diff --git a/server/src/main/java/ru/dragonestia/picker/config/TestConfig.java b/server/src/main/java/ru/dragonestia/picker/config/TestConfig.java
index af1e16c..b6af4be 100644
--- a/server/src/main/java/ru/dragonestia/picker/config/TestConfig.java
+++ b/server/src/main/java/ru/dragonestia/picker/config/TestConfig.java
@@ -14,6 +14,7 @@ import ru.dragonestia.picker.api.model.node.PickingMethod;
 import ru.dragonestia.picker.api.model.room.IRoom;
 import ru.dragonestia.picker.api.repository.type.NodeIdentifier;
 import ru.dragonestia.picker.api.repository.type.RoomIdentifier;
+import ru.dragonestia.picker.api.repository.type.UserIdentifier;
 import ru.dragonestia.picker.interceptor.DebugInterceptor;
 import ru.dragonestia.picker.model.Room;
 import ru.dragonestia.picker.model.Node;
@@ -61,7 +62,7 @@ public class TestConfig implements WebMvcConfigurer {
             roomRepository.create(room);
 
             for (int j = 0, n = rand.nextInt(slots + 1); j < n; j++) {
-                var user = new User("test-user-" + rand.nextInt(20));
+                var user = new User(UserIdentifier.of("test-user-" + rand.nextInt(20)));
                 userRepository.linkWithRoom(room, List.of(user), false);
             }
         }
diff --git a/server/src/main/java/ru/dragonestia/picker/controller/UserController.java b/server/src/main/java/ru/dragonestia/picker/controller/UserController.java
index 1afe677..5714aba 100644
--- a/server/src/main/java/ru/dragonestia/picker/controller/UserController.java
+++ b/server/src/main/java/ru/dragonestia/picker/controller/UserController.java
@@ -9,6 +9,7 @@ import ru.dragonestia.picker.api.model.user.ResponseUser;
 import ru.dragonestia.picker.api.repository.response.LinkedRoomsWithUserResponse;
 import ru.dragonestia.picker.api.repository.response.SearchUserResponse;
 import ru.dragonestia.picker.api.repository.response.UserDetailsResponse;
+import ru.dragonestia.picker.api.repository.type.UserIdentifier;
 import ru.dragonestia.picker.model.User;
 import ru.dragonestia.picker.service.UserService;
 import ru.dragonestia.picker.util.DetailsParser;
@@ -62,6 +63,6 @@ public class UserController {
             return new LinkedRoomsWithUserResponse(List.of());
         }
 
-        return new LinkedRoomsWithUserResponse(userService.getUserRoomsWithDetails(new User(userId), detailsParser.parseRoomDetails(detailsSeq)));
+        return new LinkedRoomsWithUserResponse(userService.getUserRoomsWithDetails(new User(UserIdentifier.of(userId)), detailsParser.parseRoomDetails(detailsSeq)));
     }
 }
diff --git a/server/src/main/java/ru/dragonestia/picker/model/User.java b/server/src/main/java/ru/dragonestia/picker/model/User.java
index f28f5c7..1af895b 100644
--- a/server/src/main/java/ru/dragonestia/picker/model/User.java
+++ b/server/src/main/java/ru/dragonestia/picker/model/User.java
@@ -1,13 +1,37 @@
 package ru.dragonestia.picker.model;
 
-import lombok.NonNull;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import ru.dragonestia.picker.api.model.user.IUser;
 import ru.dragonestia.picker.api.model.user.ResponseUser;
+import ru.dragonestia.picker.api.model.user.UserDetails;
+import ru.dragonestia.picker.api.repository.type.UserIdentifier;
 
-public record User(@NonNull String id) {
+public class User implements IUser {
+
+    private final String identifier;
+
+    public User(@NotNull UserIdentifier identifier) {
+        this.identifier = identifier.getValue();
+    }
+
+    @Override
+    public @NotNull String getIdentifier() {
+        return identifier;
+    }
+
+    @Override
+    public @Nullable String getDetail(@NotNull UserDetails detail) {
+        throw new UnsupportedOperationException();
+    }
+
+    public @NotNull ResponseUser toResponseObject() {
+        return new ResponseUser(identifier);
+    }
 
     @Override
     public int hashCode() {
-        return id.hashCode();
+        return identifier.hashCode();
     }
 
