{"uid":"cap_HsfjjGpxXHbI_8KenRoP2","slug":"webhook-signature-timestamp-check-d2969676","name":"Webhook Signature Timestamp Check","description":"Webhook Signature Timestamp Check: Webhook Signature Timestamp Check checks webhook timestamp age and future skew before signature verification from bounded caller-supplied values without an external provider. Call Webhook Signature Timestamp Check before accepting, caching, redirecting, or retrying a caller-supplied web response. Returns normalized web evidence, the computed finding, and an explicit pass or advisory status for Webhook Signature Timestamp Check as versioned deterministic JSON.…","url":"https://api.delx.ai/api/v1/x402/webhook-signature-timestamp-check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"now_epoch":{"type":"integer","description":"Now Epoch supplied to Webhook Signature Timestamp Check; used only for this bounded calculation and processed in memory without retention."},"timestamp_epoch":{"type":"integer","description":"Timestamp Epoch supplied to Webhook Signature Timestamp Check; used only for this bounded calculation and processed in memory without retention."},"maximum_age_seconds":{"type":"integer","description":"Maximum Age Seconds supplied to Webhook Signature Timestamp Check; used only for this bounded calculation and processed in memory without retention."},"maximum_future_skew_seconds":{"type":"integer","description":"Maximum Future Skew Seconds supplied to Webhook Signature Timestamp Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"age_seconds":120,"within_window":true,"signature_verified":false},"schema":"delx/util-webhook-signature-timestamp-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"399247a496498846768188f051c797a1de4857867f694fadcc7a0037c29feb35","external_calls":0},"operation":"web_reliability:webhook_signature_timestamp_check"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_8AawfXB1_G5uQmF403scV","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates whether a webhook timestamp is within acceptable age and future-skew bounds before signature verification proceeds","exampleAgentPrompt":"Check if this webhook timestamp is valid — the current time is epoch 1720000000, the webhook timestamp is 1719999700, with a maximum allowed age of 300 seconds and a maximum future skew of 60 seconds.","exampleUseCases":[{"title":"Replay attack prevention for payment webhooks","prompt":"Before I verify the signature on this incoming payment webhook, check if the timestamp is still fresh — current epoch is 1720100000, webhook timestamp is 1720099500, max age allowed is 300 seconds, and I'll allow up to 30 seconds of future skew."},{"title":"Strict freshness gate for security event webhook","prompt":"I need to validate a security alert webhook timestamp — now is epoch 1720200000, the event timestamp is 1719999000, max age is 60 seconds, max future skew is 10 seconds. Tell me if it passes or should be rejected."},{"title":"Retry-safe webhook ingestion pipeline","prompt":"My webhook processor is about to retry a cached webhook event — current epoch is 1720300000, the original event timestamp is 1720299800, max acceptable age is 600 seconds, max future skew is 120 seconds. Is the timestamp still within bounds?"}],"resultDescription":"Returns a versioned deterministic JSON object containing normalized evidence of the timestamp inputs, the computed age and skew values, and an explicit pass or advisory status indicating whether the webhook timestamp falls within the specified bounds.","failureModes":["Missing required epoch values return an error or undefined behavior","Maximum age or skew seconds of zero or negative values may produce unexpected results","If now_epoch is earlier than timestamp_epoch by more than max_future_skew_seconds, advisory/fail status is returned","Malformed integer inputs may cause parsing errors"],"whenToPreferThis":"Use this endpoint when you need a deterministic, stateless, versioned check of webhook timestamp freshness before proceeding with signature verification — particularly in agentic pipelines where replay attack prevention must be auditable and reproducible without maintaining server-side state. Prefer this over custom logic when you want a normalized, structured evidence trail for compliance or debugging.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:18:30.719Z","isFirstParty":false}