. $0.02 USDC on Base, charged only when a proof is returned. Your paying wallet must be the tx sender or recipient. Liquid Logic X also records proofs on Tempo mainnet. Site: https://liquidlogicx.com","url":"https://audit.liquidlogicx.com/api/prove?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["txHash"],"properties":{"memo":{"type":"string","pattern":"^[\\x20-\\x7E]*$","maxLength":64,"description":"Optional plain-text note stored on-chain with the proof (printable ASCII, max 64 chars). Public."},"txHash":{"type":"string","pattern":"^0x[0-9a-fA-F]{64}$","description":"Base mainnet (eip155:8453) transaction hash of a USDC payment (must contain a Transfer from Base USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). Your paying wallet must be its from or to."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["proofId","status","source","arc","verifyUrl","recordedAt"],"properties":{"arc":{"type":"object","required":["chain","contract","txHash"],"properties":{"chain":{"type":"string","const":"eip155:5042"},"txHash":{"type":["string","null"],"pattern":"^0x[0-9a-fA-F]{64}$","description":"Arc tx that recorded the proof"},"contract":{"type":"string","const":"0x1de52cbc4490a7873ef007e51cb91a5b374facb1"}}},"memo":{"type":"string"},"refId":{"type":"string","pattern":"^0x[0-9a-fA-F]{64}$","description":"Settlement ID on Arc = keccak256(srcTxHash, payee, amountUSDC)"},"source":{"type":"object","required":["chain","txHash","from","to","amountUsdc","timestamp"],"properties":{"to":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"},"from":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"},"chain":{"type":"string","const":"eip155:8453"},"txHash":{"type":"string","pattern":"^0x[0-9a-fA-F]{64}$"},"timestamp":{"type":"string","description":"Base block time (UTC)"},"amountUsdc":{"type":"string","description":"Decimal USDC, e.g. \"0.05\""}}},"status":{"enum":["recorded","existing"],"type":"string"},"proofId":{"type":["integer","null"],"description":"1-based position in the SettlementProofs registry on Arc"},"verifyUrl":{"type":"string","description":"Public verifier page on proofs.liquidlogicx.com"},"recordedAt":{"type":"string"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_JqdDY6jOkHJhPtquCeor5","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Given a Base USDC transaction hash, records a tamper-proof settlement receipt on the Arc blockchain and returns a public verify link.","exampleAgentPrompt":"I just sent a USDC payment on Base with tx hash 0x4a3b2c1d...e7f6 — can you record a settlement proof on Arc and give me a public verify link I can share?","exampleUseCases":[{"title":"Agent payment receipt after x402 call","prompt":"I paid an x402 API with my wallet and the Base tx hash is 0xabc123...def456 — please generate a settlement proof on Arc so I have a verifiable receipt I can attach to my logs."},{"title":"Audit trail for freelance crypto invoice","prompt":"I just paid a contractor 50 USDC on Base, tx hash 0x9f8e7d...c6b5a4 — can you anchor a proof of that payment on Arc with the memo 'Invoice #42 - design work' so I have an immutable record?"},{"title":"Verify an already-submitted proof","prompt":"I think I already recorded a settlement proof for Base tx 0x1234ab...cd5678 — can you check if it exists on Arc and give me the verify link again without charging me twice?"}],"resultDescription":"Returns a JSON object containing: proof status ('recorded' for new or 'existing' for already-seen), a refId (keccak256-derived settlement ID on Arc), source transfer details (from/to addresses, USDC amount, Base block timestamp, Base tx hash), Arc anchoring details (chain eip155:5042, contract address, Arc tx hash), optional memo, and a public verifyUrl to share as proof of payment. No Arc write and no charge if the tx was already recorded.","failureModes":["403 Forbidden — paying wallet is neither the sender nor recipient of the USDC transfer in the given tx hash","Invalid tx hash format — must be 0x followed by 64 hex characters","Tx hash contains no USDC Transfer event from Base USDC contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","Payment not made — x402 $0.02 USDC charge failed, proof not recorded","Network timeout fetching Base mainnet transaction data","Transaction not yet confirmed on Base mainnet"],"whenToPreferThis":"Choose this endpoint when you need a tamper-proof, publicly verifiable on-chain receipt for a USDC payment made on Base — especially for agentic payment flows using x402 protocols where audit trails matter. It is idempotent (safe to call twice), cheap ($0.02 USDC), and only charges when a new proof is actually written to Arc. Prefer it over off-chain logging when you need a public verify URL you can share with third parties as proof of settlement.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T07:01:12.096Z","isFirstParty":false,"canonicalSlug":"liquid-logic-audit-usdc-payment-proof-on-arc-1d2b4c14"}