{"uid":"cap_yQJBtRY_F00cQKcwJpPeX","slug":"agentread-changes-url-change-monitor-4ec1a762","name":"agentread /changes — URL Change Monitor","description":"Read a URL your own fetch failed on and get the page text back, or a verdict explaining why it cannot be read. Built for agents that just got a 403, 429, empty body or JS shell.","url":"https://agentread.midi-thumb.workers.dev/changes?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type"],"properties":{"type":{"const":"http"},"method":{"const":"POST"}},"additionalProperties":true},"output":{"type":"object","additionalProperties":true}}},"responseSchema":{"type":"json","example":{"changed":null,"first_check":true,"baseline_chars":171}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_H7tgbsrErP3OvDyL-nwU9","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a previously-fetched URL has changed since a baseline was established, returning a diff verdict or null if unchanged.","exampleAgentPrompt":"Keep an eye on that product page for me — if anything changes from what you last saw, let me know right away.","exampleUseCases":[{"title":"Price drop alert on blocked page","prompt":"Check if the price on that sneaker listing has changed since you last looked — it kept giving you a 403, so use agentread to see if anything's different now."},{"title":"News article update detector","prompt":"Has that live-blog article been updated since we last checked? I want to know if there's any new content added to it."},{"title":"Monitoring competitor landing page","prompt":"Is our competitor's homepage showing anything different from the baseline you captured yesterday? Flag it if the content has changed at all."}],"resultDescription":"Returns a JSON object with: 'changed' (boolean or null if indeterminate), 'first_check' (boolean indicating whether this is the first baseline capture), and 'baseline_chars' (integer count of characters in the stored baseline). On first check, changed is null and the baseline is established.","failureModes":["URL is unreachable or permanently blocked — returns a verdict explaining why it cannot be read","First call establishes baseline so 'changed' is always null on initial check","Rate limits or anti-bot measures may prevent content retrieval, returning an explanatory verdict","URL returns empty or JavaScript-shell page — may result in baseline_chars of 0 or a verdict string","Invalid input schema (missing 'type' field) returns a validation error"],"whenToPreferThis":"Use this endpoint when you need to detect whether a URL's content has changed since a previous check, especially for pages that returned 403, 429, empty body, or JS-only shells when fetched directly. Prefer this over general-purpose scrapers when change detection (not full content extraction) is the primary goal, or when the target URL has previously blocked your fetches.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:40:01.408Z","isFirstParty":false,"canonicalSlug":"agentread-changes-url-change-monitor-4ec1a762"}