perf: Optimize session startup, add prompt timing and clean up scripts (#991)

Author: charlesvien

apps/mobile/package.json

@@ -4,10 +4,18 @@
   "main": "expo-router/entry",
   "scripts": {
     "start": "expo start",
+    "start:clear": "expo start --clear",
     "android": "expo run:android",
     "ios": "expo run:ios",
+    "ios:device": "expo run:ios --device",
     "web": "expo start --web",
     "prebuild": "expo prebuild",
+    "prebuild:clean": "expo prebuild --clean",
+    "build:dev": "eas build --profile development --platform ios",
+    "build:dev:local": "eas build --profile development --platform ios --local",
+    "build:preview": "eas build --profile preview --platform ios",
+    "build:production": "eas build --profile production --platform ios",
+    "testflight": "npx testflight",
     "lint": "biome check .",
     "lint:fix": "biome check --write .",
     "format": "biome format --write .",

apps/twig/src/renderer/features/sessions/components/ConversationView.stories.tsx

@@ -451,6 +451,7 @@ export const WithPendingPrompt: Story = {
       return events;
     })(),
     isPromptPending: true,
+    promptStartedAt: Date.now() - 5000,
     repoPath: "/Users/jonathan/dev/twig",
   },
 };

apps/twig/src/renderer/features/sessions/components/ConversationView.tsx

@@ -28,6 +28,7 @@ import { VirtualizedList, type VirtualizedListHandle } from "./VirtualizedList";
 interface ConversationViewProps {
   events: AcpMessage[];
   isPromptPending: boolean;
+  promptStartedAt?: number | null;
   repoPath?: string | null;
   taskId?: string;
 }
@@ -38,6 +39,7 @@ const ESTIMATE_SIZE = 36;
 export function ConversationView({
   events,
   isPromptPending,
+  promptStartedAt,
   repoPath,
   taskId,
 }: ConversationViewProps) {
@@ -191,6 +193,7 @@ export function ConversationView({
           <div className="pb-16">
             <SessionFooter
               isPromptPending={isPromptPending}
+              promptStartedAt={promptStartedAt}
               lastGenerationDuration={
                 lastTurnInfo?.isComplete ? lastTurnInfo.durationMs : null
               }

apps/twig/src/renderer/features/sessions/components/GeneratingIndicator.tsx

@@ -17,6 +17,7 @@ export function formatDuration(ms: number): string {
 }
 
 interface GeneratingIndicatorProps {
+  /** Timestamp (ms) when the prompt started. Only render this component while a prompt is pending. */
   startedAt?: number | null;
 }
 

apps/twig/src/renderer/features/sessions/components/SessionFooter.tsx

@@ -5,6 +5,7 @@ import { formatDuration, GeneratingIndicator } from "./GeneratingIndicator";
 
 interface SessionFooterProps {
   isPromptPending: boolean;
+  promptStartedAt?: number | null;
   lastGenerationDuration: number | null;
   lastStopReason?: string;
   queuedCount?: number;
@@ -13,6 +14,7 @@ interface SessionFooterProps {
 
 export function SessionFooter({
   isPromptPending,
+  promptStartedAt,
   lastGenerationDuration,
   lastStopReason,
   queuedCount = 0,
@@ -39,7 +41,7 @@ export function SessionFooter({
     return (
       <Box className="pt-3 pb-1">
         <Flex align="center" gap="2">
-          <GeneratingIndicator />
+          <GeneratingIndicator startedAt={promptStartedAt} />
           {queuedCount > 0 && (
             <Text size="1" color="gray">
               ({queuedCount} queued)

apps/twig/src/renderer/features/sessions/components/SessionView.tsx

@@ -38,6 +38,7 @@ interface SessionViewProps {
   taskId?: string;
   isRunning: boolean;
   isPromptPending?: boolean;
+  promptStartedAt?: number | null;
   onSendPrompt: (text: string) => void;
   onBashCommand?: (command: string) => void;
   onCancelPrompt: () => void;
@@ -59,6 +60,7 @@ export function SessionView({
   taskId,
   isRunning,
   isPromptPending = false,
+  promptStartedAt,
   onSendPrompt,
   onBashCommand,
   onCancelPrompt,
@@ -369,6 +371,7 @@ export function SessionView({
                 <ConversationView
                   events={events}
                   isPromptPending={isPromptPending}
+                  promptStartedAt={promptStartedAt}
                   repoPath={repoPath}
                   taskId={taskId}
                 />