     @Override
@@ -15,12 +39,8 @@ public record User(@NonNull String id) {
         if (object == this) return true;
         if (object == null) return false;
         if (object instanceof User other) {
-            return id.equals(other.id);
+            return identifier.equals(other.identifier);
         }
         return false;
     }
-
-    public ResponseUser toResponseObject() {
-        return new ResponseUser(id);
-    }
 }
diff --git a/server/src/main/java/ru/dragonestia/picker/repository/impl/UserRepositoryImpl.java b/server/src/main/java/ru/dragonestia/picker/repository/impl/UserRepositoryImpl.java
index 269a0c6..73b8d62 100644
--- a/server/src/main/java/ru/dragonestia/picker/repository/impl/UserRepositoryImpl.java
+++ b/server/src/main/java/ru/dragonestia/picker/repository/impl/UserRepositoryImpl.java
@@ -124,8 +124,8 @@ public class UserRepositoryImpl implements UserRepository {
     public List<User> search(String input) {
         synchronized (usersMap) {
             return usersMap.keySet().stream()
-                    .filter(user -> user.id().startsWith(input))
-                    .sorted(Comparator.comparing(User::id))
+                    .filter(user -> user.getIdentifier().startsWith(input))
+                    .sorted(Comparator.comparing(User::getIdentifier))
                     .toList();
         }
     }
diff --git a/server/src/main/java/ru/dragonestia/picker/service/impl/RoomServiceImpl.java b/server/src/main/java/ru/dragonestia/picker/service/impl/RoomServiceImpl.java
index 5c08f10..af05a0f 100644
--- a/server/src/main/java/ru/dragonestia/picker/service/impl/RoomServiceImpl.java
+++ b/server/src/main/java/ru/dragonestia/picker/service/impl/RoomServiceImpl.java
@@ -90,7 +90,7 @@ public class RoomServiceImpl implements RoomService {
                 room.getMaxSlots(),
                 roomUsers.size(),
                 room.isLocked(),
-                roomUsers.stream().map(User::id).collect(Collectors.toSet())
+                roomUsers.stream().map(User::getIdentifier).collect(Collectors.toSet())
         );
     }
 
diff --git a/server/src/main/java/ru/dragonestia/picker/service/impl/UserServiceImpl.java b/server/src/main/java/ru/dragonestia/picker/service/impl/UserServiceImpl.java
index ad9c1cb..1b68dbe 100644
--- a/server/src/main/java/ru/dragonestia/picker/service/impl/UserServiceImpl.java
+++ b/server/src/main/java/ru/dragonestia/picker/service/impl/UserServiceImpl.java
@@ -6,6 +6,7 @@ import ru.dragonestia.picker.api.model.room.RoomDetails;
 import ru.dragonestia.picker.api.model.room.ShortResponseRoom;
 import ru.dragonestia.picker.api.model.user.ResponseUser;
 import ru.dragonestia.picker.api.model.user.UserDetails;
+import ru.dragonestia.picker.api.repository.type.UserIdentifier;
 import ru.dragonestia.picker.model.Room;
 import ru.dragonestia.picker.model.User;
 import ru.dragonestia.picker.repository.UserRepository;
@@ -67,6 +68,6 @@ public class UserServiceImpl implements UserService {
 
     @Override
     public ResponseUser getUserDetails(String userId, Set<UserDetails> details) {
-        return detailsExtractor.extract(new User(userId), details);
+        return detailsExtractor.extract(new User(UserIdentifier.of(userId)), details);
     }
 }
diff --git a/server/src/main/java/ru/dragonestia/picker/util/NamingValidator.java b/server/src/main/java/ru/dragonestia/picker/util/NamingValidator.java
index 9ed1238..d49c263 100644
--- a/server/src/main/java/ru/dragonestia/picker/util/NamingValidator.java
+++ b/server/src/main/java/ru/dragonestia/picker/util/NamingValidator.java
@@ -4,6 +4,7 @@ import org.springframework.stereotype.Component;
 import ru.dragonestia.picker.api.exception.InvalidNodeIdentifierException;
 import ru.dragonestia.picker.api.exception.InvalidRoomIdentifierException;
 import ru.dragonestia.picker.api.exception.InvalidUsernamesException;
+import ru.dragonestia.picker.api.repository.type.UserIdentifier;
 import ru.dragonestia.picker.api.util.IdentifierValidator;
 import ru.dragonestia.picker.model.User;
 
@@ -35,7 +36,7 @@ public class NamingValidator {
 
         for (var username: input) {
             if (validateUserId(username)) {
-                users.add(new User(username));
+                users.add(new User(UserIdentifier.of(username)));
                 continue;
             }