{"uid":"cap_8IjZLN-Cf7oWWFJ1qps2J","slug":"x402station-io-74590271","name":"x402station.io Watch — Webhook Monitoring for x402 Endpoint State Changes","description":"Independent risk-signal layer for x402 agentic commerce — endpoint evidence (decoy / zombie / price-trap / never-paid) before an agent authorizes payment.","url":"https://x402station.io/api/v1/watch","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["url","webhookUrl"],"properties":{"url":{"type":"string","format":"uri"},"signals":{"type":"array","items":{"type":"string"}},"webhookUrl":{"type":"string","format":"uri"}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"secret":"a1b2c3d4e5f6...64-char-hex-secret-shown-only-once","signals":["zombie","decoy_price_extreme"],"watchId":"0a44f6b8-3b7d-4f2a-9e3a-2c5fd1b0aa11","expiresAt":"2026-05-27T00:00:00.000Z","alertsPaid":100,"endpointKnown":true,"alertsRemaining":100}},"example":{"request":{"url":"https://example.com","signals":["dead","zombie","decoy_price_extreme"],"webhookUrl":"https://httpbin.org/post"},"response":{"secret":"2c6e5349eb4ee2c4ceff50ade5238ebca45dabbadca4824d8a7cef8116cb7d9e","signals":["dead","zombie","decoy_price_extreme"],"watchId":"fe43924e-f336-453c-8bd8-b7e83d039938","expiresAt":"2026-06-28T20:50:13.117Z","statusUrl":"/api/v1/watch/fe43924e-f336-453c-8bd8-b7e83d039938?secret=<secret>","alertsPaid":100,"attribution":{"url":"https://x402station.io","spec":"https://x402station.io/spec","claim":"machine-readable response provenance, not merchant endorsement","product":"Watch by x402station.io","authority":"x402station.io"},"endpointKnown":false,"deliveryFormat":{"method":"POST","headers":{"content-type":"application/json","x-x402station-alert-id":"<bigint>","x-x402station-watch-id":"<watch uuid>","x-x402station-signature":"sha256=<hmac-hex>"},"retryPolicy":"Up to 5 attempts with ~5min spacing (driven by the watch-tick cron). After 5 failures the alert is marked failed and not retried.","examplePayload":{"alertId":42,"watchId":"<uuid>","priorState":{"signals":[],"checkedAt":"2026-04-27T00:50:00.000Z","priceAmount":"0.001"},"endpointUrl":"https://example.com/","currentState":{"signals":["zombie","no_history"],"checkedAt":"2026-04-27T01:00:00.000Z","priceAmount":"0.001"},"firedSignals":["zombie"],"clearedSignals":[],"alertsRemaining":99},"signatureScheme":"HMAC-SHA256 over the raw request body, hex-encoded; verify with the secret returned above. Constant-time comparison required."},"unsubscribeUrl":"/api/v1/watch/fe43924e-f336-453c-8bd8-b7e83d039938?secret=<secret>","alertsRemaining":100,"idempotentReplay":false}},"exampleRequest":{"url":"https://example.com","signals":["dead","zombie","decoy_price_extreme"],"webhookUrl":"https://httpbin.org/post"},"tags":["x402"],"displayCostAmount":"0.010000","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"down","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.010000/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_5Li67vIPTp__3ZQBpJ_Qr","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Subscribes a webhook to receive HMAC-signed alerts when an x402 endpoint changes state, covering 30 days and up to 100 alerts for $0.01 USDC.","exampleAgentPrompt":"Set up a 30-day webhook monitor on the x402 endpoint at https://api.example.com/generate so my server at https://my-server.example.com/hooks/x402 gets HMAC-signed alerts whenever its state changes — I want signals for uptime and settlement changes.","exampleUseCases":[{"title":"Monitor third-party vendor API for payment disruption","prompt":"Watch the x402 endpoint at https://vendor.api.example.com/checkout for the next 30 days and send HMAC-signed alerts to https://my-backend.example.com/webhooks whenever it goes down or stops settling payments — I need to know immediately if our checkout integration breaks."},{"title":"Track suspicious endpoint behavior before trusting transfers","prompt":"Subscribe to alerts on https://payments.competitor.example.com/process so I can catch if it starts acting like a decoy or zombie endpoint — send HMAC-signed notifications to https://agent-monitor.example.com/x402-alerts whenever settlement count drops or behavior changes in the next month."},{"title":"Detect when a marketplace vendor becomes unreliable","prompt":"Set up a 30-day webhook subscription on https://marketplace-vendor.example.com/api/pay and alert my ops team at https://ops.example.com/risk-signals whenever the endpoint shows signs of never paying out or changes its settlement pattern — I want those HMAC-signed notifications so we can delist risky vendors early."}],"resultDescription":"A subscription confirmation indicating the watch is active for 30 days with up to 100 HMAC-signed alert deliveries; subsequent webhook POSTs to the provided webhookUrl carry signed payloads describing state changes including settlement count and recency for the monitored x402 endpoint.","failureModes":["Invalid or unreachable x402 endpoint URL — subscription rejected","Webhook URL not reachable or returning non-2xx — alerts may fail to deliver","Insufficient USDC payment — subscription not created","Malformed request body missing required url or webhookUrl fields — 400 error","Alert quota of 100 exhausted before 30 days — no further notifications sent"],"whenToPreferThis":"Use this endpoint when you need ongoing, event-driven notification about a specific x402 endpoint's state rather than a one-time preflight check; ideal for agents that depend on a particular x402 service and need to react automatically to outages, settlement count drops, or behavioral changes over a 30-day window without polling.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T23:25:09.035Z","isFirstParty":false}