flutter_session_jwt

This package allows you to store the JWT token in secure storage and can decode the json web token. Since the payload is base64 encoded you can easily know the payload data stored with no password required, there are other methods available to get expiry date, issued date, and can check whether token expired or not.

This package can help you to store the JWT token in secure storage and provide you different methods to access information from the token.

Note: Make sure to save the token before accessing other methods.

Getting started

In your pubspec.yaml file within your Flutter Project:

dependencies:
  flutter_session_jwt: <latest_version>

Example Screenshot

Example screenshot

Usage

Import the package

import 'package:flutter_session_jwt/flutter_session_jwt.dart';

Here is an exmaple to store the JWT token post login

Future<http.Response> login(String userName , String password) async{
  var response = await http.post(
    Uri.parse('https://jsonplaceholder.typicode.com/albums'),
    headers: <String, String>{
      'Content-Type': 'application/json; charset=UTF-8',
    },
    body: jsonEncode(<String, String>{
      'userName': userName,
      'password': password
    }),
  );

  if(response.statusCode == 200){
    var token = response.body.token;
    await FlutterSessionJwt.saveToken(token);
  }
}

Once token is saved, you can access the other methods as below.

  • To get payload from JWT token
//This will return payload object/map
await FlutterSessionJwt.getPayload();
  • To retrieve saved token
//This method will return saved token for further API calls
await FlutterSessionJwt.retrieveToken();
  • To get expiration date and time
//Make sure pass `exp` key in the payload
//This method will return expiration ```DateTime```
await FlutterSessionJwt.getExpirationDateTime();
  • To get issued date and time
//Make sure pass `iat` key in the payload
//This method will return issuedAt ```DateTime```
 await FlutterSessionJwt.getIssuedDateTime();
  • To get whether token has expired or not
//This will return bool with true/false
//If token expired, it will return true else false
await FlutterSessionJwt.isTokenExpired();
  • To get the time difference between issued time and current time
//This will return the token's age since issue
await FlutterSessionJwt.getDurationFromIssuedTime();
  • To delete the token from storage
//This will delete the token
await FlutterSessionJwt.deleteToken();

Decoding a token without saving it

Every method above operates on the token saved in storage. If you just want to inspect a token — for example checking a freshly received token's exp claim before deciding whether to keep it, or decoding a token that arrived via a deep link — use the static decode() method, or pass token: to any of the getters above. Neither of these touches secure storage:

// Pure decode, no storage involved
final payload = FlutterSessionJwt.decode(someToken);

// Same idea for the date/expiry helpers
final isExpired = await FlutterSessionJwt.isTokenExpired(token: someToken);
final expiry = await FlutterSessionJwt.getExpirationDateTime(token: someToken);

Access + refresh tokens

Most real-world auth flows issue a short-lived access token alongside a longer-lived refresh token. saveToken/retrieveToken/deleteToken continue to manage the access token as before; use the following to manage the refresh token alongside it:

// After login, save both tokens in one call
await FlutterSessionJwt.saveTokenPair(
  accessToken: accessToken,
  refreshToken: refreshToken,
);

// Or save/retrieve the refresh token on its own
await FlutterSessionJwt.saveRefreshToken(refreshToken);
final storedRefreshToken = await FlutterSessionJwt.retrieveRefreshToken();
final hasRefreshToken = await FlutterSessionJwt.hasRefreshToken();

// When your access token has expired, call your refresh endpoint with
// storedRefreshToken, then save the new pair the same way.

// On logout, clear both tokens
await FlutterSessionJwt.deleteTokens();

Note: unlike saveToken, saveRefreshToken does not validate a three-part JWT structure, since many backends issue opaque (non-JWT) refresh tokens.

License

MIT

Libraries

flutter_session_jwt