diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
index ed76bea..44ca2d9 100644
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -5,6 +5,10 @@
       <option name="composableFile" value="true" />
       <option name="previewFile" value="true" />
     </inspection_tool>
+    <inspection_tool class="PreviewApiLevelMustBeValid" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
     <inspection_tool class="PreviewDimensionRespectsLimit" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="composableFile" value="true" />
       <option name="previewFile" value="true" />
diff --git a/backend/src/main/java/net/buzzert/kordophone/backend/ChatRepository.kt b/backend/src/main/java/net/buzzert/kordophone/backend/ChatRepository.kt
deleted file mode 100644
index 545e770..0000000
--- a/backend/src/main/java/net/buzzert/kordophone/backend/ChatRepository.kt
+++ /dev/null
@@ -1,19 +0,0 @@
-package net.buzzert.kordophone.backend
-
-import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.launch
-import net.buzzert.kordophone.backend.model.Conversation
-import java.net.URL
-
-class ChatRepository(baseURL: URL) {
-    private val client: APIClient = APIClient(baseURL)
-    private val apiInterface: APIInterface = client.getClient().create(APIInterface::class.java)
-
-    suspend fun getVersion(): String {
-        return apiInterface.getVersion().string()
-    }
-
-    suspend fun fetchConversations(): List<Conversation> {
-        return apiInterface.getConversations().body()!!
-    }
-}
\ No newline at end of file
diff --git a/backend/src/main/java/net/buzzert/kordophone/backend/model/Message.kt b/backend/src/main/java/net/buzzert/kordophone/backend/model/Message.kt
new file mode 100644
index 0000000..3aff5a4
--- /dev/null
+++ b/backend/src/main/java/net/buzzert/kordophone/backend/model/Message.kt
@@ -0,0 +1,18 @@
+package net.buzzert.kordophone.backend.model
+
+import com.google.gson.annotations.SerializedName
+import java.util.Date
+
+data class Message(
+    @SerializedName("text")
+    val text: String,
+
+    @SerializedName("guid")
+    val guid: String,
+
+    @SerializedName("sender")
+    val sender: String?, // optional: nil means "from me"
+
+    @SerializedName("date")
+    val date: Date,
+) {}
\ No newline at end of file
diff --git a/backend/src/main/java/net/buzzert/kordophone/backend/APIClient.kt b/backend/src/main/java/net/buzzert/kordophone/backend/server/APIClient.kt
similarity index 88%
rename from backend/src/main/java/net/buzzert/kordophone/backend/APIClient.kt
rename to backend/src/main/java/net/buzzert/kordophone/backend/server/APIClient.kt
index 06785bf..f9e325d 100644
--- a/backend/src/main/java/net/buzzert/kordophone/backend/APIClient.kt
+++ b/backend/src/main/java/net/buzzert/kordophone/backend/server/APIClient.kt
@@ -1,4 +1,4 @@
-package net.buzzert.kordophone.backend
+package net.buzzert.kordophone.backend.server
 
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
diff --git a/backend/src/main/java/net/buzzert/kordophone/backend/APIInterface.kt b/backend/src/main/java/net/buzzert/kordophone/backend/server/APIInterface.kt
similarity index 58%
rename from backend/src/main/java/net/buzzert/kordophone/backend/APIInterface.kt
rename to backend/src/main/java/net/buzzert/kordophone/backend/server/APIInterface.kt
index e5a63b2..d17a5ff 100644
--- a/backend/src/main/java/net/buzzert/kordophone/backend/APIInterface.kt
+++ b/backend/src/main/java/net/buzzert/kordophone/backend/server/APIInterface.kt
@@ -1,10 +1,12 @@
-package net.buzzert.kordophone.backend
+package net.buzzert.kordophone.backend.server
 
 import net.buzzert.kordophone.backend.model.Conversation
+import net.buzzert.kordophone.backend.model.Message
 import okhttp3.ResponseBody
 import retrofit2.Call
 import retrofit2.Response
 import retrofit2.http.GET
+import retrofit2.http.Query
 
 interface APIInterface {
     @GET("/version")
@@ -12,4 +14,7 @@ interface APIInterface {
 
