Routes And Endpoints

• Register routes on the rest_api_init hook with register_rest_route( $namespace, $route, $args ).
• A route is the URL pattern; an endpoint is the method + callback bound to that route.
• For non-pretty permalinks, the route is accessed via ?rest_route=/namespace/route.

Namespacing

• Always namespace routes (vendor/v1).
• Do not use the wp/* namespace unless you are targeting core.

Methods

• Use WP_REST_Server::READABLE (GET), CREATABLE (POST), EDITABLE (PUT/PATCH), DELETABLE (DELETE).
• Multiple endpoints can share a route, one per method.

permission_callback (required)

• Always provide permission_callback.
• Public endpoints should use __return_true.
• For restricted endpoints, use capability checks (current_user_can) or object-level authorization.
• Missing permission_callback emits a _doing_it_wrong notice in modern WP.

Arguments

• Register args to validate and sanitize inputs.
• Use type, required, default, validate_callback, sanitize_callback.
• Access params via the WP_REST_Request object, not $_GET/$_POST.

Return values

• Return data via rest_ensure_response() or a WP_REST_Response.
• Return WP_Error with a status in data for error responses.
• Do not call wp_send_json() in REST callbacks.