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# atrium

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Related articles

- Display manager
- Multiseat
- Wayland

atrium is a Wayland display manager with first-class multiseat support. In a multiseat setup, multiple users share a single machine, each with their own monitor, keyboard, and mouse and an independent login session. atrium handles each seat automatically: it discovers seats, presents a login screen, authenticates users via PAM, and launches their Wayland compositor.

Note atrium supports Wayland sessions only. X11 sessions are not supported.

## Installation

Install atriumAUR.

## Configuration

Note The default configuration works for most single-seat and standard multiseat setups. This step can be skipped unless something does not work or you need to customise compositor selection.

atrium reads two configuration files at startup:

- `/etc/atrium.conf` — daemon settings (compositor command, session policy, timeouts)
- `/etc/atrium-greeter.conf` — greeter settings (font size, screen blanking timeout, passwordless users)

Both files are installed with commented-out defaults. Refer to the inline comments for available options.

atrium discovers available sessions from `/usr/share/wayland-sessions/`. Any installed Wayland compositor that provides a `.desktop` file there will appear on the login screen automatically.

## Starting

To start atrium, enable `atrium.service` and restart.

Note

- Before enabling the systemd service, disable any other display manager.
- Starting it immediately will terminate any active graphical session.

## Multiseat

atrium has built-in multiseat support. Each seat requires its own GPU; atrium discovers seats via logind and launches an independent greeter on each one. Devices must be assigned to seats with `loginctl attach`, but no additional configuration is needed.

See Multiseat Setup Guide for a step-by-step device assignment guide.

## Known limitations

- No hot-unplug — seats and displays added at runtime are detected automatically, but seat or GPU removal while atrium is running is not yet handled.
- Single password prompt — PAM stacks that emit more than one prompt (2FA, fingerprint, hardware tokens) are not supported yet.

## See also

- Releases and release notes
- r/linux_multiseat — general Linux multiseat discussion

Category:

- Display managers

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