control_device
Control a Home Assistant entity by turning it on or off.
LABSCO SUMMARY
Small on purpose: search for the entity, then act on it.
Two steps rather than one is the honest shape here — the assistant has to find the entity id before it can control anything, and the README says so rather than pretending otherwise. Colour control only lands on lights that support RGB, and the light has to be on before a colour change takes. The instance URL living in a source file rather than an environment variable is the one rough edge worth knowing about up front.
What it is
A small Home Assistant bridge built around a two-step flow: search for entities in natural language, then act on the entity_id you get back. Lights get colour and brightness control on top of on/off.
What you get
- Entity search — "find my living room lights" resolves to the entity ids you can then control
- Turning devices on and off by entity id
- set_device_color takes an entity and RGB components from 0 to 255, so "set the living room lights to red" becomes a concrete call
- The same call takes an optional brightness from 0 to 255, which can be combined with a colour change
Requirements
Python 3.11 or higher and a reachable Home Assistant instance. It needs a Long-Lived Access Token, created from your Home Assistant profile page and passed as HOME_ASSISTANT_TOKEN. The instance address defaults to http://homeassistant.local:8123; a different address means editing HA_URL in app/config.py.
Setup effort
Build from source
USE CASES
01
Turning something on without knowing its entity id
Describe the device, get the matching entities back, then act on one.
02
Setting a light to a specific colour
RGB components go in directly, with brightness as an optional fourth value.
03
Dimming a room from the chat
Brightness rides along with the colour call rather than needing a separate step.
3 tools
Listed in project code.
search_entities
Search for Home Assistant entities matching a natural language description.
set_device_color
Set the color and optionally brightness of a light entity.
BEFORE YOU INSTALL
What to know first
Tools you get
3 tools registered in the project's code.
Requires
- Python 3.11 or later
- HOME_ASSISTANT_TOKEN in your environment
INSTALLATION
Connect your client
MCP Clients
Cursor
CURSOR · TERMINAL
git clone https://github.com/hpohlmann/home-assistant-mcp.git
cd home-assistant-mcp
python -m venv .venv
source .venv/bin/activate
pip install -U pip
pip install uv
uv pip install -e .If your Home Assistant is not at http://homeassistant.local:8123, set HA_URL in app/config.py
Add the server to Cursor with the full path of this folder after --directory
CURSOR · JSON
{
"mcpServers": {
"home_assistant": {
"command": "uv",
"args": [
"--directory",
"<YOUR_PATH_TO_HOME_ASSISTANT_MCP>",
"run",
"main.py"
],
"env": {
"HOME_ASSISTANT_TOKEN": "<YOUR_HOME_ASSISTANT_TOKEN>"
},
"inheritEnv": true
}
}
}<YOUR_PATH_TO_HOME_ASSISTANT_MCP> is the full path of your clone, and <YOUR_HOME_ASSISTANT_TOKEN> is a Long-Lived Access Token from your Home Assistant profile page.
