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

# ChatSyncs for Developers

> Build on ChatSyncs: the Developer API (REST endpoints for WhatsApp messages, templates, subscribers, labels, catalogs and users) and the ChatSyncs MCP server that connects Claude, ChatGPT, Cursor and other AI apps to a ChatSyncs account. Step-by-step product guides live in the Help Center.

Everything you need to build on ChatSyncs. There are two parts:

<CardGroup cols={2}>
  <Card title="Developer API" icon="code" href="/developer-api/introduction">
    REST endpoints for messages, contacts and templates. Send WhatsApp messages,
    manage subscribers and labels, and read your catalog from your own code.
  </Card>

  <Card title="MCP server" icon="plug" href="/mcp/introduction">
    Connect Claude, ChatGPT or Cursor to your account. Then ask your AI app to
    send messages, update contacts and read conversations in plain English.
  </Card>
</CardGroup>

## Start with the Developer API

<Steps>
  <Step title="Understand the API">
    [Understanding the Developer API](/developer-api/explained): a beginner's guide to
    what it is, how it works and where your code calls it.
  </Step>

  <Step title="Make your first request">
    [Introduction](/developer-api/introduction): the base URL, your `apiToken` and
    the response shape every endpoint returns.
  </Step>

  <Step title="Find your IDs">
    [Finding your IDs and API token](/developer-api/finding-ids): where to get your
    `apiToken`, `phone_number_id`, template IDs and the other values the endpoints ask for.
  </Step>
</Steps>

## Or connect an AI app

[Which AI app should I use?](/mcp/choose-an-app) compares the apps the MCP server
works with. Then [get your API key](/mcp/api-key) and follow the setup page for
your app.

<Note>
  Looking for how to use ChatSyncs itself, such as connecting your number, building
  bots, sending broadcasts or running a shared inbox? Those step-by-step guides are in
  the [ChatSyncs Help Center](https://help.chatsyncs.com/docs).
</Note>


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