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 YES ✅

The queue_relay_player lets you "pause" queue event processing until some other event is posted, at which time the original queue event processing continues.

Here's an example:

    post: start_my_mode
    wait_for: my_mode_done

This entry will watch for the game_ending event to be posted. (game_ending is a queue event.) When it's posted, the queue relay player will pause the processing of the game_ending event and post a new event, the start_my_mode in this case.

You can use that new event to do whatever you want, like start some custom mode you want to run at game end before the machine goes back to the attract mode.

When your mode is done, you would configure it to post my_mode_done (or whatever the wait_for: is set to, and that will release the queue and progress will continue. If your mode doesn't need to do anything, it can simply post the wait_for: event and exit.


If the wait_for: event is never posted, you will break your game since MPF will wait forever.

Note that each entry under queue_event_player: (the game_ending: in the example above) must be for a queue event. (You can see which events are queue events in the event reference.) You can also use the queue_event_player: to "convert" a regular event into a queue event.

Required settings

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


Single value, type: string. Defaults to empty.

The name of the event to post to trigger your action once the queue event has been posted. (required)


Single value, type: string. Defaults to empty.

The name of the event this queue will wait for to continue. In other words, this is the event you need to post for the queue event to continue. (required)

Optional settings

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


One or more sub-entries. Each in the format of string : string

A sub-configuration of key:value pairs that will be posted with the event. This setting is optional.


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

If True pass on the arguments from the event in wait_for to the event posted in post.

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