LmsPs — LM Studio PowerShell MCP Server

A minimal, environment‑driven MCP server that exposes a persistent PowerShell session to LM Studio. It keeps a single pwsh.exe/powershell.exe process alive and offers tools to run commands, manage cwd, and get/set env vars. Responses to the client are trimmed (default 500 chars) while full I/O is logged.

Features

• Tools: ps.run, ps.cd, ps.cwd, ps.reset, ps.env_get, ps.env_set
• Persistent PowerShell between calls (stateful session)
• 500‑char response trim to the client; full logs on disk
• All paths/config via environment variables (no hardcoded paths)

Install (dev)

cd K:/Repos/LmsPs
python -m venv .venv
. .venv/Scripts/activate  # Windows
pip install -e .

Run (stdio)

• From WSL (recommended by LM Studio):

bash K:/Repos/LmsPs/scripts/start_ps_mcp_stdio.sh

• Or directly (Windows):

python -m lmsps.server

Environment variables

• LMSPS_PWSH — PowerShell executable (default pwsh.exe, fallback powershell.exe)
• LMSPS_PWSH_FALLBACK — override fallback exe if needed
• LMSPS_LOGDIR — log directory (default: <repo>/logs)
• LMSPS_TRIM_CHARS — max characters returned to client (default: 500)
• LMSPS_TIMEOUT_SEC — per‑call timeout in seconds (default: 30)

LM Studio configuration example

Add to your LM Studio settings JSON:

{
  "mcpServers": {
    "lmsps": {
      "command": "bash",
      "args": ["-lc", "K:/Repos/LmsPs/scripts/start_ps_mcp_stdio.sh"],
      "env": {
        "LMSPS_PWSH": "/mnt/c/Program Files/PowerShell/7/pwsh.exe",
        "LMSPS_LOGDIR": "/mnt/k/LMstudio/LmsPs/logs",
        "LMSPS_TRIM_CHARS": "500"
      }
    }
  }
}

Smoke test (from LM Studio)

• ps.run → Get-Process | Select-Object -First 3
• ps.cwd → should show current location
• ps.cd → change to a test directory and re‑run ps.cwd
• ps.env_set/ps.env_get → write/read a temp environment variable
• Re‑run ps.run to confirm session persistence

Logs

• Full request/response JSON lines are appended to LMSPS_LOGDIR/lmsps_server.log.

Repo layout

• src/lmsps/server.py — MCP server implementation
• scripts/start_ps_mcp_stdio.sh — stdio launcher (used by LM Studio)
• logs/ — default log directory (overridable via LMSPS_LOGDIR)

License

MIT