apps/twig/src/renderer/features/sessions/service/service.test.ts

@@ -182,6 +182,7 @@ const createMockSession = (
   startedAt: Date.now(),
   status: "connected",
   isPromptPending: false,
+  promptStartedAt: null,
   pendingPermissions: new Map(),
   messageQueue: [],
   ...overrides,

apps/twig/src/renderer/features/sessions/service/service.ts

@@ -799,8 +799,10 @@ export class SessionService {
     const msg = acpMsg.message;
 
     if (isJsonRpcRequest(msg) && msg.method === "session/prompt") {
+      // acpMsg.ts is local time (set in-process) — matches Date.now() used in sendLocalPrompt
       sessionStoreSetters.updateSession(taskRunId, {
         isPromptPending: true,
+        promptStartedAt: acpMsg.ts,
       });
     }
 
@@ -813,6 +815,7 @@ export class SessionService {
     ) {
       sessionStoreSetters.updateSession(taskRunId, {
         isPromptPending: false,
+        promptStartedAt: null,
       });
 
       const stopReason = (msg.result as { stopReason?: string }).stopReason;
@@ -1042,6 +1045,7 @@ export class SessionService {
   ): Promise<{ stopReason: string }> {
     sessionStoreSetters.updateSession(session.taskRunId, {
       isPromptPending: true,
+      promptStartedAt: Date.now(),
     });
 
     try {
@@ -1052,6 +1056,7 @@ export class SessionService {
       // Clear pending state on success
       sessionStoreSetters.updateSession(session.taskRunId, {
         isPromptPending: false,
+        promptStartedAt: null,
       });
       return result;
     } catch (error) {
@@ -1072,10 +1077,12 @@ export class SessionService {
             errorDetails ||
             "Session connection lost. Please retry or start a new task.",
           isPromptPending: false,
+          promptStartedAt: null,
         });
       } else {
         sessionStoreSetters.updateSession(session.taskRunId, {
           isPromptPending: false,
+          promptStartedAt: null,
         });
       }
 
@@ -1223,6 +1230,11 @@ export class SessionService {
 
     const previousValue = configOptions[optionIndex].currentValue;
 
+    // Skip if value is already set — avoids expensive IPC round-trip (e.g. setModel ~2s)
+    if (previousValue === value) {
+      return;
+    }
+
     // Optimistic update
     const updatedOptions = configOptions.map((opt) =>
       opt.id === configId ? { ...opt, currentValue: value } : opt,
@@ -1623,6 +1635,7 @@ export class SessionService {
       startedAt: Date.now(),
       status: "connecting",
       isPromptPending: false,
+      promptStartedAt: null,
       pendingPermissions: new Map(),
       messageQueue: [],
     };

apps/twig/src/renderer/features/sessions/stores/sessionStore.ts

@@ -39,6 +39,7 @@ export interface AgentSession {
   errorTitle?: string;
   errorMessage?: string;
   isPromptPending: boolean;
+  promptStartedAt: number | null;
   logUrl?: string;
   processedLineCount?: number;
   framework?: "claude";

apps/twig/src/renderer/features/task-detail/components/TaskLogsPanel.tsx

@@ -74,6 +74,7 @@ export function TaskLogsPanel({ taskId, task }: TaskLogsPanelProps) {
 
   const events = session?.events ?? [];
   const isPromptPending = session?.isPromptPending ?? false;
+  const promptStartedAt = session?.promptStartedAt;
 
   const isNewSessionWithInitialPrompt =
     !task.latest_run?.id && !!task.description;
@@ -317,6 +318,7 @@ export function TaskLogsPanel({ taskId, task }: TaskLogsPanelProps) {
               taskId={taskId}
               isRunning={isCloud ? false : isRunning}
               isPromptPending={isCloud ? false : isPromptPending}
+              promptStartedAt={isCloud ? undefined : promptStartedAt}
               onSendPrompt={handleSendPrompt}
               onBashCommand={handleBashCommand}
               onCancelPrompt={handleCancelPrompt}