How to contribute to Flask

Please don’t use the issue tracker for this. The issue tracker is a tool to address bugs and feature requests in Flask itself. Use one of the following resources for questions about using Flask or issues with your own code:

The channel on our Discord chat: https://discord.gg/pallets
Ask on . Search with Google first using: site:stackoverflow.com flask {search term, exception message, etc.}
Ask on our GitHub Discussions for long term discussion or larger questions.

Include the following information in your post:

Describe what you expected to happen.
If possible, include a to help us identify the issue. This also helps check that the issue is not with your own code.
Describe what actually happened. Include the full traceback if there was an exception.
List your Python and Flask versions. If possible, check if this issue is already fixed in the latest releases or the latest code in the repository.

If there is not an open issue for what you want to submit, prefer opening one for discussion before working on a PR. You can work on any issue that doesn’t have an open PR linked to it or a maintainer assigned to it. These show up in the sidebar. No need to ask if you can work on an issue that interests you.

Include the following in your patch:

Use Black to format your code. This and other tools will run automatically if you install using the instructions below.
Add an entry in CHANGES.rst. Use the same style as other entries. Also include .. versionchanged:: inline changelogs in relevant docstrings.

Download and install the latest version of git.
Configure git with your and email.
Make sure you have a .
Fork Flask to your GitHub account by clicking the Fork button.

the main repository locally.

$ git clone https://github.com/pallets/flask
$ cd flask

Add your fork as a remote to push your work to. Replace {username} with your username. This names the remote “fork”, the default Pallets remote is “origin”.
```
$ git remote add fork https://github.com/{username}/flask
```

Create a virtualenv.

Linux/macOS

$ python3 -m venv env
$ . env/bin/activate

Windows
```
> env\Scripts\activate
```

$ pip install -r requirements/dev.txt && pip install -e .

Install the pre-commit hooks.
```
$ pre-commit install
```

Create a branch to identify the issue you would like to work on. If you’re submitting a bug or documentation fix, branch off of the latest “.x” branch.
```
$ git fetch origin
$ git checkout -b your-branch-name origin/2.0.x
```
If you’re submitting a feature addition or change, branch off of the “main” branch.
```
$ git fetch origin
$ git checkout -b your-branch-name origin/main
```
Using your favorite editor, make your changes, committing as you go.
Include tests that cover any code changes you make. Make sure the test fails without your patch. Run the tests as described below.
Push your commits to your fork on GitHub and . Link to the issue being addressed with fixes #123 in the pull request.

Run the basic test suite with pytest.

$ pytest

This runs the tests for the current environment, which is usually sufficient. CI will run the full suite when you submit your pull request. You can run the full test suite with tox if you don’t want to wait.

Generating a report of lines that do not have test coverage can indicate where to start contributing. Run pytest using coverage and generate a report.

$ pip install coverage
$ coverage run -m pytest
$ coverage html

Open htmlcov/index.html in your browser to explore the report.