reasoning presets + sampling controls (functional, not mock)

Reasoning pill (Brain icon + dropdown): 8 presets matching web
(Sofort/Aus/Minimal/Niedrig/Standard/Mittel/Hoch/Maximal).
"Standard" = no override, "Sofort" = no reasoning + throughput.
Sends reasoningEffort + preferThroughput in ChatRequest.

Sampling pill (Tune icon + popover): per-parameter toggle +
slider for Temperature (0-2), Top-P (0-1), Top-K (1-100).
Each parameter independently on/off — only enabled ones are
sent. Accent highlight when any param is enabled.

Both controls are separate from mode pills (Bild/Suche/Video)
and work in chat + search modes, matching the web layout.

ChatRequest extended with temperature/topP/topK fields.
Old ChatSpeed enum no longer used for reasoning (kept for
backward compat with ServerConfig).

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

@@ -7,6 +7,11 @@ import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.infiniteRepeatable
 import androidx.compose.animation.core.rememberInfiniteTransition
 import androidx.compose.animation.core.tween
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.DropdownMenu
+import androidx.compose.material3.DropdownMenuItem
+import androidx.compose.material3.Slider
+import androidx.compose.material3.SliderDefaults
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
@@ -82,6 +87,10 @@ import androidx.compose.material.icons.rounded.PictureAsPdf
 import androidx.compose.material.icons.rounded.VideoFile
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
+import androidx.compose.material.icons.rounded.ExpandMore
+import androidx.compose.material.icons.rounded.Psychology
+import androidx.compose.material.icons.rounded.Tune
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.graphics.ImageBitmap
 import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.layout.ContentScale
@@ -142,11 +151,25 @@ fun EmptyHero(userName: String, onPick: (String) -> Unit, modifier: Modifier = M
 }
 
 @Composable
-fun ModePillsRow(activeMode: Int?, onToggle: (Int) -> Unit, modifier: Modifier = Modifier) {
+fun ModePillsRow(
+    activeMode: Int?,
+    onToggle: (Int) -> Unit,
+    reasoningPreset: ReasoningPreset,
+    onReasoningChange: (ReasoningPreset) -> Unit,
+    samplingPrefs: SamplingPrefs,
+    onSamplingChange: (SamplingPrefs) -> Unit,
+    modifier: Modifier = Modifier,
+) {
     val cs = MaterialTheme.colorScheme
     val isDark = isSystemInDarkTheme()
     val accent = LocalKaizenAccent.current
 
