> ## 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

> Z-API API overview

## API Reference

Welcome to the Z-API API reference! Here you will find all available endpoints to interact with WhatsApp through our platform.

***

## Base URL

All requests must be made to the following base URL:

```
https://api.z-api.io/instances/{instanceId}/token/{token}
```

| Parameter    | Description                                        |
| ------------ | -------------------------------------------------- |
| `instanceId` | Your instance ID, obtained from the Z-API panel    |
| `token`      | Your instance token, obtained from the Z-API panel |

***

## Authentication

In addition to the ID and Token in the URL, all requests require the security header:

| Header         | Description                                                     |
| -------------- | --------------------------------------------------------------- |
| `Client-Token` | Account security token. [Learn more](/en/security/client-token) |

***

## Request format

* All requests must include the `Content-Type: application/json` header
* Request and response bodies are in JSON format

***

## Common response codes

| Code  | Description                          |
| ----- | ------------------------------------ |
| `200` | Request completed successfully       |
| `400` | Invalid request. Check the data sent |
| `405` | Incorrect HTTP method                |
| `415` | `Content-Type` header not provided   |