# DKIM TXT Record Lookup — cm Selector

> DKIM TXT Record Lookup — cm Selector is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-01).

Retrieves the DKIM TXT DNS record at the cm._domainkey.<hostname> selector for a given domain

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-txt-dkim-cm?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dkim-txt-record-lookup-cm-selector-b2ea1609
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NXb6iPqZafut4YqHzDs9b

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 dkim-txt-record-lookup-cm-selector-b2ea1609 -d '<json body>'
```

Example prompt: What's the DKIM TXT record at the cm._domainkey selector for syntexa.ch?

## When to prefer this

Use this endpoint when you specifically need the DKIM TXT record for the 'cm' selector (i.e. the DNS name cm._domainkey.<hostname>). If you need a different DKIM selector, that is a different DNS name and a different endpoint. Prefer the free sandbox endpoint (unpaid POST /v1/sandbox/dns-txt-dkim-cm) for testing before paying $0.01 USDC per call on this production endpoint.

## Known failure modes

- Hostname does not exist in DNS — returns error or empty result
- No TXT record exists at cm._domainkey.<hostname> — record not found response
- Invalid hostname format (too long, empty, or malformed) — validation error
- DNS resolution timeout or network error — transient failure
- Domain exists but no DKIM record for cm selector specifically — empty or NXDOMAIN result

## How this service works

Call when an agent needs TXT at cm._domainkey.{hostname}. A different selector is a different DNS name. Exact $0.01 USDC. Prefer unpaid POST /v1/sandbox/dns-txt-dkim-cm first.

## Output

Returns the TXT record value published at cm._domainkey.<hostname> in DNS, which typically contains the DKIM public key and policy flags used for email authentication verification.

## 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/dkim-txt-record-lookup-cm-selector-b2ea1609/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)