# HALOWERK buerowerk — Email Suppression List Apply

> HALOWERK buerowerk — Email Suppression List Apply 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).

Filters a list of emails against a suppression list and returns only the non-suppressed (sendable) emails

## Facts

- Endpoint: POST https://buero.halowerk.com/v1/baumarkt/mail/suppression-list-apply?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-email-suppression-list-apply-e8882cbd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zn_U8k_AOoJW3IQ2OH3mO

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-email-suppression-list-apply-e8882cbd -d '<json body>'
```

Example prompt: I have a list of emails I want to send a newsletter to — can you filter out any addresses that appear in my suppression list before I send? Here are my target emails: [alice@example.com, bob@example.com, carol@example.com] and my suppressed emails: [bob@example.com, dave@example.com].

## When to prefer this

Use this endpoint when you need a simple, pay-per-call API to apply a suppression list to a batch of emails before sending — ideal for agents or automation workflows that manage email campaigns and need to filter out opted-out or blocked addresses without maintaining a full ESP subscription. Prefer this over building custom suppression logic or using heavyweight email platform APIs when you only need the filtering step.

## Known failure modes

- Invalid email format in either list causing a validation error
- Empty emails array resulting in an empty or error response
- Malformed JSON body returning a 400 bad request
- Network timeout if either list is very large
- Payment failure via x402 protocol resulting in a 402 response before processing

## How this service works

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

## Output

A JSON response containing the subset of input emails that are not present in the suppression list, effectively returning the safe-to-send addresses after applying suppression rules.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "emails": {
   "$ref": "#/$defs/me5877878f0"
  },
  "suppressed_emails": {
   "$ref": "#/$defs/me5877878f0"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-buerowerk-email-suppression-list-apply-e8882cbd/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)