# HALOWERK buerowerk — Empty Domain Label Email Review

> HALOWERK buerowerk — Empty Domain Label Email Review is a paid API for AI agents from buero.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-22).

Validates a batch of email addresses by checking for empty domain label issues (e.g. double dots or leading/trailing dots in the domain part)

## Facts

- Endpoint: POST https://buero.halowerk.com/v1/baumarkt/mail/empty-domain-label-review?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-buerowerk-empty-domain-label-email-review-0f5c400a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bV56e7V3NejMnDNyOjnLM

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 halowerk-buerowerk-empty-domain-label-email-review-0f5c400a -d '<json body>'
```

Example prompt: Can you review this list of email addresses and flag any that have empty domain label problems — things like double dots or missing segments in the domain part? Here are the addresses: user@example.com, bad..address@test.com, another@.broken.org.

## When to prefer this

Use this endpoint when you need to specifically detect empty domain label defects (double dots, leading/trailing dots in domain segments) in bulk email lists — distinct from general email syntax validation. Ideal for pre-send list hygiene, CRM data quality pipelines, or sign-up validation where RFC-compliant domain labels are critical for deliverability.

## Known failure modes

- Empty emails array — returns validation error
- Email string exceeds 320 character limit — rejected
- Array exceeds 500 items — request rejected
- Malformed JSON body — 400 error
- Payment not attached or insufficient USDC — 402 Payment Required

## How this service works

HALOWERK buerowerk — bezahlte Endpunkte nach x402. Preise in USDC auf Base Mainnet.

## Output

A JSON response indicating which of the submitted email addresses contain empty domain label issues (e.g. consecutive dots, leading or trailing dots in the domain portion), allowing the caller to identify and remove or correct malformed addresses.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "emails": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 320,
    "minLength": 1
   },
   "maxItems": 500,
   "minItems": 1
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-buerowerk-empty-domain-label-email-review-0f5c400a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from buero.halowerk.com](https://www.zero.xyz/host/buero.halowerk.com/llms.txt)