Check

from golproductions

Check if a command is runnable before running it.

🔥🔥🔥✓ VerifiedFreeQuick setup

check-mcp

MCP server for Check — a command firewall for AI agents. Validates every shell command before execution. Sub-100ms. Runnable or invalid.

A free key is minted automatically on first run. No signup, no key to paste.

Tools

`Check`

Validate a command. Returns RUNNABLE or INVALID.

Input:  { "command": "kubectl rollout restart deployment/api" }
Output: Verdict: RUNNABLE

`CheckAndExecute`

Validate then run. Invalid commands are blocked before they touch the shell.

Input:  { "command": "kubectl rollout restart deployment/api" }
Output: (command output)

How it works

Checks locally if the binary is installed on your machine
If not installed — instant block, no API call, no cost
If installed — validates syntax and targets via the Check API
Returns verdict in under 100ms

Pricing

120 free checks every day. After that, $0.0068 AUD per check. No subscriptions. Credits never expire.

Copy & paste — that's it

npx @golproductions/check --install

Before it works, you'll need: GOL_CLIENT_ID

Install

Cursor

// .cursor/mcp.json
{
  "mcpServers": {
    "Check": {
      "command": "npx",
      "args": ["@golproductions/check-mcp"]
    }
  }
}

Windsurf

// .windsurf/mcp.json
{
  "mcpServers": {
    "Check": {
      "command": "npx",
      "args": ["@golproductions/check-mcp"]
    }
  }
}

Claude Desktop

// claude_desktop_config.json
{
  "mcpServers": {
    "Check": {
      "command": "npx",
      "args": ["@golproductions/check-mcp"]
    }
  }
}

VS Code

// .vscode/mcp.json
{
  "servers": {
    "Check": {
      "type": "stdio",
      "command": "npx",
      "args": ["@golproductions/check-mcp"]
    }
  }
}

Cline

// cline_mcp_settings.json
{
  "mcpServers": {
    "Check": {
      "command": "npx",
      "args": ["@golproductions/check-mcp"]
    }
  }
}

Any other MCP client

Point it at the same command: npx @golproductions/check-mcp. Stdio transport, no other setup.

The server activates a free key on first run. To reuse an existing Client ID across machines, add it under env:

"env": { "GOL_CLIENT_ID": "your_key" }

Claude Code

For Claude Code, use the installer instead — it wires up the hook that validates every command automatically:

npx @golproductions/check --install