diff --git a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthScreen.kt b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthScreen.kt
index 4e1a106..fc25dc0 100644
--- a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthScreen.kt
+++ b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthScreen.kt
@@ -21,7 +21,6 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
@@ -32,6 +31,7 @@ import ru.myitschool.work.R
 import ru.myitschool.work.core.TestIds
 import ru.myitschool.work.ui.nav.MainScreenDestination
 
+
 @Composable
 fun AuthScreen(
     viewModel: AuthViewModel = viewModel(),
@@ -74,6 +74,10 @@ private fun Content(
     state: AuthState.Data
 ) {
     var inputText by remember { mutableStateOf("") }
+
+    val isCodeValid = inputText.length == 4 && inputText.all { it.isLetterOrDigit() }
+    val isButtonEnabled = isCodeValid
+
     Spacer(modifier = Modifier.size(16.dp))
 
     TextField(
@@ -83,16 +87,30 @@ private fun Content(
             inputText = it
             viewModel.onIntent(AuthIntent.TextInput(it))
         },
-        label = { Text(stringResource(R.string.auth_label)) }
+        label = { Text(stringResource(R.string.auth_label)) },
+        placeholder = { Text("Код") },
+        isError = state.error != null
     )
+
+    if (state.error != null) {
+        Spacer(modifier = Modifier.size(8.dp))
+        Text(
+            text = state.error,
+            color = MaterialTheme.colorScheme.error,
+            modifier = Modifier.testTag(TestIds.Auth.ERROR)
+        )
+    }
+
     Spacer(modifier = Modifier.size(16.dp))
+
     Button(
         modifier = Modifier.testTag(TestIds.Auth.SIGN_BUTTON).fillMaxWidth(),
         onClick = {
             viewModel.onIntent(AuthIntent.Send(inputText))
         },
-        enabled = true
+        enabled = isButtonEnabled
     ) {
         Text(stringResource(R.string.auth_sign_in))
     }
-}
\ No newline at end of file
+}
+
diff --git a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthState.kt b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthState.kt
index a06ba76..ff2f5f7 100644
--- a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthState.kt
+++ b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthState.kt
@@ -1,6 +1,8 @@
 package ru.myitschool.work.ui.screen.auth
 
-sealed interface AuthState {
-    object Loading: AuthState
-    object Data: AuthState
+sealed class AuthState {
+    object Loading : AuthState()
+    data class Data(
+        val error: String? = null
+    ) : AuthState()
 }
\ No newline at end of file
diff --git a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthViewModel.kt b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthViewModel.kt
index 3153640..b00a078 100644
--- a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthViewModel.kt
+++ b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthViewModel.kt
@@ -15,7 +15,7 @@ import ru.myitschool.work.domain.auth.CheckAndSaveAuthCodeUseCase
 
 class AuthViewModel : ViewModel() {
     private val checkAndSaveAuthCodeUseCase by lazy { CheckAndSaveAuthCodeUseCase(AuthRepository) }
-    private val _uiState = MutableStateFlow<AuthState>(AuthState.Data)
+    private val _uiState = MutableStateFlow<AuthState>(AuthState.Data())
     val uiState: StateFlow<AuthState> = _uiState.asStateFlow()
 
     private val _actionFlow: MutableSharedFlow<Unit> = MutableSharedFlow()
@@ -24,20 +24,30 @@ class AuthViewModel : ViewModel() {
     fun onIntent(intent: AuthIntent) {
         when (intent) {
             is AuthIntent.Send -> {
+                val code = intent.text
                 viewModelScope.launch(Dispatchers.Default) {
-                    _uiState.update { AuthState.Loading }
-                    checkAndSaveAuthCodeUseCase.invoke("9999").fold(
+                    _uiState.value = AuthState.Loading
+                    checkAndSaveAuthCodeUseCase.invoke(code).fold(
                         onSuccess = {
                             _actionFlow.emit(Unit)
                         },
                         onFailure = { error ->
-                            error.printStackTrace()
-                            _actionFlow.emit(Unit)
+
+                            val errorMsg = when {
+                                error.message?.contains("401") == true -> "Неверный код"
+                                else -> "Ошибка подключения"
+                            }
+                            _uiState.value = AuthState.Data(error = errorMsg)
                         }
                     )
                 }
             }
-            is AuthIntent.TextInput -> Unit
+
+            is AuthIntent.TextInput -> {
+                if (_uiState.value is AuthState.Data) {
+                    _uiState.value = AuthState.Data(error = null)
+                }
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/ru/myitschool/work/ui/screen/main/MainState.kt b/app/src/main/java/ru/myitschool/work/ui/screen/main/MainState.kt
new file mode 100644
index 0000000..5af9da9
--- /dev/null
+++ b/app/src/main/java/ru/myitschool/work/ui/screen/main/MainState.kt
@@ -0,0 +1,19 @@
+package ru.myitschool.work.ui.screen.main
+
+sealed interface MainState {
+    object Loading : MainState
+    data class Success(
+        val name: String,
+        val photoUrl: String,
+        val bookings: List<BookingItem>,
+    ) : MainState
+
+    data class Error(
+        val message: String,
+    ) : MainState
+}
+
+data class BookingItem(
+    val date: String,
+    val place: String,
+)
\ No newline at end of file