# dns-a-mx1-subdomain

> dns-a-mx1-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 (IPv4 address) for the mx1 subdomain of a given domain using Cloudflare DNS over HTTPS, reporting existence, records, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/mx1/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-mx1-subdomain-86a53fd0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_llRJ7CCcCWX57WOsm12W_

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-mx1-subdomain-86a53fd0
```

Example prompt: Can you check if mx1.acmecorp.com exists and what IPv4 address it resolves to? I want to know the A record and TTL for the mx1 host under acmecorp.com.

## When to prefer this

Use this endpoint when you need a fast, targeted existence and IP resolution check specifically for the mx1 host of a domain, without broader DNS enumeration. Prefer it over general DNS tools when you want a cheap ($0.01), single-purpose A-record lookup for the common mx1 mail host pattern via Cloudflare DoH.

## Known failure modes

- Domain does not have an mx1 subdomain — returns a non-existence result or empty record set
- Invalid or malformed domain name input — may return an error or empty response
- DNS resolution failure or Cloudflare DoH outage — lookup may time out or return an error
- Domain uses CNAME at mx1 rather than an A record — A record query returns no direct result

## How this service works

A record of mx1.<domain>: looks up the mx1 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 mx1 without enumerating subdomains. $0.01 per lookup.

## Output

Returns whether the mx1 subdomain of the given domain has an A record, including the resolved IPv4 address(es) and the TTL value, or indicates that no record exists.

## 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-mx1-subdomain-86a53fd0/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)