Control lights in Home Assistant. List all lights, get state of a specific light, turn lights on with brightness/color settings, or turn lights off.
AI agents use lights_control to create or update resources in HomeAssistant MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your HomeAssistant MCP environment.
This tool modifies the state of smart light devices (on/off, brightness, color). These are reversible state changes — no data is permanently deleted and no financial transactions occur. The blast radius is medium: an AI agent could disrupt lighting in a home environment, but effects are easily reversed.
From the tool's definition Control lights in Home Assistant... turn lights on with brightness/color settings, or turn lights off
Documented attack patterns abuse exactly the kind of access lights_control gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and HomeAssistant MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for lights_control:
{
"version": "1",
"default": "deny",
"tools": {
"lights_control": {
"limits": [
{
"counter": "lights_control_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}lights_control stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Control lights in Home Assistant. List all lights, get state of a specific light, turn lights on with brightness/color settings, or turn lights off. It is categorised as a Write tool in the HomeAssistant MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the HomeAssistant MCP server in PolicyLayer and add a rule for lights_control: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches HomeAssistant MCP. Nothing to install.
lights_control is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the lights_control rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for lights_control. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
lights_control is provided by the HomeAssistant MCP server (jango-blockchained/advanced-homeassistant-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from HomeAssistant MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
13 HomeAssistant MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.