Application Services (a-s) is a collection of Rust Components that are used to enable Firefox applications to integrate with Firefox accounts, sync, experimentation, etc. Each component is built using a core of shared code written in Rust, wrapped with native language bindings for different platforms.

To contribute, please review the Mozilla Community Participation Guidelines and then visit our how to contribute guide.

Get in touch with other community members on Matrix, or through issues here on GitHub.

• Matrix: #rust-components:mozilla.org (How to connect)

The Application Services Book contains high-level documentation about the code in this repository. It's built from the ./docs/ directory.

We use rustdoc to document both the public API of the components and the various internal implementation details. View them on https://mozilla.github.io/application-services/book/rust-docs/fxa_client/index.html. Once you have completed the build steps, you can view the docs by running:

cargo doc --no-deps --document-private-items --open

1. Clone or Download the repository:

  $ git clone https://github.com/mozilla/application-services # (or use the ssh link)
  $ cd application-services
  $ git submodule init
  $ git submodule update --recursive

2. Follow these instructions to install your system-level dependencies
3. Run the a-s Rust unit tests

cargo test

The application-services library primary consumers are Fenix (Firefox on Android) and Firefox iOS. Assure you are able to run integration tests (for Android and iOS if using MacOS) by following the instructions to build for Android and iOS integrations.

• Build instructions to test Fenix / android-components integration
• Fenix Auto-publication workflow for android-components and application-services

• Build instructions to test Firefox iOS integration

• Build instructions to test Firefox Desktop integration

./components/ contains the source for each component. Note that most components have their FFI generated by the uniffi library.

• See ./components/places/ for an example, where you can find:
  • The shared rust code.
  • The Kotlin bindings for use by Android applications.
  • The Swift bindings for use by iOS applications.
• See ./components/fxa-client for an example that uses uniffi to generate API wrappers for multiple languages, such as Kotlin and Swift.

• ads-client - for fetching ads via UAPI
• autofill - for storage and syncing of credit card and address information
• crashtest - testing-purposes (crashing the Rust code)
• fxa-client - for applications that need to sign in with FxA, access encryption keys for sync, and more.
• logins - for storage and syncing of a user's saved login credentials
• nimbus - for integrating with Mozilla's experimentation platform for Firefox
• places - for storage and syncing of a user's saved browsing history
• push - for applications to receive real-time updates via WebPush
• remote-settings - for integrating with Remote Settings
• support - low-level utility libraries
  • support/rc_crypto - handles cryptographic needs backed by Mozilla's NSS library
  • support/sql - utilities for storing data locally with SQL
• sync15 - shared library for accessing data in Firefox Sync
• sync_manager - integrates multiple sync engines/ stores into a single framework
• tabs - an in-memory syncing engine for remote browser tabs
• viaduct - an HTTP request library
• webext-storage - powers an implementation of the chrome.storage.sync WebExtension API

Note the above list is partial; see the actual list under the components directory.