{"uid":"cap_ajJR2JIxIrp_T3hy53Y0R","slug":"kertivo-check-payment-verify-94d85b2b","name":"Kertivo Check: Payment Verify","description":"Payment verification for x402: verify a USDC transaction on Base — did this payment really settle, and did it pay the right address the right amount? Send a tx hash (or x402 authorization): confirmations, real-USDC transfer check, expectedPayTo/expectedAmount match, fake-USDC and lookalike-address warnings, who funded the payer (external, self_funded, unknown), plain-English summary and a receipt. Body {txHash|authorization, expectedPayTo?, expectedAmount?}. Free demo: POST /demo.","url":"https://kertivo.com/check?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"token":{"type":"string","description":"Optional (aliases asset, currency): \"USDC\" or the Base USDC contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (apexfaucet-style). Any other token is a 400 unsupported_token, not charged. Responses always echo token \"USDC\"."},"txHash":{"type":"string","pattern":"^0x[0-9a-fA-F]{64}$","description":"Base mainnet transaction hash"},"minAmount":{"type":["string","number"],"description":"Optional floor (aliases min_amount, min): payment must be at least this many USDC; unlike expectedAmount it is not exact"},"authorization":{"type":"object","required":["from","nonce"],"properties":{"from":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"},"nonce":{"type":"string","pattern":"^0x[0-9a-fA-F]{64}$"},"validAfter":{"type":["string","integer"]},"validBefore":{"type":["string","integer"],"description":"unix seconds"}},"description":"Optional EIP-3009 authorization (x402 exact payload) to check when there is no tx or the tx is not found"},"expectedPayTo":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"Expected recipient (full-address, case-insensitive compare)"},"expectedPayer":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"Optional expected payer (aliases from, payer): the USDC Transfer's from must equal it"},"selfAddresses":{"type":"array","items":{"type":"string"},"maxItems":10,"description":"Optional: other addresses you control; funding from them counts as self_funded"},"expectedAmount":{"type":["string","number"],"description":"Expected USDC amount, decimal (e.g. \"0.01\")"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_IvrWfwYv8u9siOD1JwCXC","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Verifies a USDC payment on Base mainnet — checks confirmation, real USDC transfer, correct recipient and amount, and flags fake tokens or lookalike addresses","exampleAgentPrompt":"Can you verify that transaction 0xabc123...def456 on Base actually paid 0.01 USDC to my wallet 0x1234...abcd, and flag if it used a fake USDC token or a lookalike address?","exampleUseCases":[{"title":"x402 payment gate before API access","prompt":"Before I give this user access, verify their x402 payment — the authorization came from 0xPayer..., nonce 0xNonce..., and it should have paid 0.01 USDC to my address 0xMyWallet.... Tell me if it's legitimate and warn me if anything looks suspicious."},{"title":"Confirming a customer USDC payment","prompt":"A customer says they paid me 5 USDC on Base — the tx hash is 0xabc...def. Can you check it actually settled, that it went to 0xMyStore... and was exactly 5 USDC, and tell me if the token is real USDC or a fake?"},{"title":"Detecting lookalike wallet fraud","prompt":"I received a payment at tx 0x789...abc but I'm not sure if the recipient address is really mine — my wallet is 0xRealWallet.... Check if the payment went to the right address and warn me if there's a lookalike address being used."}],"resultDescription":"Returns a structured receipt with: confirmation count, whether the transfer used real USDC on Base, whether expectedPayTo and expectedAmount match, warnings for fake USDC tokens or lookalike addresses, payer funding source classification (external, self_funded, or unknown), and a plain-English summary of the payment status.","failureModes":["Invalid or malformed tx hash returns 400 bad_request","Unsupported token (non-USDC) returns 400 unsupported_token and no charge","Transaction not found on Base mainnet returns a not-found or pending status","If authorization provided but no matching tx found, authorization fields are checked instead","Mismatched expectedPayTo or expectedAmount returned as failed validation with details","Network timeout or RPC unavailability may cause transient errors"],"whenToPreferThis":"Use this endpoint when you need to validate an x402 USDC payment on Base before releasing a resource, granting API access, or fulfilling an order — especially when you need fraud signals like fake-USDC detection, lookalike-address warnings, and payer funding source classification. Prefer it over raw RPC calls when you want a human-readable summary and structured receipt without writing custom blockchain parsing logic.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T06:38:19.711Z","isFirstParty":false,"canonicalSlug":"kertivo-check-payment-verify-94d85b2b"}