{"uid":"cap_gH2pMAi6k2f0jY6FYd5sD","slug":"sentinel-url-watcher-1-hour-da1d9a2a","name":"Sentinel URL Watcher (1-Hour)","description":"Watch a URL for 1 hour: signed callbacks when its verdict changes","url":"https://sentinel.rootstuff.io/x402/watch-1h","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","description":"The http(s) URL to watch. Public hosts only."},"payload":{"type":"object","description":"Up to 4 KB of JSON echoed back in every callback."},"callback_url":{"type":"string","description":"Public https URL that receives the POSTs. Private and reserved addresses are refused; redirects are not followed."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_BGPnMNmLRU-IrY5m-r1YO","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Monitors a public URL for 1 hour and sends signed webhook callbacks whenever its reachability or status verdict changes","exampleAgentPrompt":"Watch https://api.myservice.com/health for the next hour and POST a signed callback to https://hooks.myapp.com/sentinel whenever its up/down verdict changes — include {\"env\":\"production\",\"service\":\"payments-api\"} as the payload so I know which service it came from.","exampleUseCases":[{"title":"Post-deploy site availability check","prompt":"I just deployed a new version of my app to https://staging.myapp.com — watch it for the next hour and hit https://hooks.myapp.com/alerts if its status verdict changes, so I know immediately if something breaks."},{"title":"Third-party API dependency alert","prompt":"Can you monitor https://api.stripe.com/v1 for one hour and send a signed callback to https://ops.mycompany.com/webhook whenever its verdict flips? Include {\"dependency\":\"stripe\",\"team\":\"payments\"} in the payload."},{"title":"Short-term incident response watch","prompt":"We're in the middle of an incident — watch https://status.partner-service.com for the next hour and POST to https://my-pagerduty-bridge.com/sentinel whenever the verdict changes, so our on-call engineer gets notified automatically."}],"resultDescription":"The endpoint registers the watch and then delivers HTTP POST callbacks to the specified callback_url whenever the target URL's verdict (up/down/reachable/unreachable) changes during the 1-hour window. Each callback is cryptographically signed and echoes back the original payload. No polling is required by the caller.","failureModes":["callback_url is a private or reserved IP address — request is refused","target URL is not a public host — rejected at registration","callback_url returns non-2xx repeatedly — retries may be exhausted silently","payload exceeds 4 KB limit — request rejected","watch window expires after exactly 1 hour with no further callbacks","callback_url has redirect chains — not followed, treated as failure"],"whenToPreferThis":"Choose this endpoint when you need short-term (1-hour) URL monitoring with push-based signed callbacks rather than polling. It is ideal for post-deploy checks, incident response windows, or any situation where you want automatic notification of verdict changes without managing a long-running watcher. Prefer the 24-hour sibling endpoint for longer monitoring needs, or the consensus-check endpoint for a one-shot multi-region availability snapshot instead of ongoing watching.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:49:31.628Z","isFirstParty":false}