# Fastmail DKIM TXT DNS Record Lookup

> Fastmail DKIM TXT DNS Record Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-01).

Looks up the DKIM TXT record at the fastmail._domainkey.{hostname} DNS path for a given hostname

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-txt-dkim-fastmail?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastmail-dkim-txt-dns-record-lookup-0ee74c88
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kDAAALSmIKhRjuuZI9b-_

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 fastmail-dkim-txt-dns-record-lookup-0ee74c88 -d '<json body>'
```

Example prompt: Can you look up the Fastmail DKIM TXT record for the domain example.com — specifically the one at fastmail._domainkey.example.com?

## When to prefer this

Use this endpoint when you specifically need to retrieve the DKIM TXT record published under the Fastmail selector (fastmail._domainkey) for a given hostname — for example, to verify Fastmail email authentication is properly configured, to audit DNS records, or to debug email deliverability. Prefer the free sandbox version (POST /v1/sandbox/dns-txt-dkim-fastmail) first if available. If you need a different DKIM selector or a different mail provider's DKIM record, this endpoint is not appropriate.

## Known failure modes

- No TXT record exists at the queried DNS name — returns empty or not-found response
- Invalid or malformed hostname input causing a DNS resolution error
- DNS timeout if the authoritative nameserver is slow or unreachable
- Hostname exceeds 253 characters — rejected by schema validation

## How this service works

Call when an agent needs TXT at fastmail._domainkey.{hostname}. A different selector is a different DNS name. Exact $0.008 USDC. Prefer unpaid POST /v1/sandbox/dns-txt-dkim-fastmail first.

## Output

Returns the TXT record value found at the fastmail._domainkey.{hostname} DNS path, which contains the DKIM public key or configuration string used by Fastmail for email authentication for that 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/fastmail-dkim-txt-dns-record-lookup-0ee74c88/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)