{"uid":"cap_MF1fAIFOVSp1pKwu_TBcC","slug":"sentinel-6-hour-url-watcher-f73700f4","name":"Sentinel 6-Hour URL Watcher","description":"Watch a URL for 6 hours: signed callbacks when its verdict changes","url":"https://sentinel.rootstuff.io/x402/watch-6h","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":"0.2","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":"$0.2/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.2","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.2","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ZlTHa8HgsO5LLfSHD9p4o","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.2","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 6 hours and delivers signed webhook callbacks whenever its up/down verdict changes","exampleAgentPrompt":"Watch https://api.myservice.com/health for the next 6 hours and POST a signed callback to https://hooks.myapp.com/sentinel whenever its status changes — include {\"service\":\"myservice\",\"env\":\"prod\"} in the payload so I can identify it.","exampleUseCases":[{"title":"Deployment health check window","prompt":"After I deploy my new release, watch https://app.example.com/ping for 6 hours and notify https://hooks.example.com/alerts whenever its verdict flips — include {\"deploy_id\":\"v2.4.1\"} in every callback so I can correlate it."},{"title":"Scheduled maintenance window monitoring","prompt":"We have a maintenance window starting now — keep an eye on https://checkout.mystore.com for 6 hours and send signed callbacks to https://ops.mystore.com/webhook if it goes down or comes back up, with {\"window\":\"maintenance-2024-06\"} in the payload."},{"title":"Third-party dependency outage detection","prompt":"I need to know if our payment provider's API at https://api.paymentco.com/v1/status changes availability in the next 6 hours — send any verdict changes to https://notify.mycompany.com/deps with payload {\"vendor\":\"paymentco\"}."}],"resultDescription":"No direct response body is returned to the caller; instead, signed HTTP POST callbacks are delivered to the specified callback_url whenever the monitored URL's up/down verdict changes during the 6-hour watch window. Each callback includes the verdict change details and the echoed custom payload provided at registration. Callbacks are cryptographically signed so the receiver can verify authenticity.","failureModes":["Invalid or non-public target URL — private/reserved IP ranges refused","callback_url is not a public HTTPS endpoint — private or reserved addresses rejected","callback_url uses redirects — redirects are not followed, delivery will fail","Payload exceeds 4 KB limit — request rejected","URL becomes permanently unreachable and no verdict changes occur — no callbacks sent","Callback endpoint is down when verdict changes — delivery may be lost"],"whenToPreferThis":"Choose this endpoint when you need short-term URL availability monitoring (up to 6 hours) without running your own polling infrastructure, and you want push-based signed webhook notifications rather than polling for status. It is ideal for deployment windows, maintenance periods, or short-lived incidents where the 24-hour watch would be excessive. Prefer this over the 24-hour watcher when cost or watch duration needs to be minimized. Use when cryptographic signing of callbacks is important for verifying authenticity at your receiver.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:44:26.082Z","isFirstParty":false}