asar_repack

SERVERJshookmcp SOURCE@jshookmcp/jshook

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-vmoranv-jshookmcp/asar-repack.md

WHAT IT DOES

What asar_repack does on Jshookmcp

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

RISK

Why asar_repack is rated Medium

Creates/overwrites an ASAR archive file, enabling tampering with Electron app bundles.

From the tool's definition Pack a directory tree into an Electron ASAR archive

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs asar_repack safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Jshookmcp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For asar_repack, this is the rule to start with:

asar_repack Rate-limited

asar_repack 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": {
    "asar_repack": {
      "limits": [
        {
          "counter": "asar_repack_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Jshookmcp, apply this rule, and every asar_repack call is checked against it from then on.

FAQ

Questions about asar_repack

What does the asar_repack tool do? +

Pack a directory tree into an Electron ASAR archive (inverse of asar_extract). Walks the input directory and writes a valid .asar (4xUInt32LE pickle prefix + JSON header + data segment) that parseAsarBuffer and Electron accept. Closes the unpack → patch → repack → retest loop without leaving jshookmcp. It is categorised as a Write tool in the Jshookmcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on asar_repack? +

Register the Jshook MCP server in PolicyLayer and add a rule for asar_repack: 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 Jshookmcp. Nothing to install.

What risk level is asar_repack? +

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

Can I rate-limit asar_repack? +

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

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

asar_repack is provided by the Jshook MCP server (@jshookmcp/jshook). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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