You can edit user and registration data in the admin ui. This is handled using forms, each tenant and application can be assigned a custom form to edit a user or user registration respectively.

More details here: https://fusionauth.io/docs/v1/tech/guides/advanced-registration-forms/#editing-user-data-in-the-admin-ui

We’ve discussed allowing direct JSON editing. It is too error prone.

Perhaps in the future we could enable a “danger - expert only - no fences” mode and allow it. Using the forms we can perform custom validation, type safety, etc.