diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 709aaa3..5b2e959 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -68,6 +68,7 @@ dependencies {
     implementation("com.squareup.okhttp3:okhttp:4.11.0")
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.1")
     testImplementation("junit:junit:4.13.2")
+    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.7.1")
     androidTestImplementation("androidx.test.ext:junit:1.1.5")
     androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
     androidTestImplementation(platform("androidx.compose:compose-bom:2023.03.00"))
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 0b7e3d2..5ac4331 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools">
     <uses-permission android:name="android.permission.INTERNET" />
     <application
+        android:name=".TasksApplication"
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
diff --git a/app/src/main/java/com/example/taskapp/TasksApplication.kt b/app/src/main/java/com/example/taskapp/TasksApplication.kt
new file mode 100644
index 0000000..34fef6b
--- /dev/null
+++ b/app/src/main/java/com/example/taskapp/TasksApplication.kt
@@ -0,0 +1,16 @@
+package com.example.taskapp
+
+import android.app.Application
+import com.example.taskapp.data.AppContainer
+import com.example.taskapp.data.DefaultAppContainer
+
+
+
+class TasksApplication: Application() {
+    lateinit var container: AppContainer
+
+    override fun onCreate() {
+        super.onCreate()
+        container = DefaultAppContainer()
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/example/taskapp/data/AppContainer.kt b/app/src/main/java/com/example/taskapp/data/AppContainer.kt
new file mode 100644
index 0000000..0a7ba0c
--- /dev/null
+++ b/app/src/main/java/com/example/taskapp/data/AppContainer.kt
@@ -0,0 +1,33 @@
+package com.example.taskapp.data
+
+import com.example.taskapp.network.TaskApiService
+import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import kotlinx.serialization.json.Json
+import okhttp3.MediaType.Companion.toMediaType
+import retrofit2.Retrofit
+
+interface AppContainer {
+    val tasksRepository: TasksRepository
+}
+
+//container that takes care of dependencies
+class DefaultAppContainer(): AppContainer{
+
+    private val baseUrl = "http://10.0.2.2:3000"
+    private val retrofit = Retrofit.Builder()
+        .addConverterFactory(
+            Json.asConverterFactory("application/json".toMediaType())
+        )
+        .baseUrl(baseUrl)
+        .build()
+
+    private val retrofitService : TaskApiService by lazy {
+        retrofit.create(TaskApiService::class.java)
+    }
+
+
+    override val tasksRepository: TasksRepository by lazy {
+        ApiTasksRepository(retrofitService)
+    }
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/example/taskapp/data/TasksRepository.kt b/app/src/main/java/com/example/taskapp/data/TasksRepository.kt
new file mode 100644
index 0000000..555a5a7
--- /dev/null
+++ b/app/src/main/java/com/example/taskapp/data/TasksRepository.kt
@@ -0,0 +1,17 @@
+package com.example.taskapp.data
+
+import com.example.taskapp.model.Task
+import com.example.taskapp.network.TaskApiService
+import com.example.taskapp.network.asDomainObjects
+
+interface TasksRepository {
+    suspend fun getTasks(): List<Task>
+}
+
+class ApiTasksRepository(
+    private val taskApiService: TaskApiService
+): TasksRepository{
+    override suspend fun getTasks(): List<Task> {
+        return taskApiService.getTasks().asDomainObjects()
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/example/taskapp/network/TaskApiService.kt b/app/src/main/java/com/example/taskapp/network/TaskApiService.kt
index 9f37855..a3316ad 100644
--- a/app/src/main/java/com/example/taskapp/network/TaskApiService.kt
+++ b/app/src/main/java/com/example/taskapp/network/TaskApiService.kt
@@ -7,20 +7,13 @@ import okhttp3.MediaType.Companion.toMediaType
 import retrofit2.Retrofit
 import retrofit2.http.GET
 
-private const val BASE_URL = "http://10.0.2.2:3000"
-private val retrofit = Retrofit.Builder()
-    .addConverterFactory(
-        Json.asConverterFactory("application/json".toMediaType())
-    )
-    .baseUrl(BASE_URL)
-    .build()
+
 
 //create the actual function implementations (expensive!)
-object TaskApi{
-    val retrofitService : TaskApiService by lazy {
-        retrofit.create(TaskApiService::class.java)
-    }
-}
+//no longer needed --> moved to the AppContainer
+//object TaskApi{
+//
+//}
 
