# Portable STEP Service Runtime

## Goal

Run the STEP save backend from this project folder on another Windows machine without installing system Python or system FreeCAD.

## Expected layout

Put these runtimes inside the project root:

```text
Online3DViewer/
  runtime/
    python/
      python.exe
      ...
    freecad/
      bin/
        FreeCADCmd.exe
      ...
```

## One-time setup on the source machine

1. Copy a full Windows Python runtime into `runtime/python`.
2. Copy the FreeCAD folder into `runtime/freecad`.
3. Install backend dependencies into the portable Python:

```bat
tools\step_service\setup_portable_python.bat
```

## Start the backend

Use the portable launcher:

```bat
tools\step_service\start_portable_server.bat
```

This launcher only uses `runtime/python/python.exe`. It does not modify system PATH.

## How FreeCAD is resolved

The backend now checks FreeCAD in this order:

1. `runtime/freecad/bin/FreeCADCmd.exe`
2. `FreeCADCmd` from the current environment

So your existing local setup still works, but the portable folder takes priority when present.

## Notes

- Copy the whole project folder to the target machine.
- The target machine still needs normal Windows runtime support that FreeCAD and Python depend on.
- If you want zero manual commands on the target machine, use `start_portable_server.bat` instead of `python tools/step_service/server.py`.