app/build.gradle.kts

@@ -50,7 +50,6 @@ dependencies {
     implementation(libs.androidx.compose.ui.tooling.preview)
     implementation(libs.androidx.core.ktx)
     implementation(libs.androidx.lifecycle.runtime.ktx)
-    implementation(libs.androidx.lifecycle.runtime.compose)
     // Networking + JSON for the real backend (POST /api/v1/auth/token, /chat, /me)
     implementation(libs.okhttp)
     implementation(libs.kotlinx.serialization.json)

app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt

@@ -34,14 +34,12 @@ import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
-import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
-import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -49,10 +47,7 @@ import androidx.compose.ui.draw.shadow
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalConfiguration
-import androidx.compose.material3.Text
-import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
 import dev.kaizen.app.haptics.rememberHaptics
 import dev.kaizen.app.net.ChatHttpException
 import dev.kaizen.app.net.ChatSpeed
@@ -64,8 +59,6 @@ import dev.kaizen.app.net.SessionViewModel
 import dev.kaizen.app.net.WireMessage
 import dev.kaizen.app.settings.SettingsScreen
 import dev.kaizen.app.settings.SettingsViewModel
-import androidx.lifecycle.compose.LifecycleResumeEffect
-import kotlinx.coroutines.async
 import kotlinx.coroutines.launch
 
 // Screen enumeration for modular state-driven navigation (Zero Technical Debt)
@@ -107,40 +100,20 @@ fun ChatScreen(
     var conversationId by remember { mutableStateOf<String?>(null) }
     var conversations by remember { mutableStateOf<List<ConversationSummary>>(emptyList()) }
 
-    var loadError by remember { mutableStateOf<String?>(null) }
-
     LaunchedEffect(session.config?.baseUrl, session.config?.token) {
         val cfg = session.config ?: return@LaunchedEffect
-        loadError = null
+        // Fetch fresh models from server and cache them locally if successful
         val fetchedModels = KaizenApi.fetchModels(cfg.baseUrl, cfg.token)
-        if (fetchedModels != null) {
+        if (fetchedModels.isNotEmpty()) {
             models = fetchedModels
-            if (fetchedModels.isNotEmpty()) session.store.saveModelsCache(fetchedModels)
+            session.store.saveModelsCache(fetchedModels)
         }
-        val fetchedConvos = KaizenApi.fetchConversations(cfg.baseUrl, cfg.token)
+        conversations = KaizenApi.fetchConversations(cfg.baseUrl, cfg.token)
-        if (fetchedConvos != null) {
-            conversations = fetchedConvos
-        }
-        if (fetchedModels == null || fetchedConvos == null) {
-            loadError = "Verbindung zum Server fehlgeschlagen"
-        }
-    }
-
-    // Warm the HTTP/2 connection pool on every app resume (covers background → foreground
-    // after OkHttp's 5-minute keep-alive has expired). On first composition, the
-    // LaunchedEffect above already warms the pool via fetchModels/fetchConversations.
-    LifecycleResumeEffect(session.config?.baseUrl) {
-        session.config?.let { cfg ->
-            scope.launch { KaizenApi.prewarm(cfg.baseUrl) }
-        }
-        onPauseOrDispose { }
     }
 
     fun refreshConversations() {
         val cfg = session.config ?: return
-        scope.launch {
+        scope.launch { conversations = KaizenApi.fetchConversations(cfg.baseUrl, cfg.token) }
-            KaizenApi.fetchConversations(cfg.baseUrl, cfg.token)?.let { conversations = it }
-        }
     }
 
     /** Start a fresh chat — drops the active conversation, the next send creates a new one. */
@@ -195,19 +168,17 @@ fun ChatScreen(
             haptics.thinkingStart()
             var sawContent = false
             try {
-                // Launch conversation creation in parallel — the chat stream does not
+                // Ensure a server conversation exists before the exchange is persisted.
-                // need a conversation id, only the post-stream persistence does. This
+                val convId = conversationId ?: KaizenApi.createConversation(cfg.baseUrl, cfg.token)?.also {
-                // eliminates a full network RTT from the TTFT on new chats.
+                    conversationId = it
-                val convIdDeferred = if (conversationId == null) {
+                }
-                    async { KaizenApi.createConversation(cfg.baseUrl, cfg.token) }
-                } else null
 
