Headless PreForm Server

PreForm Server is PreForm without its user interface. It serves the same PreForm API, so a script written against PreForm runs unchanged against PreForm Server. Use it where no one watches the screen, such as a computer that prepares each incoming order as it arrives, or an application that runs as a service.

Most scripts don't need PreForm Server: get started by connecting to the PreForm window you already have open.

Download PreForm Server#

PreForm Server is distributed separately from PreForm. Download the build for macOS or Windows from Formlabs API downloads and release notes.

The SDK starts the server from the path of its executable. On macOS, that's the executable inside the app bundle, because the .app folder itself isn't an executable.

Start PreForm Server from Python#

To check the setup, start the server, print its version, and shut it down:

Python

import os

from formlabs_sdk import FormlabsClient

# On macOS, set PREFORM to the executable inside PreFormServer.app.
PREFORM = os.environ.get("PREFORM", "PreFormServer.exe")

with FormlabsClient() as client:
    # launch() waits up to 60 seconds for the server to start. Leaving the with block
    # shuts the server down.
    with client.preform.launch(PREFORM) as preform:
        print(f"PreForm Server {preform.version} at {preform.base_url}")

The script prints the server version and http://localhost:44388. The launch() method fails with PORT_IN_USE when another server already listens on port 44388. To use another port, pass the port argument.

The SDK owns a server that launch() starts: leaving the with block shuts it down. launch() also logs the server in with the client's account, when the client has one. Every other call is the same as against PreForm, so a script from Create your first script runs headless once connect() is replaced with launch() and the path of the PreForm Server executable.

Start PreForm Server from a terminal#

PreForm Server also runs on its own. The --port argument is required:

Terminal

/Applications/PreFormServer.app/Contents/MacOS/PreFormServer --port 44388

PowerShell

C:\PreFormServer\PreFormServer.exe --port 44388

The server prints READY FOR INPUT after it starts accepting requests. A script then attaches with the connect() method, exactly as it does to PreForm, and closing the client leaves the server running. The connect() method leaves the server's login as it is, so a server started this way stays logged out until it's logged in. For more information, see Log PreForm in.

For the other options, see CLI & command-line options.

What's next#

PreForm client