# dns-txt-login-subdomain

> dns-txt-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 TXT DNS record for the login.<domain> subdomain via Cloudflare DoH and reports its existence, record values, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/login/txt?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-txt-login-subdomain-5dfe4535
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UW0gpb7eGf_2M__DG17aj

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-txt-login-subdomain-5dfe4535
```

Example prompt: Can you check if example.com has a TXT record set up at its login subdomain — I want to know if login.example.com exists in DNS and what the record says?

## When to prefer this

Use this endpoint when you need a quick, targeted existence check for the login subdomain of a specific domain without enumerating all subdomains. Prefer it over full DNS enumeration tools when you only care about TXT records at the login host, and when using DoH (Cloudflare) resolution is acceptable. It is cost-effective at $0.01 per lookup for spot checks in security audits, infrastructure validation, or pre-deployment checks.

## Known failure modes

- Domain does not exist — returns not-found or NXDOMAIN result
- No TXT record at login subdomain — exists flag false, empty records
- Invalid or malformed domain input — request may fail or return error
- Cloudflare DoH upstream timeout — transient resolution failure
- Rate limiting or payment failure — 402 payment required if credits exhausted

## How this service works

TXT record of login.<domain>: looks up the login host under the domain you give (TXT 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> subdomain exists in DNS, the full TXT record values found at that host, and the TTL of those records, as resolved 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-txt-login-subdomain-5dfe4535/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)