                 KaizenApi.chat(cfg.baseUrl, cfg.token, cfg.model, history, cfg.speed).collect { visible ->
                     val idx = messages.indexOfLast { it.id == assistantId }
                     if (idx < 0) return@collect
                     if (!sawContent && visible.isNotEmpty()) {
                         sawContent = true
-                        haptics.responseStart()
+                        haptics.responseStart() // the answer begins (reasoning may have streamed first)
                     }
                     messages[idx] = messages[idx].copy(
                         thinking = if (sawContent) false else messages[idx].thinking,
@@ -218,9 +189,6 @@ fun ChatScreen(
                 val finalContent = if (idx >= 0) messages[idx].content else ""
                 if (idx >= 0) messages[idx] = messages[idx].copy(streaming = false, thinking = false)
 
-                // Await the conversation id — the create ran in parallel with the stream
-                val convId = convIdDeferred?.await()?.also { conversationId = it } ?: conversationId
-
                 // Persist the exchange (best-effort); auto-title + sidebar refresh on a new conversation.
                 if (convId != null && finalContent.isNotEmpty()) {
                     val saved = KaizenApi.saveMessages(
@@ -235,15 +203,11 @@ fun ChatScreen(
                 }
             } catch (e: Exception) {
                 val idx = messages.indexOfLast { it.id == assistantId }
-                if (idx >= 0) {
+                if (idx >= 0) messages[idx] = messages[idx].copy(
-                    val existing = messages[idx].content
-                    val errorSuffix = "\n\n⚠ ${chatErrorText(e)}"
-                    messages[idx] = messages[idx].copy(
                     streaming = false,
                     thinking = false,
-                        content = if (existing.isNotBlank()) existing + errorSuffix else chatErrorText(e),
+                    content = chatErrorText(e),
                 )
-                }
             } finally {
                 isStreaming = false
                 haptics.responseEnd()
@@ -251,18 +215,11 @@ fun ChatScreen(
         }
     }
 
-    // Auto-scroll: isolated from the main composition via derivedStateOf + snapshotFlow.
+    // Keep pinned to the bottom as the stream grows
-    // Only the snapshot read triggers work — the root composable does NOT recompose on
+    val lastLength = messages.lastOrNull()?.content?.length ?: 0
-    // every streamed character, eliminating the recomposition storm that previously
+    LaunchedEffect(messages.size, lastLength) {
-    // re-drew the entire screen (top bar, input, background) at 60+ fps.
-    val autoScrollKey by remember {
-        derivedStateOf { messages.size to (messages.lastOrNull()?.content?.length ?: 0) }
-    }
-    LaunchedEffect(Unit) {
-        snapshotFlow { autoScrollKey }.collect {
         if (messages.isNotEmpty()) listState.scrollToItem(messages.lastIndex)
     }
-    }
 
     // Single source of truth Screen routing
     when (currentScreen) {
@@ -384,27 +341,6 @@ fun ChatScreen(
                             )
                         }
 
-                        // Error banner when initial data load fails
-                        if (loadError != null) {
-                            Box(
-                                modifier = Modifier
-                                    .align(Alignment.TopCenter)
-                                    .statusBarsPadding()
-                                    .padding(top = 62.dp, start = 24.dp, end = 24.dp)
-                                    .clip(RoundedCornerShape(12.dp))
-                                    .background(Color(0xFFDC2626).copy(alpha = 0.15f))
-                                    .border(1.dp, Color(0xFFDC2626).copy(alpha = 0.3f), RoundedCornerShape(12.dp))
-                                    .padding(horizontal = 14.dp, vertical = 8.dp),
-                            ) {
-                                Text(
-                                    loadError!!,
-                                    color = Color(0xFFDC2626),
-                                    fontSize = 12.sp,
-                                    fontWeight = FontWeight.Medium,
-                                )
-                            }
-                        }
-
                         // 3. Floating Bottom Control Dock (responsive centering and clear bottom margins)
                         Column(
                             modifier = Modifier

app/src/main/java/dev/kaizen/app/chat/ModelSheet.kt

@@ -69,7 +69,7 @@ private fun groupFor(m: KaizenModel): String = when {
 private fun buildGroups(models: List<KaizenModel>, favorites: Set<String>, query: String): List<ModelGroup> {
     val q = query.trim().lowercase()
     val filtered = if (q.isEmpty()) models
-    else models.filter { it.name?.lowercase()?.contains(q) == true || it.id.lowercase().contains(q) }
+    else models.filter { it.name.lowercase().contains(q) || it.id.lowercase().contains(q) }
 
     val groups = mutableListOf<ModelGroup>()
     val favs = filtered.filter { it.id in favorites }
@@ -267,7 +267,7 @@ private fun ModelRow(
         // Model Name & Clean Technical ID
         Column(modifier = Modifier.weight(1f)) {
             Text(
-                model.name ?: model.id,
+                model.name,
                 color = cs.onBackground,
                 fontSize = 15.sp,
                 fontWeight = if (selected) FontWeight.SemiBold else FontWeight.Medium,

app/src/main/java/dev/kaizen/app/net/KaizenApi.kt

@@ -13,9 +13,8 @@ import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
-import android.util.Log
+import java.io.ByteArrayOutputStream
 import java.io.IOException
-import java.io.InputStreamReader
 import java.util.concurrent.TimeUnit
 
