# dns-txt-smtp-tls-subdomain

> dns-txt-smtp-tls-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 _smtp._tls.<domain> via Cloudflare DoH and reports its existence, content, and TTL.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/host/smtp-tls/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-smtp-tls-subdomain-6eb82225
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_O1R4HodszNbf9WQiipX9v

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-smtp-tls-subdomain-6eb82225
```

Example prompt: Can you check if example.com has an _smtp._tls TXT DNS record configured — I want to know if it exists, what it says, and what the TTL is?

## When to prefer this

Use this endpoint when you specifically need to check the _smtp._tls subdomain TXT record (used for SMTP TLS reporting policy) for a domain, rather than enumerating all subdomains or fetching general DNS records. Ideal for targeted existence checks and quick audits of SMTP TLS DNS configuration.

## Known failure modes

- Domain does not exist — record reported as absent
- _smtp._tls subdomain has no TXT record — existence reported as false
- Cloudflare DoH upstream timeout or error
- Invalid or malformed domain name input causing lookup failure
- NXDOMAIN response for the _smtp._tls host

## How this service works

TXT record of _smtp._tls.<domain>: looks up the _smtp._tls 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 _smtp._tls without enumerating subdomains. $0.01 per lookup.

## Output

Returns whether the _smtp._tls.<domain> TXT DNS record exists, the full record content if present, and the TTL value, 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-smtp-tls-subdomain-6eb82225/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)