git-export · Jj MCP: Risk & Policy

WHAT IT DOES

What git-export does on Jj

AI agents use git-export 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-export needs a policy

This tool writes changes to a Git repository by exporting jj changes. While the changes themselves are reversible (Git commits can be undone, branches can be reset), the tool modifies version control state in potentially significant ways.

From the tool's definition Tool description states it will 'Update the underlying Git repo with changes made in the Jujutsu (jj) repository' and is 'Useful for syncing jj changes back to Git'.

Risk signalsAdmin/system-level operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

git-export Rate-limited

git-export 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-export": {
      "limits": [
        {
          "counter": "git-export_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-export

What does the git-export tool do? +

Update the underlying Git repo with changes made in the Jujutsu (jj) repository. Useful for syncing jj changes back to Git. Parameters: repoPath (Optional path to repo root or working directory), cwd (Optional working directory to run the command in). 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-export? +

Register the Jj MCP server in PolicyLayer and add a rule for git-export: 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-export? +

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

Can I rate-limit git-export? +

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

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

git-export 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.