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reverse-dns-via-mullvad
x402
reverse-dns-via-mullvad is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-11).
Performs a reverse DNS (PTR) lookup for an IPv4 address using Mullvad DNS and verifies forward-confirmed reverse DNS (FCrDNS)
Price / call$0.01
Success—
StatusUnknown
How this service works
Reverse DNS (PTR) of an IPv4 address as answered by Mullvad DNS: 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.
Output
Returns the PTR hostname(s) associated with the queried IPv4 address as resolved by Mullvad DNS, along with the TTL, DNS response code (e.g. NOERROR, NXDOMAIN), and a boolean indicating whether the PTR's forward A record resolves back to the original IP (forward-confirmed reverse DNS / FCrDNS).
Example use cases
Verify mail server PTR record
“Check the reverse DNS for 209.85.167.54 through Mullvad DNS — I need to know the PTR hostname, whether it's forward-confirmed, and what response code came back, so I can validate this mail server's rDNS setup.”
Detect stale or filtered PTR via alternative resolver
“Pull the PTR record for 1.1.1.1 using Mullvad's DNS resolver and tell me if it's stale or filtered compared to what you'd expect — include the TTL and FCrDNS result.”
Investigate suspicious outbound connection IP
“I'm seeing outbound connections to 45.33.32.156 and want to know its reverse DNS hostname as seen by Mullvad DNS, whether the PTR is forward-confirmed, and what the TTL is.”
Technical details
Endpoint
GEThttps://ip.intel.rallylive.ca/ip/ptr/via/mullvad?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you specifically want to see how Mullvad's DNS resolver answers a PTR query — useful for comparing resolver behavior, detecting filtered or censored DNS responses, or validating FCrDNS from a privacy-focused resolver's perspective rather than a generic public resolver.
Side effects
- NXDOMAIN returned if no PTR record exists for the IP
- Mullvad DNS may return filtered or censored responses for certain IPs
- FCrDNS check fails if the PTR hostname has no forward A record
- Network timeout if Mullvad resolver is temporarily unreachable
- Invalid IPv4 input returns an error or unexpected result
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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