28th July 2026 - Link Blog

uv 0.12.0. Some interesting breaking changes in this release of uv, in particular to the default project produced by the uv init command.

uv init is the uv shortcut for creating a new project. The previous version of uv, version 0.11.x, produced this directory when you ran uv init uv-init.

Here's what you get with uv 0.12. I have a GitHub repository that automatically snapshots the output of uv init, so you can also see the full diff:

GitHub diff view. uv-init/main.py is an old __name__=="__main__" file that has been entirely deleted. The pyproject.toml now has an authors list and a new project.scripts block defining uv-init as uv_init:main - and a new build-system block that uses uv_build as the build-backend. A new src/uv_init/__init__.py file contains a main() method with a -> None type annotation that prints Hello from uv-init.

uv init now defaults to a src/ shaped package, instead of dropping main.py in the root of the project. It also configures the uv_build backend for building wheels and .tar.gz distribution files when you run uv build. Finally, it sets up uv-init as a script alias which, when run with uv run uv-init, executes a new main() function in src/uv_init/__init__.py.

I've so far avoided using src layout in my own projects just out of inertia. I think it's time I switched.

I wonder when uv will be judged ready for a 1.0 release?