Skip to content


This is a config file reference. Click for instructions.

This page is reference material which explains every setting and option for this section of an MPF yaml config file. See the instructions for config files for formatting and other details. See our guide to config file examples for more examples of real configs in action.

Valid in
machine config files YES ✅
mode config files NO 🚫

The machine_vars: section of your machine-wide config file lets you specify the initial state of machine variables that are set when MPF starts up.

Required settings

The following sections are required in the machine_vars: section of your config:


Single value, type: string. Defaults to empty.

The initial value of this machine variable that you're setting. This is set when MPF starts.

Optional settings

The following sections are optional in the machine_vars: section of your config. (If you don't include them, the default will be used).


Single value, type: boolean (true/false). Default: true

True/False value which controls whether this machine variable will be persisted to when MPF shuts down.


Single value, type: one of the following options: str, float, int. Default: int

Select one of the options from this list: int (integer), float, or str (string). The default is "int", and there is no intelligence to try to detect which type of value you have, so if you have a floating point number or a string, you also need to set the value_type.

Something missing or wrong? You can fix it!

This website is edited by people like you! Is something wrong or missing? Is something out of date, or can you explain it better?

Please help us! You can fix it yourself and be an official "open source" contributor!

It's easy! See our Beginner's guide to editing the docs.

Page navigation via the keyboard: < >

You can navigate this site via the keyboard. There are two modes:

General navigation, when search is not focused:

  • F , S , / : open search dialog
  • P , , : go to previous page
  • N , . : go to next page

While using the search function:

  • Down , Up : select next / previous result
  • Esc , Tab : close search
  • Enter : go to highlighted page in the results