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x-402 Web Page Change Detector
x402
x-402 Web Page Change Detector is a paid API for AI agents from api.x-402.online, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).
Checks whether a web page's main content has changed since a previous fetch, using a SHA-256 checksum comparison.
Price / call$0.005
Success—
StatusUnknown
How this service works
Tell whether a page changed since the last time you read it. Has a page changed since you last read it? Send a URL and the content_sha256 you kept from a previous call; get back changed: true or false, the current checksum and the current length. Without a checksum, returns the starting point. Main content only, navigat…
Output
Returns a JSON object with: a `changed` boolean (true if the page content differs from the supplied checksum, false if identical), the `current content_sha256` checksum of the page's main content as fetched now, and the `current length` in bytes. If no prior checksum is supplied, returns the initial baseline checksum and length without a change comparison.
Example use cases
News article update tracker
“Has the article at https://bbc.com/news/article-12345 changed since I last fetched it? My saved checksum is d4e9a2b7c1f08345.”
Competitor pricing page monitor
“Check if the pricing page at https://competitor.com/pricing still matches the checksum I recorded last week: 9b3c7f1a2e456d80. I want to know immediately if they've updated their prices.”
Establish baseline for new page
“I want to start monitoring https://myregulator.gov/updates/policy — can you fetch it now and get me the current checksum and length so I can track changes going forward?”
Technical details
Endpoint
GEThttps://api.x-402.online/v1/web/changed?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need lightweight, low-cost change detection ($0.005/call) on a specific URL without maintaining your own scraping infrastructure. It is ideal for polling loops where you already have a stored checksum from a prior call and want a simple true/false answer. Prefer this over full-scrape endpoints when you don't need the page content itself — only whether it changed. It strips navigation and boilerplate to focus on main content, reducing false positives from peripheral page updates.
Side effects
- URL is unreachable or returns a non-200 status — endpoint may error or return an indeterminate result
- Page blocks bots or requires authentication — main content cannot be fetched
- Supplied checksum format is invalid — comparison may fail or be skipped
- Rate limiting or payment failure for the $0.005 USDC per-call fee — request rejected
- Dynamic pages with ads or timestamps may falsely report changed=true due to non-content elements
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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