Ship icon sets in your theme and load them centrally

Icons that live in files are versioned in Git and deployed with the code. Pick the place: the theme, or one central folder for every site.

Switches

Under Icons → Features:

• Theme & folder sources: required for everything on this page.
• Multiple collections: needed to see these icons in the WordPress Icon block (WordPress 7.1 or newer).

easy_svg_icon() in PHP works with Theme & folder sources alone.

Option A: in the theme

wp-content/themes/acme/
└── assets/icons/
    ├── manifest.json
    ├── phone.svg
    └── mail.svg

{
  "version": 1,
  "slug": "acme",
  "label": "ACME icons",
  "icons": {
    "phone": { "label": "Phone", "keywords": ["call", "contact"] },
    "mail": { "label": "Email", "keywords": ["contact"] }
  }
}

<?php echo easy_svg_icon( 'acme/phone', array( 'label' => __( 'Call us', 'acme' ) ) ); ?>

Without a manifest the collection is called theme ("Theme icons"), so the call is easy_svg_icon( 'theme/phone' ).

Child theme overrides

wp-content/themes/acme-child/
└── assets/icons/
    └── phone.svg

A file with the same name in the child theme replaces the parent's icon. Everything else still comes from the parent. Parent and child stay one collection; a label or slug in the child's manifest.json wins.

Option B: one central folder for every site

Ship the icons in a must-use plugin (or in your own plugin, installed with Composer). Two ways to hand the folder to Pro:

<?php
/**
 * Plugin Name: Agency icons
 */

defined( 'ABSPATH' ) || exit;

add_filter(
	'easy_svg_pro_source_dirs',
	static function ( $dirs ): array {
		$dirs   = is_array( $dirs ) ? $dirs : array();
		$dirs[] = __DIR__ . '/agency-icons/brand';
		return $dirs;
	}
);

<?php
/**
 * Plugin Name: Agency icons
 */

defined( 'ABSPATH' ) || exit;

add_action(
	'init',
	static function (): void {
		if ( function_exists( 'easy_svg_register_icon_collection' ) ) {
			easy_svg_register_icon_collection( 'agency', 'Agency icons', __DIR__ . '/agency-icons/brand' );
		}
	}
);

wp-content/mu-plugins/
├── agency-icons.php
└── agency-icons/brand/
    ├── manifest.json
    └── *.svg

Want it as a normal plugin with its own version? Start from the Icon Pack Starter.

When it worked

• Icons → Packs, list Export a collection: your collection is there, with its origin, for example "Theme ACME" (your theme's name) or "Must-use plugin agency-icons".
• wp easy-svg icons list shows it with an icon count (needs WP-CLI under Icons → Features).
• The Icon block's icon picker shows the collection.

Pitfalls

• Files must really be in the folder. An SVG that is a symlink pointing outside the folder is skipped without a message. Copy the files in instead of linking them one by one.
• Limits per folder: 1000 icons and 2 MB per file. Raise the first with the easy_svg_pro_source_max_icons filter. Files Pro could not use are listed by wp easy-svg icons problems and under the collection in Icons → Packs.
• Renaming breaks content. Posts and templates store collection/icon. Changing the manifest slug or the name in code later leaves those references empty.