feat(ext): add chat history

packages/extension/src/entrypoints/sidepanel/App.tsx

@@ -1,4 +1,4 @@
-import { Send, Settings, Square } from 'lucide-react'
+import { History, Send, Settings, Square } from 'lucide-react'
 import { useCallback, useEffect, useRef, useState } from 'react'
 
 import { Button } from '@/components/ui/button'
@@ -8,20 +8,47 @@ import {
 	InputGroupButton,
 	InputGroupTextarea,
 } from '@/components/ui/input-group'
+import { saveSession } from '@/lib/db'
 
 import { useAgent } from '../../agent/useAgent'
 import { ConfigPanel } from './components/ConfigPanel'
+import { HistoryDetail } from './components/HistoryDetail'
+import { HistoryList } from './components/HistoryList'
 import { ActivityCard, EventCard } from './components/cards'
 import { EmptyState, Logo, StatusDot } from './components/misc'
 
+type View =
+	| { name: 'chat' }
+	| { name: 'config' }
+	| { name: 'history' }
+	| { name: 'history-detail'; sessionId: string }
+
 export default function App() {
-	const [showConfig, setShowConfig] = useState(false)
+	const [view, setView] = useState<View>({ name: 'chat' })
 	const [inputValue, setInputValue] = useState('')
 	const historyRef = useRef<HTMLDivElement>(null)
 	const textareaRef = useRef<HTMLTextAreaElement>(null)
 
 	const { status, history, activity, currentTask, config, execute, stop, configure } = useAgent()
 
+	// Persist session when task finishes
+	const prevStatusRef = useRef(status)
+	useEffect(() => {
+		const prev = prevStatusRef.current
+		prevStatusRef.current = status
+
+		if (
+			prev === 'running' &&
+			(status === 'completed' || status === 'error') &&
+			history.length > 0 &&
+			currentTask
+		) {
+			saveSession({ task: currentTask, history, status }).catch((err) =>
+				console.error('[SidePanel] Failed to save session:', err)
+			)
+		}
+	}, [status, history, currentTask])
+
 	// Auto-scroll to bottom on new events
 	useEffect(() => {
 		if (historyRef.current) {
@@ -56,19 +83,36 @@ export default function App() {
 		}
 	}
 
-	if (showConfig) {
+	// --- View routing ---
+
+	if (view.name === 'config') {
 		return (
 			<ConfigPanel
 				config={config}
 				onSave={async (newConfig) => {
 					await configure(newConfig)
-					setShowConfig(false)
+					setView({ name: 'chat' })
 				}}
-				onClose={() => setShowConfig(false)}
+				onClose={() => setView({ name: 'chat' })}
 			/>
 		)
 	}
 
+	if (view.name === 'history') {
+		return (
+			<HistoryList
+				onSelect={(id) => setView({ name: 'history-detail', sessionId: id })}
+				onBack={() => setView({ name: 'chat' })}
+			/>
+		)
+	}
+
+	if (view.name === 'history-detail') {
+		return <HistoryDetail sessionId={view.sessionId} onBack={() => setView({ name: 'history' })} />
+	}
+
+	// --- Chat view ---
+
 	const isRunning = status === 'running'
 	const showEmptyState = !currentTask && history.length === 0 && !isRunning
 
@@ -85,7 +129,15 @@ export default function App() {
 					<Button
 						variant="ghost"
 						size="icon-sm"
-						onClick={() => setShowConfig(true)}
+						onClick={() => setView({ name: 'history' })}
+						className="cursor-pointer"
+					>
+						<History className="size-3.5" />
+					</Button>
+					<Button
+						variant="ghost"
+						size="icon-sm"
+						onClick={() => setView({ name: 'config' })}
 						className="cursor-pointer"
 					>
 						<Settings className="size-3.5" />

