WordPress REST API

ES2024 in WordPress scripts: Object.groupBy and Promise.withResolvers ECMAScript 2024 is a small edition, but two of its additions remove boilerplate that almost every admin script has: grouping an array with reduce() and capturing the resolve function of a promise in an outer variable. A third helper, Array.fromAsync(), is not part of ES2024 yet, but it…

WordPress Application Passwords for secure REST API authentication Application Passwords (WordPress 5.6+) let external scripts, apps and services authenticate to the REST API and XML-RPC without the user’s main password. Each one is a 24-character credential created per user and per application in Users → Profile → Application Passwords, shown in plain text only once…

A fetch() wrapper with timeout and retry for WordPress scripts fetch() has no timeout: on a bad mobile connection a request can hang for a minute while the spinner turns. It also does not repeat anything: one dropped packet or one 503 from an overloaded server, and the visitor sees an error. Both can be…

The WooCommerce REST API for a headless storefront In a headless shop, WordPress and WooCommerce keep the products, orders and payments, and a separate frontend (Next.js, Nuxt, Astro) renders the pages. WooCommerce has two APIs for this, and the most common mistake is using the wrong one: the authenticated REST API wc/v3 is for servers,…

Infinite scroll with the Fetch API and the WordPress REST API Infinite scroll loads the next page of posts when the visitor reaches the end of the list. With an Intersection Observer watching a marker below the list and the REST API delivering the posts as JSON, it needs no plugin and no jQuery. Done…

Register custom REST API endpoints with authentication and schema validation register_rest_route() adds your own endpoints to the WordPress REST API. A route has a namespace (by convention myplugin/v1), a path (with optional regex parameters) and one or more handlers, each with HTTP methods, a callback, a permission callback and a description of the parameters. The…

Replace jQuery AJAX with the native Fetch API to read and write WordPress data through the REST API, including authentication with nonces for protected endpoints.

Versioning a plugin’s REST API: v1 and v2 side by side Once an app, a theme or another site uses a plugin’s REST routes, changing what they return breaks them. Core solves it with versions in the namespace (wp/v2), and a plugin can do the same: keep ha/v1 exactly as it is, add ha/v2 with…

Trigger CSS animations and lazy-load iframes when elements enter the viewport using the Intersection Observer API.