How to make Better Auth use provider (AAD) user id instead of generating a new one?
Next.jsOAuth relatedWe’re migrating from NextAuth to Better Auth (social provider: Microsoft Entra ID). Our product already has a users table keyed by the AAD objectId (UUID). Everything downstream—chat ownership, audit logs, etc.—expects that ID.
With NextAuth we always surfaced that same id in session.user.id. In Better Auth we override getUserInfo and return id:
What we’ve tried:
- Overriding
- Using
- Looking through docs for a
What we’d like:
- Either a supported way to tell Better Auth “use the id coming from this provider/custom logic” when creating the user, or
- An official hook (before/after user creation) where we can atomically upsert our own user record and sync ids, without re-querying on every session fetch.
Any guidance or best practices would be super helpful—thanks!
With NextAuth we always surfaced that same id in session.user.id. In Better Auth we override getUserInfo and return id:
graphProfile.idsession.user.idauth.api.getSessiondbUser.idWhat we’ve tried:
- Overriding
getUserInfo- Using
mapProfileToUser- Looking through docs for a
generateIdWhat we’d like:
- Either a supported way to tell Better Auth “use the id coming from this provider/custom logic” when creating the user, or
- An official hook (before/after user creation) where we can atomically upsert our own user record and sync ids, without re-querying on every session fetch.
Any guidance or best practices would be super helpful—thanks!