 
 //define what the API looks like
diff --git a/app/src/main/java/com/example/taskapp/ui/TaskItem.kt b/app/src/main/java/com/example/taskapp/ui/TaskItem.kt
index 74c0c81..cb1043c 100644
--- a/app/src/main/java/com/example/taskapp/ui/TaskItem.kt
+++ b/app/src/main/java/com/example/taskapp/ui/TaskItem.kt
@@ -26,6 +26,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -46,7 +47,7 @@ fun TaskItem(
     Card(
         modifier = modifier.padding(dimensionResource(R.dimen.padding_small)),
     ) {
-        var expanded by remember { mutableStateOf(false) }
+        var expanded by rememberSaveable { mutableStateOf(false) }
         val color by animateColorAsState(
             targetValue = if (expanded) {
                 MaterialTheme.colorScheme.tertiaryContainer
diff --git a/app/src/main/java/com/example/taskapp/ui/TaskOverview.kt b/app/src/main/java/com/example/taskapp/ui/TaskOverview.kt
index 817d295..971a1c7 100644
--- a/app/src/main/java/com/example/taskapp/ui/TaskOverview.kt
+++ b/app/src/main/java/com/example/taskapp/ui/TaskOverview.kt
@@ -19,7 +19,7 @@ fun TaskOverview(
     addingVisible: Boolean,
     onVisibilityChanged: (Boolean) -> Unit,
     modifier: Modifier = Modifier,
-    taskOverviewViewModel: TaskOverviewViewModel = viewModel(),
+    taskOverviewViewModel: TaskOverviewViewModel = viewModel(factory = TaskOverviewViewModel.Factory),
 ) {
     val taskOverviewState by taskOverviewViewModel.uiState.collectAsState()
 
diff --git a/app/src/main/java/com/example/taskapp/ui/TaskOverviewViewModel.kt b/app/src/main/java/com/example/taskapp/ui/TaskOverviewViewModel.kt
index 7fa7d4a..c75b0fe 100644
--- a/app/src/main/java/com/example/taskapp/ui/TaskOverviewViewModel.kt
+++ b/app/src/main/java/com/example/taskapp/ui/TaskOverviewViewModel.kt
@@ -4,11 +4,15 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.ViewModelProvider.AndroidViewModelFactory.Companion.APPLICATION_KEY
 import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.viewmodel.initializer
+import androidx.lifecycle.viewmodel.viewModelFactory
+import com.example.taskapp.TasksApplication
 import com.example.taskapp.data.TaskSampler
+import com.example.taskapp.data.TasksRepository
 import com.example.taskapp.model.Task
-import com.example.taskapp.network.TaskApi
-import com.example.taskapp.network.asDomainObjects
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
@@ -16,7 +20,7 @@ import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import java.io.IOException
 
-class TaskOverviewViewModel : ViewModel() {
+class TaskOverviewViewModel(private val tasksRepository: TasksRepository) : ViewModel() {
     // use StateFlow (Flow: emits current state + any updates)
     private val _uiState = MutableStateFlow(TaskOverviewState(TaskSampler.getAll()))
     val uiState: StateFlow<TaskOverviewState> = _uiState.asStateFlow()
@@ -61,11 +65,13 @@ class TaskOverviewViewModel : ViewModel() {
     private fun getApiTasks(){
         viewModelScope.launch {
             try{
-                val listResult = TaskApi.retrofitService.getTasks()
+                //use the repository
+                //val tasksRepository = ApiTasksRepository() //repo is now injected
+                val listResult = tasksRepository.getTasks()
                 _uiState.update {
-                    it.copy(currentTaskList = listResult.asDomainObjects())
+                    it.copy(currentTaskList = listResult)
                 }
-                taskApiState = TaskApiState.Success(listResult.asDomainObjects())
+                taskApiState = TaskApiState.Success(listResult)
             }
             catch (e: IOException){
                 //show a toast? save a log on firebase? ...
@@ -75,6 +81,18 @@ class TaskOverviewViewModel : ViewModel() {
 
         }
     }
+
+    //object to tell the android framework how to handle the parameter of the viewmodel
+    companion object {
+        val Factory: ViewModelProvider.Factory = viewModelFactory {
+            initializer {
+                val application = (this[APPLICATION_KEY] as TasksApplication)
+                val tasksRepository = application.container.tasksRepository
+                TaskOverviewViewModel(tasksRepository = tasksRepository
+                )
+            }
+        }
+    }
 }
 
