urllib3 is a community-maintained project and we happily accept contributions.

If you wish to add a new feature or fix a bug:

  1. Check for open issues or open a fresh issue to start a discussion around a feature idea or a bug. There is a Contributor Friendly tag for issues that should be ideal for people who are not very familiar with the codebase yet.
  2. Fork the urllib3 repository on Github to start making your changes.
  3. Write a test which shows that the bug was fixed or that the feature works as expected.
  4. Send a pull request and bug the maintainer until it gets merged and published. :) Make sure to add yourself to CONTRIBUTORS.txt.

Setting up your development environment

It is recommended, and even enforced by the make file, that you use a virtualenv:

$ python3 -m venv venv3
$ source venv3/bin/activate
$ pip install -r dev-requirements.txt

Running the tests

We use some external dependencies, multiple interpreters and code coverage analysis while running test suite. Our Makefile handles much of this for you as long as you’re running it inside of a virtualenv:

$ make test-quick
[... magically installs dependencies and runs tests on your virtualenv]
Ran 182 tests in 1.633s


There is also a make target for running all of our tests and multiple python versions.

$ make test-all

Note that code coverage less than 100% is regarded as a failing run. Some platform-specific tests are skipped unless run in that platform. To make sure the code works in all of urllib3’s supported platforms, you can run our tox suite:

$ make test-all
[... tox creates a virtualenv for every platform and runs tests inside of each]
py26: commands succeeded
py27: commands succeeded
py32: commands succeeded
py33: commands succeeded
py34: commands succeeded

Our test suite runs continuously on Travis CI with every pull request.


Please consider sponsoring urllib3 development, especially if your company benefits from this library.

We welcome your patronage on Bountysource:

Your contribution will go towards adding new features to urllib3 and making sure all functionality continues to meet our high quality standards.

We also welcome sponsorship in the form of time. We greatly appreciate companies who encourage employees to contribute on an ongoing basis during their work hours. Please let us know and we’ll be glad to add you to our sponsors list!

Project Grant

A grant for contiguous full-time development has the biggest impact for progress. Periods of 3 to 10 days allow a contributor to tackle substantial complex issues which are otherwise left to linger until somebody can’t afford to not fix them.

Contact @shazow to arrange a grant for a core contributor.

Huge thanks to all the companies and individuals who financially contributed to the development of urllib3. Please send a PR if you’ve donated and would like to be listed.