write_and_commit · Fs Git MCP: Risk & Policy

WHAT IT DOES

What write_and_commit does on Fs Git

AI agents use write_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 write_and_commit needs a policy

This tool creates or modifies files and commits them to git, which is reversible. It does not delete data (would be Destructive) or execute arbitrary code (would be Execute). However, it carries high severity because an AI agent could write malicious code, overwrite critical files, or corrupt repository history if misused.

From the tool's definition Tool description states 'Write a file and create an atomic git commit with templated message.' The primary action is writing/modifying file content, with git commit as a side effect. This is reversible through git operations (revert, reset).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

write_and_commit Rate-limited

write_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": {
    "write_and_commit": {
      "limits": [
        {
          "counter": "write_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 write_and_commit

What does the write_and_commit tool do? +

Write a file and create an atomic git commit with templated message. 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 write_and_commit? +

Register the Fs Git MCP server in PolicyLayer and add a rule for write_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 write_and_commit? +

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

Can I rate-limit write_and_commit? +

Yes. Add a rate_limit block to the write_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 write_and_commit completely? +

Set action: deny in the PolicyLayer policy for write_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 write_and_commit? +

write_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.