1. Almost never - it's a lot of work to get from a library to a server that has a strong persistence layer, is scalable, has all the management around it (e.g. write and create clients). Also, upgrading a server is much easier than upgrading a library! 2. We plan to have ORY Kratos v0.6 out of alpha (what we call sandbox) and in "incubating" status. That means that we feel confident that APIs won't change as much an more but there is still risk that you have to deal with some breaking changes. For version 1.0 it is probably going to land in 2022, as we usually stay 1 year in sandbox, 1 year in incubating and if everything has stabilized go to stable. Having said that, you can still use this stuff in prod. For us, alpha/sandbox just means: "Careful, there will be breaking changes!". But we never release insecure, untested or half-baked stuff.