{"uid":"cap_8f0nrGlQF47KeTI6rlytR","slug":"402oracle-com-url-freshness-verifier-522344c4","name":"402oracle.com URL Freshness Verifier","description":"Check that a URL is live and its data is fresh before your agent acts on its contents. A freshness oracle: returns HTTP status, Last-Modified/ETag, a content SHA-256, and whether the content changed versus a prior hash. Returns a signed attestation.","url":"https://402oracle.com/verify/freshness","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","description":"Full URL including https://"},"prior_hash":{"type":"string","description":"Optional prior SHA-256 hex to compare against"}}},"responseSchema":{"type":"json","example":{"signature":{"alg":"ES256","jwks":"/.well-known/jwks.json"},"attestation":{"type":"freshness_verification","result":{"status":200,"changed":false,"reachable":true,"content_sha256":"9f86d081884c7d65"},"subject":{"url":"https://example.com/data.json"},"confidence":0.98}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_3id2nbWjn697yF0wD1GBM","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a URL is live and its content is current by returning HTTP status, caching headers, a SHA-256 content hash, and a signed attestation indicating whether the content changed since a prior check.","exampleAgentPrompt":"Before you summarize that report, can you check if https://example.com/annual-report-2024.pdf is still live and whether its content has changed since the SHA-256 hash abc123def456 I got last week?","exampleUseCases":[{"title":"Stale link guard before agent action","prompt":"Before you pull data from https://partner.io/pricing-sheet.json and use it to generate a quote, verify the URL is still live and that the content hasn't changed since hash 9f8e7d6c5b4a."},{"title":"Invoice document integrity check","prompt":"I'm about to approve a payment based on an invoice at https://vendor.com/invoices/INV-4421.pdf — can you confirm that URL is still reachable and that its content matches the hash 3a1b2c4d5e6f I recorded yesterday?"},{"title":"Research source freshness verification","prompt":"I have 10 URLs from a research report saved last month. Starting with https://reports.globaldata.com/market-outlook-q3.html, check if the page is still live and flag it if the content has changed since hash 7f2e9a0b1c3d."}],"resultDescription":"Returns the HTTP status code of the URL, Last-Modified and ETag caching headers if available, a SHA-256 hash of the current content, a boolean indicating whether the content changed relative to a previously provided hash, and a cryptographically signed attestation of the result.","failureModes":["URL is unreachable or returns a non-200 status (4xx/5xx) — attestation reflects the error status","Network timeout when fetching the target URL — may return an error or timeout indicator","URL redirects to a login page or paywall, resulting in a hash of the redirect destination rather than intended content","No prior hash provided — change detection cannot be performed, only current state returned","Invalid URL format submitted — request rejected with validation error"],"whenToPreferThis":"Choose this endpoint when your agent needs cryptographic assurance that a URL is live and its content is current or unchanged before taking an action that depends on it — such as approving a payment, summarizing a document, or citing a source. The signed attestation makes this especially valuable in agentic pipelines where you need auditable proof of content state. Prefer this over a simple HTTP HEAD check when content-change detection and signed provenance are required.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:37:47.580Z","isFirstParty":false}