auto_pack · Formlabs Local MCP: Risk & Policy

WHAT IT DOES

What auto_pack does on Formlabs Local

AI agents invoke auto_pack to trigger actions in Formlabs Local. 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 auto_pack needs a policy

This tool performs an automated packing/arrangement operation on a 3D printer, which is an Execute action—it runs an algorithm/operation whose effects depend on the models provided as arguments and directly impacts the printer's state and intended print job. It is not merely Read (no data retrieval), Write (not creating/modifying reversible data), Destructive (not deleting data), or Financial.

From the tool's definition Pack models into the build volume. SLS printers only (Fuse 1+, Fuse 1). The tool executes a packing operation that arranges 3D models in the printer's build chamber, which is a substantive computational operation that triggers physical printer behavior.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

auto_pack Rate-limited

auto_pack 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": {
    "auto_pack": {
      "limits": [
        {
          "counter": "auto_pack_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 Formlabs Local, so you can run agents against it safely.

FAQ

Questions about auto_pack

What does the auto_pack tool do? +

Pack models into the build volume. SLS printers only (Fuse 1+, Fuse 1). It is categorised as a Execute tool in the Formlabs Local MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on auto_pack? +

Register the Formlabs Local MCP server in PolicyLayer and add a rule for auto_pack: 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 Formlabs Local. Nothing to install.

What risk level is auto_pack? +

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

Can I rate-limit auto_pack? +

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

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

auto_pack is provided by the Formlabs Local MCP server (mkebiclioglu/formlabs-local-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.