# STUN TCP SRV Record Lookup

> STUN TCP SRV Record Lookup is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-22).

Resolves _stun._tcp.<domain> SRV DNS records via Cloudflare DoH, returning the priority, weight, port, and target host for a domain's STUN service.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/srv/stun-tcp?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stun-tcp-srv-record-lookup-d2edfb08
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_f3ygPXUReRU39zaC1qJyl

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 stun-tcp-srv-record-lookup-d2edfb08
```

Example prompt: Look up the STUN TCP SRV record for example.com so I can find out the hostname and port of its STUN server.

## When to prefer this

Use this endpoint when you need to programmatically discover a domain's STUN service endpoint without manually guessing hostnames. Ideal for WebRTC, VoIP, or NAT traversal applications that need to dynamically configure STUN servers from DNS. Prefer this over generic DNS resolvers when you specifically need _stun._tcp SRV records in a structured, pay-per-lookup API format.

## Known failure modes

- Domain has no _stun._tcp SRV record — returns empty result or NXDOMAIN
- Invalid or malformed domain name input — may return an error
- Cloudflare DoH upstream timeout or failure — transient error
- Domain exists but STUN SRV record is misconfigured — returns whatever DNS has, which may be incorrect

## How this service works

STUN service discovery (_stun._tcp.<domain>): SRV records with priority, weight, port and target host, from Cloudflare DoH. Tells a client where the domain's stun service lives without guessing hosts. $0.01 per lookup.

## Output

Returns one or more SRV records for the _stun._tcp.<domain> DNS lookup, each containing: priority (integer), weight (integer), port (integer), and target hostname. If no SRV records exist, returns an empty or negative result. Data is sourced from Cloudflare DoH for reliability and speed.

## 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/stun-tcp-srv-record-lookup-d2edfb08/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)