got a question on self hosted kratos - i need something to interact with an already existing oauth/oidc provider is kratos just going to be like "ok, you're logged in, here's your session cookie, and redirect to that provider" ? or is there other mechanisms for interacting with that provider?

Did you see https://www.ory.sh/docs/self-hosted/kratos/configuration/oidc? Kratos fully supports OIDC out of the box.