# Syntexa DNS MX Lookup

> Syntexa DNS MX Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-29).

Looks up MX (Mail Exchange) DNS records for a given hostname, returning each record's priority and exchange server.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-mx?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/syntexa-dns-mx-lookup-0c17251a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2AMgTMfiJ9d69oAB1_fCq

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 syntexa-dns-mx-lookup-0c17251a -d '<json body>'
```

Example prompt: Can you look up the MX records for github.com and tell me the priority and exchange server for each one?

## When to prefer this

Choose this endpoint when you need only MX record data (priority + exchange) for a hostname in a structured format suitable for agent pipelines. Prefer the free sandbox endpoint POST /v1/sandbox/dns-mx when available; use this paid endpoint when the sandbox is unavailable or rate-limited. Avoid if you need full DNS record sets (A, AAAA, TXT, etc.) — use a more general DNS API in that case.

## Known failure modes

- Hostname does not exist or has no MX records — returns empty list or NXDOMAIN error
- Malformed hostname (too long, invalid characters) — rejected by schema validation
- Transient DNS resolution failure — may return timeout or upstream error
- Payment failure (insufficient USDC) — request rejected before DNS query is performed

## How this service works

Call when an agent needs MX records only, formatted as priority and exchange. Exact $0.008 USDC. Prefer unpaid POST /v1/sandbox/dns-mx first.

## Output

Returns a list of MX records for the given hostname, each containing a numeric priority value and the fully-qualified domain name of the mail exchange server. Records are typically ordered by priority (lower = higher preference).

## 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/syntexa-dns-mx-lookup-0c17251a/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)