OLX Poland vs WooCommerce

OLX Poland's Partner API lets approved integrators create and manage classified-ad listings and handle buyer/seller messaging programmatically. Access runs on an OAuth2 client-credentials flow, confirmed live by an invalid_client error from the real token endpoint, and the older v1 REST resource has been explicitly deprecated in favor of this OAuth-secured surface. Developer access comes through an application and approval process rather than a published self-serve fee.

WooCommerce's REST API isn't a centrally hosted service — every self-hosted WooCommerce store exposes its own instance, authenticated by a consumer key/secret pair sent as HTTP Basic Auth credentials over HTTPS, per WooCommerce's own documentation. Because CORS support depends entirely on each merchant's own server configuration rather than the protocol itself, it can't be verified as a single blanket property of "the API." The protocol ships free with the open-source plugin; the only cost is whatever the merchant already pays to host their own store.