omarchy_theme_set · Omarchy MCP: Risk & Policy

WHAT IT DOES

What omarchy_theme_set does on Omarchy

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

WHY IT NEEDS A POLICY

Why omarchy_theme_set needs a policy

This tool modifies the current theme setting, which is a reversible write operation. Users can easily switch back to a previous theme. There is no data deletion, code execution, or financial impact. The blast radius is minimal—a misused theme change merely affects desktop appearance and can be undone by setting another theme.

From the tool's definition Tool name 'omarchy_theme_set' and description 'Set the current Omarchy theme' indicate a reversible modification operation. The server context confirms this is a desktop theme management tool without destructive or financial implications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

omarchy_theme_set Rate-limited

omarchy_theme_set 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": {
    "omarchy_theme_set": {
      "limits": [
        {
          "counter": "omarchy_theme_set_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 Omarchy, so you can run agents against it safely.

FAQ

Questions about omarchy_theme_set

What does the omarchy_theme_set tool do? +

Set the current Omarchy theme. It is categorised as a Write tool in the Omarchy MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on omarchy_theme_set? +

Register the Omarchy MCP server in PolicyLayer and add a rule for omarchy_theme_set: 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 Omarchy. Nothing to install.

What risk level is omarchy_theme_set? +

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

Can I rate-limit omarchy_theme_set? +

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

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

omarchy_theme_set is provided by the Omarchy MCP server (servicestack/omarchy-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.