Fill4Me will automatically insert fuel and/or ammunition from your main inventory into entities when you place them. It is mod-agnostic and will learn about items & entities in other mods. It is an alternative to the Autofill mod.
Utilities
Mod category: Utilities
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.
Unless I'm wrong, I believe I'm doing this in the "standard accepted fashion" of defining my button as mod_gui.get_button_flow(player).add({ ... }). So, I'm going to blame Warptorio (who's putting it in get_frame_flow), unless I get corrected.