> ## Documentation Index
> Fetch the complete documentation index at: https://developer.hubmessage.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Understand how free messages work in Hub Message

export const projectName = 'Hub Message';

## What are free messages?

Free messages are messages you send **without needing an approved template**. You can send text, image, audio, video, document — any supported format — with complete freedom of content.

The only condition: the [conversation window](/en/conversation-window) of **24 hours** must be open.

## When can I use them?

The window opens when the **customer sends you a message**. From that moment, you have 24 hours to send free messages. Each new message from the customer resets the timer.

```
Customer sends message → Window opens (24h) → You send free messages
```

## What if the window is closed?

If the customer hasn't sent a message in the last 24 hours, the window is closed. In this case, the only option is to send a **Meta-approved template** through the [Send template](/en/messages/send-template) endpoint.

After the customer **replies** to the template, the window reopens and you can use free messages again.

```
Window closed → Send template → Customer replies → Window reopens (24h)
```

<Info>
  Need to send a template? See how at [Send template](/en/messages/send-template). To create and manage your templates, go to the [Templates](/en/templates/introduction) section.
</Info>

## Available types

All endpoints in this section use the same route:

`POST /v1/channels/{channelId}/messages`

What changes is the `content.type` field:

| Type                 | Description                                     |
| -------------------- | ----------------------------------------------- |
| `TEXT`               | Simple text message                             |
| `IMAGE`              | Image message                                   |
| `AUDIO`              | Audio message                                   |
| `VIDEO`              | Video message                                   |
| `CONTACT`            | Contact card                                    |
| `STICKER`            | Sticker                                         |
| `INTERACTIVE_ACTION` | Message with action buttons (URL and call)      |
| `INTERACTIVE_BUTTON` | Message with quick reply buttons                |
| `TEMPLATE`           | Meta-approved template (outside the 24h window) |