+    var showReasoningMenu by remember { mutableStateOf(false) }
+    var showSamplingPopup by remember { mutableStateOf(false) }
+
+    val inactiveBg = if (isDark) cs.surface.copy(alpha = 0.35f) else cs.surface.copy(alpha = 0.55f)
+    val inactiveBorder = if (isDark) Color.White.copy(alpha = 0.08f) else Color.Black.copy(alpha = 0.06f)
+
     Row(
         modifier
             .fillMaxWidth()
@@ -154,19 +177,87 @@ fun ModePillsRow(activeMode: Int?, onToggle: (Int) -> Unit, modifier: Modifier =
             .padding(horizontal = 14.dp),
         horizontalArrangement = Arrangement.spacedBy(8.dp),
     ) {
-        chatModes.filter { it.labelRes != R.string.mode_standard }.forEach { mode ->
+        // Reasoning pill (dropdown)
+        Box {
+            Row(
+                Modifier
+                    .clip(KaizenShapes.pill)
+                    .background(inactiveBg)
+                    .border(1.2.dp, inactiveBorder, KaizenShapes.pill)
+                    .clickable { showReasoningMenu = true }
+                    .padding(horizontal = 13.dp, vertical = 8.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Icon(Icons.Rounded.Psychology, null, tint = cs.onSurfaceVariant, modifier = Modifier.size(16.dp))
+                Spacer(Modifier.width(6.dp))
+                Text(stringResource(reasoningPreset.label), color = cs.onSurfaceVariant, fontSize = 13.sp, fontWeight = FontWeight.Medium)
+                Spacer(Modifier.width(4.dp))
+                Icon(Icons.Rounded.ExpandMore, null, tint = cs.onSurfaceVariant.copy(alpha = 0.5f), modifier = Modifier.size(14.dp))
+            }
+            DropdownMenu(expanded = showReasoningMenu, onDismissRequest = { showReasoningMenu = false }) {
+                ReasoningPreset.entries.forEach { preset ->
+                    DropdownMenuItem(
+                        text = {
+                            Text(
+                                stringResource(preset.label),
+                                fontSize = 14.sp,
+                                color = if (preset == reasoningPreset) accent.primary else cs.onBackground,
+                                fontWeight = if (preset == reasoningPreset) FontWeight.SemiBold else FontWeight.Normal,
+                            )
+                        },
+                        onClick = { onReasoningChange(preset); showReasoningMenu = false },
+                    )
+                }
+            }
+        }
+
+        // Sampling pill (popover)
+        Box {
+            val anyEnabled = samplingPrefs.temperature.enabled || samplingPrefs.topP.enabled || samplingPrefs.topK.enabled
+            Row(
+                Modifier
+                    .clip(KaizenShapes.pill)
+                    .background(if (anyEnabled) accent.primary.copy(alpha = if (isDark) 0.18f else 0.14f) else inactiveBg)
+                    .border(1.2.dp, if (anyEnabled) accent.primary.copy(alpha = 0.4f) else inactiveBorder, KaizenShapes.pill)
+                    .clickable { showSamplingPopup = !showSamplingPopup }
+                    .padding(horizontal = 13.dp, vertical = 8.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Icon(Icons.Rounded.Tune, null, tint = if (anyEnabled) accent.primary else cs.onSurfaceVariant, modifier = Modifier.size(16.dp))
+                Spacer(Modifier.width(6.dp))
+                Text(stringResource(R.string.mode_sampling), color = if (anyEnabled) cs.onBackground else cs.onSurfaceVariant, fontSize = 13.sp, fontWeight = FontWeight.Medium)
+                Spacer(Modifier.width(4.dp))
+                Icon(Icons.Rounded.ExpandMore, null, tint = cs.onSurfaceVariant.copy(alpha = 0.5f), modifier = Modifier.size(14.dp))
+            }
+            DropdownMenu(expanded = showSamplingPopup, onDismissRequest = { showSamplingPopup = false }) {
+                Column(Modifier.padding(horizontal = 16.dp, vertical = 8.dp).width(240.dp)) {
+                    SamplingRow(
+                        label = stringResource(R.string.sampling_temperature),
+                        param = samplingPrefs.temperature, min = 0f, max = 2f, steps = 200,
+                        onUpdate = { onSamplingChange(samplingPrefs.copy(temperature = it)) },
+                    )
+                    Spacer(Modifier.height(12.dp))
+                    SamplingRow(
+                        label = stringResource(R.string.sampling_top_p),
+                        param = samplingPrefs.topP, min = 0f, max = 1f, steps = 100,
+                        onUpdate = { onSamplingChange(samplingPrefs.copy(topP = it)) },
+                    )
+                    Spacer(Modifier.height(12.dp))
+                    SamplingRow(
+                        label = stringResource(R.string.sampling_top_k),
+                        param = samplingPrefs.topK, min = 1f, max = 100f, steps = 99,
+                        onUpdate = { onSamplingChange(samplingPrefs.copy(topK = it)) },
+                    )
+                }
+            }
+        }
+
+        // Mode pills (Bild, Suche, Video, Audio)
+        chatModes.filter { it.labelRes != R.string.mode_standard && it.labelRes != R.string.mode_sampling }.forEach { mode ->
             val label = stringResource(mode.labelRes)
             val active = mode.labelRes == activeMode
-            val backgroundFill = if (active) {
+            val backgroundFill = if (active) accent.primary.copy(alpha = if (isDark) 0.18f else 0.14f) else inactiveBg
-                accent.primary.copy(alpha = if (isDark) 0.18f else 0.14f)
+            val borderColor = if (active) accent.primary.copy(alpha = 0.4f) else inactiveBorder
-            } else {
-                if (isDark) cs.surface.copy(alpha = 0.35f) else cs.surface.copy(alpha = 0.55f)
-            }
-            val borderColor = if (active) {
-                accent.primary.copy(alpha = 0.4f)
-            } else {
-                if (isDark) Color.White.copy(alpha = 0.08f) else Color.Black.copy(alpha = 0.06f)
-            }
 
