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 isak@192.168.0.5  (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 → isak@192.168.0.5:/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

The canonical npm package is @imrrd/powershell-mcp.

Run it directly from npm in an MCP client:

{
  "mcpServers": {
    "powershell": {
      "command": "npx",
      "args": ["-y", "@imrrd/powershell-mcp@latest"]
    }
  }
}

Or install the CLI globally:

npm install -g @imrrd/powershell-mcp

Migrating: powershell-mcp is deprecated and will not receive a patched legacy release. Remove it and install @imrrd/powershell-mcp@0.5.3 or later.

For development from source:

npm install
npm run build

See examples/claude_desktop_config.json for the canonical package-based client configuration.

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

• winrm_exec sends caller-controlled connection details to the local PowerShell child over stdin; credentials are not placed in process arguments or environment variables.
• 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)