create_automation · Home Assistant MCP Server MCP

WHAT IT DOES

What create_automation does on Home Assistant MCP Server

AI agents use create_automation to create or update resources in Home Assistant MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Home Assistant MCP Server environment.

WHY IT NEEDS A POLICY

Why create_automation needs a policy

This tool creates new automations that will execute persistent rules in the home automation system. While reversible (automations can be deleted via delete_automation), it modifies the system's operational state and could trigger unwanted device actions if misconfigured.

From the tool's definition Tool name 'create_automation' and description 'Create a new Home Assistant automation from YAML configuration' explicitly describes creating (Write operation) persistent automation rules that alter home automation behavior.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_automation Rate-limited

create_automation 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_automation": {
      "limits": [
        {
          "counter": "create_automation_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Home Assistant MCP Server, so you can run agents against it safely.

FAQ

Questions about create_automation

What does the create_automation tool do? +

Create a new Home Assistant automation from YAML configuration. It is categorised as a Write tool in the Home Assistant MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_automation? +

Register the Home Assistant MCP Server MCP server in PolicyLayer and add a rule for create_automation: 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 MCP Server. Nothing to install.

What risk level is create_automation? +

create_automation is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_automation? +

Yes. Add a rate_limit block to the create_automation 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.

How do I block create_automation completely? +

Set action: deny in the PolicyLayer policy for create_automation. 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.

What MCP server provides create_automation? +

create_automation is provided by the Home Assistant MCP Server MCP server (mjrestivo16/mcp-homeassistant). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.