developerOnlyAttribute

You should use WriteAttributes in the user pool client to control how attributes can be mutated for new use cases instead of using DeveloperOnlyAttribute . Specifies whether the attribute type is developer only. This attribute can only be modified by an administrator. Users won't be able to modify this attribute using their access token. For example, DeveloperOnlyAttribute can be modified using AdminUpdateUserAttributes but can't be updated using UpdateUserAttributes.