What it is

2FAS is an open-source Android application for two-factor authentication, and its listing describes it as a local-first 2FA authenticator and password manager. The project lives in the password and secret management ecosystem, and the repository contains the source code for the 2FAS Auth Android app, written in Kotlin and licensed under the GNU General Public License v3.0. The README presents 2FAS as an authentication method that adds a second factor, such as a one-time password shown on a phone, alongside a username and password.

It solves the problem of credential-only account access. If a password is compromised, the second factor can still prevent unauthorized access because the service requires a code from the user's device. The README states that the app supports time-based one-time passwords and HMAC-based one-time passwords, and that it is compatible with services supporting those standards, including Google, Microsoft, and Dropbox. The project also notes that app graphics are not part of the open-source code and have separate licensing terms.

Key capabilities

• The app generates time-based one-time passwords (TOTP) as a second authentication factor.
• The app supports HMAC-based one-time passwords (HOTP) as an authentication standard.
• The app works with services that support TOTP or HOTP, including Google, Microsoft, and Dropbox.
• The project publishes the Android source code under the GNU General Public License v3.0, while graphics have separate licensing terms.
• The README directs bug reports to GitHub issues and security vulnerabilities to [email protected].

Who uses it and how

• Individuals protect accounts by entering a username and password, then supplying a phone-displayed one-time password.
• Android users install the official app from the releases page and follow on-screen setup instructions.
• Users of Google, Microsoft, Dropbox, or other services that support those standards can use the app during sign-in.
• Contributors review the Kotlin source code, file bugs in GitHub issues, and follow the contribution guide.

Getting started

The README says to download the app from the releases page at 2fas.com, install it on an Android device, and follow the on-screen instructions to set up 2FAS for online accounts.

When to use it — and when not to

2FAS is appropriate when a user needs an official Android app for TOTP and HOTP authentication under GPL-3.0, and it is less appropriate when a user requires documented cross-platform password management, because the README describes only the Android 2FA app and separates graphics from the open-source code. The metadata lists 0 contributors, a 0-year repo age, and 125 open issues, so a prospective user should inspect the project before relying on it for account security.