# AgentShelf CardDAV SRV DNS Lookup

> AgentShelf CardDAV SRV DNS Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).

Looks up DNS SRV records at _carddav._tcp.{hostname} for a given registrable domain to discover CardDAV server endpoints.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-srv-carddav?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-carddav-srv-dns-lookup-981e0c25
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yjD8LJLn9MwRamKGl0PEe

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-carddav-srv-dns-lookup-981e0c25 -d '<json body>'
```

Example prompt: Can you look up the CardDAV SRV DNS records for apple.com so I can find out where their contacts sync server is?

## When to prefer this

Use this endpoint when an agent needs to auto-discover a CardDAV contacts synchronization server for a given domain via the standard _carddav._tcp DNS SRV lookup mechanism. Prefer this over manual configuration or generic DNS tools when you specifically need CardDAV service location. Use the free sandbox POST /v1/sandbox/dns-srv-carddav first when available to avoid the $0.003 USDC charge.

## Known failure modes

- Domain has no _carddav._tcp SRV record — returns empty result
- Invalid or malformed hostname input — validation error
- DNS resolution timeout or upstream DNS failure — service error
- Domain does not exist in DNS — NXDOMAIN response
- Payment failure for x402 micropayment — request rejected before processing

## How this service works

Call when an agent needs SRV records at _carddav._tcp.{hostname} for CardDAV. The caller sends the registrable domain, not the underscored name. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/dns-srv-carddav first.

## Output

Returns the DNS SRV record(s) found at _carddav._tcp.{hostname}, including fields such as priority, weight, port, and target hostname of the CardDAV server. If no records exist, returns an empty or null result indicating CardDAV is not configured for the domain.

## 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-carddav-srv-dns-lookup-981e0c25/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)