---
title: Run a headless engine
description: Keep agents working on an always-on machine.
section: Guides
order: 9
---

# Run a headless engine

A headless engine runs Admiral's engine on a machine with no window: a VPS, a home server, a build box. It hosts projects like any desktop. You drive it from your other devices.

## When to use it

- The work must continue when your laptop closes or leaves home.
- The project needs to live on a specific machine: more memory, a deploy target, a database.
- Several people steer work that runs on one machine.

## Start headless

Run the engine without a window:

```bash
admiral headless
```

## Run it as a service

For an always-on machine, install the engine as a user service. It starts at login and restarts on failure:

```bash
admiral daemon install
admiral daemon start
admiral daemon status
```

The daemon subcommands are `install`, `start`, `stop`, `restart`, `status`, and `uninstall`. On macOS the service uses launchd; on Linux it uses systemd user units.

## Sign in on a headless machine

Sign in from a terminal with an interactive prompt:

```bash
admiral login
```

Two rules:

1. Sign in or sign out only while the engine is stopped.
2. A headless engine started by a service manager has no terminal for sign-in. Run `admiral login` first; the service picks up the session when it starts.

## Use the machine

After it runs, the machine behaves like any host:

1. Sign in on your laptop or phone with the same account.
2. Select the headless machine in the device switcher.
3. Add a project folder on it, and start sessions. The machine runs the agents; you steer from anywhere.

## Keep it current

Update the CLI with:

```bash
admiral update
```

## Next steps

- [Connect another device](connect-another-device.md): the client side of this setup.
- [Command line](../reference/cli.md): every command and flag.