             Row(
                 Modifier
@@ -185,6 +276,28 @@ fun ModePillsRow(activeMode: Int?, onToggle: (Int) -> Unit, modifier: Modifier =
     }
 }
 
+@Composable
+private fun SamplingRow(label: String, param: SamplingParam, min: Float, max: Float, steps: Int, onUpdate: (SamplingParam) -> Unit) {
+    val cs = MaterialTheme.colorScheme
+    val accent = LocalKaizenAccent.current
+    Row(verticalAlignment = Alignment.CenterVertically) {
+        Checkbox(checked = param.enabled, onCheckedChange = { onUpdate(param.copy(enabled = it)) }, modifier = Modifier.size(20.dp))
+        Spacer(Modifier.width(8.dp))
+        Text(label, color = cs.onBackground, fontSize = 13.sp, modifier = Modifier.weight(1f))
+        Text(
+            if (max > 2f) param.value.toInt().toString() else "%.2f".format(param.value),
+            color = cs.onSurfaceVariant, fontSize = 12.sp,
+        )
+    }
+    Slider(
+        value = param.value, onValueChange = { onUpdate(param.copy(value = it)) },
+        valueRange = min..max, steps = steps,
+        enabled = param.enabled,
+        colors = SliderDefaults.colors(thumbColor = accent.primary, activeTrackColor = accent.primary),
+        modifier = Modifier.fillMaxWidth(),
+    )
+}
+
 @Composable
 fun MessageRow(message: Message) {
     val cs = MaterialTheme.colorScheme

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

@@ -18,6 +18,25 @@ import dev.kaizen.app.net.ToolEvent
 
 enum class Role { User, Assistant }
 
+enum class ReasoningPreset(val label: Int, val effort: String?, val throughput: Boolean) {
+    Instant(R.string.reasoning_instant, "none", true),
+    None(R.string.reasoning_none, "none", false),
+    Minimal(R.string.reasoning_minimal, "minimal", false),
+    Low(R.string.reasoning_low, "low", false),
+    Standard(R.string.reasoning_standard, null, false),
+    Medium(R.string.reasoning_medium, "medium", false),
+    High(R.string.reasoning_high, "high", false),
+    XHigh(R.string.reasoning_xhigh, "xhigh", false),
+}
+
+data class SamplingParam(val enabled: Boolean, val value: Float)
+
+data class SamplingPrefs(
+    val temperature: SamplingParam = SamplingParam(false, 1f),
+    val topP: SamplingParam = SamplingParam(false, 1f),
+    val topK: SamplingParam = SamplingParam(false, 40f),
+)
+
 data class Message(
     val id: Long,
     val role: Role,

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

@@ -98,6 +98,8 @@ fun ChatScreen(
     var isStreaming by remember { mutableStateOf(false) }
     var nextId by remember { mutableStateOf(0L) }
     var activeMode by remember { mutableStateOf<Int?>(null) }
+    var reasoningPreset by remember { mutableStateOf(ReasoningPreset.Standard) }
+    var samplingPrefs by remember { mutableStateOf(SamplingPrefs()) }
 
     // Navigation State
     var currentScreen by remember { mutableStateOf(AppScreen.Chat) }
@@ -337,9 +339,14 @@ fun ChatScreen(
                 } else null
 
                 KaizenApi.chat(
-                    cfg.baseUrl, cfg.token, cfg.model, history, cfg.speed,
+                    cfg.baseUrl, cfg.token, cfg.model, history,
+                    reasoningEffort = reasoningPreset.effort,
+                    preferThroughput = reasoningPreset.throughput,
                     attachments = uploadedAtts.takeIf { it.isNotEmpty() },
                     webSearch = activeMode == R.string.mode_search,
+                    temperature = samplingPrefs.temperature.takeIf { it.enabled }?.value,
+                    topP = samplingPrefs.topP.takeIf { it.enabled }?.value,
+                    topK = samplingPrefs.topK.takeIf { it.enabled }?.value?.toInt(),
                 ).collect { state ->
                     val idx = messages.indexOfLast { it.id == assistantId }
                     if (idx < 0) return@collect
@@ -627,6 +634,10 @@ fun ChatScreen(
                                     activeMode = if (activeMode == mode) null else mode
                                     haptics.tick()
                                 },
+                                reasoningPreset = reasoningPreset,
+                                onReasoningChange = { reasoningPreset = it; haptics.tick() },
+                                samplingPrefs = samplingPrefs,
+                                onSamplingChange = { samplingPrefs = it },
                             )
                             Spacer(Modifier.height(10.dp))
                             ChatInput(

