Home Assistant Scene MCP

A Model Context Protocol (MCP) server for controlling Home Assistant lights and managing scenes. Complements the official Home Assistant MCP by providing detailed light control with colors and scene management.

Features

• Show Lights - View all lights with full details:
  • State, brightness, RGB colors, color temperature
  • Color mode and supported modes
  • Available effects (colorloop, etc.)
  • Color temperature range (min/max Kelvin)
• Adjust Light - Control lights (on/off, brightness, RGB color, color temperature, effects)
• Create Scene - Save current lighting as a scene with two modes:
  • exclusive - Turns off other lights when activated
  • additive - Only affects lights in the scene
• List Scenes - View all saved scenes
• Activate Scene - Activate a saved scene (with IKEA Tradfri support)
• Update Scene - Update an existing scene with current light states
• Delete Scene - Remove a scene
• Blackout - Turn off all lights

Why This MCP?

The official Home Assistant MCP is limited - it can't show light colors or provide detailed state information. This MCP fills that gap:

| Feature | Official HA MCP | This MCP | |---------|-----------------|----------| | Show light colors | ❌ | ✅ | | Show brightness | Limited | ✅ Full detail | | Show color modes | ❌ | ✅ | | Show effects | ❌ | ✅ | | Set RGB colors | ❌ | ✅ | | Color temperature | ❌ | ✅ | | Set effects | ❌ | ✅ | | Create scenes | ❌ | ✅ | | IKEA Tradfri fixes | ❌ | ✅ |

Installation

npm install -g ha-mcp-server

Or clone and build:

git clone https://github.com/Koneisto/HomeAssistant-Light-MCP.git
cd HomeAssistant-Light-MCP
npm install
npm run build

Configuration

Add to Claude Desktop config:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "ha-scenes": {
      "command": "ha-mcp-server",
      "env": {
        "HA_URL": "http://your-home-assistant-ip:8123",
        "HA_TOKEN": "your-long-lived-access-token"
      }
    }
  }
}

Get your Home Assistant token

1. Go to Home Assistant → Profile (bottom left)
2. Scroll to "Long-Lived Access Tokens"
3. Click "Create Token"
4. Copy the token

Usage Examples

Show lights

"Show me all the lights"

"What lights are on?"

Control lights

"Turn on living room light"

"Set bedroom to 50% brightness"

"Make the kitchen light red"

"Set studio lights to warm white"

"Start colorloop on the hallway light"

Create a scene

"Save this as Movie Night"

Activate a scene

"Activate Movie Night"

Update a scene

"Update Evening Lights with current settings"

Blackout

"Turn off all lights"

Tools Reference

| Tool | Description | |------|-------------| | scene_show_lights | Show all lights with state, brightness, colors, effects, color modes | | scene_adjust_light | Control a light (on/off, brightness, color, effects) | | scene_create | Create a new scene from current light states | | scene_list | List all scenes | | scene_activate | Activate a scene | | scene_update | Update existing scene with current lights | | scene_delete | Delete a scene | | scene_blackout | Turn off all lights | | scene_configure | Set Home Assistant URL and token |

Light Properties

scene_show_lights returns:

• state - on/off
• brightness / brightness_pct - 0-255 / 0-100%
• rgb_color - [R, G, B] values
• color_temp_kelvin - Color temperature
• color_mode - Current mode (xy, color_temp, rgb, hs)
• supported_color_modes - What the light supports
• effect - Active effect (if any)
• effect_list - Available effects
• color_temp_range - Min/max Kelvin (if supported)

Scene Modes

• Exclusive: Turns off all lights not in the scene. Good for room-specific scenes.
• Additive: Only affects lights in the scene. Good for accent lighting.

IKEA Tradfri Support

IKEA Tradfri lights have a known issue when switching between RGB color mode and color temperature (Kelvin) mode. The bulbs need time to process the mode change before accepting brightness or color values.

Note: Home Assistant's native scenes don't work reliably with Tradfri lights due to these timing issues. This MCP provides a workaround by managing scenes independently with proper delays.

This MCP automatically handles Tradfri lights by:

• Detecting Tradfri devices by manufacturer name
• Adding a 500ms delay between mode switch and subsequent commands
• Properly sequencing color/temperature changes with brightness adjustments

Without these fixes, Tradfri lights often ignore commands or produce incorrect colors when switching modes.

Security

Your Data Stays Local

• All communication happens directly between your computer and your Home Assistant instance
• No data is sent to external servers or third parties
• The MCP server runs locally on your machine via stdio (no open network ports)

No Tracking

• We don't care enough to track you

Token Safety

• Your Home Assistant token is stored only on your local machine
• Use environment variables to avoid storing tokens in files
• The token is only sent to your own Home Assistant instance
• You can revoke the token anytime from Home Assistant settings

What This Server Can Access

• Only lights and scenes in your Home Assistant
• Cannot access other Home Assistant entities (sensors, locks, cameras, etc.)
• Cannot make changes outside of light control and scene management

License

MIT

Author

Koneisto

Built by people with questionable priorities