install_addon

Install an add-on from its slug (must already be in a registered repository).

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/install-addon.md

WHAT IT DOES

What install_addon does on Ha Nexus Agent

AI agents invoke install_addon 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 install_addon is rated High

Installing an add-on triggers an external operation that downloads and installs software onto the Home Assistant host system. This is an Execute-category action with high severity because a misused tool could install malicious or unwanted software, potentially compromising the smart home environment.

From the tool's definition Install an add-on from its slug (must already be in a registered repository)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs install_addon 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 install_addon, this is the rule to start with:

install_addon Rate-limited

install_addon 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": {
    "install_addon": {
      "limits": [
        {
          "counter": "install_addon_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 install_addon call is checked against it from then on.

FAQ

Questions about install_addon

What does the install_addon tool do? +

Install an add-on from its slug (must already be in a registered repository). 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 install_addon? +

Register the Ha Nexus Agent MCP server in PolicyLayer and add a rule for install_addon: 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 install_addon? +

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

Can I rate-limit install_addon? +

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

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

install_addon 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.

KEEP EXPLORING

More on Ha Nexus Agent, and thousands of servers like it.

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All 276 Ha Nexus Agent tools → High-risk tools on this server →

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All high-risk MCP tools → The MCP Attack Database →

Guides

Govern code and CI agents →Agent sandbox →Least privilege for MCP →