{"uid":"cap_G1mSDcOCubN3hmIpUztAM","slug":"nova-monitor-check-e9c0df52","name":"NOVA Monitor Check","description":"Machine-facing pay-per-call utility services using x402 on Base with USDC.","url":"https://nova-demand-worker.vercel.app/x402/monitor-check?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string"},"selector":{"type":"string"},"previousHash":{"type":["string","null"]}}},"responseSchema":{"type":"json","example":{"hash":"sha256...","changed":null,"checkedAt":"2026-09-24T00:00:00.000Z"}},"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_XhybK1V1MyNXdUiq6pdBG","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":"Checks a web page element for content changes by comparing a SHA-256 hash of the selected content against a previous hash","exampleAgentPrompt":"Check if the main headline on https://example.com/news has changed since last time — use the selector 'h1.headline' and compare against my previous hash 'sha256abc123'.","exampleUseCases":[{"title":"E-commerce price change detection","prompt":"Check whether the price shown on https://store.example.com/product/widget has changed — use the selector '.price-tag' and compare against my last recorded hash 'sha256def456'."},{"title":"News headline monitoring","prompt":"Has the top story on https://newssite.com changed? Use the selector '#top-story h2' and tell me if it's different from my previous hash 'sha256xyz789'."},{"title":"Government regulation page tracking","prompt":"Monitor https://regulations.gov/rule/XYZ for any updates to the rule text — use the selector '.rule-body' and let me know if anything has changed since hash 'sha256prev001'."}],"resultDescription":"Returns a JSON object containing a SHA-256 hash of the current content at the selected element, a 'changed' boolean indicating whether it differs from the previousHash, and a 'checkedAt' ISO timestamp of when the check was performed.","failureModes":["Invalid or unreachable URL returns an error","CSS selector matches no elements, resulting in empty or null hash","Network timeout if the target page is slow to load","Invalid previousHash format may cause comparison failure","Payment failure via x402/USDC will block the request"],"whenToPreferThis":"Use this endpoint when you need a lightweight, pay-per-call web content change detector that hashes a specific CSS-selected element rather than the entire page. Ideal for agents that need to poll a URL periodically and only act when something has actually changed, without storing full page snapshots.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T06:41:32.925Z","isFirstParty":false,"canonicalSlug":"nova-monitor-check-e9c0df52"}