{"uid":"cap_bBcG_OziCFcHRuWZfzd18","slug":"halowerk-x402werk-replay-guard-181e92d3","name":"HALOWERK x402werk — Replay Guard","description":"HALOWERK x402werk — bezahlte Endpunkte nach x402. Preise in USDC auf Base Mainnet.","url":"https://x402.netzhandwerker.de/guard/replay","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"nonce":{"type":"string","maxLength":512,"minLength":1,"description":"Nonce of the signed payment authorisation. Stored only as a SHA-256 fingerprint."},"record":{"type":"boolean","default":true,"description":"Whether this call is remembered. Set to false to check without writing, so repeated checks of the same payment do not report themselves as duplicates."},"payment_id":{"type":"string","maxLength":512,"minLength":1,"description":"Payment identifier of the x402 payment-identifier extension, or any identifier your client treats as unique per payment. Stored only as a SHA-256 fingerprint."},"payload_hash":{"type":"string","maxLength":512,"minLength":1,"description":"Hash of the request payload that was paid for. Stored only as a SHA-256 fingerprint of the value you send."},"window_seconds":{"type":"integer","default":3600,"maximum":86400,"minimum":1,"description":"How far back a sighting still counts as a duplicate for the recommendation. Fingerprints are kept for 24 hours regardless."}}},"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_8pOEiAOpjjzRhRlJUPNK_","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":"Detects duplicate/replayed x402 payment authorizations by fingerprinting nonces, payment IDs, and payload hashes within a configurable time window.","exampleAgentPrompt":"Before accepting this x402 payment, check if the nonce 'abc123xyz' and payment ID 'pay_9f8e7d' with payload hash 'sha256_deadbeef' have been seen in the last 3600 seconds — and record this sighting if they haven't been used before.","exampleUseCases":[{"title":"Block replayed micropayment in real time","prompt":"I just received an x402 payment with nonce 'nonce_A1B2C3', payment ID 'pay_001', and payload hash 'hash_FEED1234' — can you check if this combo has been seen in the last hour and record it so it can't be replayed again?"},{"title":"Dry-run duplicate check without recording","prompt":"Check whether payment ID 'pay_XYZ789' with nonce 'nonce_qwerty' and payload hash 'hash_ABCD5678' is a duplicate within the last 30 minutes, but don't record this check — I just want to verify without writing anything."},{"title":"Tighten replay window for high-frequency API","prompt":"For my paid endpoint, I want a tighter replay window of 300 seconds — check if nonce 'nonce_FAST01', payment ID 'pay_F999', and payload hash 'hash_C0FFEE99' have been seen before and record the fingerprint."}],"resultDescription":"Returns whether the submitted combination of nonce, payment ID, and payload hash has been seen within the specified time window, indicating a potential replay attack. If `record` is true, the fingerprints (stored only as SHA-256 hashes) are written for future duplicate checks. Fingerprints are retained for up to 24 hours regardless of the window setting.","failureModes":["Missing required fields (nonce, payment_id, or payload_hash absent) returns a validation error","window_seconds exceeds 86400 returns a parameter error","Malformed or overly long input strings (beyond 512 chars) rejected","Payment not made or insufficient USDC balance returns HTTP 402","Service unavailability or internal errors return 5xx"],"whenToPreferThis":"Use this endpoint when building x402-compatible paid APIs on Base Mainnet that need server-side replay protection — specifically when you want a lightweight, pay-per-check external guard that stores SHA-256 fingerprints of nonces/payment IDs/payload hashes without retaining raw values. Prefer this over rolling your own replay store when you want a managed, 24-hour retention window and a simple boolean duplicate recommendation without maintaining your own database.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:48:04.270Z","isFirstParty":false}