Get started contributing to Blockly

Blockly is open source and is primarily maintained by a small team. We welcome contributions from developers outside the core team; there is no way for us to build every requested feature or fix every reported bug without our community. This section contains general guides that may be helpful to you especially if you are new to open source development.

For information specific to Blockly that you should read before making a contribution, see the Contributing to Core and Contributing to Samples sections.

Which repository?

A repository contains all the files for a single project. Blockly has two repositories: blockly core and blockly-samples.

Blockly core is the repository for the Blockly library. Use this repository if you want to make a change to core Blockly behaviour in a way that will apply to all users of the library.

Blockly samples is the repository for samples, plugins, and codelabs. Use this repository if you want to create or modify a plugin; write a codelab; or create or modify a sample.

Step by step

These are the general steps you will follow any time you make a change.

  1. Install Git and Node, following the links in the Tools section.
  2. Fork and clone the repository. GitHub has a wonderful tutorial about forking a repo. To apply it to blockly, just replace every instance of octocat/Spoon-Knife with google/blockly or google/blockly-samples, depending on which repository you want to work in.
  3. Sync your fork. GitHub provides a tutorial for syncing a fork as well.
  4. Check out the main branch. In blockly core, this is the develop branch. In blockly-samples this is the master branch.
  5. Install dependencies and build tools by running npm install in the root directory.
  6. Create a new branch by running git checkout -b myBranchName in a terminal. The name should help you remember what you're working on.
  7. Make your changes.
  8. Validate your changes, following the guide for core or samples.
  9. Save your changes with git commit -am "fix: My commit message". Read more about commit messages.
  10. Push your changes to GitHub with git push origin myBranchName.
  11. Open a pull request when your code is ready. A member of the Blockly team will review your changes and merge them into Blockly if they are approved. For more information see PR Review Process.