# Matrix SRV DNS Lookup

> Matrix SRV DNS Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-02).

Resolves _matrix._tcp SRV DNS records for a given hostname to support Matrix federation discovery

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-srv-matrix?utm_source=zero.xyz
- Price: $0.009/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/matrix-srv-dns-lookup-942f687e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wZjq6WQFahHu6BjIdx2jK

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 matrix-srv-dns-lookup-942f687e -d '<json body>'
```

Example prompt: Can you look up the Matrix SRV DNS record for matrix.org so I can find what server handles its federation?

## When to prefer this

Use this endpoint when an agent needs to resolve Matrix federation SRV records programmatically, especially when implementing Matrix client or server federation discovery logic. Prefer the free sandbox endpoint (/v1/sandbox/dns-srv-matrix) for testing before using this paid endpoint.

## Known failure modes

- No SRV record exists for the domain — returns empty or not-found response
- Invalid or malformed hostname input — validation error
- DNS resolution timeout or upstream failure — network error
- Domain does not support Matrix federation — no SRV entry found

## How this service works

Call when an agent needs SRV records at _matrix._tcp.{hostname} for Matrix. The caller sends the registrable domain, not the underscored name. Exact $0.009 USDC. Prefer unpaid POST /v1/sandbox/dns-srv-matrix first.

## Output

Returns the SRV record data for _matrix._tcp.{hostname}, including fields such as priority, weight, port, and target hostname, enabling Matrix federation endpoint discovery.

## 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/matrix-srv-dns-lookup-942f687e/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)