powershell-mcp

A Model Context Protocol server that gives AI agents real, non-intrusive access to Windows PowerShell.

Most tools that let an agent run Windows commands spawn a visible console window for every call — which steals focus and interrupts whatever you're typing. powershell-mcp runs everything in a hidden process (windowsHide: true / no CreateWindow), captures structured output, enforces hard timeouts, and exposes purpose-built tools for service and system management. Built for running unattended next to a human at the keyboard.

Why

• No popup windows. Commands run hidden; your foreground app keeps focus.
• Structured + safe. Every call returns { stdout, stderr, exit_code, duration, timed_out }. Hard timeout with tree-kill. Output is capped so a runaway command can't flood the context.
• Real Windows management. First-class tools for services and system info, not just a raw shell — handy for managing Windows servers and backup systems.
• Cross-shell. Prefers pwsh (PowerShell 7+) and falls back to powershell.exe; override with PWSH_MCP_EXE.

Tools

Native programs: Windows PowerShell routes a native command's stdout to the console, so run hidden it is lost. Use run_program (direct-exec) for console binaries like gh/git/docker; use run_powershell for PowerShell/cmdlet logic.

See it work

Real calls, real output — headless, no console window, structured results:

# ssh_exec — run a command on a Linux box, in-process (no ssh.exe, no WSL)
> ssh_exec  host=192.168.0.5  username=isak  command="uptime; systemctl is-active app"
$ ssh [email protected]  (exit=0, 818ms)
 2 days, 23:53,  load average: 0.00, 0.01, 0.04
active

# sftp_upload — deploy a file, in-process (no scp.exe)
> sftp_upload  localPath=C:\deploy\app.py  remotePath=/home/isak/app.py  host=192.168.0.5 ...
sftp upload: C:\deploy\app.py → [email protected]:/home/isak/app.py
OK (9129 bytes, 714ms)

Remote operations

powershell-mcp manages more than the local box. Windows' own ssh.exe produces no capturable output when run from a windowless/background process, and shipping WSL to every server doesn't scale — so remote exec is built in:

• `ssh_exec` uses the pure-JS ssh2 client (no external binary), so it works headless and needs nothing on the target beyond an SSH server. Ideal for Linux hosts.
• `winrm_exec` uses native PowerShell Remoting, so a Windows fleet needs only WinRM enabled — no per-server install.

Telemetry (anonymous, opt-out)

On startup the server sends a one-time ping (host id, version, OS, timestamp) and flushes per-tool call counts every 30 minutes (and on exit). This helps prioritise which tools matter. No command content, arguments, output, or paths are ever sent.

• Disable entirely: set POWERSHELL_MCP_NO_TELEMETRY=1.
• Override the endpoint: set POWERSHELL_MCP_TELEMETRY_URL.

The collector under collector/ is a standalone Node.js service (JSONL append, systemd unit, nginx snippet, deploy.sh) deployed separately.

Install

npm install
npm run build

Then register it with your MCP host. For Claude Desktop, add to claude_desktop_config.json (see examples/):

{
  "mcpServers": {
    "powershell": { "command": "node", "args": ["C:\\path\\to\\powershell-mcp\\dist\\index.js"] }
  }
}

Develop

npm run dev        # run from source (tsx)
npm test           # unit + (where a shell is present) integration tests
npm run typecheck

CI runs build + tests on both windows-latest and ubuntu-latest.

Security notes

• control_service and many commands require the MCP host process to run with sufficient privileges.
• The server runs whatever script it's given — run it only in environments you trust, behind a host (like Claude) that you control. A future release will add an optional allow/deny policy and confirmation gating.

License

MIT © IMR Research & Development (UK)