Callback URL not approved for this client application. in Android-Firebase-TwitterLogin

Understanding the “Callback URL Not Approved” Error

What it Means

This error indicates that the Callback URL you’ve configured in your Firebase project doesn’t match the one specified in your Twitter application settings.

Why it Occurs

• Incorrect Configuration: You may have entered different Callback URLs in Firebase and Twitter.
• Case Sensitivity: Callback URLs are case-sensitive.
• Missing Domain: The Callback URL in Firebase might be missing the domain part (e.g., ‘https://’ or ‘http://’).
• Domain Mismatch: Your Android app is running on a different domain than the one registered in Twitter.

Troubleshooting the Error

1. Verify Your Callback URLs

Firebase

• Navigate to your Firebase project’s settings.
• Go to the “Authentication” tab.
• Select “Sign-in method” and then “Twitter.”
• Note the Callback URL specified here.

Twitter

• Visit the Twitter Developer portal and access your app.
• Under the “Settings & Permissions” tab, locate “Callback URL.”
• Compare this URL with the one in Firebase.

2. Ensure Case Sensitivity

Double-check that both URLs match exactly, including capitalization.

3. Complete Domain in Firebase

If the Firebase Callback URL is missing ‘https://’ or ‘http://’, add it.

4. Resolve Domain Mismatch

If you’re running your app on a local server or emulator, Twitter won’t recognize the default ‘http://10.0.2.2’. Consider using ngrok or a similar tool to create a public URL for your app.

Example: Setting up Callback URLs

Twitter App Settings

// Twitter Developer Portal
Callback URL: https://your-firebase-project-id.firebaseapp.com/__/auth/handler

Firebase Settings

// Firebase Console
Callback URL: https://your-firebase-project-id.firebaseapp.com/__/auth/handler

Code Snippet for Twitter Authentication

// Inside your Android app
// ...
Button loginButton = findViewById(R.id.login_button);
loginButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        // Configure Twitter authentication in Firebase
        TwitterAuth.getInstance()
                .signInWithCredential(AuthCredential.fromTwitter(twitterAuthToken));
    }
});
// ...

Comparison of Callback URLs