     @GET("/conversations")
     suspend fun getConversations(): Response<List<Conversation>>
+
+    @GET("/messages")
+    suspend fun getMessages(@Query("guid") conversationGUID: String): Response<List<Message>>
 }
\ No newline at end of file
diff --git a/backend/src/main/java/net/buzzert/kordophone/backend/server/ChatRepository.kt b/backend/src/main/java/net/buzzert/kordophone/backend/server/ChatRepository.kt
new file mode 100644
index 0000000..19593d6
--- /dev/null
+++ b/backend/src/main/java/net/buzzert/kordophone/backend/server/ChatRepository.kt
@@ -0,0 +1,24 @@
+package net.buzzert.kordophone.backend.server
+
+import net.buzzert.kordophone.backend.model.Conversation
+import net.buzzert.kordophone.backend.model.Message
+import java.net.URL
+
+class ChatRepository(apiInterface: APIInterface) {
+    // private val client: APIClient = APIClient(baseURL)
+    // private val apiInterface: APIInterface = client.getClient().create(APIInterface::class.java)
+
+    private val apiInterface: APIInterface = apiInterface
+
+    suspend fun getVersion(): String {
+        return apiInterface.getVersion().string()
+    }
+
+    suspend fun fetchConversations(): List<Conversation> {
+        return apiInterface.getConversations().body()!!
+    }
+
+    suspend fun fetchMessages(conversation: Conversation): List<Message> {
+        return apiInterface.getMessages(conversation.guid).body()!!
+    }
+}
\ No newline at end of file
diff --git a/backend/src/main/java/net/buzzert/kordophone/backend/server/MockServer.kt b/backend/src/main/java/net/buzzert/kordophone/backend/server/MockServer.kt
new file mode 100644
index 0000000..76c8603
--- /dev/null
+++ b/backend/src/main/java/net/buzzert/kordophone/backend/server/MockServer.kt
@@ -0,0 +1,36 @@
+package net.buzzert.kordophone.backend.server
+
+import net.buzzert.kordophone.backend.model.Conversation
+import net.buzzert.kordophone.backend.model.Message
+import okhttp3.MediaType
+import okhttp3.ResponseBody
+import retrofit2.Response
+
+class MockServer: APIInterface {
+    val version = "Kordophone-2.0"
+    val conversations: MutableList<Conversation> = mutableListOf()
+    val messages: MutableMap<String, MutableList<Message>> = mutableMapOf()
+
+    override suspend fun getVersion(): ResponseBody {
+        return ResponseBody.create(MediaType.get("text/plain"), version)
+    }
+
+    override suspend fun getConversations(): Response<List<Conversation>> {
+        return Response.success(conversations)
+    }
+
+    override suspend fun getMessages(conversationGUID: String): Response<List<Message>> {
+        return Response.success(messages[conversationGUID])
+    }
+
+    fun addConversation(conversation: Conversation) {
+        conversations.add(conversation)
+    }
+
+    fun addMessagesToConversation(conversation: Conversation, messages: List<Message>) {
+        val guid = conversation.guid
+        this.messages[guid]?.addAll(messages) ?: run {
+            this.messages[guid] = messages.toMutableList()
+        }
+    }
+}
\ No newline at end of file
diff --git a/backend/src/test/java/net/buzzert/kordophone/backend/ExampleUnitTest.kt b/backend/src/test/java/net/buzzert/kordophone/backend/ExampleUnitTest.kt
index 48bbb85..ff20f21 100644
--- a/backend/src/test/java/net/buzzert/kordophone/backend/ExampleUnitTest.kt
+++ b/backend/src/test/java/net/buzzert/kordophone/backend/ExampleUnitTest.kt
@@ -1,10 +1,18 @@
 package net.buzzert.kordophone.backend
 
 import kotlinx.coroutines.runBlocking
+import net.buzzert.kordophone.backend.model.Conversation
+import net.buzzert.kordophone.backend.model.Message
+import net.buzzert.kordophone.backend.server.APIClient
+import net.buzzert.kordophone.backend.server.APIInterface
+import net.buzzert.kordophone.backend.server.ChatRepository
+import net.buzzert.kordophone.backend.server.MockServer
 import org.junit.Test
 
 import org.junit.Assert.*
 import java.net.URL
+import java.util.Date
+import java.util.UUID
 
 /**
  * Example local unit test, which will execute on the development machine (host).
@@ -12,22 +20,58 @@ import java.net.URL
  * See [testing documentation](http://d.android.com/tools/testing).
  */
 class ExampleUnitTest {
-    val repository = ChatRepository(URL("http://localhost:5738"))
+    private val mockServer = MockServer().also {
+        val conversation = Conversation(
+            date = Date(),
+            participants = listOf("james@magahern.com"),
+            displayName = null,
+            unreadCount = 0,
+            lastMessagePreview = "Hello",
+            guid = UUID.randomUUID().toString()
+        )
 
-    @Test
-    fun addition_isCorrect() {
-        assertEquals(4, 2 + 2)
+        it.addConversation(conversation)
+
+        val message = Message(
+            date = Date(),
+            text = "Hey",
+            guid = UUID.randomUUID().toString(),
+            sender = null,
+        )
+
+        it.addMessagesToConversation(conversation, listOf(message))
+    }
+
+    private val repository = ChatRepository(mockServer)
+
+    private fun getLiveRepo(host: String): ChatRepository {
+        val client = APIClient(URL(host))
+        return ChatRepository(client.getClient().create(APIInterface::class.java))
     }
 
     @Test
     fun testGetVersion() = runBlocking {
         val version = repository.getVersion()
-        println("Version: $version")
+        assertEquals(version, mockServer.version)
     }
 
     @Test
     fun testFetchConversations() = runBlocking {
         val conversations = repository.fetchConversations()
-        println("Conversations: $conversations")
+        assertEquals(conversations.count(), 1)
+
+        val conversation = conversations.first()
+        assertEquals(conversation.participants, listOf("james@magahern.com"))
     }
+
+    @Test
+    fun testFetchMessages() = runBlocking {
+        val conversations = repository.fetchConversations()
+        val messages = repository.fetchMessages(conversations.first())
+        assertEquals(messages.count(), 1)
+
+        val message = messages.first()
+        assertEquals(message.text, "Hey")
+    }
+
 }
\ No newline at end of file