# dns-a-login-subdomain

> dns-a-login-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 the login.<domain> subdomain via Cloudflare DNS-over-HTTPS and reports whether it exists, its IP records, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/login/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-login-subdomain-c319663d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4GpClVigqUwvjXZHfdPDP

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-login-subdomain-c319663d
```

Example prompt: Can you check if the login subdomain exists for example.com — look up the A record for login.example.com and tell me the IP and TTL?

## When to prefer this

Use this endpoint when you need a fast, cheap single-host existence check specifically for the login subdomain of a domain, using Cloudflare DoH for reliable resolution. Prefer it over full subdomain enumeration tools when you only need to confirm whether a login host is present and what IP it resolves to.

## Known failure modes

- NXDOMAIN if login subdomain does not exist for the given domain
- Invalid or malformed domain input returns an error
- Network or upstream Cloudflare DoH unavailability causes lookup failure
- Rate limiting or payment failure (x402) prevents the lookup from completing

## How this service works

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

## Output

Returns whether the login.<domain> A record exists, the resolved IPv4 addresses, TTL value, and DNS response code (e.g. NOERROR or NXDOMAIN). Provides a quick existence check without full subdomain enumeration.

## 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-login-subdomain-c319663d/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)