This is an example how you can add BuddyPress notifications for users when they gain / lose myCRED points.

mycred-log-to-bp-notification

/**
 * Register Custom BP Notifications
 * Inform BuddyPress about our custom myCRED related notifications.
 * @since 1.0
 * @version 1.0
 */
function mycredpro_register_custom_bp_notifications() {

	buddypress()->mycred_notifications = new stdClass;
	buddypress()->mycred_notifications->notification_callback = 'mycredpro_render_bp_notification';

	buddypress()->active_components['mycred_notifications'] = 1;

}
add_action( 'bp_setup_globals', 'mycredpro_register_custom_bp_notifications' );

/**
 * Capture myCRED Event
 * Whenever we add to the log we add a notification.
 * @since 1.0
 * @version 1.0
 */
function mycredpro_log_to_bp_notification( $insert_id, $request ) {

	if ( $insert_id === false ) return $insert_id;

	extract( $request );

	if ( function_exists( 'bp_notifications_add_notification' ) )
		bp_notifications_add_notification( array(
			'user_id'           => $user_id,
			'item_id'           => $insert_id,
			'secondary_item_id' => $user_id,
			'component_name'    => 'mycred_notifications',
			'component_action'  => 'mycred_points'
		) );

	return $insert_id;

}
add_filter( 'mycred_new_log_entry_id', 'mycredpro_log_to_bp_notification', 90, 2 );

/**
 * Render Notification
 * Help BuddyPress out by rendering the log entry into something it can understand.
 * @since 1.0
 * @version 1.0.1
 */
function mycredpro_render_bp_notification( $action, $item_id, $secondary_item_id, $total_items, $format = 'string', $id = 0 ) {

	$return = false;

	if ( $action == 'mycred_points' ) {

		global $wpdb, $mycred;

		$text  = $link = '';
		$entry = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$mycred->log_table} WHERE id = %d;", $item_id ) );
		if ( isset( $entry->id ) ) {

			$mycred = mycred( $entry->ctype );

			// In this example we link to the ledger in the users profile
			// this needs to be changed to the URL you have setup (if you have this enabled)
			// or to something specific.
			$link   = bp_loggedin_user_domain() . 'points-ledger/';

			$text   = $mycred->parse_template_tags( $entry->entry, $entry );
			$title  = strip_tags( $text );

		}

	}

	if ( 'string' == $format ) {
		$return = '<a href="' . esc_url( $link ) . '" title="' . esc_attr( $title ) . '">' . esc_html( $text ) . '</a>';
	}
	else {
		$return = array(
			'text' => $text,
			'link' => $link
		);
	}

	return $return;

}

This snippet works great, however, the notifications aren't marked as read after you click on them, any tip on how to fix that?

Here:

	$args = array(
		'action'        => 'mod_org_become_org_moderator_request_mark_read',
		'item_id'       => $item_id,
		'secondary_id'  => $secondary_item_id
	);
	
	// Add the args to the URL.
	$custom_link = add_query_arg( $args, $link );

Mark notification as read

function mod_org_become_org_moderator_request_mark_read() {

	   if (isset($_GET['item_id']) && isset($_GET['secondary_id']) && isset($_GET['action']) && $_GET['action'] === 'mod_org_become_org_moderator_request_mark_read') {
 
		  $user_id = get_current_user_id();
		  $item_id = htmlentities($_GET['item_id'], ENT_QUOTES, 'UTF-8');
		  $component_name = 'mod_org_notifications';
		  $component_action = 'mod_org_become_org_moderator_request';
		  $secondary_item_id = htmlentities($_GET['secondary_id']);
		  $is_new = 0;
 
		  bp_notifications_mark_notifications_by_item_id( $user_id, $item_id, $component_name, $component_action, $secondary_item_id, $is_new );
 
	   }
 }
 add_action('wp', 'mod_org_become_org_moderator_request_mark_read');