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How to Contribute


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👋 We're so excited you're interested in helping with Blitz! We happy to help you get started, even if you don't have any previous open-source experience :)

First Things First

  1. New to open source? take a look at How to Contribute to an Open Source Project on GitHub
  2. Familiarize yourself with the Blitz Code of Conduct
  3. Learn how the community operates

Video Overview of Our Codebase

NOTE: This video is currently outdated as our codebase is going through some significant refactorings. We'll record a new one soon. But it's probably still somewhat helpful. Watch this video for a walkthrough of the entire Blitz codebase. This is a great way to get an overview of the various parts and how they fit together!

What to Work On?

Issues with the label status/ready-to-work-on are the best place to start.

We also label issues as good first issue and good second issue when appropriate.

If you find one that looks interesting and no one else is already working on it, comment in the issue that you are going to work on it. But only claim an issue if you can start work on it within a couple days.

Please ask as many questions as you need, either directly in the issue or in Discord. We're happy to help!

The website and documentation repo also has issues with ready to work on | help wanted.

Things that are ALWAYS welcome

  • Adding tests
  • Improved documentation
  • Improved error messages
  • Improved logging (i.e. more clear, more beautiful)
  • Performance or security improvements
  • Educational content like blogs, videos, courses

If there's some other way you'd like to contribute, ask us about it in Discord!

After you contribute in any way, please add yourself as a contributor via the @all-contributors bot!

Our Codebase is a Garden

The Blitz codebase is like a community garden. There's a lot of beautiful plants and vegetables, but it won't take long until you find some weeds! When you find weeds, please remove them :) Minor refactoring is always encouraged. If you'd like to do some major refactoring, it's best to first either open an issue or check with us in Discord. Most likely we'll agree with you.

What to Expect After Submitting a PR

A Blitz maintainer will review your PR, usually within a couple days.

If your PR changes user facing code, make sure you also made a PR to the docs repo, otherwise this will block your PR from being merged.

You also need to add tests to cover the changes you made.

Once all the requirements are met and the maintainer is happy with your code, they will merge it to the canary branch. It will then be included in the next Blitz release.

Lastly, you will be added the all-contributors list as an official Blitz contributor. Congratulations!!

Project Management

We use a GitHub Project Board to track all issues and PRs.

Commit Access

We give liberal commit access to the Blitz repo to anyone who is a half-way regular contributor. This allows you to push branches directly to the Blitz repo without using a fork.

We'll often give someone access if we notice they are regularly contributing. But you're also welcome to ask for access if you are regularly helping but haven't been given access yet.

In the main Blitz repo, code reviews by code owners are required to merge PRs.

But in the docs repo, anyone can merge PRs once someone else has approved the PR.

Development Setup

1. Fork the blitz repo

2. Clone your forked repo

# replace USERNAME below with your GitHub username
git clone
cd blitz

3. Install dependencies


4. Start the package server. This must be running for any package development or example development

yarn dev

Running Tests

Blitz.js Tests

Unit Tests

Most Blitz packages in packages/ have jest unit tests.

  • Run tests in a single package by running yarn test inside that package folder (like packages/core/)
  • Run all unit tests from the repo root by running yarn testonly:packages. (Make sure you have ran yarn build or yarn dev prior to running this)

Integration Tests

Blitz integration tests are inside the root test/ folder.

Make sure you have chromedriver installed for your Chrome version. You can install it with

  • brew install --cask chromedriver on Mac OS X
  • chocolatey install chromedriver on Windows
  • Or manually download the version that matches your installed chrome version (if there's no match, download a version under it, but not above) from the chromedriver repo and add the binary to <blitz-repo>/node_modules/.bin

You can run all integration tests by running yarn test:integration from the repo root. Or you can run yarn testheadless to run them in headless mode (so it doesn't open a web browser window).

To run a specific integration test, you can run this:

yarn testheadless --testPathPattern "integration/queries"

where integration/queries is the path inside test/.

You can manually run the integration app by running blitz dev inside the integration test folder, like test/integration/queries/.

Example App Tests (to be deprecated)

The example apps have been functioning as our integration tests, but we'll be moving those tests into the above integation test setup.

To run an example app, first run yarn build or yarn dev from the repo root. Then in another window, change to the example app folder like examples/auth/ and run blitz dev.

To run the example app tests, run yarn test from the example app folder.

Next.js Tests

All Next.js tests are inside nextjs/test/. There are a lot of tests, so probably you will want to run only one at a time.

To run these tests, run the following inside the nextjs/ folder.

  • To run in normal mode (open a browser): yarn testonly --testPathPattern "integration/basic"
  • To run in headless mode: yarn testheadless --testPathPattern "integration/basic"

The typical workflow will be only run next.js integation tests related to your change. Then push to CI and see if any other intergration tests fail. If they do, then locally run the one that fails and fix the issue.

Testing Development Version of Blitz Inside an App


Currently, to test the local dev version of Blitz, you can only test an app inside the blitz/examples/ folder. In there, the blitz dependency will automatically use the local dev version. We mainly use the auth and store example apps. We use them for development testing and for blitz integration tests. You must also make sure you are running yarn dev in the blitz folder at the same time.

For using in apps outside the repo, yalc should work, but hasn't been tested yet. If you figure out how to use yalc, please make a PR to this page explaining how to set it up!

Sync your fork

git merge upstream/canary

Link the Blitz CLI (Optional)

The following will link the development CLI as a local binary so you can use it anywhere for testing.

yarn link-cli
yarn link blitz
// `yarn unlink blitz`
// `yarn unlink-cli`  will unlink


If you run into issues that should be documented here, please submit a PR! ❤️

Windows Subsystem for Linux

node-pty error when running yarn. Fix by installing node-pty dependencies

sudo apt install -y make python build-essential

Yarn policies error

This issue is related with yarn > 1.19.1, if you get an error like this in your console:

An unexpected error occurred: "expected workspace package to exist for \"@wessberg/rollup-plugin-ts\"

Fix it with this command:

yarn policies set-version 1.19.1

Git errors

Are you unable to commit? Do you get errors like yarn: command not found or stdin is not a tty? That's probably a Husky error! Try checking their troubleshoot guide.

Preconstruct errors

If you run into symlink and EPERM errors when trying to run Preconstruct on Windows, you may need to enable Windows Developer Mode so that Preconstruct can create symlinks.

Missing files in Windows

If you have errors about missing files even after you run yarn build, try cloning again your repository with the configuration core.symlinks set to true like this: git clone -c core.symlinks=true <URL>.

Idea for improving this page? Edit it on GitHub.