resave_packages · Unreal MCP: Risk & Policy

WHAT IT DOES

What resave_packages does on Unreal

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

WHY IT NEEDS A POLICY

Why resave_packages needs a policy

This tool bulk-writes/resaves all packages in the project, modifying files on disk. While it doesn't delete data, it overwrites package files in bulk across the entire project, which could have a large blast radius if misused (e.g., corrupting or overwriting packages with unintended changes).

From the tool's definition Bulk resave all packages in the project (runs ResavePackages commandlet)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

resave_packages Rate-limited

resave_packages 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": {
    "resave_packages": {
      "limits": [
        {
          "counter": "resave_packages_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 Unreal, so you can run agents against it safely.

FAQ

Questions about resave_packages

What does the resave_packages tool do? +

Bulk resave all packages in the project (runs ResavePackages commandlet). It is categorised as a Write tool in the Unreal MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on resave_packages? +

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

What risk level is resave_packages? +

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

Can I rate-limit resave_packages? +

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

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

resave_packages is provided by the Unreal MCP server (sam-david/unreal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.