 // --- Wire DTOs (additive v1 contract — ignoreUnknownKeys tolerates new fields) ---
@@ -35,7 +34,7 @@ import java.util.concurrent.TimeUnit
 @Serializable
 data class KaizenModel(
     val id: String,
-    val name: String? = null,
+    val name: String,
     val provider: String? = null,
 )
 
@@ -96,8 +95,6 @@ class ChatHttpException(val code: Int) : IOException("chat failed: HTTP $code")
  */
 object KaizenApi {
 
-    private const val TAG = "KaizenApi"
-
     private val client = OkHttpClient.Builder()
         .connectTimeout(15, TimeUnit.SECONDS)
         .readTimeout(0, TimeUnit.SECONDS) // streaming chat — never time out a healthy stream
@@ -140,13 +137,13 @@ object KaizenApi {
                     if (!resp.isSuccessful) return@use null
                     json.decodeFromString<MeResponse>(resp.body!!.string()).defaultModel
                 }
-            } catch (e: Exception) {
+            } catch (e: IOException) {
                 null
             }
         }
 
-    /** GET /api/v1/models — the full model catalog for the picker. Returns null on failure (with logged reason). */
+    /** GET /api/v1/models — the full model catalog for the picker (best-effort, empty on any failure). */
-    suspend fun fetchModels(baseUrl: String, token: String): List<KaizenModel>? =
+    suspend fun fetchModels(baseUrl: String, token: String): List<KaizenModel> =
         withContext(Dispatchers.IO) {
             val req = Request.Builder()
                 .url("$baseUrl/api/v1/models")
@@ -154,20 +151,16 @@ object KaizenApi {
                 .build()
             try {
                 client.newCall(req).execute().use { resp ->
-                    if (!resp.isSuccessful) {
+                    if (!resp.isSuccessful) return@use emptyList()
-                        Log.w(TAG, "fetchModels: HTTP ${resp.code} from $baseUrl")
-                        return@use null
-                    }
                     json.decodeFromString<ModelsResponse>(resp.body!!.string()).models
                 }
-            } catch (e: Exception) {
+            } catch (e: IOException) {
-                Log.w(TAG, "fetchModels: ${e.javaClass.simpleName}: ${e.message}")
+                emptyList()
-                null
             }
         }
 
-    /** GET /api/v1/conversations — the sidebar list. Returns null on failure (with logged reason). */
+    /** GET /api/v1/conversations — the sidebar list (best-effort, empty on any failure). */
-    suspend fun fetchConversations(baseUrl: String, token: String): List<ConversationSummary>? =
+    suspend fun fetchConversations(baseUrl: String, token: String): List<ConversationSummary> =
         withContext(Dispatchers.IO) {
             val req = Request.Builder()
                 .url("$baseUrl/api/v1/conversations")
@@ -175,15 +168,11 @@ object KaizenApi {
                 .build()
             try {
                 client.newCall(req).execute().use { resp ->
-                    if (!resp.isSuccessful) {
+                    if (!resp.isSuccessful) return@use emptyList()
-                        Log.w(TAG, "fetchConversations: HTTP ${resp.code} from $baseUrl")
-                        return@use null
-                    }
                     json.decodeFromString<ConversationsResponse>(resp.body!!.string()).conversations
                 }
-            } catch (e: Exception) {
+            } catch (e: IOException) {
-                Log.w(TAG, "fetchConversations: ${e.javaClass.simpleName}: ${e.message}")
+                emptyList()
-                null
             }
         }
 
