Home Assistant

Home Assistant is free and open-source software used for home automation. It serves as an integration platform and smart home hub, allowing users to control smart home devices. The software emphasizes local control and privacy and is designed to be independent of any specific Internet of Things (IoT) ecosystem. Its interface can be accessed through a web-based user interface, by using companion apps for Android and iOS, or by voice commands via a supported virtual assistant, such as Google Assistant, Amazon Alexa, Apple Siri, and Home Assistant's own "Assist" (a built-in local voice assistant) using natural language.

The Home Assistant software application is commonly run on a computer appliance with "Home Assistant Operating System" that will act as a central control system for home automation (commonly called a smart home hub/gateway/bridge/controller),   that has the purpose of controlling IoT connectivity technology devices, software, applications and services from third-parties via modular integration components, including native integration components for common wired or wireless communication protocols and standards for IoT products such as Bluetooth, Zigbee, Z-Wave, EnOcean, and Thread/Matter (used to create either local personal area networks or direct ad hoc connections with small smart home devices using low-power digital radios), or Wi-Fi and Ethernet connected devices on a home network / local area network (LAN).

Home Assistant as such supports controlling devices and services connected via either open and proprietary ecosystems or commercial smart home hubs/gateways/bridges as long they provide public access via some kind of Open API or MQTT interface to allow for third-party integration over either the local area network or Internet, which includes integrations for Alexa Smart Home (Amazon Echo), Google Nest (Google Home), HomeKit (Apple Home), Samsung SmartThings, and Philips Hue.

Information from all devices and their attributes (entities) that the application sees can be used and controlled via automation or script using scheduling and/or subroutines (including preconfigured "blueprint"), e.g. for controlling lighting, climate, entertainment systems and smart home appliances.

History
The project was started as a Python application by Paulus Schoutsen in September 2013 and first published publicly on GitHub in November 2013.

In July 2017, a managed operating system called Hass.io was initially introduced to make it easier to use Home Assistant on single-board computers like the Raspberry Pi series. This has since been renamed to "Home Assistant Operating System" (and is often referred to as "Home Assistant OS"), and uses the concept of a bundled "supervisor" management system that allows users to manage, backup, update the local installation and enable the option to extend the functionality of the software with add-ons (plug-in applications) to run as services on the same platform for tighter integrations with Home Assistant core.

An optional "Home Assistant Cloud" subscription service was introduced in December 2017 as an external cloud computing service officially supported by the Home Assistant founders to solve the complexities associated with secured remote access, as well as linking to various third-party cloud services, such as Amazon Alexa and Google Assistant. Nabu Casa, Inc. was formed in September 2018 to take over this subscription service. The company's funding is based solely on revenue from the "Home Assistant Cloud" subscription service. The money earned is used to finance the project's infrastructure and to pay for full-time employees contributing to the Home Assistant and ESPHome projects.

In January 2020, branding was adjusted to make it easier to refer to different parts of the project. The main piece of software was renamed Home Assistant Core, while the full suite of software with the Hass.io embedded operating system with a bundled "supervisor" management system was renamed Home Assistant (though it is also commonly referred to as "HAOS" as in short for "Home Assistant OS").

In the beginning of January 2021, Home Assistant made a public service announcement, disclosing vulnerabilities with its third-party custom integrations. Later in January 2021, it made a second security disclosure about a security vulnerability.

In April 2024, ownership of the Home Assistant source code and brand name was transferred to the newly created "Open Home Foundation" non-profit organization. The founder of Home Assistant made statements in the announcement that this transfer of ownership and change in governance should mean no practical change to its developers or users as it was primarily done to ensure that Home Assistant source code will remain a free and open-source software and with a continued focus on privacy and local control. Statements in the press release also included secondary plans and goals of making Home Assistant transition from an enthusiast platform to a mainstream consumer product. Ownership of many of the open-source libraries that Home Assistant uses as dependencies and other related entities was also transferred to the Open Home Foundation non-profit organization.

Hardware
Home Assistant is supported and can be installed on multiple platforms. Pre-installed hardware appliances are also available for purchase from a few different manufacturers. Compatible hardware platforms include single-board computers (for example Hardkernel ODROID, Raspberry Pi, Asus Tinkerboard, Intel NUC), operating systems like Windows, macOS, Linux as well as virtual machines and NAS systems. Windows support is via a Windows VM or installing the Windows Subsystem for Linux (WSL).

On officially supported hardware platforms like the ODROID N2+ and Raspberry Pi 3/4 single-board computers, the installation requires flashing a corresponding system image onto a microSD card, eMMC, or other local storage from which the system can boot. It is possible to use Home Assistant as a gateway or bridge for devices using different IoT technologies like Zigbee or Z-Wave; necessary hardware can be mounted onto GPIO (Serial/I2C/SMBus), UART, or using USB ports. Moreover, it can connect directly or indirectly to local IoT devices, control hubs/gateways/bridges or cloud services from many different vendors, including other open and closed smart home ecosystems.

