# WhatsApp message templates and broadcasts by API

A WhatsApp template is a message approved by Meta in advance: the only way to write first to a customer, or to write after 24 hours of silence. With Nodium you create templates, deploy them and follow Meta's review through the API, then send them one by one or as a broadcast to many contacts.

## Templates

- `POST /templates` writes a template for one client; `POST /templates/{id}/deploy` submits it to the WhatsApp accounts of that client's numbers. Numbers connected later receive it on their own.
- Meta reviews it account by account; each change of status reaches your webhook.
- Placeholders are numbered (`{{1}}`) or named (`{{client_name}}`), filled in `variables`. A placeholder left empty is refused before anything leaves.
- Headers can be a text, an image, a video or a document; buttons can open a link, copy a code or open a [Flow](https://nodium.io/en/features/flows).

```bash
curl https://nodium.io/api/v1/messages \
  -H "Authorization: Bearer $NODIUM_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "channelId": "<channel id>",
    "to": "+33612345678",
    "type": "template",
    "templateName": "order_ready",
    "templateLanguage": "en",
    "variables": { "1": "Karim" },
    "idempotencyKey": "order-1042-confirmation"
  }'
```

## Broadcasts

- `POST /broadcasts/preview` counts who would receive it; `POST /broadcasts` sends one template to many contacts, now or at `scheduledAt`.
- Marketing consent is respected: a contact who tapped **Stop** no longer receives marketing templates.
- The number's messaging tier is checked before the broadcast starts: more recipients than Meta allows per 24 hours is refused, not half sent.
- A broadcast whose sends are refused over and over for an account reason is paused; fix the cause, then resume it. Nothing is sent twice.

## What Meta charges

Every template is billed by Meta to the WhatsApp Business account of the number, by category and by the recipient's country. See [Meta's pricing explained](https://nodium.io/en/guides/meta-pricing).

## Frequently asked questions

### How long does Meta take to approve a template?

Meta decides, usually within minutes to a few hours. Nodium does not take part in the review: it submits the template and reports each status change by webhook.

### Can I send a template to someone who never wrote to me?

Yes, this is what templates are for. For a marketing template, the person must have agreed to receive your messages.

Updated 2026-11-10 · https://nodium.io/en/features/templates-broadcasts