Fluff is a SQL formatter that I like a lot. I built this app because I often want to format one-off, adhoc sql that isn't even worth saving to a file.
You can use the application on Heroku.
Set up a python (3.8) environment:
$ pip install -r requirements-dev.txt
Run the app locally:
$ flask run
Lint and run unit tests:
$ tox
Run the production application:
$ python -m app.wsgi