I would recommend Shopifys APIs. Theres a lot to them, they’re well documented, and you can build a developers store for free.
Adobe commerce is another one. You can get a dockerized store up and running pretty quickly, also free and their documentation includes some basic suggested workflows.
Edit: these are mostly for practicing consuming apis, not sure if thats what you were looking for.
It’s not popular amongst those with f*ck trudeau bumper stickers on their jacked up, under-utilized vanity trucks.
But nothing tied to his name is popular with them.