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

@@ -36,6 +36,9 @@ import java.util.concurrent.TimeUnit
     val preferThroughput: Boolean? = null,
     val attachments: List<Attachment>? = null,
     val webSearch: Boolean? = null,
+    val temperature: Float? = null,
+    val topP: Float? = null,
+    val topK: Int? = null,
 )
 
 /** One entry from GET /api/v1/models — the picker's row. `provider == "vertex"` drives the hoster badge. */
@@ -439,18 +442,25 @@ object KaizenApi {
         token: String,
         model: String,
         messages: List<WireMessage>,
-        speed: ChatSpeed = ChatSpeed.Normal,
+        reasoningEffort: String? = null,
+        preferThroughput: Boolean = false,
         attachments: List<Attachment>? = null,
         webSearch: Boolean = false,
+        temperature: Float? = null,
+        topP: Float? = null,
+        topK: Int? = null,
     ): Flow<StreamState> = flow {
         val payload = json.encodeToString(
             ChatRequest(
                 model = model,
                 messages = messages,
-                reasoningEffort = speed.reasoningEffort,
+                reasoningEffort = reasoningEffort,
-                preferThroughput = if (speed.preferThroughput) true else null,
+                preferThroughput = if (preferThroughput) true else null,
                 attachments = attachments?.takeIf { it.isNotEmpty() },
                 webSearch = if (webSearch) true else null,
+                temperature = temperature,
+                topP = topP,
+                topK = topK,
             ),
         ).toRequestBody(jsonMedia)
         val req = Request.Builder()

app/src/main/res/values-en/strings.xml

@@ -74,6 +74,21 @@
     <string name="sidebar_confirm">Confirm</string>
     <string name="sidebar_save">Save</string>
 
+    <!-- Reasoning presets -->
+    <string name="reasoning_instant">Instant</string>
+    <string name="reasoning_none">Off</string>
+    <string name="reasoning_minimal">Minimal</string>
+    <string name="reasoning_low">Low</string>
+    <string name="reasoning_standard">Standard</string>
+    <string name="reasoning_medium">Medium</string>
+    <string name="reasoning_high">High</string>
+    <string name="reasoning_xhigh">Maximum</string>
+
+    <!-- Sampling -->
+    <string name="sampling_temperature">Temperature</string>
+    <string name="sampling_top_p">Top-P</string>
+    <string name="sampling_top_k">Top-K</string>
+
     <!-- Biometric unlock -->
     <string name="biometric_title">Unlock Chat</string>
     <string name="biometric_subtitle">Confirm your identity</string>

app/src/main/res/values/strings.xml

@@ -76,6 +76,21 @@
     <string name="sidebar_confirm">Bestätigen</string>
     <string name="sidebar_save">Speichern</string>
 
+    <!-- Reasoning presets -->
+    <string name="reasoning_instant">Sofort</string>
+    <string name="reasoning_none">Aus</string>
+    <string name="reasoning_minimal">Minimal</string>
+    <string name="reasoning_low">Niedrig</string>
+    <string name="reasoning_standard">Standard</string>
+    <string name="reasoning_medium">Mittel</string>
+    <string name="reasoning_high">Hoch</string>
+    <string name="reasoning_xhigh">Maximal</string>
+
+    <!-- Sampling -->
+    <string name="sampling_temperature">Temperatur</string>
+    <string name="sampling_top_p">Top-P</string>
+    <string name="sampling_top_k">Top-K</string>
+
     <!-- Biometric unlock -->
     <string name="biometric_title">Chat entsperren</string>
     <string name="biometric_subtitle">Bestätige deine Identität</string>