In December 2020, a customized ODROID N2+ computer appliance with bundled software was introduced under the product name "Home Assistant Blue" as an officially supported common hardware reference platform. The same package is also referred to as "ODROID-N2+ Home Assistant Bundle" when sold without the official custom-made enclosure. It comes with Home Assistant OS pre-installed on local eMMC storage, a power-adapter, and a custom Home Assistant themed enclosure. Home Assistant founders made it clear that the release of official hardware would not keep them from supporting other hardware platforms like the Raspberry Pi series.

In September 2021, Home Assistant developers at Nabu Casa announced a crowdfunding campaign on Crowd Supply for pre-orders of "Home Assistant Yellow" (initially called "Home Assistant Amber"), a new official home automation controller hardware platform with Home Assistant pre-installed, a spiritual successor to "Home Assistant Blue". "Home Assistant Yellow" is designed to be an appliance, and its internals are architected with a carrier board (or "baseboard") for a computer-on-modules compatible with the Raspberry Pi Compute Module 4 (CM4) embedded computer as well as an integrated M.2 expansion slot meant for either an NVMe SSD as expanded storage or for an AI accelerator card, and an onboard EFR32 based radio module made by Silicon Labs capable of acting as a Zigbee Coordinator or Thread Leader (Thread Border Router), as well as optional variant with PoE (Power over Ethernet) support. The most otherwise notable features missing on "Home Assistant Yellow" are an HDMI or DisplayPort to connect a monitor, (which is likely due to it like most smart home hubs being purpose-built to act as a headless system), as well as lack of onboard Bluetooth, Wi-Fi, and a USB 3.0 port by default. Shipping of "Home Assistant Yellow" is targeted for June 2022.

In June of 2022, Home Assistant developers at Nabu Casa announced their officially supported "Home Assistant SkyConnect", a multi-protocol IoT USB radio dongle capable of Zigbee and/or Thread low-power wireless protocols, that enable plug-and-play support for Home Assistant's built-in Zigbee gateway (the "ZHA" integration) and experimental Thread/Matter integrations. That same initial SkyConnect USB radio dongle model has since been renamed to "Home Assistant Connect ZBT-1" in preparation of future IoT USB radio dongle models in the same series, where an upcoming Z-Wave dongle has been announced and planned for launch in the end of 2024.

In September 2023, Home Assistant developers at Nabu Casa announced their officially supported "Home Assistant Green" as an entry-level computer appliance that is meant to make it easier for new users to get started with Home Assistant from scratch. It does however only feature an Ethernet port (for connection to the user's LAN) and two USB ports. That is, unlike the previous "Home Assistant Yellow" this new computer appliance does not include any built-in IoT radios for Zigbee and Thread low-power wireless protocols, so users wanting to connect such devices will need to buy separate USB radio dongles for each such protocol.

Dashboard
The primary front-end dashboard system is called Lovelace (named after Ada Lovelace), which offers different cards to display information and control devices. Cards can display information provided by a connected device or control a resource (lights, thermostats, and other devices). The interface design language is based on Material Design and can be customized using global themes. The GUI is customizable using the integrated editor or by modifying the underlying YAML code. Cards can be extended with custom resources, which are often created by community members.

Automation
Home Assistant acts as a central smart home controller hub by combining different devices and services in a single place and integrating them as entities. The provided rule-based system for automation allows creating custom routines based on a trigger event, conditions and actions, including scripts. These enable building automation, alarm management of security alarms and video surveillance for home security system as well as monitoring of energy measuring devices. Since December 2020, it is possible to use automation blueprints - pre-made automation from the community that can be easily added to an existing system.

Security
Home Assistant is an on-premises software product with a focus on local control, which has been described as beneficial to the security of the platform, specifically when compared to closed-source home automation software based on proprietary hardware and cloud-services.

There is no remote access enabled by default and data is stored solely on the device itself. User accounts can be secured with two-factor authentication to prevent access even if the user password becomes compromised. Add-ons receive a security rating based on their access to system resources.

In January 2021, cybersecurity analyst Oriel Goel found a directory traversal security vulnerability in third party custom integrations. The issue was disclosed on January 22, 2021, and addressed in Home Assistant version 2021.1.5, released on January 23. There is no information about whether the vulnerability was exploited.

In March 2023, a full authentication bypass was discovered in Home Assistant, earning a CVE score of 10/10. This security issue affected Home Assistant's default remote access solution, Nabu Casa, due to Nabu Casa's remote access security model that publicly exposes the local Home Assistant server to the public internet. This security issue allows bad actors full control of any Home Assistant server they can access due to the full auth bypass.

Reception
Home Assistant took second place in 2017 and 2018 for the Thomas Krenn Award (formerly Open Source Grant), later winning first place in 2019. Home Assistant also won an DINACon award in 2018 for their "Open Internet Award" category, as well as being a nominee for the same awards in 2013.

Home Assistant has been included in a number of product and platform comparisons, where, like many other non-commercial smart home hubs/gateways/bridges/controllers for home automation, it has often been criticized for forcing users into a tedious file-based setup procedure using text-based YAML markup-language instead of graphical user interfaces. However, newer versions of Home Assistant produced by the core development team make the configuration (from initial installation as well as most basic configurations) more user-friendly by allowing configuration using the web-based graphical user interface as well as the original YAML scripting. GitHub's "State of the Octoverse" in 2019 listed Home Assistant as the tenth biggest open-source project on its platform with 6,300 contributors.