# Add to Block List

> Block one email address or domain.

<Note>
  **Beta.** This endpoint is not in production yet and may change before it ships.
</Note>

Requires an API key with the `write` scope.

The value is lowercased and classified: anything with an `@` is an email, anything else a domain. `@acme.com`, `*.acme.com` and `https://acme.com/page` are all stored as the domain `acme.com`. For many values at once use [Bulk Add](/api-reference/block-list/bulk-add).

## Body Parameters

<ParamField body="value" type="string" required>An email address or a domain.</ParamField>
<ParamField body="note" type="string">Optional note, up to 500 characters.</ParamField>

## Response

Returns the entry with a `201` status code.

<ResponseField name="data" type="object">
  <Expandable title="data">
    <ResponseField name="id" type="string">Entry identifier.</ResponseField>
    <ResponseField name="kind" type="string">`email` or `domain`.</ResponseField>
    <ResponseField name="value" type="string">Lowercased address or domain.</ResponseField>
    <ResponseField name="source" type="string">`manual`, `import`, `unsubscribe` or `api`.</ResponseField>
    <ResponseField name="note" type="string">Optional note, or `null`.</ResponseField>
    <ResponseField name="createdBy" type="string">User id that added it, or `null` for unsubscribes.</ResponseField>
    <ResponseField name="createdAt" type="string">ISO 8601 timestamp.</ResponseField>
  </Expandable>
</ResponseField>

<RequestExample>
```bash cURL
curl -X POST "https://api.foxreach.io/api/v1/block-list" \
  -H "X-API-Key: otr_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value": "acme.com", "note": "Asked us to stop"}'
```

```python Python SDK (beta)
from foxreach import FoxReach

client = FoxReach(api_key="otr_your_key")
entry = client.block_list.add("acme.com", note="Asked us to stop")
```

```typescript TypeScript SDK (beta)
import { FoxReach } from "foxreach";

const client = new FoxReach({ apiKey: "otr_your_key" });
const entry = await client.blockList.add({ value: "acme.com", note: "Asked us to stop" });
```
</RequestExample>

<ResponseExample>
```json
{
  "data": {
    "id": "blk_abc123",
    "kind": "domain",
    "value": "acme.com",
    "source": "api",
    "note": "Asked us to stop",
    "createdBy": "usr_abc123",
    "createdAt": "2026-11-04T10:00:00Z"
  }
}
```
</ResponseExample>

## Errors

| Status | Description |
|--------|-------------|
| `401` | Missing, invalid, revoked or expired API key |
| `403` | API key does not have the required scope: `write` |
| `409` | `Already on the block list.` |
| `422` | `value` is missing or not a valid email or domain |

## Rate Limit

- **120 requests per minute, shared by every `write` call in your workspace.** Fixed 60-second window.
- Every response includes `X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Reset` (unix epoch seconds) and `X-RateLimit-Bucket` (`write`).
- A `429` response includes a `Retry-After` header (seconds until the bucket resets).

For client-side patterns, see [Rate Limiting](/rate-limiting).