git-clone · Jj MCP: Risk & Policy

WHAT IT DOES

What git-clone does on Jj

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

WHY IT NEEDS A POLICY

Why git-clone needs a policy

git-clone creates a new repository on the local filesystem by cloning a remote Git repo. This is a Write operation (creates new data/directories) rather than Execute, as it is a well-defined VCS operation with predictable behavior. It does not delete or overwrite existing data irreversibly.

From the tool's definition Create a new Jujutsu (jj) repository backed by a clone of a Git repo

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

git-clone Rate-limited

git-clone 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": {
    "git-clone": {
      "limits": [
        {
          "counter": "git-clone_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 Jj, so you can run agents against it safely.

FAQ

Questions about git-clone

What does the git-clone tool do? +

Create a new Jujutsu (jj) repository backed by a clone of a Git repo. The Git repo will be a bare git repo stored inside the .jj/ directory. Parameters: source (URL or path of the Git repo to clone), destination (Optional destination directory for the clone), remoteName (Optional name for the newly created remote, default: origin), colocate (Optional flag to colocate the jj repo with the git repo), depth (Optional depth for shallow clone). It is categorised as a Write tool in the Jj MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on git-clone? +

Register the Jj MCP server in PolicyLayer and add a rule for git-clone: 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 Jj. Nothing to install.

What risk level is git-clone? +

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

Can I rate-limit git-clone? +

Yes. Add a rate_limit block to the git-clone 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 git-clone completely? +

Set action: deny in the PolicyLayer policy for git-clone. 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 git-clone? +

git-clone is provided by the Jj MCP server (jj-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.