WordPress at a glance
action is not described

init action-hook . WP 1.5.0

Fires after WordPress has finished loading but before any headers are sent.

Most of WP is loaded at this stage, and the user is authenticated. WP continues to load on the 'init' hook that follows (e.g. widgets), and many plugins instantiate themselves on it for all sorts of reasons (e.g. they need a user, a taxonomy, etc.).

If you wish to plug an action once WP is loaded, use the 'wp_loaded' hook below.

Usage

add_action( 'init', 'action_function_name_2145' );
function action_function_name_2145(){
	// action...
}

Changelog

Since 1.5.0 Introduced.

Where the hook is called

In file: /wp-settings.php
init
wp-settings.php 560
do_action( 'init' );

Where in WP core the hook is used WordPress

wp-includes/blocks/archives.php 119
add_action( 'init', 'register_block_core_archives' );
wp-includes/blocks/block.php 72
add_action( 'init', 'register_block_core_block' );
wp-includes/blocks/calendar.php 61
add_action( 'init', 'register_block_core_calendar' );
wp-includes/blocks/categories.php 97
add_action( 'init', 'register_block_core_categories' );
wp-includes/blocks/index.php 68
add_action( 'init', 'register_core_block_types_from_metadata' );
wp-includes/blocks/latest-comments.php 157
add_action( 'init', 'register_block_core_latest_comments' );
wp-includes/blocks/latest-posts.php 205
add_action( 'init', 'register_block_core_latest_posts' );
wp-includes/blocks/rss.php 106
add_action( 'init', 'register_block_core_rss' );
wp-includes/blocks/search.php 120
add_action( 'init', 'register_block_core_search' );
wp-includes/blocks/shortcode.php 31
add_action( 'init', 'register_block_core_shortcode' );
wp-includes/blocks/social-link.php 57
add_action( 'init', 'register_block_core_social_link' );
wp-includes/blocks/tag-cloud.php 54
add_action( 'init', 'register_block_core_tag_cloud' );
wp-includes/class-wp-customize-manager.php 370
remove_action( 'init', 'wp_cron' );
wp-includes/class.wp-scripts.php 143
add_action( 'init', array( $this, 'init' ), 0 );
wp-includes/default-filters.php 574
add_action( 'init', 'wp_widgets_init', 1 );
wp-includes/default-filters.php 554
add_action( 'init', 'create_initial_taxonomies', 0 ); // Highest priority.
wp-includes/default-filters.php 429
add_action( 'init', '_show_post_preview' );
wp-includes/default-filters.php 529
add_action( 'init', 'kses_init' );
wp-includes/default-filters.php 515
add_action( 'init', 'create_initial_post_types', 0 ); // Highest priority.
wp-includes/default-filters.php 490
add_action( 'init', 'wp_sitemaps_get_server' );
wp-includes/default-filters.php 483
add_action( 'init', 'rest_api_init' );
wp-includes/default-filters.php 318
add_action( 'init', 'check_theme_switched', 99 );
wp-includes/default-filters.php 399
add_action( 'init', 'wp_schedule_delete_old_privacy_export_files' );
wp-includes/default-filters.php 379
add_action( 'init', 'smilies_init', 5 );
wp-includes/default-filters.php 353
add_action( 'init', 'wp_schedule_https_detection' );
wp-includes/default-filters.php 349
add_action( 'init', 'wp_cron' );
wp-includes/default-filters.php 319
add_action( 'init', array( 'WP_Block_Supports', 'init' ), 22 );
wp-includes/default-filters.php 317
add_action( 'init', '_register_core_block_patterns_and_categories' );
wp-includes/default-filters.php 131
add_action( 'init', 'wp_init_targeted_link_rel_filters' );
wp-includes/ms-default-filters.php 16
add_action( 'init', 'ms_subdomain_constants' );
wp-includes/ms-default-filters.php 25
add_action( 'init', 'maybe_add_existing_user_to_blog' );
wp-includes/update.php 903
add_action( 'init', 'wp_schedule_update_checks' );