Allow easy addition of custom fields to Bearer token response

src/ResponseTypes/BearerTokenResponse.php

@@ -11,6 +11,7 @@
 
 namespace League\OAuth2\Server\ResponseTypes;
 
+use League\OAuth2\Server\Entities\AccessTokenEntityInterface;
 use League\OAuth2\Server\Entities\RefreshTokenEntityInterface;
 use Psr\Http\Message\ResponseInterface;
 
@@ -48,6 +49,8 @@ class BearerTokenResponse extends AbstractResponseType
             $responseParams['refresh_token'] = $refreshToken;
         }
 
+        $responseParams = array_merge($this->getExtraParams($this->accessToken), $responseParams);
+
         $response = $response
             ->withStatus(200)
             ->withHeader('pragma', 'no-cache')
@@ -58,4 +61,17 @@ class BearerTokenResponse extends AbstractResponseType
 
         return $response;
     }
+
+    /**
+     * Add custom fields to your Bearer Token response here, then override
+     * AuthorizationServer::getResponseType() to pull in your version of
+     * this class rather than the default.
+     *
+     * @param AccessTokenEntityInterface $accessToken
+     * @return array
+     */
+    protected function getExtraParams(AccessTokenEntityInterface $accessToken)
+    {
+        return [];
+    }
 }