{"uid":"cap_XWCxhpZg9hw8wbzarugAg","slug":"changecheck-f9c85a5c","name":"ChangeCheck","description":"Paid x402 API that detects meaningful changes on public webpages.","url":"https://changecheck-mainnet-production.up.railway.app/change?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","format":"uri","description":"Public webpage to check for changes"},"previous_content":{"type":"string","description":"Optional previous snapshot. Omit on the first call to create a baseline."}}},"responseSchema":{"type":"json","example":{"changed":true,"summary":"The closing date moved from 20 October to 27 October.","confidence":0.96,"material_change":true,"baseline_created":false,"important_changes":["Closing date changed"]}},"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_B_cmKB4KRZyUUUNJS3Tut","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":"Detects and summarizes meaningful changes on a public webpage compared to a previous snapshot, returning a confidence-scored summary of what changed.","exampleAgentPrompt":"Check if this webpage has changed since my last snapshot — here's the URL https://example.com/announcements and here's the previous content I saved: 'Closing date: 20 October 2024'. Tell me what changed and whether it's a meaningful update.","exampleUseCases":[{"title":"Track job listing deadline changes","prompt":"Keep an eye on this job posting at https://careers.example.com/job/123 — I saved the page last week and the deadline was October 20th. Has anything changed, especially the closing date or requirements?"},{"title":"Monitor competitor product pricing page","prompt":"Check whether the pricing page at https://competitor.com/pricing has changed from the snapshot I have — I want to know if they've updated their plans or prices and how significant the change is."},{"title":"Watch government regulation page for updates","prompt":"Has this government regulation page at https://regulations.gov/notice/2024-001 changed at all from this snapshot I saved last month? Let me know if there are any material updates I should act on."}],"resultDescription":"Returns a JSON object with: a boolean 'changed' indicating whether the page differs from the baseline, a human-readable 'summary' of what changed, a 'confidence' score (0–1) reflecting certainty of the analysis, a 'material_change' boolean indicating whether the change is substantive, a 'baseline_created' boolean indicating if this was the first call establishing a baseline, and an 'important_changes' array listing specific notable changes detected.","failureModes":["URL is not publicly accessible or returns a non-200 status — endpoint may fail to retrieve content","previous_content is malformed or truncated — may reduce comparison accuracy and confidence score","Webpage uses heavy JavaScript rendering — static fetch may miss dynamically loaded content","Payment failure or insufficient USDC balance — request rejected before processing","URL points to a binary file or non-text content — change detection may be unreliable"],"whenToPreferThis":"Choose ChangeCheck when you need to detect and summarize meaningful changes on a specific public webpage, especially when you have a prior snapshot to compare against. It is ideal for monitoring deadlines, announcements, policy pages, product listings, or any text-heavy public page where semantic understanding of what changed matters — not just a byte-level diff. Prefer it over generic web scrapers when you need a confidence-scored, human-readable summary of changes rather than raw content.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T12:30:13.391Z","isFirstParty":false,"canonicalSlug":"changecheck-f9c85a5c"}