set-user-claims-list.java

@Service
@RequiredArgsConstructor
public class UserManagementService {

    private final FirebaseAuth firebaseAuth;

    public void setUserClaims(String uid, List<Permission> requestedPermissions) throws FirebaseAuthException {
        List<String> permissions = requestedPermissions
                .stream()
                .map(Enum::toString)
                .collect(Collectors.toList());

        Map<String, Object> claims = Map.of("custom_claims", permissions);

        firebaseAuth.setCustomUserClaims(uid, claims);
    }
}