# AgentShelf DNS SRV _sips._tcp Lookup

> AgentShelf DNS SRV _sips._tcp Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-29).

Resolves SRV records at _sips._tcp.{hostname} for SIP over TLS by accepting a registrable domain name

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-srv-sips?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-dns-srv-sips-tcp-lookup-8263b71e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gNZ9MU9dabGeWLoGbmnrw

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 agentshelf-dns-srv-sips-tcp-lookup-8263b71e -d '<json body>'
```

Example prompt: Can you look up the _sips._tcp SRV records for example.com so I can find out which server and port handle SIP over TLS for that domain?

## When to prefer this

Use this endpoint when you specifically need SRV records for SIP over TLS (_sips._tcp prefix) and the caller only knows the registrable domain, not the full underscored DNS name. It is distinct from generic SRV lookup endpoints because it automatically prepends the _sips._tcp service label. Prefer the free sandbox endpoint (/v1/sandbox/dns-srv-sips) when available to avoid the $0.004 USDC charge; use this paid endpoint when sandbox access is unavailable or production accuracy is required.

## Known failure modes

- Domain does not exist — NXDOMAIN response, returns empty records
- No _sips._tcp SRV record configured for the domain — returns empty records array
- Hostname exceeds 253 characters or is empty — validation error
- DNS resolver timeout — transient error response
- Invalid domain format — request rejected with error

## How this service works

Call when an agent needs SRV records at _sips._tcp.{hostname} for SIP over TLS. The caller sends the registrable domain, not the underscored name. Exact $0.004 USDC. Prefer unpaid POST /v1/sandbox/dns-srv-sips first.

## Output

Returns the SRV records found at _sips._tcp.{hostname}, including fields such as priority, weight, port, and target for each record. An empty records array is returned if no SRV records exist at that location.

## 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/agentshelf-dns-srv-sips-tcp-lookup-8263b71e/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)