default model

src/workspaces/officerdev/src/apps/Chat/ChatLauncher/ChatLauncher.tsx

@@ -112,6 +112,7 @@ export function ChatLauncher({
         model={selectedModel}
         isConnected={true}
         isGenerating={false}
+        hasStarted={false}
       />
 
       <WebpageDialog open={urlDialogOpen} onOpenChange={setUrlDialogOpen} onSubmit={attachWebpage} />

src/workspaces/officerdev/src/apps/Chat/EmbeddableChat/useEmbeddableChat.ts

@@ -35,6 +35,7 @@ export function useEmbeddableChat(params: UseEmbeddableChatParams) {
     sessionId,
     model,
     selectedModel,
+    hasStarted,
     setSelectedModel,
     sendPrompt,
     stopGeneration,
@@ -170,6 +171,7 @@ export function useEmbeddableChat(params: UseEmbeddableChatParams) {
     sessionId,
     model,
     selectedModel,
+    hasStarted,
     setSelectedModel,
     sendPrompt,
     stopGeneration,

src/workspaces/officerdev/src/apps/Chat/components/InputArea.tsx

@@ -28,6 +28,7 @@ export const InputArea = ({ manager }: InputAreaProps) => {
     selectedModel,
     setSelectedModel,
     model,
+    hasStarted,
     attachments,
     attachWebpage,
     attachImage,
@@ -94,6 +95,7 @@ export const InputArea = ({ manager }: InputAreaProps) => {
         model={model}
         isConnected={isConnected}
         isGenerating={isGenerating}
+        hasStarted={hasStarted}
       />
 
       <WebpageDialog open={urlDialogOpen} onOpenChange={setUrlDialogOpen} onSubmit={attachWebpage} />

src/workspaces/officerdev/src/apps/Chat/components/ModelSelector.tsx

@@ -27,6 +27,7 @@ type ModelSelectorProps = {
   model: string | null;
   isConnected: boolean;
   isGenerating: boolean;
+  hasStarted: boolean;
 };
 
 export function ModelSelector({
@@ -37,23 +38,40 @@ export function ModelSelector({
   model,
   isConnected,
   isGenerating,
+  hasStarted,
 }: ModelSelectorProps) {
   const providers = [...new Set(availableModels.map((m) => m.provider).filter(Boolean))] as string[];
 
-  const activeProvider = availableModels.find((m) => m.id === selectedModel)?.provider ?? providers[0];
+  // Determine which model to display: selectedModel takes precedence, then model (from server), then fallback
+  const displayModel = selectedModel || model;
+  
+  const activeProvider = availableModels.find((m) => m.id === displayModel)?.provider ?? providers[0];
   const providerModels = availableModels.filter((m) => m.provider === activeProvider);
   const fallbackModelId = providerModels[0]?.id ?? null;
 
+  // Lock after session has started
+  const isLocked = hasStarted || isGenerating || !isConnected;
+
   const handleProviderClick = (provider: string) => {
+    if (isLocked) return;
     const firstModel = availableModels.find((m) => m.provider === provider);
     if (firstModel) onModelChange(firstModel.id);
   };
 
   const displayName = (provider: string) => PROVIDER_DISPLAY[provider] ?? provider;
 
+  // Get display text for the model
+  const getModelDisplayText = () => {
+    if (displayModel) {
+      const found = availableModels.find((m) => m.id === displayModel);
+      return found?.name || displayModel;
+    }
+    return 'Select model';
+  };
+
   return (
     <div className="flex items-center justify-between mt-2">
-      {messages.length > 0 ? (
+      {isLocked ? (
         <span className="rounded-md bg-duck-dark/80 px-3 py-1 text-xs font-medium text-white">
           {activeProvider ? displayName(activeProvider) : 'Pi'}
         </span>
@@ -77,9 +95,9 @@ export function ModelSelector({
       <div className="text-xs text-duck-dark/50">
         {providerModels.length > 0 ? (
           <Select
-            value={selectedModel ?? fallbackModelId ?? undefined}
-            onValueChange={(v) => onModelChange(v)}
-            disabled={isGenerating || !isConnected}
+            value={displayModel ?? fallbackModelId ?? undefined}
+            onValueChange={(v) => !isLocked && onModelChange(v)}
+            disabled={isLocked}
           >
             <SelectTrigger className="h-auto border-0 bg-transparent p-0 text-xs text-duck-dark/50 shadow-none focus:ring-0 gap-1 cursor-pointer">
               <SelectValue />
@@ -93,7 +111,7 @@ export function ModelSelector({
             </SelectContent>
           </Select>
         ) : (
-          <span>{model ?? 'Pi'}</span>
+          <span>{getModelDisplayText()}</span>
         )}
       </div>
     </div>

src/workspaces/officerdev/src/hooks/usePiChat.ts

@@ -1,6 +1,7 @@
 import { useState, useEffect, useRef } from 'react';
 import { useChatWebSocket } from 'hooks/useChatWebSocket';
 import { useChatSessions } from 'state/useChatSessions';
+import { useSettings } from 'state/useSettings';
 import type { ChatMessage, ServerMessage, TaskInfo, Message } from '../apps/Chat/types';
 
 const SAVE_DEBOUNCE_MS = 1000;
@@ -27,6 +28,19 @@ export function usePiChat(initialSessionId?: string, initialModel?: string | nul
   const [selectedModel, setSelectedModel] = useState<string | null>(initialModel ?? null);
   const [cwd, setCwd] = useState<string | null>(null);
 
+  // Track if session has started (first message sent)
+  const [hasStarted, setHasStarted] = useState(false);
+
+  // Get user settings for default model
+  const { settings } = useSettings();
+
+  // Set default model from settings when starting a new chat (no initialSessionId, no initialModel)
+  useEffect(() => {
+    if (!initialSessionId && !initialModel && settings?.chat?.defaultModel) {
+      setSelectedModel(settings.chat.defaultModel);
+    }
+  }, [initialSessionId, initialModel, settings]);
+
   const streamingRef = useRef('');
   const rafRef = useRef<number | null>(null);
   const sessionIdRef = useRef<string | null>(initialSessionId ?? null);
@@ -238,6 +252,11 @@ export function usePiChat(initialSessionId?: string, initialModel?: string | nul
     cwdParam?: { root?: string; path: string },
     groupSlug?: string | null,
   ) {
+    // Mark session as started on first message
+    if (!hasStarted) {
+      setHasStarted(true);
+    }
+    
     setMessages((prev) => [...prev, { role: 'user', text, ...(images?.length ? { images } : {}) }]);
     setIsGenerating(true);
     streamingRef.current = '';
@@ -277,6 +296,7 @@ export function usePiChat(initialSessionId?: string, initialModel?: string | nul
     sessionId,
     model,
     selectedModel,
+    hasStarted,
     cwd,
     setSelectedModel,
     sendPrompt,