{"uid":"cap_-n9NRsKXOA5qMcMgv9kld","slug":"reverse-dns-via-dnssb-097328ae","name":"reverse-dns-via-dnssb","description":"Reverse DNS (PTR) of an IPv4 address as answered by DNS.SB: the hostname(s), TTL and response code, plus whether the PTR's forward A record points back (forward-confirmed reverse DNS). Compare resolvers for stale or filtered answers. $0.01 per lookup.","url":"https://ip.intel.rallylive.ca/ip/ptr/via/dnssb?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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":"0.01","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":"$0.01/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_ScHFqaMow_aKX5AuRprB8","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Performs a reverse DNS (PTR) lookup for an IPv4 address using the DNS.SB resolver, returning hostnames, TTL, response code, and forward-confirmed reverse DNS (FCrDNS) status.","exampleAgentPrompt":"What is the reverse DNS hostname for 8.8.8.8 according to DNS.SB, and does its PTR record forward-confirm back to the same IP?","exampleUseCases":[{"title":"Email server identity verification","prompt":"I need to check if the IP 203.0.113.45 has a valid reverse DNS entry that forward-confirms back to itself — we're debugging an email deliverability issue and need to know what DNS.SB returns for its PTR record."},{"title":"Detecting stale resolver PTR answers","prompt":"Can you query the reverse DNS for 1.2.3.4 via DNS.SB and tell me the hostname, TTL, and response code so I can compare it against what another resolver is returning?"},{"title":"IP reputation and abuse investigation","prompt":"I'm investigating a suspicious IP — 198.51.100.22 — can you do a reverse DNS lookup using DNS.SB and tell me if it has a hostname and whether it's forward-confirmed?"}],"resultDescription":"Returns the PTR hostname(s) associated with the queried IPv4 address as answered by DNS.SB, along with the TTL (time-to-live), the DNS response code (e.g. NOERROR, NXDOMAIN), and a forward-confirmed reverse DNS (FCrDNS) flag indicating whether the PTR record's hostname resolves back to the original IP via an A record.","failureModes":["IP has no PTR record — DNS.SB returns NXDOMAIN response code","PTR exists but forward A record does not point back — FCrDNS flag is false","DNS.SB resolver timeout or unavailability — service may return an error or empty response","Invalid IPv4 address input — may return a validation error","PTR record exists but is stale — TTL may indicate cached data that differs from other resolvers"],"whenToPreferThis":"Use this endpoint when you specifically want the DNS.SB resolver's perspective on a PTR record — useful for comparing resolver answers, detecting filtered or stale PTR entries, or validating forward-confirmed reverse DNS (FCrDNS) as part of email authentication checks or IP reputation analysis. Prefer this over generic reverse DNS tools when resolver-specific attribution matters.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T18:43:37.337Z","isFirstParty":false,"canonicalSlug":"reverse-dns-via-dnssb-097328ae"}