# Introduction

What Zero is, the words its docs use, and which page to read first.

Zero is a Mac app for coding agents. It runs Claude Code, Codex and OpenCode, each signed in with your own account. You give an agent a job and a folder to work in. When it needs you, it asks in the inbox, where every agent asks and you answer.

## The parts of Zero

- **The window.** Your tasks and their conversations. The rail on its left side leads to Home, the Inbox, Later, Scratchpads, Loops, Integrations and Settings.
- **The control bar.** A small bar on the right edge of your screen. It shows the inbox and a mark for each task. It keeps your agents in view while you work in another app.
- **The inbox.** Everything your agents have asked you: questions, choices, commands to allow. It opens beside the control bar, and it's also a page in the window.
- **The iPhone app.** Your inbox and tasks on your phone, coming soon.

## Words these docs use

- **Task**: one agent that works on one job, in one folder. Each task has a conversation, like a chat.
- **Worker**: a task that another task started for part of its job. It shows under the task that started it, and it reports back to that task.
- **Ask**: something an agent needs from you, such as an answer, a choice or your go-ahead.
- **Account**: a sign-in for Claude Code, Codex or OpenCode that Zero keeps and gives to the agent.
- **Project**: a folder on your Mac that you added to Zero. Tasks start in a project.
- **Workspace**: a set of tasks kept apart from the rest, such as your own projects and your job. Each task belongs to one workspace.

## Where to start

New to Zero? Start with [Getting started](/docs/getting-started). Then:

| Page | What it covers |
|---|---|
| [Tasks and workers](/docs/tasks-and-workers) | Starting a task, talking to it while it works, and following its workers. |
| [The inbox and asks](/docs/inbox-and-asks) | Every kind of ask, and how to answer. |
| [The control bar](/docs/control-bar) | The bar on the edge of your screen. |
| [Accounts and models](/docs/accounts-and-models) | Signing in agents, and picking models. |
| [Workspaces and folders](/docs/workspaces-and-folders) | Keeping tasks apart, and telling Zero where your projects are. |
| [Later, scratchpads and loops](/docs/later-scratchpads-loops) | Saving things for later, notes agents can read, and instructions you hand agents by name. |
| [Following and integrations](/docs/following-and-integrations) | Agents watching pull requests and issues, and the services you connect. |
| [Browsers and MCP servers](/docs/browsers-and-mcp) | Letting agents use your browser, and giving them more tools. |
| [Settings](/docs/settings) | Every setting: what it does and where it is. |
| [Keyboard shortcuts](/docs/keyboard-shortcuts) | Every key Zero answers to. |
| [The iPhone app](/docs/iphone) | Zero on your phone. |
| [The zero command](/docs/cli) | How agents reach you. |
| [Troubleshooting](/docs/troubleshooting) | What to do when something doesn't work. |

## Zero's code

Zero is free and open source, under the [GNU General Public License v3 or later](https://github.com/arsenstorm/zero/blob/main/LICENSE). The code is [on GitHub](https://github.com/arsenstorm/zero). To help build Zero, read [CONTRIBUTING.md](https://github.com/arsenstorm/zero/blob/main/CONTRIBUTING.md) first.