# GitHub Actions integration

You can use _Black_ within a GitHub Actions workflow without setting your own Python
environment. Great for enforcing that your code matches the _Black_ code style.

## Compatibility

This action is known to support all GitHub-hosted runner OSes. In addition, only
published versions of _Black_ are supported (i.e. whatever is available on PyPI).

Finally, this action installs _Black_ with the `colorama` extra so the `--color` flag
should work fine.

## Usage

Create a file named `.github/workflows/black.yml` inside your repository with:

```yaml
name: Lint

on: [push, pull_request]

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - uses: psf/black@stable
```

We recommend the use of the `@stable` tag, but per version tags also exist if you prefer
that. Note that the action's version you select is independent of the version of _Black_
the action will use.

### Versions

The version of _Black_ the action will use can be configured via `version` or read from
the `pyproject.toml` file. The action defaults to the latest release available on PyPI.

`version` can be any
[valid version specifier](https://packaging.python.org/en/latest/glossary/#term-Version-Specifier)
or just the version number if you want an exact version.

If you want to match versions covered by Black's
[stability policy](labels/stability-policy), you can use the compatible release operator
(`~=`):

```yaml
- uses: psf/black@stable
  with:
    options: "--check --verbose"
    src: "./src"
    version: "~= 26.0"
```

To read the version from the `pyproject.toml` file instead, set `use_pyproject` to
`true`. This will first look into the `tool.black.required-version` field, then the
`dependency-groups` table, then the `project.dependencies` array and finally the
`project.optional-dependencies` table. Note that this requires Python >= 3.11, so using
the setup-python action may be required, for example:

**Security note:** `use_pyproject` only accepts standard version specifiers for `black`
(for example `==`, `~=`, `>=` and ranges like `>=25,<26`). Direct references such as
`black @ https://...` are not supported. If your workflow runs on untrusted pull
requests (for example from forks), prefer setting `with.version` explicitly.

```yaml
- uses: actions/setup-python@v6
  with:
    python-version: "3.13"
- uses: psf/black@stable
  with:
    options: "--check --verbose"
    src: "./src"
    use_pyproject: true
```

Only versions available from PyPI are supported, so no commit SHAs or branch names.

### Jupyter Notebooks

If you want to include Jupyter Notebooks, it can be enabled by setting `jupyter` to
`true` (default is `false`):

```yaml
- uses: psf/black@stable
  with:
    jupyter: true
```

See the [Jupyter Notebooks guide](../guides/using_black_with_jupyter_notebooks.md) for
more details.

### CLI Options

You can also configure the arguments passed to _Black_ via `options` (defaults to
`'--check --diff'`) and `src` (default is `'.'`). Please note that the
[`--check` flag](labels/exit-code) is required so that the workflow fails if _Black_
finds files that need to be formatted.

Here's an example configuration:

```yaml
- uses: psf/black@stable
  with:
    options: "--check --verbose"
    src: "./src"
    jupyter: true
    version: "21.5b1"
```
