carton

https://github.com/dtcristo/carton

Split your app into Cartons with explicit imports and exports. Each has its own dependencies and runs in a separate Ruby::Box, so Ruby enforces the boundaries at runtime. Only what a Carton exports is reachable, monkey patches stay where they are made, and two Cartons can use different versions of the same gem. No manifest needed. Requires Ruby 4.0.7+.