[WRITE] Expose or unexpose entities to a voice assistant. MODIFIES voice assistant configuration - requires approval. Changes take effect immediately (no HA restart needed).
Part of the Home Assistant server.
Free to start. No card required.
AI agents invoke ha_expose_entities to trigger processes or run actions in Home Assistant. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.
ha_expose_entities can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.
Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.
{
"version": "1",
"default": "deny",
"tools": {
"ha_expose_entities": {
"limits": [
{
"counter": "ha_expose_entities_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}See the full Home Assistant policy for all 96 tools.
These attack patterns abuse exactly the kind of access ha_expose_entities gives an agent. Each links to the full case and the policy that stops it:
Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
[WRITE] Expose or unexpose entities to a voice assistant. MODIFIES voice assistant configuration - requires approval. Changes take effect immediately (no HA restart needed).. It is categorised as a Execute tool in the Home Assistant MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Home Assistant MCP server in PolicyLayer and add a rule for ha_expose_entities: 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 Home Assistant. Nothing to install.
ha_expose_entities is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the ha_expose_entities 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 ha_expose_entities. 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.
ha_expose_entities is provided by the Home Assistant MCP server (@coolver/home-assistant-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 96 Home Assistant tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.