# agent402.tools ASN Info Lookup

> agent402.tools ASN Info Lookup is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Looks up the Autonomous System Number (ASN), IP prefix, country, registry, and allocation date for an IPv4 address or hostname using Team Cymru's DNS-based mapping.

## Facts

- Endpoint: POST https://agent402.tools/api/asn-info
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-asn-info-lookup-dd5c4bf2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yFWsjlYpvb0v3zxsjdvwq

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agent402-tools-asn-info-lookup-dd5c4bf2 -d '<json body>'
```

Example prompt: Can you look up the ASN, IP prefix, country, and registry for 8.8.8.8? I want to know which autonomous system and network block it belongs to and when it was allocated.

## When to prefer this

Use this endpoint when you need fast, lightweight ASN and BGP prefix lookups for a single IPv4 address or hostname without requiring API keys or authentication. Ideal for network investigation, threat intelligence enrichment, or identifying ISPs and network operators behind an IP. Prefer this over WHOIS-based tools when you specifically need ASN/prefix routing data rather than registrant contact details.

## Known failure modes

- Invalid or private/reserved IP address returns no ASN data
- Hostname cannot be resolved — DNS resolution failure
- Malformed input (non-IPv4 address when ip field is used)
- Team Cymru DNS service unavailable or timing out
- IP address in bogon/unrouted space returns empty results

## How this service works

Look up the Autonomous System (ASN), prefix, country, registry, and allocation date for an IPv4 address - or for a hostname (which is resolved first). Uses Team Cymru's free DNS-based IP→ASN mapping; no HTTPS upstream, no auth, no rate-limit headaches.

## Output

Returns the ASN number, BGP prefix/CIDR block, country code, registry (e.g. ARIN, RIPE, APNIC), and allocation date for the queried IP address or resolved hostname.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ip": {
   "type": "string",
   "description": "IPv4 address to look up (mutually exclusive with host)"
  },
  "host": {
   "type": "string",
   "description": "Hostname to resolve first (also accepts hostname/domain/url/email)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ip": "8.8.8.8",
  "asn": "AS15169",
  "owner": "GOOGLE",
  "prefix": "8.8.8.0/24",
  "country": "US",
  "registry": "arin",
  "queriedAt": "2026-06-19T22:00:00.000Z",
  "allocationDate": "1992-12-01"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-asn-info-lookup-dd5c4bf2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)