{"uid":"cap_XajEbYxLQ7aL3XDo22uC9","slug":"change-diff-check-2aaa95ab","name":"Change / Diff Check","description":"Compare normalized public webpage text with a prior SHA-256 hash.","url":"https://mcp.dropenginehq.com/api/check-change?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","format":"uri","maxLength":4096},"previous_hash":{"type":"string","maxLength":80,"minLength":1}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_5eB2ahTpnwJKeo3MxdobK","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Compares normalized public webpage text against a previously stored SHA-256 hash to detect whether the page content has changed.","exampleAgentPrompt":"Check if the content at https://example.com/pricing has changed since I last recorded it — here's the previous SHA-256 hash: a3f1c2d9e4b7...","exampleUseCases":[{"title":"Price page change detection","prompt":"Has https://competitor.com/pricing changed since yesterday? Here's the SHA-256 hash I stored from the last check: b4e2a1f9c3d8..."},{"title":"Policy document update monitor","prompt":"Can you check if the terms of service at https://example.com/terms is still the same as it was when I hashed it — previous hash is 9c1d3e7f2a4b..."},{"title":"Autonomous agent content integrity check","prompt":"Before I proceed, verify that https://docs.api.example.com/v2/reference hasn't been modified since we last fetched it — the hash from our last run was 7f3a2c8e1b9d..."}],"resultDescription":"Returns whether the current normalized text of the webpage matches, differs from, or cannot be compared to the provided SHA-256 hash — likely including a changed/unchanged status flag and potentially the new hash of the current page content.","failureModes":["URL is unreachable or returns non-200 status","URL points to a non-public or paywalled page","previous_hash is malformed or wrong length","webpage content cannot be normalized for comparison","rate limiting or payment failure via x402 protocol"],"whenToPreferThis":"Use this endpoint when you need lightweight, hash-based change detection for a specific public webpage without storing full snapshots. Ideal for autonomous agents that need to cheaply verify whether a page has been modified since a prior crawl, rather than doing a full re-extract. Preferred over full-extract endpoints when you only need a yes/no change signal and already have a stored hash.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T18:34:23.028Z","isFirstParty":false,"canonicalSlug":"change-diff-check-2aaa95ab"}