WooCommerce REST API Caching just landed in the 10.5 experimental features, and if you’re building headless stores or mobile apps, this is the update you’ve been waiting for. I’ve spent over a decade wrestling with WooCommerce performance bottlenecks, and the API has always been a particular pain point—especially when you’re trying to scale a React-based storefront or a high-traffic mobile app.
This isn’t the only performance win in the latest release; we’ve also seen significant improvements in WooCommerce variation price caching. However, while object caching handles the database queries, this new experimental engine handles the entire response lifecycle, reducing latency by up to 70% in early testing.
Why We Need Built-in REST API Caching
Standard page caching plugins (like WP Rocket or W3 Total Cache) often struggle with REST API endpoints because they are designed for HTML, not JSON responses. When you’re hitting the /products endpoint with 20,000 items, the standard overhead is massive. WooCommerce testing shows response times dropping from 2.5 seconds (cache miss) down to 0.6 seconds (cache hit). That’s a game-changer for UX.
How to Implement WooCommerce REST API Caching
The core of this feature is the RestApiCache trait. It’s an opt-in mechanism that allows you to wrap your controller callbacks. If you are already using WooCommerce product object caching, this REST API layer is the logical next step for your custom integrations.
Here is how you would refactor a standard controller to use the new caching engine. Notice the use of the with_cache method to wrap the callback:
<?php
// bbioon_example_controller.php
class Bbioon_Custom_Controller {
use RestApiCache; // The new experimental trait
protected function get_default_response_entity_type(): ?string {
return 'custom_endpoint';
}
public function register_routes() {
register_rest_route(
'bbioon/v1',
'/data',
array(
'methods' => WP_REST_Server::READABLE,
// Wrapping the callback enables the caching engine
'callback' => $this->with_cache( array( $this, 'get_item' ) )
)
);
}
public function get_item( $request ) {
// Your logic here
return new WP_REST_Response( array( 'status' => 'success' ), 200 );
}
}Headers and Revalidation
The engine doesn’t just store JSON; it handles the HTTP headers correctly. It generates ETag hashes based on the response data. This allows clients to send an If-None-Match header. If the data hasn’t changed, WooCommerce returns a 304 Not Modified status, saving bandwidth and client-side processing time. You can find the raw source of the RestApiCache trait on GitHub.
The “Gotchas”: Nginx and Cache Invalidation
I’ve seen plenty of “experimental” features break in production because of server configurations. Specifically, many Nginx setups strip the If-None-Match header or modify the Date header. If your 304 responses aren’t working, you might need a workaround like this to restore the header via a custom X-WC-If-None-Match header:
<?php
add_filter( 'rest_pre_dispatch', function( $result, $server, $request ) {
$custom_header = $request->get_header( 'X-WC-If-None-Match' );
if ( $custom_header ) {
$request->set_header( 'If-None-Match', $custom_header );
}
return $result;
}, 0, 3 );Furthermore, remember that WooCommerce REST API Caching requires a persistent object cache like Redis or Memcached to store the responses. Without it, you’ll only benefit from the HTTP headers, not the backend speed boost.
Look, if this WooCommerce REST API Caching stuff is eating up your dev hours, let me handle it. I’ve been wrestling with WordPress since the 4.x days.
Summary of the 10.5 Update
This feature is currently experimental and disabled by default. You can enable it under WooCommerce → Settings → Advanced → Features. For now, it mainly supports product endpoints (v2, v3, and v4), but the infrastructure is there for us to extend it to custom entities. Check the official WooCommerce Developer Blog for the original call for testing and share your findings on their GitHub discussion board.
