{"uid":"cap_eRz02Q1xbGKBv3Mo5DLgL","slug":"x402-base-usdc-payment-checker-c5d324cc","name":"x402 Base USDC Payment Checker","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://paycheck.hectichustle.workers.dev/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":{"type":"json","example":{"mode":"live_paid","block":52409752,"found":true,"match":{"ok":true,"payToMatch":true,"amountMatch":true},"funding":{"verdict":"external","scannedBlocks":{"to":52409752,"from":52360000,"complete":false,"stoppedEarly":"enough recent funding found"}},"payment":{"to":"0x509e55c4f898b43c856fb0e51048b1b7bfbc9ede","from":"0xfc1e390266f3b29179b5d63a7937a689d1e5279a","amount":"1"},"receipt":{"reason":null,"verdict":"external","rpcCalls":9,"priceCharged":"0.01 USDC","blocksScanned":{"to":52409752,"from":52360000,"complete":false}},"summary":"1 USDC from 0xfc1e… to 0x509e… at block 52409752. Matches expected payment. Payer was funded externally.","warnings":[],"confirmed":true,"confirmations":1200}},"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_eBO2hnJ_hXsO2wVqAw5JW","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 Base mainnet USDC payment by transaction hash, checking confirmations, real USDC transfers, expected recipient/amount match, fake-USDC warnings, and payer funding source","exampleAgentPrompt":"Can you verify this Base mainnet USDC payment for me — tx hash 0xabc123...def456 — and confirm it actually sent 0.01 USDC to 0xRecipientAddress...5678, and flag any fake-USDC or lookalike address issues?","exampleUseCases":[{"title":"Merchant payment verification before fulfillment","prompt":"Before I ship this order, verify that tx hash 0x4f2a...b9c1 on Base actually sent 0.50 real USDC to my store address 0xA1B2...C3D4, and let me know if there are any fake-token or scam-address red flags."},{"title":"Freelancer invoice payment confirmation","prompt":"I just got paid for a project — can you check Base transaction 0x7e3d...f012 and confirm it sent exactly 150 USDC to 0xMyWallet...9988, and tell me how the payer funded their wallet?"},{"title":"Fraud detection on incoming crypto payment","prompt":"Someone paid me via Base with tx hash 0xc9a1...3344 — run a full check to see if it's a real USDC transfer, if the amount and recipient match, and whether the token contract looks legit or is a fake USDC lookalike."}],"resultDescription":"Returns a structured report including: number of confirmations, detected USDC transfer details, boolean match results for expectedPayTo and expectedAmount, fake-USDC and lookalike-address warnings, payer funding source classification (external | self_funded | unknown) with reason code (no_inbound_in_window | scan_incomplete), a plain-English summary of the payment status, and a receipt showing blocks scanned, RPC calls made, and cost.","failureModes":["Invalid or malformed txHash (not a valid 0x-prefixed 64-char hex) returns validation error","Transaction not found on Base mainnet returns not-found error","Transaction exists but involves no USDC transfer — mismatch flagged","Fake or non-standard USDC contract detected — warning returned with details","RPC rate limits or node connectivity issues may cause scan_incomplete funding classification","expectedPayTo or expectedAmount mismatch returns failed verification with details"],"whenToPreferThis":"Choose this endpoint when you need to cryptographically verify a specific Base mainnet USDC payment before fulfilling an obligation, especially when fraud risk is a concern. It is uniquely suited for detecting fake USDC tokens, lookalike recipient addresses, and tracing payer funding origin — features not typically available in generic block explorers. Prefer it over manual block explorer checks when you need a structured, machine-readable result with plain-English summary and fraud signals in a single API call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-16T00:38:39.633Z","isFirstParty":false,"canonicalSlug":"x402-base-usdc-payment-checker-c5d324cc"}