# AgentShelf DNS TXT DMARC Lookup

> AgentShelf DNS TXT DMARC Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Looks up the DMARC TXT record (starting with v=DMARC1) at the _dmarc subdomain of a given hostname via DNS

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-txt-dmarc?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-dns-txt-dmarc-lookup-a8704857
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Y0Xmjb-HxgUD_4Cznh3rF

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-txt-dmarc-lookup-a8704857 -d '<json body>'
```

Example prompt: Can you look up the DMARC TXT record for example.com and tell me what policy it has configured?

## When to prefer this

Use this endpoint when an agent specifically needs to retrieve the DMARC policy TXT record for a domain (the v=DMARC1 entry at _dmarc.<hostname>). Prefer the free sandbox variant /v1/sandbox/dns-txt-dmarc first if available. Choose this over generic DNS lookup APIs when you only need the DMARC-specific TXT record and want a clean, parsed result without handling raw DNS responses.

## Known failure modes

- No DMARC record found at _dmarc subdomain — domain may not have DMARC configured
- Invalid or malformed hostname input returns a validation error
- DNS resolution timeout if the authoritative nameserver is unresponsive
- Non-DMARC TXT records present at _dmarc but none starting with v=DMARC1
- Payment failure if USDC balance is insufficient for the $0.003 fee

## How this service works

Call when an agent needs TXT at _dmarc that starts with v=DMARC1. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/dns-txt-dmarc first.

## Output

The DMARC TXT record content found at _dmarc.<hostname>, typically a string beginning with v=DMARC1 followed by DMARC policy tags such as p=reject, rua=, ruf=, etc. If no DMARC record exists, the response will indicate absence.

## 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-txt-dmarc-lookup-a8704857/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)