# Machines and infrastructure

> Your app controls the work. Your machines execute it.

Source: https://usefiretower.com/docs/architecture

## The parts of an installation

**Machine**

A physical or virtual computer where your agents run. One machine can host several workspaces.

**Worker**

The Firetower program installed on a machine. It starts agents and manages their working files.

**Control plane**

The server that coordinates work and manages accounts, credentials and access.

**Client**

The desktop or mobile app you use to start work and review results.

Your devices **Desktop & mobile** Start, review and continue work

↕

Your infrastructure **Control plane** Accounts, access and coordination

↕ SSH

Your worker machines **Workers → agent processes** Repositories, tools and execution

## What happens when something disconnects?

| Event | What continues | What you lose temporarily |
| --- | --- | --- |
| You close the app | Agents already running on a worker | Live visibility until you reconnect |
| The control plane restarts | Existing agent processes on other machines | Coordination, new starts and server-side actions |
| A worker machine stops | Work on other machines | Every process on the stopped machine |

Agent processes run under tmux and can outlive the connection to the control plane. A lost machine does not automatically move its work to another machine.

## Where work lives

The control plane stores shared state and credentials. Each worker keeps the working files and executes tools as its SSH account. A separate VM is the isolation boundary when work must not share host access.

**A new installation starts empty**

Installing the control plane does not create a worker. [Add a machine](https://usefiretower.com/docs/machines) before starting your first task.