# DNS SRV Record Lookup for TURNS (_turns._tcp)

> DNS SRV Record Lookup for TURNS (_turns._tcp) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-02).

Looks up SRV records at _turns._tcp.{hostname} for TURNS (Traversal Using Relays around NAT with TLS) service discovery given a registrable domain name.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-srv-turns?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-srv-record-lookup-for-turns-turns-tcp-64bfeed9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6LPcaK3nr6wlSMjJTPkAT

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-srv-record-lookup-for-turns-turns-tcp-64bfeed9 -d '<json body>'
```

Example prompt: Can you look up the TURNS SRV records for example.com so I can find its TURNS relay server address and port?

## When to prefer this

Use this endpoint when you need to programmatically discover TURNS relay server endpoints for a given domain via DNS SRV lookup, particularly in WebRTC, VoIP, or NAT traversal contexts. Prefer the free sandbox endpoint POST /v1/sandbox/dns-srv-turns first if available; use this paid endpoint when the sandbox is unavailable or production reliability is required.

## Known failure modes

- Domain has no _turns._tcp SRV records configured — returns empty or NXDOMAIN result
- Invalid or malformed hostname input — validation error
- DNS resolution timeout or upstream DNS failure
- Hostname exceeds 253 characters or is empty — schema validation error
- Payment not provided or insufficient — HTTP 402 response

## How this service works

Call when an agent needs SRV records at _turns._tcp.{hostname} for TURNS. The caller sends the registrable domain, not the underscored name. Exact $0.008 USDC. Prefer unpaid POST /v1/sandbox/dns-srv-turns first.

## Output

Returns the SRV record set found at _turns._tcp.{hostname}, including priority, weight, port, and target fields for each record, enabling the caller to connect to the appropriate TURNS relay server.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "hostname": {
   "type": "string",
   "examples": [
    "example.com"
   ],
   "maxLength": 253,
   "minLength": 1,
   "description": "Public DNS hostname such as example.com. Not a URL, not an IP literal, and not a private name."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dns-srv-record-lookup-for-turns-turns-tcp-64bfeed9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)