# dns-a-auth-subdomain

> dns-a-auth-subdomain is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Looks up the A record for auth.<domain> via Cloudflare DNS over HTTPS and reports whether the auth subdomain exists, its IP records, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/auth/a?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-a-auth-subdomain-3bbcc20f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__ORt_z5evrfNENn8kZvC7

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-auth-subdomain-3bbcc20f
```

Example prompt: Does example.com have an auth subdomain set up? Look up its DNS A record and tell me the IP address and TTL if it exists.

## When to prefer this

Use this endpoint when you need a quick, single-host existence check for the auth subdomain of a specific domain without enumerating all subdomains. Prefer this over generic DNS resolvers when you want a structured, agent-friendly response and are specifically interested in whether a domain has isolated its authentication on a dedicated auth host.

## Known failure modes

- Domain does not exist — NXDOMAIN returned, no records found
- auth subdomain not configured — lookup returns no A records
- Invalid or malformed domain input — API may return error or empty result
- Cloudflare DoH upstream timeout — transient failure
- Rate limiting or payment failure for the $0.01 USDC per-call fee

## How this service works

A record of auth.<domain>: looks up the auth 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 auth without enumerating subdomains. $0.01 per lookup.

## Output

Returns whether the auth.<domain> subdomain exists as a DNS A record, the resolved IP address(es), the TTL in seconds, and metadata about the lookup via Cloudflare DoH.

## 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-auth-subdomain-3bbcc20f/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)