It’s often desirable to have an action within the container application coincide with an event (or multiple events) within a timeline. For instance, an animated and interactive spot illustration that walks a user through an on-boarding experience might send messages to the container app to sync state changes in the experience with the animation; a guide character motions for three interface elements to be made visible in sequence and synced to 00:16.08, 00:19.12, and 00:22.04 respectively.
Yep, we have plans to add this! We actually used to have this in an older version of the tool. You can create an event and trigger it on a timeline.
One example use-case for this is footsteps for a character (until we add audio support in Rive, you can use the footstep event to trigger a sound effect in your engine).