{"uid":"cap_EXSEgtlaiQiOrRaWOpsAJ","slug":"nostr-zap-receipt-checker-8edfefa1","name":"Nostr Zap Receipt Checker","description":"Takes a kind 9735 receipt directly or fetches it from relays by event id, then runs eight named checks and reports each one separately with its reason. The receipt signature and the signature of the zap request enclosed in the description tag are verified per BIP-340. The invoice is decoded and its amount is compared against the amount tag of the zap request, since those two can disagree and only the invoice was payable.","url":"https://nostr.halowerk.com/zap-receipt-check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"relays":{"type":"array","items":{"type":"string"},"maxItems":12,"description":"wss relay addresses used when fetching by event_id."},"receipt":{"type":"object","description":"The complete kind 9735 event. Either this or event_id is required."},"event_id":{"type":"string","description":"Event id of the receipt as hex, note or nevent. Fetched from the relays when receipt is not given."},"recipient_lightning_address":{"type":"string","description":"Lightning address of the recipient, for example name@domain. Given, the issuer is compared against the nostrPubkey published there."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_FkBNkxk0uplKxZxzsdHbz","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a Nostr kind 9735 zap receipt by running eight named cryptographic and structural checks, including BIP-340 signature verification and invoice amount comparison.","exampleAgentPrompt":"Can you check whether this Nostr zap receipt is valid — here's the event ID: nevent1qqsxyz... — run all eight checks including signature verification and make sure the invoice amount matches the zap request?","exampleUseCases":[{"title":"Audit suspicious zap receipt","prompt":"I received a zap receipt on Nostr and I'm not sure it's legitimate — can you run all eight validation checks on this event ID nevent1qqsabc123 and tell me if the BIP-340 signatures are valid and if the invoice amount matches the zap request?"},{"title":"Verify zap before crediting user","prompt":"Before I credit a user for a zap payment, can you validate this kind 9735 receipt I received directly and tell me exactly which checks pass or fail, especially whether the invoice amount and the zap request amount agree?"},{"title":"Debug malformed zap receipt","prompt":"My app is producing zap receipts that are getting rejected — can you fetch this zap receipt by event ID note1defxyz from the relays and run all eight checks to tell me which ones are failing and why?"}],"resultDescription":"A structured report of eight named checks, each with a pass/fail result and a human-readable reason explaining the outcome. Covers: receipt signature validity (BIP-340), zap request signature validity (BIP-340), invoice decoding, invoice amount vs zap request amount tag comparison, and other structural integrity checks on the kind 9735 event.","failureModes":["Event ID not found on any relay — check returns not-found error","Malformed event JSON provided — parsing fails before checks run","Invalid bech32 or hex event ID format — rejected at input","Relay timeout or unreachable relays — fetch may return partial results","Invoice unparseable — invoice check fails with decode error"],"whenToPreferThis":"Use this endpoint when you need granular, per-check validation of a Nostr kind 9735 zap receipt, especially when you need to distinguish between receipt signature failure, zap request signature failure, and invoice/amount mismatches as separate failure modes. Prefer this over a summary-only validator when debugging broken zap flows or auditing individual receipts for payment integrity.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:51:18.272Z","isFirstParty":false}