{"uid":"cap_YHI1KGTcgI_rm7-d6t25Q","slug":"attest402-signed-evidence-of-public-web-api-response-81f606d1","name":"Attest402 — Signed Evidence of Public Web/API Response","description":"Cryptographically signed and timestamped evidence of a public web or API response. Pay per call with x402 (0.20 USDC on Base). No account, no API key. Built for AI agents.","url":"https://attest402.com/v1/attest?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","format":"uri","description":"Public HTTPS URL to capture (GET only, max 2 MB, max 3 redirects)."},"externalReference":{"type":"string","maxLength":100,"description":"Optional caller-side correlation id, embedded in the signed record."},"includeTrustedTimestamp":{"type":"boolean","description":"Also anchor the record with an independent RFC-3161 timestamp."}}},"responseSchema":{"type":"json","example":{"bodyHash":"sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855","finalUrl":"https://api.example.com/prices/btc","httpStatus":200,"observedAt":"2026-08-01T19:50:00.123Z","attestation":{"keyId":"attest-prod-2026-01","algorithm":"Ed25519","signature":"base64:...","schemaVersion":"1.0","canonicalRecordHash":"sha256:..."},"contentType":"application/json","headersHash":"sha256:98fdc32...","requestedUrl":"https://api.example.com/prices/btc","attestationId":"attest_9f8a1b2c3d4e","contentLength":4281,"redirectChain":[],"verificationUrl":"https://attest402.com/v1/verify/attest_9f8a1b2c3d4e","trustedTimestamp":{"type":"RFC3161","status":"VALID","tokenHash":"sha256:..."},"evidencePackageUrl":"https://attest402.com/v1/evidence/attest_9f8a1b2c3d4e"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.2","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":"$0.2/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.2","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.2","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_KcA6sxWTiDgOwcJ02oUcc","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.2","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Fetches a public URL and returns cryptographically signed, timestamped evidence of the HTTP response — body hash, headers hash, HTTP status, and an Ed25519 attestation — payable per-call with x402 USDC.","exampleAgentPrompt":"Fetch https://api.coinbase.com/v2/prices/BTC-USD/spot right now and give me a cryptographically signed, timestamped attestation of exactly what it returned — body hash, HTTP status, Ed25519 signature, and a verification link I can share.","exampleUseCases":[{"title":"Price feed proof for smart contract","prompt":"Grab https://api.coinbase.com/v2/prices/ETH-USD/spot and generate a signed, timestamped attestation of the response so I can submit cryptographic proof of the ETH price to my on-chain contract."},{"title":"Compliance snapshot of public record","prompt":"Attest the current content of https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001018724&type=10-K — I need a tamper-evident, RFC3161-timestamped evidence package I can attach to our audit file."},{"title":"Dispute resolution for web content","prompt":"I need a cryptographically signed snapshot of https://example.com/terms-of-service as it exists right now — with a body hash, headers hash, and a verification URL — so I have legally defensible proof of what the page said today."}],"resultDescription":"A JSON object containing: the requested and final URLs, HTTP status code, content type and length, a SHA-256 hash of the response body and headers, the timestamp of observation, a redirect chain, an Ed25519 digital signature with key ID and algorithm, a canonical record hash, a schema version, a trusted RFC3161 timestamp token hash and status, a unique attestation ID, a public verification URL, and a URL to download the full evidence package.","failureModes":["Non-public or authenticated URLs will fail or return incomplete evidence","Target URL returns non-200 status — attestation still issued but records actual HTTP status","Payment not received or x402 flow fails — request not processed","Target URL unreachable or times out — no attestation issued","Invalid or malformed URL input — request rejected","Target server returns unexpected content type or very large body — may affect processing"],"whenToPreferThis":"Choose Attest402 when you need cryptographically verifiable, independently auditable proof of what a public URL returned at a specific moment — especially for smart contract oracles, legal/compliance evidence, dispute resolution, or any workflow where trusting a screenshot or log is insufficient. Prefer it over simple HTTP fetching when tamper-evidence, a trusted RFC3161 timestamp, and a public verification link are required. It is purpose-built for AI agents via x402 pay-per-call with no account setup.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T12:33:05.131Z","isFirstParty":false,"canonicalSlug":"attest402-signed-evidence-of-public-web-api-response-81f606d1"}