Thank you for your interest! Sanic is always looking for contributors. If you don't feel comfortable contributing code, adding docstrings to the source files, or helping with the Sanic User Guide by providing documentation or implementation examples would be appreciated!

We are committed to providing a friendly, safe and welcoming environment for all, regardless of gender, sexual orientation, disability, ethnicity, religion, or similar personal characteristic. Our code of conduct sets the standards for behavior.


To develop on Sanic (and mainly to just run the tests) it is highly recommend to install from sources.

So assume you have already cloned the repo and are in the working directory with a virtual environment already set up, then run:

pip install -e ".[dev]"

Dependency Changes#

Sanic doesn't use requirements*.txt files to manage any kind of dependencies related to it in order to simplify the effort required in managing the dependencies. Please make sure you have read and understood the following section of the document that explains the way sanic manages dependencies inside the file.

Dependency Type Usage Installation
requirements Bare minimum dependencies required for sanic to function pip3 install -e .
tests_require / extras_require['test'] Dependencies required to run the Unit Tests for sanic pip3 install -e '.[test]'
extras_require['dev'] Additional Development requirements to add contributing pip3 install -e '.[dev]'
extras_require['docs'] Dependencies required to enable building and enhancing sanic documentation pip3 install -e '.[docs]'

Running all tests#

To run the tests for Sanic it is recommended to use tox like so:


See it's that simple!

tox.ini contains different environments. Running tox without any arguments will run all unittests, perform lint and other checks.

Run unittests#

tox environment -> [testenv]

To execute only unittests, run tox with environment like so:

tox -e py37 -v -- tests/
# or
tox -e py310 -v -- tests/

Run lint checks#

tox environment -> [testenv:lint]

Permform flake8\ , black and isort checks.

tox -e lint

Run type annotation checks#

tox environment -> [testenv:type-checking]

Permform mypy checks.

tox -e type-checking

Run other checks#

tox environment -> [testenv:check]

Perform other checks.

tox -e check

Run Static Analysis#

tox environment -> [testenv:security]

Perform static analysis security scan

tox -e security

Run Documentation sanity check#

tox environment -> [testenv:docs]

Perform sanity check on documentation

tox -e docs

Code Style#

To maintain the code consistency, Sanic uses the following tools:

  1. isort
  2. black
  3. flake8
  4. slotscheck


isort sorts Python imports. It divides imports into three categories sorted each in alphabetical order:

  1. built-in
  2. third-party
  3. project-specific


black is a Python code formatter.


flake8 is a Python style guide that wraps the following tools into one:

  1. PyFlakes
  2. pycodestyle
  3. Ned Batchelder's McCabe script


slotscheck ensures that there are no problems with __slots__ (e.g., overlaps, or missing slots in base classes).

isort, black, flake8, and slotscheck checks are performed during tox lint checks.

The easiest way to make your code conform is to run the following before committing:

make pretty

Refer to tox documentation for more details.

Pull requests#

So the pull request approval rules are pretty simple:

  1. All pull requests must pass unit tests.
  2. All pull requests must be reviewed and approved by at least one current member of the Core Developer team.
  3. All pull requests must pass flake8 checks.
  4. All pull requests must match isort and black requirements.
  5. All pull requests must be PROPERLY type annotated, unless exemption is given.
  6. All pull requests must be consistent with the existing code.
  7. If you decide to remove/change anything from any common interface a deprecation message should accompany it in accordance with our deprecation policy.
  8. If you implement a new feature you should have at least one unit test to accompany it.
  9. An example must be one of the following:
    • Example of how to use Sanic
    • Example of how to use Sanic extensions
    • Example of how to use Sanic and asynchronous library


Check back. We are reworking our documentation so this will change.