{"uid":"cap_0MNHvTzmTiEJ0Hzvdihvg","slug":"forest-web-detect-changes-in-static-page-229658c8","name":"Forest Web – Detect Changes in Static Page","description":"Detect bounded changes across one static page surface using one HTML fetch plus at most one robots.txt fetch. Forest hashes HTTP identity, page metadata, normalized JSON-LD, downloadable links, form schema and robots context without storing snapshots, rendering JavaScript or submitting anything. Base mainnet USDC","url":"https://http--forest-gas-station-mainnet--lcjl27p8lmjs.code.run/site/changed-since?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","pattern":"^https?://","maxLength":2048,"minLength":1,"description":"Public HTTP(S) URL to inspect, resolve, or compare."},"user_agent":{"type":"string","maxLength":128,"minLength":1,"description":"Public user agent value used to scope this lookup."},"previous_hash":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."},"previous_dimensions":{"type":"object","required":["http","page","structured","downloads","forms","robots"],"properties":{"http":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."},"page":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."},"forms":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."},"robots":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."},"downloads":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."},"structured":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$","description":"Earlier result hash used to detect a material change."}},"description":"Public previous dimensions value used to scope this lookup.","additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.004","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":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_NQR5jKmOlh6bkp53S7Ivl","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Detects bounded, deterministic changes across a static HTML page by comparing multi-dimensional SHA-256 hashes (HTTP identity, metadata, JSON-LD, links, forms, robots) against a previously captured baseline.","exampleAgentPrompt":"Check if https://example.com/about has materially changed since my last scan — compare it against the previous full hash sha256:4a3bc1...def9 and also check dimensions for HTTP, page, structured data, downloads, forms, and robots individually.","exampleUseCases":[{"title":"Job listing change detection","prompt":"Tell me if the job posting at https://careers.acme.com/jobs/12345 has changed since yesterday — I have the previous combined hash sha256:9f1a2b...cc44 and the previous dimension hashes for http, page, structured, downloads, forms, and robots from my last check."},{"title":"Product page price or metadata update","prompt":"Has the product page at https://shop.brand.com/product/widget changed at all since my last scan? Use my previous full hash sha256:de2f44...b901 and my previous dimension hashes to tell me which specific parts changed."},{"title":"Documentation page structure monitoring","prompt":"I want to know if the docs page at https://docs.myapi.com/reference has been updated — compare it against these previous hashes for all six dimensions and tell me if anything is different."}],"resultDescription":"Returns a change detection result indicating whether the page has materially changed since the previous hash was recorded, along with dimension-level comparisons (HTTP identity, page metadata, normalized JSON-LD, downloadable links, form schema, and robots context) — without storing snapshots, executing JavaScript, or submitting any forms.","failureModes":["Invalid or inaccessible URL returns an error","Malformed previous_hash pattern (not sha256:[64 hex chars]) causes a validation rejection","Page requires JavaScript rendering — result will reflect static HTML only, dynamic content not captured","robots.txt fetch may fail silently if not present, affecting robots dimension hash","Payment not included or invalid returns HTTP 402"],"whenToPreferThis":"Use this endpoint when you need lightweight, deterministic, privacy-safe change detection on a static HTML page without storing full snapshots. It is ideal for monitoring pages where you already have a previous hash baseline and want to know precisely which dimension (metadata, links, forms, JSON-LD, robots) changed, rather than extracting full content. Prefer this over full-extraction endpoints when bandwidth or cost matters and you only need a changed/unchanged signal with dimension-level granularity.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:44:21.073Z","isFirstParty":false,"canonicalSlug":"forest-web-detect-changes-in-static-page-229658c8"}