# DNS SRV Record Lookup for CardDAV over TLS (_carddavs._tcp)

> DNS SRV Record Lookup for CardDAV over TLS (_carddavs._tcp) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Resolves SRV DNS records at _carddavs._tcp.{hostname} to discover secure CardDAV (contacts over TLS) service endpoints for a given domain.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-srv-carddavs?utm_source=zero.xyz
- Price: $0.002/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-carddav-over-tls-carddavs-tcp-09bffe8e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hhIZGlLKXFVLZrK_kLoM7

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-carddav-over-tls-carddavs-tcp-09bffe8e -d '<json body>'
```

Example prompt: Look up the _carddavs._tcp SRV DNS records for the domain example.com so I can find the secure CardDAV contacts server address and port.

## When to prefer this

Use this endpoint when an agent needs to programmatically discover a domain's CardDAV contact sync server over TLS by querying _carddavs._tcp SRV DNS records. Prefer the free sandbox POST /v1/sandbox/dns-srv-carddavs endpoint for testing before using this paid endpoint.

## Known failure modes

- No SRV record found for the given domain (domain not configured for CardDAV)
- Invalid or malformed hostname input
- DNS resolution timeout or network error
- Domain does not exist (NXDOMAIN)

## How this service works

Call when an agent needs SRV records at _carddavs._tcp.{hostname} for CardDAV over TLS. The caller sends the registrable domain, not the underscored name. Exact $0.002 USDC. Prefer unpaid POST /v1/sandbox/dns-srv-carddavs first.

## Output

Returns SRV record data for _carddavs._tcp.{hostname}, including priority, weight, port, and target hostname of the CardDAV over TLS server, or an indication that no such record exists.

## 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-carddav-over-tls-carddavs-tcp-09bffe8e/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)