 
diff --git a/app/src/test/java/com/example/taskapp/ApiTaskRepositoryTest.kt b/app/src/test/java/com/example/taskapp/ApiTaskRepositoryTest.kt
new file mode 100644
index 0000000..ae8131b
--- /dev/null
+++ b/app/src/test/java/com/example/taskapp/ApiTaskRepositoryTest.kt
@@ -0,0 +1,17 @@
+package com.example.taskapp
+
+import com.example.taskapp.data.ApiTasksRepository
+import com.example.taskapp.fake.FakeDataSource
+import com.example.taskapp.fake.FakeTasksApiService
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ApiTaskRepositoryTest {
+    @Test
+    fun apiTaskRepository_getTasks_verifyTasksList() =
+        runTest{
+        val repository = ApiTasksRepository(FakeTasksApiService())
+        assertEquals(FakeDataSource.tasks, repository.getTasks())
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/com/example/taskapp/TaskOverviewViewModelTest.kt b/app/src/test/java/com/example/taskapp/TaskOverviewViewModelTest.kt
index 2f39003..3c9f715 100644
--- a/app/src/test/java/com/example/taskapp/TaskOverviewViewModelTest.kt
+++ b/app/src/test/java/com/example/taskapp/TaskOverviewViewModelTest.kt
@@ -1,17 +1,46 @@
 package com.example.taskapp
 
+import com.example.taskapp.fake.FakeApiTasksRepository
 import com.example.taskapp.ui.TaskOverviewViewModel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.test.TestDispatcher
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
 import org.junit.Assert
+import org.junit.Rule
 import org.junit.Test
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
 
 class TaskOverviewViewModelTest {
-    private val viewModel = TaskOverviewViewModel()
+
+
     private val someTaskName = "some task name"
 
+    @get:Rule
+    val testDispatcher = TestDispatcherRule()
+
     @Test
     fun settingNameChangesState() {
+        val viewModel = TaskOverviewViewModel(
+            tasksRepository = FakeApiTasksRepository()
+        )
         viewModel.setNewTaskName(someTaskName)
-
         Assert.assertEquals(viewModel.uiState.value.newTaskName, someTaskName)
+
+    }
+
+}
+
+class TestDispatcherRule(
+    val testDispatcher: TestDispatcher = UnconfinedTestDispatcher()
+): TestWatcher(){
+    override fun starting(description: Description) {
+        Dispatchers.setMain(testDispatcher)
+    }
+
+    override fun finished(description: Description) {
+        Dispatchers.resetMain()
     }
 }
diff --git a/app/src/test/java/com/example/taskapp/fake/FakeApiTasksRepository.kt b/app/src/test/java/com/example/taskapp/fake/FakeApiTasksRepository.kt
new file mode 100644
index 0000000..5da32a9
--- /dev/null
+++ b/app/src/test/java/com/example/taskapp/fake/FakeApiTasksRepository.kt
@@ -0,0 +1,11 @@
+package com.example.taskapp.fake
+
+import com.example.taskapp.data.TasksRepository
+import com.example.taskapp.model.Task
+import com.example.taskapp.network.asDomainObjects
+
+class FakeApiTasksRepository: TasksRepository {
+    override suspend fun getTasks(): List<Task> {
+        return FakeDataSource.tasks.asDomainObjects()
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/com/example/taskapp/fake/FakeDataSource.kt b/app/src/test/java/com/example/taskapp/fake/FakeDataSource.kt
new file mode 100644
index 0000000..74b9c08
--- /dev/null
+++ b/app/src/test/java/com/example/taskapp/fake/FakeDataSource.kt
@@ -0,0 +1,14 @@
+package com.example.taskapp.fake
+
+import com.example.taskapp.network.ApiTask
+
+object FakeDataSource {
+    const val nameOne = "feed dog"
+    const val nameTwo = "feed cat"
+    const val descriptionOne = "food is in the cellar"
+    const val descriptionTwo = "food is also in the cellar"
+
+    val tasks = listOf(
+        ApiTask(nameOne, descriptionOne),
+        ApiTask(nameTwo, descriptionTwo))
+}
\ No newline at end of file
diff --git a/app/src/test/java/com/example/taskapp/fake/FakeTasksApiService.kt b/app/src/test/java/com/example/taskapp/fake/FakeTasksApiService.kt
new file mode 100644
index 0000000..e77d2f1
--- /dev/null
+++ b/app/src/test/java/com/example/taskapp/fake/FakeTasksApiService.kt
@@ -0,0 +1,10 @@
+package com.example.taskapp.fake
+
+import com.example.taskapp.network.ApiTask
+import com.example.taskapp.network.TaskApiService
+
+class FakeTasksApiService: TaskApiService {
+    override suspend fun getTasks(): List<ApiTask> {
+        return FakeDataSource.tasks
+    }
+}
\ No newline at end of file