You can plan this migration ahead of time by moving your models into gems stored in, say, vendor/future_gems/. Then just reference each gem in bundler as: gem

You can plan this migration ahead of time by moving your models into gems stored in, say, vendor/future_gems/. Then just reference each gem in bundler as: gem "my_models", path: "vendor/future_gems/my_models/" Once you are able to break them out completely, just remove the path reference and use a gem server instead.