Home Assistant Operating System (formerly HassOS) is a Linux based operating system optimized to host Home Assistant and its Add-ons.

Home Assistant Operating System uses Docker as its container engine. By default it deploys the Home Assistant Supervisor as a container. Home Assistant Supervisor in turn uses the Docker container engine to control Home Assistant Core and Add-Ons in separate containers. Home Assistant Operating System is not based on a regular Linux distribution like Ubuntu. It is built using Buildroot and it is optimized to run Home Assistant. It targets single board compute (SBC) devices like the Raspberry Pi or ODROID but also supports x86-64 systems with UEFI.

Home Assistant - A project from the Open Home Foundation

• Lightweight and memory-efficient
• Minimized I/O
• Over The Air (OTA) updates
• Offline updates
• Modular using Docker container engine

The list of supported hardware is defined by ADR-0015. Every new hardware addition must meet at least requirements defined in ADR-0017 and pass through an architecture design proposal.

For documentation explaining details of the individual supported boards, see Board support section of the Home Assistant Developer Docs.

If you just want to use Home Assistant the official getting started guide and installation instructions take you through how to download Home Assistant Operating System and get it running on your machine.

If you're interested in finding out more about Home Assistant Operating System and how it works read on...

If you don't have experience with embedded systems, Buildroot or the build process for Linux distributions it is recommended to read up on these topics first (e.g. Bootlin has excellent resources).

The Home Assistant Operating System documentation can be found on the Home Assistant Developer Docs website.

• Bootloader:
  • GRUB for devices that support UEFI
  • U-Boot for devices that don't support UEFI
• Operating System:
  • Buildroot LTS Linux
• File Systems:
  • SquashFS for read-only file systems (using LZ4 compression)
  • ZRAM for /tmp, /var and swap (using LZ4 compression)
• Container Platform:
  • Docker Engine for running Home Assistant components in containers
• Updates:
  • RAUC for Over The Air (OTA) and USB updates
• Security:
  • AppArmor Linux kernel security module

The Development build GitHub Action Workflow is a manually triggered workflow which creates Home Assistant OS development builds. The development builds are available at https://os-artifacts.home-assistant.io/index.html.