Has anyone managed to get Hashicorp Vault to authenticate against kratos / hydra as a non-user-facing service? (so, the user logs into an app, and that app's backend then connects to vault, passing on the auth cookie to vault which then gives access to that user's stored secrets)

Hey Benjamin, I think there are some users out there who have done this, but we would need some digging to find out more 🙂 I found an article that mentions supplying the secrets to Ory Kratos via vault https://maibaloc.com/posts/vault_argocd_gitops/ Not exactly what you are looking for 🤔