How to Retrieve a User's Email Using Facebook Graph API

The Facebook Graph API grants access to basic account registration information, including email addresses, but accessing this data may require specific permission handling.

Understanding Permission Management

The API requires extended permissions for certain fields, including email. To acquire permission, include "email" in the "scope" parameter during the OAuth authentication process. If accessing a user's email address, this step is crucial.

Utilizing the OAuth Authentication Process

Consider employing an SDK rather than the file_get_contents method, as it streamlines the OAuth authentication process. The SDK will automatically handle permission handling and make it easier to retrieve the necessary data.

Sample Code

Following successful authentication, use the SDK's methods to retrieve the user's email address:

// PHP sample code using the Facebook SDK
// Requires installation of the Facebook SDK: https://developers.facebook.com/docs/php/getting-started/
use Facebook\Facebook;

$facebook = new Facebook([
  'app_id' => 'YOUR_APP_ID',
  'app_secret' => 'YOUR_APP_SECRET',
]);

$permissions = ['email'];
$loginUrl = $facebook->getRedirectLoginHelper()->getLoginUrl('YOUR_REDIRECT_URI', $permissions);

Once the user grants permission, the SDK will provide access to the email field. Remember, email address retrieval is limited to the logged-in user and does not extend to their friends' email addresses.