OAuth Interceptor

Oven-ready Dio interceptor for handling OAuth 2.0.


  • Easily request authentication tokens using OAuth 2.0 grants
  • Add an interceptor to your Dio instance which adds the Bearer token to every request
  • Stores tokens using Flutter Secure Storage
  • Automatically refreshes expired tokens


Pub Version

flutter pub add oauth_interceptor


Step 1: Create an OAuth instance

final oAuth = OAuth(
    tokenUrl: 'oauth/token',
    clientId: '1',
    clientSecret: 'secret',
    dio: myBaseDio, // Optional; if ommitted OAuth will use a basic Dio instance
    name: 'client', // Required if you have multiple instances of OAuth e.g. for storing client and password tokens separately

Step 2: Add the OAuth instance as a Dio interceptor

final authenticatedDio = Dio()..interceptors.add(oAuth);

Step 3: Use the login/logout methods

final isSignedIn = await oAuth.isSignedIn; // Will be true if a token exists in storage

oAuth.login(const ClientCredentialsGrant());
    PasswordGrant(username: 'me@example.com', password: 'password'),


oAuth.refresh(); // This should happen automatically if a token has expired, but you can also manually refresh tokens if you like.

Creating your own grant type

The packages exposes an OAuthGrantType abstract class which can be implemented, allowing you to create your own custom grant types.

class CustomGrantType implements OAuthGrantType {
    FutureOr<RequestOptions> handle(RequestOptions request) async {
        // Do something fancy with the request
        return request;