hassapi — Home Assistant Python API Client

A Python client for the Home Assistant REST API and WebSocket API.

Installation

pip install hassapi

Quick Start

from hassapi import Hass

hass = Hass(hassurl="http://192.168.1.10:8123", token="YOUR_LONG_LIVED_TOKEN")

# Control devices
hass.turn_on("light.living_room")
hass.turn_off("switch.coffee_machine")
hass.toggle("light.bedroom")

# Read state
state = hass.get_state("sensor.temperature")
print(state.state)           # e.g. "21.5"
print(state.attributes)      # dict of entity attributes
print(state.last_changed)    # datetime

# Run a script
hass.run_script("good_morning")

Configuration

Constructor arguments

hass = Hass(
    hassurl="http://IP_ADDRESS:8123",
    token="YOUR_HASS_TOKEN",
    verify=True,   # Set to False to skip TLS certificate verification (e.g. self-signed certs)
    timeout=3,     # Request timeout in seconds
)

Environment variables

If hassurl or token are not passed, the client reads from environment variables:

export HASS_URL=http://192.168.1.10:8123
export HASS_TOKEN=your_long_lived_token

hass = Hass()  # reads from env

API Reference

States

# Get the state of a single entity
state: State = hass.get_state("light.living_room")

# Get states of all entities
states: StateList = hass.get_states()

# Set state and optionally attributes of an entity
state: State = hass.set_state("sensor.my_sensor", state="42", attributes={"unit": "°C"})

State object fields:

Services

# Call any service
hass.call_service("turn_on", entity_id="light.living_room", brightness=200)

# Convenience methods
hass.turn_on("light.living_room")
hass.turn_off("switch.fan")
hass.toggle("light.bedroom")

# Covers
hass.open_cover("cover.garage")
hass.close_cover("cover.garage")
hass.set_cover_position("cover.garage", position=50)

# Input entities
hass.select_option("input_select.mode", option="Away")
hass.set_value("input_number.brightness", value=75)

# Scripts and shell commands
hass.run_script("good_morning")
hass.run_shell_command("backup")

# List all available services
services: ServiceList = hass.get_services()

Events

# List all registered event listeners
events: EventList = hass.get_events()

# Fire an event
hass.fire_event("MY_CUSTOM_EVENT")
hass.fire_event("MY_CUSTOM_EVENT", event_data={"key": "value"})

Real-time events (WebSocket)

Subscriptions are non-blocking — they start a background thread and return immediately.

import time

def on_change(event):
    data = event["data"]
    print(data["entity_id"], data["old_state"]["state"], "->", data["new_state"]["state"])

# Watch a specific entity for state changes
hass.subscribe_to_state_changes(on_change, entity_id="light.living_room")

# Watch all state changes
hass.subscribe_to_state_changes(on_change)

# Watch a specific event type
hass.subscribe_to_events(on_change, event_type="call_service")

# Watch all events
hass.subscribe_to_events(on_change)

# Keep the main thread alive while listening
try:
    while True:
        time.sleep(1)
except KeyboardInterrupt:
    hass.unsubscribe()

The client reconnects automatically on dropped connections using exponential backoff, and gives up after 5 consecutive failures.

Templates

# Render a Jinja2 template
result: str = hass.render_template("{{ states('sensor.temperature') }}")

Getting a Long-Lived Access Token

1. Open Home Assistant in your browser
2. Go to your profile: Settings → Your profile → Security
3. Scroll to Long-lived access tokens and create one

Contributing

# Install dev dependencies and run all checks
pip install tox
tox

Individual environments:

tox -e pytest        # run tests
tox -e flake8        # lint
tox -e mypy          # type check
tox -e format        # auto-format code
tox -e format-check  # check formatting without modifying

License

MIT