prowlarr_sync_apps · Homelab MCP: Risk & Policy

WHAT IT DOES

What prowlarr_sync_apps does on Homelab

AI agents invoke prowlarr_sync_apps to trigger actions in Homelab. 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.

WHY IT NEEDS A POLICY

Why prowlarr_sync_apps needs a policy

This tool triggers an external synchronization operation across multiple connected applications (Radarr, Sonarr). It is not a simple read or write — it actively pushes configuration/indexer data to external apps, which is an execution of an operational workflow.

From the tool's definition Force Prowlarr to sync all indexers to connected apps (Radarr, Sonarr)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

prowlarr_sync_apps Rate-limited

prowlarr_sync_apps 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": {
    "prowlarr_sync_apps": {
      "limits": [
        {
          "counter": "prowlarr_sync_apps_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about prowlarr_sync_apps

What does the prowlarr_sync_apps tool do? +

Force Prowlarr to sync all indexers to connected apps (Radarr, Sonarr). Use after adding a new indexer. It is categorised as a Execute tool in the Homelab MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on prowlarr_sync_apps? +

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

What risk level is prowlarr_sync_apps? +

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

Can I rate-limit prowlarr_sync_apps? +

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

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

prowlarr_sync_apps is provided by the Homelab MCP server (nainounen/homelab-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.