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Hi, and thanks in advance for contributing to Mapbox GL. Here's how we work. Please follow these conventions when submitting an issue or pull request.

Preparing your Development Environment


Install the Xcode Command Line Tools Package

xcode-select --install

Install node.js version 18

brew install node@18

Install yarn

brew install yarn

Clone the repository

git clone

Install node module dependencies

yarn install


Install git, node.js version 18, GNU Make, and libglew-dev

sudo apt-get update
curl -sL | sudo bash -
sudo apt-get install build-essential git nodejs libglew-dev libxi-dev

Install yarn

curl -o- -L | bash

(It is also possible to install yarn from Debian/Ubuntu packages. See yarn's install instructions).

Clone the repository

git clone

Install node module dependencies

yarn install


Install git, node.js version 18, yarn, npm and node-gyp.

Clone the repository

git clone

Install node module dependencies

yarn install

Install headless-gl dependencies

copy node_modules/headless-gl/deps/windows/dll/x64/*.dll c:\windows\system32

Serving the Debug Page

Start the debug server


Open the debug page at http://localhost:9966/debug

Creating a Standalone Build

A standalone build allows you to turn the contents of this repository into mapbox-gl.js and mapbox-gl.css files that can be included on an html page.

To create a standalone build, run

yarn run build-prod-min
yarn run build-css

Once those commands finish, you will have a standalone build at dist/mapbox-gl.js and dist/mapbox-gl.css

Writing & Running Tests

See test/

Writing & Running Benchmarks

See bench/

Code Conventions

  • We use error events to report user errors.
  • We use assert to check invariants that are not likely to be caused by user error. These assert statements are stripped out of production builds.
  • We use the following ES6 features:
    • let/const
    • for...of loops
    • Arrow functions
    • Classes
    • Template strings
    • Computed and shorthand object properties
    • Default parameters
    • Rest parameters
    • Destructuring
    • Modules
    • Spread (...) operator
    • Iterators and generators
    • "Library" features such as Map, Set, array.find, etc.

The conventions for module exports are:

  • No exported "namespace objects" -- modules should export either classes or functions, with an occasional exception as needed for stubbing.
  • If a module exports something with the same name as the file name (modulo case), it should be the default export.
  • Anything else should be a named export.

Version Control Conventions

Here is a recommended way to get setup:

  1. Fork this project
  2. Clone your new fork, git clone
  3. cd mapbox-gl-js
  4. Add the Mapbox repository as an upstream repository: git remote add upstream
  5. Create a new branch git checkout -b your-branch for your contribution
  6. Write code, open a PR from your branch when you're ready
  7. If you need to rebase your fork's PR branch onto main to resolve conflicts: git fetch upstream, git rebase upstream/main and force push to Github git push --force origin your-branch

Changelog Conventions is a valuable document many people read. It contains a formatted, lightly editorialized history of changes in the project. Pull requests are the unit of change and are normally categorized and summarized when reviewed. The changelog is maintained by combining automated content search and formatting with a final human edit.

What warrants a changelog entry?

  • Any change that affects the public API, visual appearance or user security must have a changelog entry
  • Any performance improvement or bugfix should have a changelog entry
  • Any contribution from a community member may have a changelog entry, no matter how small (accompanied by a hat-tip in the final changelog: (h/t [<user>](<user>)))
  • Any documentation related changes should not have a changelog entry
  • Any regression change introduced and fixed within the same release should not have a changelog entry
  • Any internal refactoring, technical debt reduction, render test, unit test or benchmark related change should not have a changelog entry

How to add your changelog? Changelog entries are written inside the <changelog></changelog> tag in the PR template. A changelog entry should:

  • be descriptive and concise; it should explain the change to a reader without context
  • describe the surface bug and not the underlying problem. This might require some research.
  • be labeled skip changelog if the PR has no impact on end users and does not require a changelog entry
  • be labeled breaking change if the PR is a breaking change
  • reference a PR and optionally an issue.

Documentation Conventions

API documentation is written as JSDoc comments and processed with documentationjs in the source code of mapbox-gl-js.

  • Classes, methods, events, and anything else in the public interface must be documented with JSDoc comments. Everything outside of the public interface may be documented and must be tagged as @private.
  • Text within JSDoc comments may use markdown formatting. Code identifiers must be surrounded by `backticks`.
  • Documentation must be written in grammatically correct sentences ending with periods.
  • Documentation must specify measurement units when applicable.
  • Documentation descriptions must contain more information than what is obvious from the identifier and JSDoc metadata.
  • Class descriptions should describe what the class is, or what its instances are. They do not document the constructor, but the class. They should begin with either a complete sentence or a phrase that would complete a sentence beginning with "A T is..." or "The T class is..." Examples: "Lists are ordered indexed dense collections." "A class used for asynchronous computations."
  • Function descriptions should begin with a third person singular present tense verb, as if completing a sentence beginning with "This function..." If the primary purpose of the function is to return a value, the description should begin with "Returns..." Examples: "Returns the layer with the specified id." "Sets the map's center point."
  • @param, @property, and @returns descriptions should be capitalized and end with a period. They should begin as if completing a sentence beginning with "This is..." or "This..."
  • Functions that do not return a value (return undefined), should not have a @returns annotation.
  • Member descriptions should document what a member represents or gets and sets. They should also indicate whether the member is read-only.
  • Event descriptions should begin with "Fired when..." and so should describe when the event fires. Event entries should clearly document any data passed to the handler, with a link to MDN documentation of native Event objects when applicable.

Github Issue Labels

Our labeling system is

  • minimalistic: Labels' usefulness are inversely proportional to how many we have.
  • objective: Labels should be objective enough that any two people would agree on a labeling decision.
  • useful: Labels should track state or capture semantic meaning that would otherwise be hard to search.

We have divided our labels into categories to make them easier to use.

  • type (blue)
  • actionable status (red)
  • non-actionable status (grey)
  • importance / urgency (green)
  • topic / project / misc (yellow)

Recommended Reading

Learning WebGL

GL Performance