$text_field = $wp_customize->add_control( new WP_Customize_Control( $wp_customize, 'text_field', array( 'label' => __( 'Text Field', 'mytheme' ), 'section' => 'mytheme_section', 'type' => 'text', 'settings' => 'text_field_setting' ) ) );
$checkbox = $wp_customize->add_control( new WP_Customize_Control( $wp_customize, 'checkbox', array( 'label' => __( 'Checkbox', 'mytheme' ), 'section' => 'mytheme_section', 'type' => 'checkbox', 'settings' => 'checkbox_setting' ) ) );In this example, we're adding a checkbox to the "mytheme_section" section, with a label of "Checkbox". This control will be saved to the "checkbox_setting" setting. Based on the use of the "$wp_customize" object and the "WP_Customize_Control" class, these examples appear to be using the WordPress customization API.