What shadcn/ui is

shadcn/ui gives you designed components, blocks, and the tools to copy their source into your own project. The top layer of component code becomes part of your application.

That changes the ownership model. You can inspect and adapt a Button or Dialog instead of fighting a distant package API, but updates are also your responsibility. Current shadcn/ui can generate components on different accessible primitive bases, including Base UI, Radix, and React Aria. Do not assume every project uses the same base or composition API.

The generated file is yours, but it can still import runtime packages for primitives, class composition, icons, and animation. Think of shadcn/ui as a source distribution layer over those dependencies. A registry update does not automatically patch your local Button, and upgrading a primitive package can still change its behavior.

This model is strongest when the team wants to shape a small component system around its product. It is weaker when nobody will own accessibility tests, local changes, and dependency upgrades. “Copy and paste” describes delivery, not the maintenance cost.

Base UI is the current default base, while Radix and React Aria remain supported choices. Read the source generated for this project. An example using asChild, render, or another composition mechanism may belong to a different base even when the visual result looks identical.

Compare this model with one component library installed from npm. Trace a generated Button from your file to its runtime imports, then list one advantage, one maintenance responsibility, and one upgrade path created by owning the source.