wp-rest-api

To register a custom WordPress REST API endpoint, use register_rest_route with a unique namespace, define route arguments, implement input validation, and attach a permission_callback to secure access. This ensures safe route registration and properly formatted responses.

WordPress REST API 401 or 403 errors occur when authentication fails or permission callbacks restrict access. Troubleshoot by verifying authentication credentials and ensuring your route's permission_callback explicitly grants the current user access.

To expose custom post types via the WordPress REST API, set show_in_rest to true when registering your post type or taxonomy. This automatically adds your CPTs to the wp-json responses for robust API design.

The best way to structure WordPress REST API responses is by using controller-based endpoints to shape data, implementing pagination for large datasets, and utilizing embedding within wp-json responses for robust and efficient API design.

Add argument validation to WordPress REST API routes by defining validation rules within the register_rest_route arguments array. This ensures incoming data meets your endpoint requirements before processing requests.

A custom WordPress REST API route returns a 404 when the namespace or route path is incorrect or the rest_api_init hook is missing. Verify your unique namespace and ensure registration occurs within the proper hook.