# dns-a-sip-subdomain

> dns-a-sip-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 sip.<domain> subdomain via Cloudflare DoH and reports whether it exists, its IP records, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/sip/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-sip-subdomain-19a37be4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SSo0mDBx2MZDiuIy6FgRU

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-sip-subdomain-19a37be4
```

Example prompt: Can you check if sip.acmecorp.com exists in DNS and what IP address it resolves to?

## When to prefer this

Use this endpoint when you need a quick, targeted existence check for the sip.<domain> subdomain specifically, without enumerating all subdomains. Ideal for VoIP/SIP infrastructure validation, vendor due diligence, or troubleshooting SIP connectivity issues for a known domain.

## Known failure modes

- Domain does not have a sip subdomain A record — returns non-existence result
- Invalid or malformed domain input — may return error or empty result
- Cloudflare DoH upstream timeout or error — lookup fails
- Domain input missing — required parameter not provided

## How this service works

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

## Output

Returns whether the sip.<domain> A record exists, the resolved IP address(es), and the TTL of the record. If the record does not exist, reports absence. Data is sourced via 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-sip-subdomain-19a37be4/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)