AI agents invoke send_command to trigger actions in Nvim. 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.
The server explicitly supports command execution in Neovim sessions. A 'send_command' tool on such a server almost certainly sends arbitrary commands to a live Neovim instance, which can execute shell commands, run scripts, modify files, or cause destructive effects.
From the tool's definition Tool name 'send_command' on a server described as enabling 'command execution' and 'control running Neovim sessions via RPC socket'
Documented attack patterns abuse exactly the kind of access send_command gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Nvim, and nothing reaches the server without passing your rules. This is the rule we recommend for send_command:
{
"version": "1",
"default": "deny",
"tools": {
"send_command": {
"limits": [
{
"counter": "send_command_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}send_command 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.
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send_command. It is categorised as a Execute tool in the Nvim MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Nvim MCP server in PolicyLayer and add a rule for send_command: 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 Nvim. Nothing to install.
send_command is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the send_command 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.
Set action: deny in the PolicyLayer policy for send_command. 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.
send_command is provided by the Nvim MCP server (paulburgess1357/nvim-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 17 Nvim tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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17 Nvim tools catalogued and risk-classified — across an index of 42,500+ MCP servers.