@@ -198,14 +187,10 @@ object KaizenApi {
                 .build()
             try {
                 client.newCall(req).execute().use { resp ->
-                    if (!resp.isSuccessful) {
+                    if (!resp.isSuccessful) return@use null
-                        Log.w(TAG, "createConversation: HTTP ${resp.code}")
-                        return@use null
-                    }
                     json.decodeFromString<CreatedConversation>(resp.body!!.string()).id
                 }
-            } catch (e: Exception) {
+            } catch (e: IOException) {
-                Log.w(TAG, "createConversation: ${e.javaClass.simpleName}: ${e.message}")
                 null
             }
         }
@@ -219,14 +204,10 @@ object KaizenApi {
                 .build()
             try {
                 client.newCall(req).execute().use { resp ->
-                    if (!resp.isSuccessful) {
+                    if (!resp.isSuccessful) return@use emptyList()
-                        Log.w(TAG, "fetchMessages($id): HTTP ${resp.code}")
-                        return@use emptyList()
-                    }
                     json.decodeFromString<ConversationDetail>(resp.body!!.string()).messages
                 }
-            } catch (e: Exception) {
+            } catch (e: IOException) {
-                Log.w(TAG, "fetchMessages($id): ${e.javaClass.simpleName}: ${e.message}")
                 emptyList()
             }
         }
@@ -241,12 +222,8 @@ object KaizenApi {
                 .header("Authorization", "Bearer $token")
                 .build()
             try {
-                client.newCall(req).execute().use { resp ->
+                client.newCall(req).execute().use { resp -> resp.isSuccessful }
-                    if (!resp.isSuccessful) Log.w(TAG, "saveMessages($id): HTTP ${resp.code}")
+            } catch (e: IOException) {
-                    resp.isSuccessful
-                }
-            } catch (e: Exception) {
-                Log.w(TAG, "saveMessages($id): ${e.javaClass.simpleName}: ${e.message}")
                 false
             }
         }
@@ -261,7 +238,7 @@ object KaizenApi {
                 .build()
             try {
                 client.newCall(req).execute().use { }
-            } catch (e: Exception) {
+            } catch (e: IOException) {
                 // best-effort: a missing title is cosmetic
             }
         }
@@ -269,12 +246,8 @@ object KaizenApi {
     /**
      * POST /api/v1/chat — streams the assistant reply. Emits the cumulative *visible*
      * text after each network chunk (sentinels stripped), so the caller just assigns
-     * it to the message content.
+     * it to the message content. The full byte buffer is re-decoded each chunk to keep
-     *
+     * UTF-8 multi-byte sequences that span chunk boundaries intact.
-     * Uses [InputStreamReader] for correct UTF-8 multi-byte boundary handling and
-     * [StreamConsumer.Incremental] for O(chunk-size) parsing — each character is
-     * visited exactly once across the entire stream, avoiding the O(N²) cost of
-     * re-decoding and re-scanning the full buffer on every chunk.
      *
      * [speed] maps to the additive `reasoningEffort`/`preferThroughput` v1 fields.
      */
@@ -307,29 +280,14 @@ object KaizenApi {
         }
 
         resp.body!!.byteStream().use { input ->
-            val reader = InputStreamReader(input, Charsets.UTF_8)
+            val raw = ByteArrayOutputStream()
-            val consumer = StreamConsumer.Incremental()
+            val buf = ByteArray(4096)
-            val charBuf = CharArray(4096)
             while (true) {
-                val n = reader.read(charBuf)
+                val n = input.read(buf)
                 if (n == -1) break
-                emit(consumer.append(charBuf, 0, n))
+                raw.write(buf, 0, n)
+                emit(StreamConsumer.visibleText(raw.toByteArray().decodeToString()))
             }
         }
     }.flowOn(Dispatchers.IO)
-
-    /**
-     * Warm the OkHttp HTTP/2 connection pool against [baseUrl]. Fire-and-forget
-     * GET to the unauth `/api/v1/meta` endpoint — eliminates the cold TCP/TLS
-     * handshake (~150-300ms on mobile) from the first real request after app
-     * start or background resume.
-     */
-    suspend fun prewarm(baseUrl: String) = withContext(Dispatchers.IO) {
-        try {
-            val req = Request.Builder().url("$baseUrl/api/v1/meta").build()
-            client.newCall(req).execute().close()
-        } catch (_: Exception) {
-            // best-effort — a failed prewarm just means the first real request pays the cold cost
-        }
-    }
 }

gradle/libs.versions.toml

@@ -21,7 +21,6 @@ junit = { group = "junit", name = "junit", version.ref = "junit" }
 androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
-androidx-lifecycle-runtime-compose = { group = "androidx.lifecycle", name = "lifecycle-runtime-compose", version.ref = "lifecycleRuntimeKtx" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
 androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
 androidx-compose-ui = { group = "androidx.compose.ui", name = "ui" }