Hi everybody. I want to create a project with the v3 api of Rancher. Does anybody know how to do this? I can't find any documentation about the api spec.

Documentation for v3 is over at https://docs.ranchermanager.rancher.io/pages-for-subheaders/about-the-api. The UI will make use of the v3 api to create projects and that docs page contains a section on tracking it's requests. That way you can understand how to craft your own v3 requests

ok. thanks! i was wondering why isn't there a openapi spec of the full api? Json / YAML Then i can work with Swagger / Postman to create my api calls.

There's a more technical spec defined here, however Rancher is migrating away from a more custom API and towards manipulation of kube resources by the standard kube api. There's not much of an update i can give there, but it's something actively being discussed internally