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Firebase JavaScript library for web and Node.js

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Firebase Javascript SDK

The Firebase JavaScript SDK implements the client-side libraries used by applications using Firebase services. This SDK is distributed via:

To get started using Firebase, see Add Firebase to your JavaScript Project.

SDK Dev Workflow



Before you can start working on the Firebase JS SDK, you need to have Node.js 8.0.0 or greater installed on your machine.

To download Node.js visit

NOTE: You can use a tool like NVM or N to install and manage multiple node versions


In addition to Node.js we use yarn to facilitate multi package development.

To install yarn follow the instructions listed on their website:

Verify Prerequisites

You can verify your setup by running the following commands in your terminal:

$ node -v
$ yarn -v

Your Node.js version should be 8.0.0 or greater and your yarn version should be 1.0.0 or greater.

NOTE: We will update the documentation as new versions are required, however for continuing development on the SDK, staying up to date on the stable versions of these packages is advised

Install Dependencies

Once you have Node.js and yarn installed on your machine and have validated that you are running the proper version, you can set up the development environment by running the following at the root of the SDK:

$ yarn

Testing the SDK

Test Setup

A production project is required to test the Firebase JS SDK. You can create a new project by visiting the Firebase Console.

Automated Setup

Most of the test setup can be done by running the following command at the root of the package:

yarn test:setup

Authentication Support

This is the only piece of config that must be done manually. Visit the authentication config in your project and enable the Anonymous sign-in provider to complete your project config.

Running the tests

Each of the directories in the integration directory as well as the packages directory have their own test suites. These can be run altogether by running the following command at the root of the package:

$ yarn test

In addition, you can run any of the tests individually by running yarn test in an individaul package directory.

Building the SDK


The Firebase JS SDK is built with a series of individual packages that are all contained in this repository. Development is coordinated via yarn workspaces and Lerna (a monorepo management tool).

Each package in the packages directory, constitute a piece of our implementation. The SDK is built via a combination of all of these packages which are published under the firebase scope on NPM.

Helper Scripts

Each package in the packages directory exposes a dev script. This script will set up a watcher for development on the indiviual piece of the SDK. In addition, there is a top level dev script that can be run to start all of the watch tasks as well as a sandbox server.

You can run the dev script by running the following at the root of the package:

yarn dev

Prepush Hooks

As part of this repo, we use the NPM package husky to implement git hooks. We leverage the prepush hook to do two things:

  • Automated code styling (using prettier)
  • Automated LICENSE header insertion


See Contributing for more information on contributing to the Firebase JavaScript SDK.

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