firebase_verify_token_dart 2.1.3

Package to verify a firebase jwt token across multiple Firebase projects

Firebase Verify Token

A Dart/Flutter plugin to verify Firebase JWT tokens, supporting multiple Firebase projects across any platform.

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📱 Supported Platforms

Android	iOS	macOS	Web	Linux	Windows
✔️	✔️	✔️	✔️	✔️	✔️

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🔍 Overview

firebase_verify_token_dart verifies Firebase JWT tokens entirely in Dart without relying on backend services. It performs:

• ✅ Project ID validation against a whitelist
• ✅ Issuer check to ensure token is from Firebase
• ✅ Expiration check
• ✅ JWT structure validation

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⚙️ Installation

Add the dependency:

dependencies:
  firebase_verify_token_dart: ^latest

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Then run:

flutter pub get

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🚀 Quick Start

1. Import the package

import 'package:firebase_verify_token/firebase_verify_token.dart';

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2. Initialize with your Firebase project IDs

FirebaseVerifyToken.projectIds = [
  'project-id-1',
  'project-id-2',
];

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🔐 Token Verification

✅ Basic Verification

final isValid = await FirebaseVerifyToken.verify('your-firebase-jwt-token');

if (isValid) {
  // Token is valid
}

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🧠 With Callback (for project ID and duration)

await FirebaseVerifyToken.verify(
  'your-firebase-jwt-token',
  onVerifySuccessful: ({required bool status, String? projectId, int? duration}) {
    if (status) {
      print('Valid token for project: $projectId in ${duration}ms');
    } else {
      print('Invalid token (checked in ${duration}ms)');
    }
  },
);

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📘 API Reference

Method	Description
Future<bool> FirebaseVerifyToken.verify(String token, { void Function({required bool status, String? projectId, int? duration})? onVerifySuccessful })	Verifies the JWT token and optionally provides project ID and verification duration.
String FirebaseVerifyToken.getUserID(String token)	Extracts the user ID (sub claim) from a JWT without verifying it.
String? FirebaseVerifyToken.getProjectID(String token)	Extracts the Firebase project ID (aud claim) from a JWT without verifying it.

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🔄 Complete Example

import 'package:firebase_verify_token/firebase_verify_token.dart';

void main() async {
  // Set your Firebase project IDs
  FirebaseVerifyToken.projectIds = ['cbes-c64d6', 'test-1'];

  // Sample Firebase JWT token
  const token = 'eyJhbGciOiJSUzI1NiIsImtpZCI6ImE4Z...'; // shortened for clarity

  // Verify the token with callback
  await FirebaseVerifyToken.verify(
    token,
    onVerifySuccessful: ({
      required bool status,
      String? projectId,
      required int duration,
    }) {
      if (status) {
        print('✅ Token verified for project: \$projectId (\$duration ms)');
      } else {
        print('❌ Token verification failed (\$duration ms)');
      }
    },
  );
}

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💡 Common Use Cases

• 🔐 Cross-project auth: Accept users from multiple Firebase projects
• 🔑 Secure APIs: Verify Firebase tokens server-side or client-side
• 🌐 Multi-app integration: Authenticate users across a shared ecosystem

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🤝 Contributing

Issues and pull requests are welcome!
→ Open an issue
→ Submit a PR

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📃 License

MIT — See LICENSE