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x402 URL Liveness Probe
x402
x402 URL Liveness Probe is a paid API for AI agents from x402.shortforge.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).
Given a public HTTP(S) URL, returns a structured liveness verdict (LIVE, PAUSED, GATED, CHALLENGED, DEGRADED, DEAD, or UNKNOWN) with sourced reasons explaining the status.
Price / call$0.01
Success—
StatusUnknown
How this service works
Given any public HTTP(S) URL, returns a measured liveness verdict - LIVE, PAUSED, GATED, CHALLENGED, DEGRADED, DEAD or UNKNOWN - with every reason carrying the source it was read from. The point is the case a status check misses: a front door answering 200 over a back end that stopped. Also sold at this origin: good ($149.00, POST /x402/good) - The x402 rail, ninety days - framed print, 24 x 36 in; census ($100.00, GET /x402/census) - The x402 rail census, ninety days, whole.
Output
A structured liveness verdict object with one of seven categorical labels (LIVE, PAUSED, GATED, CHALLENGED, DEGRADED, DEAD, UNKNOWN), accompanied by a list of reasons each tagged with the source from which the evidence was read. This goes beyond a simple HTTP status code check by detecting cases where a front-end proxy answers 200 while the back end is non-functional.
Example use cases
Third-party API availability check
“Before my workflow runs, probe https://api.partner.com/v2/data with GET and tell me if it's truly live or just returning a fake 200 — I need to know if the back end is actually responding.”
Detecting paywalled or gated content
“Can you check https://premium.news.example.com/article/12345 with a GET request and tell me if it's openly accessible or gated behind a login or paywall?”
Monitoring a deployed service for degradation
“Probe https://myapp.production.example.com/api/status with a HEAD request and give me its liveness verdict — specifically whether it's DEGRADED or fully LIVE right now.”
Technical details
Endpoint
GEThttps://x402.shortforge.dev/x402/probe?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need to go beyond a naive HTTP status check and detect subtle failures like a gateway returning 200 while the upstream service is dead, or when you need a machine-readable categorical verdict with sourced evidence. Ideal for agent workflows that gate on real service availability before making downstream calls, monitoring pipelines, or any situation where a simple ping is insufficient.
Side effects
- Invalid or non-public URL returns an error or UNKNOWN verdict
- URL behind a firewall or IP block may return DEAD incorrectly
- Very slow endpoints may time out and return DEGRADED or UNKNOWN
- Redirecting URLs may require following chains not captured in a single probe
- Endpoints requiring POST or non-supported methods cannot be probed (only GET/HEAD/DELETE supported)
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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