--- layout: page title: "Multiple Instances" description: "Quick primer on how multiple instances work together." date: 2016-04-16 14:24 -07:00 sidebar: true comments: false sharing: true footer: true --- # {% linkable_title This has been deprecated and is no longer supported. %} Home Assistant supports running multiple synchronized instances using a master-slave model. Whenever `events.fire` or `states.set` is called on the slave it will forward it to the master. The master will replicate all events and changed states to its slaves.

Overview of the Home Assistant architecture for multiple devices.

A slave instance can be started with the following code and has the same support for components as a master instance. ```python import homeassistant.remote as remote import homeassistant.bootstrap as bootstrap # Location of the Master API: host, password, port. # Password and port are optional. remote_api = remote.API("127.0.0.1", "password", 8124) # Initialize slave hass = remote.HomeAssistant(remote_api) # To add an interface to the slave on localhost:8123 bootstrap.setup_component(hass, 'frontend') hass.start() hass.block_till_stopped() ```

Because each slave maintains its own Service Registry it is possible to have multiple slaves respond to one service call.