subscribe_trigger

Wait for a HA trigger to fire. Returns the trigger context when it fires.

SERVERHa Nexus Agent SOURCEfistacho/ha-nexus-agent

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/fistacho-ha-nexus-agent/subscribe-trigger.md

WHAT IT DOES

What subscribe_trigger does on Ha Nexus Agent

AI agents invoke subscribe_trigger to trigger actions in Ha Nexus Agent. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

RISK

Why subscribe_trigger is rated High

This tool executes trigger-based operations in Home Assistant. While superficially passive (waiting/listening), triggers in Home Assistant are tied to automation rules that cause real-world effects (turning lights on/off, adjusting thermostats, unlocking doors, etc.).

From the tool's definition Tool subscribes to and waits for Home Assistant triggers to fire, returning trigger context. The description 'Wait for a HA trigger to fire' indicates it executes/monitors reactive operations based on trigger events, which are tied to home automation actions.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs subscribe_trigger safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Ha Nexus Agent, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For subscribe_trigger, this is the rule to start with:

subscribe_trigger Rate-limited

subscribe_trigger stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "subscribe_trigger": {
      "limits": [
        {
          "counter": "subscribe_trigger_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Ha Nexus Agent, apply this rule, and every subscribe_trigger call is checked against it from then on.

FAQ

Questions about subscribe_trigger

What does the subscribe_trigger tool do? +

Wait for a HA trigger to fire. Returns the trigger context when it fires. It is categorised as a Execute tool in the Ha Nexus Agent MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on subscribe_trigger? +

Register the Ha Nexus Agent MCP server in PolicyLayer and add a rule for subscribe_trigger: 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 Ha Nexus Agent. Nothing to install.

What risk level is subscribe_trigger? +

subscribe_trigger is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit subscribe_trigger? +

Yes. Add a rate_limit block to the subscribe_trigger 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 subscribe_trigger completely? +

Set action: deny in the PolicyLayer policy for subscribe_trigger. 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 subscribe_trigger? +

subscribe_trigger is provided by the Ha Nexus Agent MCP server (fistacho/ha-nexus-agent). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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