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

# Introduction

> zapo is a high-performance TypeScript implementation of the WhatsApp Web protocol, built for high-scale, multi-session bot and automation workloads.

<img src="https://mintcdn.com/beccabot-de3dfb12/0P_n4xRsGyoRYIz4/images/hero.png?fit=max&auto=format&n=0P_n4xRsGyoRYIz4&q=85&s=39e2494695c0c60fce0a71ebfa05485d" alt="Zapo" noZoom style={{ width: "100%", maxWidth: "640px", borderRadius: "14px", margin: "0 0 1.5rem" }} width="1000" height="260" data-path="images/hero.png" />

`zapo` (published on npm as [`zapo-js`](https://www.npmjs.com/package/zapo-js)) is an independent, runtime implementation of the WhatsApp Web protocol written in TypeScript. It is **not** a wrapper or fork of an existing WhatsApp client library — the protocol source of truth is the deobfuscated WhatsApp Web client, and the goal is behavior parity with WhatsApp Web while improving CPU, memory, and allocation efficiency.

<Warning>
  **Stability.** `zapo` is **`1.0` and stable**. It follows [semantic versioning](https://semver.org) — breaking changes only ever land in a new major release. You can upgrade across minors and patches safely; still validate major upgrades against the changelog.
</Warning>

## Why zapo

<CardGroup cols={2}>
  <Card title="Coordinator-first API" icon="diagram-project">
    Every feature area is a focused coordinator: `client.message`, `client.group`, `client.newsletter`, `client.privacy`, and more.
  </Card>

  <Card title="Pluggable storage" icon="database">
    One `createStore` factory, per-domain provider selection, and official backends for SQLite, PostgreSQL, MySQL, Redis, and MongoDB.
  </Card>

  <Card title="Multi-session ready" icon="layer-group">
    Every query is scoped by `sessionId`, so a single process can drive many accounts — built for multi-tenant workloads.
  </Card>

  <Card title="Performance-disciplined" icon="gauge-high">
    `Uint8Array` everywhere, zero-copy in hot paths, bounded in-memory structures, async I/O, and synchronous crypto (bar elliptic-curve ops) for raw throughput.
  </Card>
</CardGroup>

## Design principles

These principles drive every implementation decision in the codebase:

* **index-first** — protocol behavior is validated against WhatsApp Web before anything is implemented.
* **performance-first** — optimize for low CPU, low RAM, low allocations, and zero-copy in hot paths.
* **async-first I/O** — I/O and network operations are asynchronous. Crypto, by contrast, runs **synchronously** — only elliptic-curve operations are async. Keeping the rest of crypto sync delivered a large, measurable throughput gain.

## Requirements

* **Node.js** `>= 20.9.0`
* A package manager (`npm`, `pnpm`, or similar)
* No mandatory runtime dependencies — backends and logging are opt-in peer dependencies.

## Get started

<CardGroup cols={2}>
  <Card title="Installation" icon="download" href="/en/installation" arrow>
    Install `zapo-js`, pick a storage backend, and wire up optional peers.
  </Card>

  <Card title="Quickstart" icon="rocket" href="/en/quickstart" arrow>
    Connect, scan a QR code, and reply to your first message in minutes.
  </Card>

  <Card title="Architecture" icon="sitemap" href="/en/concepts/architecture" arrow>
    Understand the client, coordinators, stores, and event flow.
  </Card>

  <Card title="Sending messages" icon="paper-plane" href="/en/guides/sending-messages" arrow>
    Text, replies, mentions, media, polls, reactions, and more.
  </Card>
</CardGroup>

## Disclaimer

This project is an independent implementation for engineering and interoperability research. It is **not** affiliated with or endorsed by WhatsApp.