# DNS A Record Lookup for www Subdomain via Cloudflare DoH

> DNS A Record Lookup for www Subdomain via Cloudflare DoH is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-21).

Looks up the A (IPv4) DNS record for the www subdomain of a given domain using Cloudflare DNS-over-HTTPS, returning existence status, IP records, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/www/a?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-a-record-lookup-for-www-subdomain-via-cloudflare-doh-3da73fc4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_A3g0nUKD46gL2z4IpokB4

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 dns-a-record-lookup-for-www-subdomain-via-cloudflare-doh-3da73fc4
```

Example prompt: Can you check if www.example.com has a valid DNS A record — I need to know the IP it resolves to and its TTL?

## When to prefer this

Use this endpoint when you specifically need to check whether the www host of a domain is configured with an IPv4 A record, without enumerating all subdomains. Prefer this over general DNS lookup services when you want a targeted, quick existence check for the canonical www subdomain, especially when building domain validation pipelines or monitoring web presence.

## Known failure modes

- Domain does not exist — NXDOMAIN response with no records
- www subdomain not configured — no A record found but domain itself may exist
- Invalid domain format in query — request rejected
- Cloudflare DoH upstream timeout or failure — lookup may return an error
- Network unreachability — endpoint itself may be temporarily unavailable

## How this service works

A record of www.<domain>: looks up the www host under the domain you give (A via Cloudflare DoH) and reports whether it exists, its records and TTL. Quick existence check for common hosts like www without enumerating subdomains. $0.01 per lookup.

## Output

Returns whether the www subdomain has an A record, the IPv4 address(es) it resolves to, the TTL of the record, and the DNS response code indicating existence or non-existence of the host.

## Request schema (JSON Schema)

```json
{
 "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"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dns-a-record-lookup-for-www-subdomain-via-cloudflare-doh-3da73fc4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dns.intel.rallylive.ca](https://www.zero.xyz/host/dns.intel.rallylive.ca/llms.txt)