{"uid":"cap_KQsUBFbWaZomdfPvqfUor","slug":"freshproof-http-api-0d25f25c","name":"FreshProof HTTP API","description":"Paid machine-to-machine public URL observations with timestamped SHA-256 response-body fingerprints. POST /observe costs $0.005 USDC per call on Base via x402 v2. The price is the same for shared_cache and fresh_fetch results. A fresh_fetch means FreshProof performed a new public-network HTTP request at the recorded time. The destination itself may serve content from its own CDN, proxy, or cache.","url":"https://freshproof-http.ricardobessellp-11d.workers.dev/observe?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","format":"uri","description":"Public HTTP or HTTPS URL to observe"},"max_age":{"type":"integer","minimum":0,"description":"Maximum acceptable observation age in seconds. Defaults to 300. Set to 0 to force a fresh public-network request."}}},"responseSchema":{"type":"json","example":{"url":"https://example.com","etag":null,"source":"fresh_fetch","status":200,"final_url":"https://example.com/","age_seconds":0,"observed_at":"2026-09-23T10:00:00.000Z","content_hash":"sha256:ff67a9d764d6a2367a187734e697f6a53217db9a21c101d410a113ca871a299d","last_modified":null,"content_length":559,"fetch_duration_ms":8}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_WgfvTdOzmbFdSVMWkWTjR","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","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 a timestamped SHA-256 fingerprint of the response body, proving what content was served at a specific moment in time.","exampleAgentPrompt":"Get me a fresh SHA-256 fingerprint of https://example.com/terms-of-service right now — force a new network request so I have a timestamped proof of exactly what that page contains today.","exampleUseCases":[{"title":"Audit a public policy page","prompt":"Fetch https://acme.com/privacy-policy and give me a cryptographic fingerprint of what it contains today — I need a timestamped SHA-256 hash as proof of the current version, so use a max_age of 0 to make sure it's a fresh fetch."},{"title":"Monitor a live API endpoint for changes","prompt":"Check https://api.partner.com/v1/status for me and return a SHA-256 hash of the response body — use a max_age of 60 seconds so I can compare it against the hash I recorded an hour ago and see if anything changed."},{"title":"Certify a public file's content at a moment in time","prompt":"I need a verified observation of https://releases.myproject.io/latest/manifest.json — grab it fresh and give me the SHA-256 hash, observed timestamp, and final URL so I can attach this as evidence to our compliance report."}],"resultDescription":"A JSON object containing: the observed URL and final URL after redirects, HTTP status code, source ('fresh_fetch' or 'shared_cache'), SHA-256 content hash of the response body, ISO 8601 observed_at timestamp, age_seconds, content_length in bytes, fetch_duration_ms, and optional ETag and Last-Modified headers if present.","failureModes":["URL is not publicly reachable — network error or timeout returned","URL returns a non-200 status (e.g. 403, 404, 500) — status is recorded but may not represent expected content","shared_cache result returned when max_age > 0 and a recent observation already exists — may not reflect the very latest content","Payment failure or insufficient USDC balance — request rejected before observation is made","URL redirects to a private or internal address — may fail or return unexpected content","Response body too large — may cause timeout or truncation in the fingerprint"],"whenToPreferThis":"Choose FreshProof when you need cryptographically verifiable, timestamped proof of what a public URL served at a specific moment — particularly for auditing, compliance, content integrity checks, or dispute resolution. It is ideal when you need to prove a page said something at a given time, detect content drift over repeated observations, or create an immutable audit trail. Prefer max_age=0 when freshness is critical. Use over generic HTTP clients when the timestamped SHA-256 fingerprint and machine-to-machine payment via x402 are required as part of the workflow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T03:06:36.817Z","isFirstParty":false,"canonicalSlug":"freshproof-http-api-0d25f25c"}