replace_and_commit · Fs Git MCP: Risk & Policy

WHAT IT DOES

What replace_and_commit does on Fs Git

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

WHY IT NEEDS A POLICY

Why replace_and_commit needs a policy

This tool modifies file content (reversible via git history/revert) and commits the change. It is Write category because the changes are reversible through version control, not Destructive. However, severity is high because an AI agent could maliciously modify critical files across a repository, even if technically undoable.

From the tool's definition Tool name 'replace_and_commit' and description 'Replace text in file and commit' indicate modification of file content with automatic git commit.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

replace_and_commit Rate-limited

replace_and_commit 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": {
    "replace_and_commit": {
      "limits": [
        {
          "counter": "replace_and_commit_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 Fs Git, so you can run agents against it safely.

FAQ

Questions about replace_and_commit

What does the replace_and_commit tool do? +

Replace text in file and commit. It is categorised as a Write tool in the Fs Git MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on replace_and_commit? +

Register the Fs Git MCP server in PolicyLayer and add a rule for replace_and_commit: 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 Fs Git. Nothing to install.

What risk level is replace_and_commit? +

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

Can I rate-limit replace_and_commit? +

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

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

replace_and_commit is provided by the Fs Git MCP server (wojons/fs-git-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.