diff --git a/app/src/main/java/ru/myitschool/work/core/OurConstants.kt b/app/src/main/java/ru/myitschool/work/core/OurConstants.kt
new file mode 100644
index 0000000..ea99bec
--- /dev/null
+++ b/app/src/main/java/ru/myitschool/work/core/OurConstants.kt
@@ -0,0 +1,9 @@
+package ru.myitschool.work.core
+
+import androidx.datastore.preferences.core.intPreferencesKey
+
+// Не добавляйте ничего, что уже есть в Constants!
+object OurConstants {
+    const val SHABLON = "^[a-zA-Z0-9]*\$"
+    const val DS_AUTH_KEY = "authkey"
+}
\ No newline at end of file
diff --git a/app/src/main/java/ru/myitschool/work/data/repo/AuthRepository.kt b/app/src/main/java/ru/myitschool/work/data/repo/AuthRepository.kt
index 3ef28f1..febfcbb 100644
--- a/app/src/main/java/ru/myitschool/work/data/repo/AuthRepository.kt
+++ b/app/src/main/java/ru/myitschool/work/data/repo/AuthRepository.kt
@@ -1,15 +1,17 @@
 package ru.myitschool.work.data.repo
 
+import android.content.Context
+import ru.myitschool.work.data.source.DataStoreDataSource.createAuthCode
 import ru.myitschool.work.data.source.NetworkDataSource
 
 object AuthRepository {
-
     private var codeCache: String? = null
-
+    // TODO: разобраться с контекстом
     suspend fun checkAndSave(text: String): Result<Boolean> {
         return NetworkDataSource.checkAuth(text).onSuccess { success ->
             if (success) {
                 codeCache = text
+                createAuthCode(context = appContext, code = text)
             }
         }
     }
diff --git a/app/src/main/java/ru/myitschool/work/data/source/DataStoreDataSource.kt b/app/src/main/java/ru/myitschool/work/data/source/DataStoreDataSource.kt
new file mode 100644
index 0000000..16bd7ee
--- /dev/null
+++ b/app/src/main/java/ru/myitschool/work/data/source/DataStoreDataSource.kt
@@ -0,0 +1,27 @@
+package ru.myitschool.work.data.source
+
+import android.content.Context
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import ru.myitschool.work.core.OurConstants.DS_AUTH_KEY
+
+val Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "auth")
+val AUTH_KEY = stringPreferencesKey(DS_AUTH_KEY)
+
+object DataStoreDataSource {
+    fun authFlow(context : Context): Flow<String> = context.dataStore.data.map { preferences ->
+        (preferences[AUTH_KEY] ?: 0).toString()
+    }
+    // TODO: разобраться с контекстом
+    suspend fun createAuthCode (context : Context, code : String) {
+        context.dataStore.updateData {
+            it.toMutablePreferences().also { preferences ->
+                preferences[AUTH_KEY] = code
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/ru/myitschool/work/data/source/NetworkDataSource.kt b/app/src/main/java/ru/myitschool/work/data/source/NetworkDataSource.kt
index fbdfef5..f12b719 100644
--- a/app/src/main/java/ru/myitschool/work/data/source/NetworkDataSource.kt
+++ b/app/src/main/java/ru/myitschool/work/data/source/NetworkDataSource.kt
@@ -30,7 +30,7 @@ object NetworkDataSource {
 
     suspend fun checkAuth(code: String): Result<Boolean> = withContext(Dispatchers.IO) {
         return@withContext runCatching {
-            val response = client.get(getUrl(code, Constants.AUTH_URL))
+            val response = client.get(getUrl(code, Constants.AUTH_URL)) // TODO: Отпрвка запроса на сервер
             when (response.status) {
                 HttpStatusCode.OK -> true
                 else -> error(response.bodyAsText())
diff --git a/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthAction.kt b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthAction.kt
new file mode 100644
index 0000000..939a280
--- /dev/null
+++ b/app/src/main/java/ru/myitschool/work/ui/screen/auth/AuthAction.kt
@@ -0,0 +1,6 @@
+package ru.myitschool.work.ui.screen.auth
+
+sealed interface AuthAction {
+    data class ShowError(val message: String) : AuthAction
+    
+}
\ No newline at end of file
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 a8aac84..845e8ab 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
@@ -29,6 +29,7 @@ import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigation.NavController
 import ru.myitschool.work.R
+import ru.myitschool.work.core.OurConstants.SHABLON
 import ru.myitschool.work.core.TestIds
 import ru.myitschool.work.ui.nav.MainScreenDestination
 
@@ -74,6 +75,7 @@ private fun Content(
     state: AuthState.Data
 ) {
     var inputText by remember { mutableStateOf("") }
+    var errorText : String? by remember { mutableStateOf(null) }
     Spacer(modifier = Modifier.size(16.dp))
     TextField(
         modifier = Modifier.testTag(TestIds.Auth.CODE_INPUT).fillMaxWidth(),
@@ -88,12 +90,20 @@ private fun Content(
     Button(
         modifier = Modifier.testTag(TestIds.Auth.SIGN_BUTTON).fillMaxWidth(),
         onClick = {
-            viewModel.onIntent(AuthIntent.Send(inputText))
+            if (!inputText.isEmpty() || inputText.length == 4 || inputText.matches(Regex(SHABLON))){
+                viewModel.onIntent(AuthIntent.Send(inputText))
+            }
         },
         enabled = true
 
-    ) { Text(stringResource(R.string.auth_sign_in))
+    ) { Text(stringResource(R.string.auth_sign_in)) }
+    ShowError(errorText) // TODO: раскидать в коде когда показывается ошибка и когда нет
 
+}
 
+@Composable
+fun ShowError(text : String?){
+    if (text != null){
+        Text(text, modifier = Modifier.testTag(TestIds.Auth.ERROR))
     }
-}
\ 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..4f5ea07 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
@@ -18,21 +18,23 @@ class AuthViewModel : ViewModel() {
     private val _uiState = MutableStateFlow<AuthState>(AuthState.Data)
     val uiState: StateFlow<AuthState> = _uiState.asStateFlow()
 
-    private val _actionFlow: MutableSharedFlow<Unit> = MutableSharedFlow()
-    val actionFlow: SharedFlow<Unit> = _actionFlow
+    private val _actionFlow: MutableSharedFlow<AuthAction> = MutableSharedFlow()
+    val actionFlow: SharedFlow<AuthAction> = _actionFlow
 
     fun onIntent(intent: AuthIntent) {
         when (intent) {
             is AuthIntent.Send -> {
-                viewModelScope.launch(Dispatchers.Default) {
+                viewModelScope.launch(Dispatchers.IO) {
                     _uiState.update { AuthState.Loading }
-                    checkAndSaveAuthCodeUseCase.invoke("9999").fold(
+                    checkAndSaveAuthCodeUseCase.invoke(intent.text).fold(
                         onSuccess = {
-                            _actionFlow.emit(Unit)
+                             // TODO: Поведение при успехе
                         },
                         onFailure = { error ->
                             error.printStackTrace()
-                            _actionFlow.emit(Unit)
+                            if (error.message != null) {
+                                _actionFlow.emit(AuthAction.ShowError(error.message.toString()))
+                            }
                         }
                     )
                 }