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

# Quickstart

> Get a reply on WhatsApp in under 5 minutes. Pick a managed agent or route messages to your own code.

There are two ways to build on Wassist. Both work on the free **sandbox number**, so you don't need a WhatsApp Business Account, a credit card, or your own number to get started.

<CardGroup cols={2}>
  <Card title="Managed agent" icon="robot" href="/quickstart/managed-agent">
    **Wassist runs the AI.** Write a prompt, pick a model, add tools and knowledge. No server needed.

    Best if you want an agent live today.
  </Card>

  <Card title="Webhook routing" icon="code" href="/quickstart/webhook-routing">
    **Your code handles every message.** Wassist forwards each inbound WhatsApp message to your endpoint, and you reply through the API.

    Best if you already have an agent or backend.
  </Card>
</CardGroup>

## Which one should I pick?

| | Managed agent | Webhook routing |
| - | - | - |
| Who writes the replies | The Wassist agent (LLM + your prompt) | Your code |
| Where it runs | On Wassist | On your server, serverless function, or laptop |
| Setup time | About 2 minutes, no code | About 5 minutes, one small file |
| Tools, knowledge, Shopify, apps | Built in | Up to you |
| Works on the sandbox | Yes | Yes |

Want your own MCP tools to know which customer and conversation they're serving? That's an [App](/guides/build-an-app) (alpha): an MCP server you install on your agents. [Build on Wassist](/guides/overview) compares all three options.

You can switch any time. Routing is a per-number setting (**Agent**, **Webhook** or **No action**), so the same number can move from a managed agent to your webhook and back without re-linking anything.

## Before you begin

Both paths need:

* A Wassist account. [Sign up free](https://wassist.app/login) with your phone number.
* WhatsApp on that same phone. The sandbox only routes messages that come from the number you signed in with.

## How the sandbox works

The sandbox is a shared Wassist WhatsApp number. It appears under **Numbers → Sandbox numbers** in the dashboard, and it's the number that sent your login code.

Everyone shares it, but routing is per user. When you connect an agent or a webhook to the sandbox, only **your own** chat with it changes. Other people's chats aren't affected, and yours isn't affected by theirs.

<Note>
  The sandbox has no business profile, templates or analytics. When you're ready for real customers, [connect your own WhatsApp number](/guides/connect-whatsapp). The same routing controls apply.
</Note>


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