I can deploy Lightning Pages, aka Flexi Pages with the Metadata API. In order to active a Lightning Page, I can do so in the Page-Builder via Setup-Home -> Object Manager -> Account -> Lightning Record Pages. But howto do this with the Metadata API? I would assume, that this configuration is also stored in the CustomObject of the Account but after downloading it, I couldn't find such an entry and there is also no documentation of such a thing here.
So: How can I active a Lightning Record Page with the API?
Best Answer
I have the same issue and spent quite a lot of time to find the solution. Unfortunately, there are nothing about ability to activate Lightning record page via API. So it turns out that we have only Lightning App Builder for now to do this. Finally I left post at IdeaExchange. Hope Salesforce could offer any solution in the future.