Auth3 Flutter Login

The official Auth3 Flutter Login library.


This library provides a quick and secure way to integrate with the Auth3 Identity Platform to protect your mobile Flutter application running across different devices.

For additional help and a guided walkthrough, with an example reference application and further reasoning, check out our article here.

Platform support

Our libraries can be run on the following environments:

  • iOS
  • Android
  • Mac OS
  • Web (flutter web)


To depend on this library run:

flutter pub add auth3_login

Alternatively, add to your pubspec.yaml:

auth3_login: <version> # find the latest version on

Then run:

pub get



In order to capture the callback url, the following activity needs to be added to your AndroidManifest.xml. Be sure to relpace YOUR_CALLBACK_URL_SCHEME_HERE with your actual callback url scheme (auth3 by default on mobile platforms, https on the web).


    <activity android:name="com.linusu.flutter_web_auth.CallbackActivity" android:exported="true">
      <intent-filter android:label="flutter_web_auth">
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="YOUR_CALLBACK_URL_SCHEME_HERE" />



On the Web platform an endpoint must to be created that captures the callback URL and sends it to the application using the JavaScript postMessage() method. In the ./web folder of the project, create an HTML file with the name e.g. auth.html with content:

<!DOCTYPE html>
  <title>Authentication completed</title>
  <p>If this does not happen automatically, please close the window.</p>

      'flutter-web-auth': window.location.href
    }, window.location.origin);

Looking to integrate with your backends?

Check out our official SDKs to integrate with the Administrative API to integrate and manipulate your Auth3 identities:


At this time we don't accept external contributions, but we're open for feedbacks and requests. We're always looking for contributions on our security, refer to our dedicated page for more.


Customers of the Auth3 Identity Platform can access support through the official channels available on our website. We won't be able to accomodate Customer requests through the bug tracker for security reasons.


Read the LICENSE.