Home Assistant REPL

A REPL shell custom designed for Home Assistant custom component developers, tinkerers and native Python speakers. Makes it easy as pie!

It is an opinionated REPL (Read-Eval-Print-Loop) shell that aims are to make it easier without any configuration to:

• Exploring of the APIs in context of a live working instance
• Trialling out snippets of code
• Debugging code (but see note below)
• Hotfixing issues that don't have built in support to do so from existing components.

$ uv run --with homeassistant-repl ha-repl --token=<insert token here>
Home Assistant REPL (API client mode) connected to ws://homeassistant.local:8123/api/websocket. `obj` only, read-only - no `hass`. Ctrl-D to exit.
>>> obj["/mqtt/binary_sensor/kitchen_terrace_window_tilt"].state
'off'
>>> [o.name for o in obj["/rflink/binary_sensor"].values() if o.state=='unavailable']
['Shed Intruder Alarm', 'Panic Keyfob']
>>> {(o.entity_id, o.state) for o in obj.find(domain="binary_sensor",platform="mqtt")}
{
    ('binary_sensor.terrace_pir_occupancy', 'unavailable'),
    ('binary_sensor.scullery_smoke_alarm_battery_low', 'off'),
    ('binary_sensor.kitchen_terrace_window_tweaked', 'off'),
    ('binary_sensor.scullery_water_detector_water_leak', 'dry'),
    ('binary_sensor.boiler_co_detector_battery_low', 'off'),
    ('binary_sensor.pantry_sensor_occupancy', 'off')
}
>>>

If you're not already comfortable using Python tools to manipulate data on the fly, or better REPL shells in other languages, this is a great way to learn, and faster at the keyboard than clicking around Jupyter notebooks.

This is primarily for developers of custom components, and their LLM agents, though may be of interest for other folk tinkering with Home Assistant. It is a potentially sharp tool, so NOT appropriate for general Home Assistant users.

Features

• Integrated with rich for pretty object printouts and stack traces
• Access to all entities via dictionary like interface, obj
• Usual multi-line editing support and history of Python
• Integrated with homeassistant-api as hass_api object, available in both modes
• Auto-awaits coroutines for easy shell use (can be switched off or overridden)
• Dedicated shell that can be run without installation with uv
• Usable from inside ipython shell, Marimo notebooks or plain python -m asyncio

All of the above works with standard Home Assistant APIs, referred to as api mode.

Home Assistant REPL also has an advanced live mode that taps directly into a live Home Assistant using an optional server component available via HACS.

Live Mode

This mode requires a custom component to be installed on the target Home Assistant server via HACS, or use the supplied scripts to install on a local devcontainer. It adds:

• Full access to the core Home Assistant Python API via hass
• Read/write access to the actual objects, e.g. entities and their helpers
• A frisson of danger

HA REPL Server

A HACS component that taps into the Home Assistant and acts as a session server over web sockets. It has been designed for HomeAssistant 2026.8 or greater.

Needed for live mode only, since api mode only uses standard Home Assistant APIs.

Future Developments

See the Roadmap for where this might go, and your feedback welcome.

!!! note It is not intended to ever be a replacement for a Python debugger, although it may complement one. It also does not intend to replicate PyScript, instead focusing on standard python (PyScript uses MicroPython) even at expense of general usability or home assistance access, and not a general automation script execution service. For most non-developer cases, homeassistant-cli is a better choice, with pre-packaged access to devices, entities, services etc.

Quick Start

Use the api mode with uv (traditional install also available via pip install homeassistant-repl).

If Home Assistant available via http://homeassistant.local:8123 then you can skip the --server argument. You will also need to create a Long Lived Access Token by going to the personal settings on your Home Assistant mobile or desktop app.

uv run --with homeassistant-repl ha-repl --token <<<my long lived access token>>>

Using the Shell

The shell is a full Python REPL shell, with multi-line editing, history etc, living inside an asyncio loop that exposes the live Home Assistant instance as:

• obj - the Object Tree exposed as a dictionary object and common methods
• hass_api - the Home Assistant web socket / REST API exposed using the homeassistant-api library

In live mode it offers, in addition to what api mode offers:

• hass - the HomeAssistant class at the root of the Python API
• sql - SQL access to the Recorder databases

So I can write code at the command line like:

>>> pir = obj["/rflink/binary_sensor/hall_pir"]
>>> pir.state = "on"  # non-strict mode, sets entity state with repl as context

The return value of the object is returned to the shell, value printed and available to Python code as _. Tracebacks are printed also, as if they were local (in general everything feels like its local)

The homeassistant-api integration can be used like:

>>> len(hass_api.get_domain('cover'))
12

!!! note The hass_api object returns AsyncEntity objects rather than ApiEntity objects - this is because it comes from a separate project, homeassistant-api that is focused solely on API development, whereas the ApiEntity class is designed for custom code development, being a subset of the real Entity in HomeAssistant, that you'd also get in live mode.

See also Alternative Integration options for how to use this in your own plain python shell, ipython, Marimo or similar.

Starting the Shell

Use the HASS_SERVER environment variable, exported or in a local .env file, or the --server command line argument if the Home Assistant server is not running locally at usual address( i.e. http://homeassistant.local:8123). A long lived access token is needed at --token or in an HASS_TOKEN environment variable.

Live Mode for Real Server

On a real instance, install via HACS:

• it's not in the default HACS repository, so you'll have to add https://github.com/rhizomatics/homeassistant-repl as a Custom Repository from the top-right dot menu first
• Search for Home Assistant REPL in the HACS menu and choose Download
• Restart Home Assistant for it to recognize the new custom component available
• From Settings → Devices & services → Add integration find Home Assistant REPL Server in the list and install, there's no further config needed
  • Alternatively add ha_repl_server: to configuration.yaml, which is imported as a config entry)
• Run ha-repl with the live argument

The quickest way to run the shell is using uv, which you can do without cloning this repo or making any other downloads.

uv run --with homeassistant-repl ha-repl         

Get help on the arguments in the usual way,

uv run --with homeassistant-repl ha-repl --help       ,

If you do have this repo checked out, you can also use a direct run which means you can also tinker locally with homeassistant_repl code.

uv run ha-repl         

Configuration

All modes require a Long Lived Access Token which can be provided via HASS_TOKEN enivironment variable, a HASS_TOKEN=xxxx line in an .env file, or the --token argument on ha-repl.

The URL will default to http://homeassistant.local:8123 or can be set using the HASS_SERVER enivironment variable, a HASS_SERVER=xxxx line in an .env file, or the --server argument on ha-repl.

Note, although homeassistant-api itself has different env vars, when used within ha-repl it will be set up automatically using the same server and token as the main shell.