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

# Introduction

> Understand how messages work in Z-API

## Overview

First, what you need to understand about messages is that they can be sent to a contact, a group, or a broadcast list.

In the "contacts" topic we'll come back to this, but it's important that you also know that for WhatsApp everything is a chat, whether it's a contact, group, or broadcast list.

To send any message, it needs the chat ID, which are:

* For **contacts**, it's the phone number itself;
* For **groups**, it's the concatenation of the group founder's number with a timestamp;
* For **broadcast lists**, it's the concatenation of the string 'broadcast' with the timestamp.

These IDs are all returned by the get/chats method, which you'll learn about a little further ahead.

<Tip>
  Speaking of IDs, we strongly recommend that you store in your application the **messageId** that our response will return, because if you need to reply to, mark, or even delete a message, you will need to provide the messageId as an attribute in the method.
</Tip>

***

## Standard response

Every successfully sent message returns the following attributes:

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "zaapId": "3999984263738042930CD6ECDE9VDWSA",
  "messageId": "D241XXXX732339502B68",
  "id": "D241XXXX732339502B68"
}
```

***

## Text formatting

<Note>
  You can format your texts by sending formatting characters to make your message more elegant.
</Note>

| Format        | Syntax         | Example  |
| ------------- | -------------- | -------- |
| Bold          | `*text*`       | **text** |
| Italic        | `_text_`       | *text*   |
| Strikethrough | `~text~`       | ~~text~~ |
| Monospace     | ` ```text``` ` | `text`   |