vim_macro · Mcp Neovim Server MCP: Risk & Policy

WHAT IT DOES

What vim_macro does on Mcp Neovim Server

AI agents invoke vim_macro to trigger actions in Mcp Neovim Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why vim_macro needs a policy

Macros in Neovim are sequences of recorded keystrokes that can be replayed to execute arbitrary editor commands, including file modifications, shell commands (via :! or similar), and other operations. Playing back a macro executes a potentially complex sequence of actions whose effects depend on the recorded content, making this an Execute-category tool.

From the tool's definition Record, stop, and play Neovim macros

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vim_macro Rate-limited

vim_macro stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "vim_macro": {
      "limits": [
        {
          "counter": "vim_macro_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Mcp Neovim Server, so you can run agents against it safely.

FAQ

Questions about vim_macro

What does the vim_macro tool do? +

Record, stop, and play Neovim macros. It is categorised as a Execute tool in the Mcp Neovim Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on vim_macro? +

Register the Mcp Neovim Server MCP server in PolicyLayer and add a rule for vim_macro: 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 Mcp Neovim Server. Nothing to install.

What risk level is vim_macro? +

vim_macro is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit vim_macro? +

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

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

vim_macro is provided by the Mcp Neovim Server MCP server (mcp-neovim-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.