EDIT: Ignore this comment, I was mistaken

I don't believe that will ever happen due to the underlying Vitess tech [0] that PlanetScale uses

[0] https://vitess.io/blog/2021-06-15-online-ddl-why-no-fk/

We are working on foreign key constraint support right now. :)

It's going to happen.

Very cool! I didn't know that was on the roadmap.

It's on the official Vitess roadmap, though you do have to search on this page for it https://vitess.io/docs/resources/roadmap/

It's on its way!

This is great news. I strolled around https://github.com/vitessio/vitess/issues/12967.

Are there any public discussions of more trade-offs vitess has to make to enable fks?

This is the only thing that is stopping me from trying PlanetScale. I can't imagine not having the database do this work for me

This is the only real thing stopping me from trying PlanetScale as well, glad to see in the comments that it's coming.