tox.ini file

The tox.ini file in your charm’s root directory is a typical tox configuration file.

See also

Configuration in the tox documentation

Charmcraft creates this file and defines the following tox environments:

Environment	Purpose
format	Apply coding style standards
lint	Check code against coding style standards and static checks
unit	Run the charm’s unit tests
integration	Run the charm’s integration tests

To run the commands in an environment, use tox -e <env-name>.

tox.ini requires the tox-uv plugin. First make sure that uv is installed on the current host. Then use uv to install tox and tox-uv:

uv tool install tox --with tox-uv

Configuration of testing and linting tools is specified in the pyproject.toml file. Dependencies are also specified in pyproject.toml. You’ll need to create the uv.lock file before using tox.

For 12-factor app profiles targeting Ubuntu 24.04 LTS or lower: tox.ini doesn’t require any plugins. Dependencies are specified in the requirements.txt file instead of pyproject.toml.