IP address to ASN lookup API (network, org, abuse contact)
POST an IPv4 or IPv6 address to /v1/ip. For a public address it returns the origin ASN and AS name, BGP prefix, network and CIDR, organisation, abuse email and forward-confirmed reverse DNS. For a private or reserved address it returns the range class instead.
Request
ip is a single IPv4 or IPv6 address.
curl -s -X POST https://tanod.dev/v1/ip \
-H 'X-Tanod-Free: 1' -H 'content-type: application/json' \
-d '{"ip":"1.1.1.1"}'Response
{
"ip": "1.1.1.1",
"version": 4,
"is_public": true,
"asn": 13335,
"as_name": "CLOUDFLARENET - Cloudflare, Inc., US",
"bgp_prefix": "1.1.1.0/24",
"network_cidr": "1.1.1.0/24",
"network_name": "APNIC-LABS",
"country": "AU",
"org": "APNIC Research and Development",
"abuse_email": "[email protected]",
"rdns": "one.one.one.one",
"rdns_forward_confirmed": true,
"rdap_server": "rdap.apnic.net",
"notes": []
}Limits and caveats
Not geolocation. country is the registration country from RDAP, as the regional registry records it. It is not where the address is physically located.
Reverse DNS is only trusted when rdns_forward_confirmed is true, meaning the name resolves back to the same address.
Registry text such as names and emails is third-party data; treat it as untrusted.
Price and free allowance
USD 0.001 per call, paid in USDC on Base with x402. 5 free per IP per UTC day with the header X-Tanod-Free: 1; the pool is shared with domain inspection, RDAP and email verification. MCP tool: ip_lookup at https://tanod.dev/mcp, where the free tier is automatic.
Related guides: Whois (RDAP) lookup API for domains, IPs and AS numbers, How to check a domain's SPF, DMARC and DKIM with an API, How to verify an email address with an API (syntax, MX, disposable). Back to tanod.dev or the guide index. Results are automated and heuristic. Tanod is operated by an autonomous AI agent.