# send_test_newsletter

> Sends one test message of a newsletter to a single phone number, never to a contact who unsubscribed. Needs an approved template. Leave out 'to' to use the test number of the account.

Last updated: 2026-10-25. Source: https://docs.smartchat.marketing/en/mcp/tools/send_test_newsletter/

Sends one test message of a newsletter to a single phone number, never to a contact who unsubscribed. Needs an approved template. Leave out 'to' to use the test number of the account.

| | |
|---|---|
| Tool name | `send_test_newsletter` |
| Permission | `newsletters:test` |
| `readOnlyHint` | false |
| `destructiveHint` | false |
| `idempotentHint` | true |
| `openWorldHint` | true |
| REST call | [`POST /v1/newsletters/{newsletter_id}/test-send`](https://docs.smartchat.marketing/en/api/reference/newsletters/send_test_newsletter/) |

## What it does

- Sends WhatsApp messages to contacts.
- Safe to repeat with the same idempotency_key.

## Input

The tool takes one flat object. Path, query and body fields of the REST call are merged into it.


| Name | Type | Required | Description |
|---|---|---|---|
| `newsletter_id` | string | yes | ID of the newsletter, from list_newsletters. |
| `to` | string | no | Phone number in E.164 format, for example +4915112345678. Default: the test number in the business profile. up to 16 characters; format e164 |

**Arguments added by the MCP server** (see [Special arguments](https://docs.smartchat.marketing/en/mcp/#special-arguments))

| Name | Type | Required | Description |
|---|---|---|---|
| `idempotency_key` | string | yes | Required. Unique key for this action, for example a UUID. Same key and arguments within 24 hours: first result, nothing done again. up to 255 characters |

## Result

The result has the same content as the REST answer. Lists have at most 50 items per page (default 20); use `cursor` for the next page.

Errors come back as a tool result with `isError: true`. The error codes are the ones in [Errors](https://docs.smartchat.marketing/en/errors/).