{"uid":"cap_9FMiIB53o8jmBAJFLodm-","slug":"is-port-53-open-watch-076ad7fe","name":"is-port-53-open-watch","description":"Change watch for is port 53 open: runs the check, compares it with the result from your previous call for the same host (kept 90 days) and returns the current answer, changed true/false, the fields that changed with before/after values, and when it was last seen. Schedule it to be alerted when this changes. $0.02 per check.","url":"https://ip.intel.rallylive.ca/watch/ip/port/53?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_xZbRItGQ7spX3rGNznJG5","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Change-watches whether TCP port 53 (DNS) is open on a host, returning current status, a changed flag, before/after diffs, and last-seen timestamp compared against the previous call.","exampleAgentPrompt":"Keep an eye on whether port 53 is open on 203.0.113.42 and let me know if anything changes from the last time you checked.","exampleUseCases":[{"title":"DNS server outage alerting","prompt":"Watch port 53 on my DNS server at 198.51.100.10 and tell me the moment it goes from open to closed — I need to know immediately if DNS goes down."},{"title":"Unauthorized DNS listener detection","prompt":"Check if port 53 has started opening on 10.0.0.55 since the last time you looked — I want to catch any unauthorized DNS services that have appeared."},{"title":"DNS service restoration confirmation","prompt":"Has port 53 come back up on 203.0.113.75 since my last check? Show me what changed and when it was last seen open."}],"resultDescription":"Returns the current open/closed status of port 53 on the target host, a boolean 'changed' field indicating whether it differs from the previous call (cached up to 90 days), a diff of changed fields with before and after values, and a last-seen timestamp.","failureModes":["Host unreachable or invalid hostname returns an error or closed status","No prior call stored for that host means no meaningful diff on first invocation","Payment failure (x402) blocks the check from running","Rate limiting or Cloudflare edge connectivity issues may cause timeouts","Cached result expired after 90 days, losing diff baseline"],"whenToPreferThis":"Choose this endpoint when you need to detect state transitions on port 53 specifically (DNS) rather than just a point-in-time open/closed check. It is ideal for scheduled polling workflows where you want to be alerted only when something changes, avoiding noise from repeated same-state results. Prefer it over a plain port-check endpoint when you need the before/after diff and last-seen timestamp for audit or alerting pipelines.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T00:41:46.639Z","isFirstParty":false,"canonicalSlug":"is-port-53-open-watch-076ad7fe"}