# dns-a-mx2-subdomain

> dns-a-mx2-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 mx2 subdomain of a given domain via Cloudflare DNS over HTTPS and reports whether it exists, its records, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/mx2/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-mx2-subdomain-626a271e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HTk_fK6CmnS_kBFmx5a5X

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-mx2-subdomain-626a271e
```

Example prompt: Can you check whether mx2.example.com exists in DNS — I want to know if the mx2 host is configured for that domain, its IP address, and the TTL?

## When to prefer this

Use this endpoint when you need a quick, targeted existence check specifically for the mx2 host under a domain without enumerating all subdomains. It is ideal for mail infrastructure audits, onboarding checks, or monitoring scenarios where the mx2 common subdomain pattern is the specific concern. Prefer this over general DNS A record lookups when you want a pre-scoped mx2 check via Cloudflare DoH specifically.

## Known failure modes

- Domain does not have an mx2 subdomain (NXDOMAIN response)
- Invalid or malformed domain name input
- Cloudflare DoH upstream timeout or error
- Network connectivity issue to the DNS intel service
- Payment failure or insufficient USDC balance for the $0.01 fee

## How this service works

A record of mx2.<domain>: looks up the mx2 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 mx2 without enumerating subdomains. $0.01 per lookup.

## Output

Returns whether the A record for mx2.<domain> exists, the resolved IP address(es), the TTL of the record, and the DNS response code (e.g. NOERROR or NXDOMAIN), as answered by Cloudflare DNS over HTTPS.

## 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-mx2-subdomain-626a271e/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)