packages/extension/src/entrypoints/sidepanel/components/HistoryDetail.tsx

@@ -0,0 +1,51 @@
+import { ArrowLeft } from 'lucide-react'
+import { useEffect, useState } from 'react'
+
+import { Button } from '@/components/ui/button'
+import { type SessionRecord, getSession } from '@/lib/db'
+
+import { EventCard } from './cards'
+
+export function HistoryDetail({ sessionId, onBack }: { sessionId: string; onBack: () => void }) {
+	const [session, setSession] = useState<SessionRecord | null>(null)
+
+	useEffect(() => {
+		getSession(sessionId).then((s) => setSession(s ?? null))
+	}, [sessionId])
+
+	if (!session) {
+		return (
+			<div className="flex items-center justify-center h-screen text-xs text-muted-foreground">
+				Loading...
+			</div>
+		)
+	}
+
+	return (
+		<div className="flex flex-col h-screen bg-background">
+			{/* Header */}
+			<header className="flex items-center gap-2 border-b px-3 py-2">
+				<Button variant="ghost" size="icon-sm" onClick={onBack} className="cursor-pointer">
+					<ArrowLeft className="size-3.5" />
+				</Button>
+				<span className="text-sm font-medium truncate">History</span>
+			</header>
+
+			{/* Task */}
+			<div className="border-b px-3 py-2 bg-muted/30">
+				<div className="text-[10px] text-muted-foreground uppercase tracking-wide">Task</div>
+				<div className="text-xs font-medium" title={session.task}>
+					{session.task}
+				</div>
+			</div>
+
+			{/* Events (read-only) */}
+			<div className="flex-1 overflow-y-auto p-3 space-y-2">
+				{session.history.map((event, index) => (
+					// eslint-disable-next-line react-x/no-array-index-key
+					<EventCard key={index} event={event} />
+				))}
+			</div>
+		</div>
+	)
+}

packages/extension/src/entrypoints/sidepanel/components/HistoryList.tsx

@@ -0,0 +1,119 @@
+import { ArrowLeft, CheckCircle, Trash2, XCircle } from 'lucide-react'
+import { useCallback, useEffect, useState } from 'react'
+
+import { Button } from '@/components/ui/button'
+import { type SessionRecord, clearSessions, deleteSession, listSessions } from '@/lib/db'
+
+function timeAgo(ts: number): string {
+	const seconds = Math.floor((Date.now() - ts) / 1000)
+	if (seconds < 60) return 'just now'
+	const minutes = Math.floor(seconds / 60)
+	if (minutes < 60) return `${minutes}m ago`
+	const hours = Math.floor(minutes / 60)
+	if (hours < 24) return `${hours}h ago`
+	const days = Math.floor(hours / 24)
+	return `${days}d ago`
+}
+
+export function HistoryList({
+	onSelect,
+	onBack,
+}: {
+	onSelect: (id: string) => void
+	onBack: () => void
+}) {
+	const [sessions, setSessions] = useState<SessionRecord[]>([])
+	const [loading, setLoading] = useState(true)
+
+	const load = useCallback(async () => {
+		setSessions(await listSessions())
+		setLoading(false)
+	}, [])
+
+	useEffect(() => {
+		// eslint-disable-next-line react-hooks/set-state-in-effect
+		load()
+	}, [load])
+
+	const handleDelete = async (e: React.MouseEvent, id: string) => {
+		e.stopPropagation()
+		await deleteSession(id)
+		setSessions((prev) => prev.filter((s) => s.id !== id))
+	}
+
+	return (
+		<div className="flex flex-col h-screen bg-background">
+			{/* Header */}
+			<header className="flex items-center gap-2 border-b px-3 py-2">
+				<Button variant="ghost" size="icon-sm" onClick={onBack} className="cursor-pointer">
+					<ArrowLeft className="size-3.5" />
+				</Button>
+				<span className="text-sm font-medium flex-1">History</span>
+				{sessions.length > 0 && (
+					<Button
+						variant="ghost"
+						size="sm"
+						onClick={async () => {
+							await clearSessions()
+							setSessions([])
+						}}
+						className="text-[10px] text-muted-foreground hover:text-destructive cursor-pointer h-6 px-2"
+					>
+						<Trash2 className="size-3 mr-1" />
+						Clear All
+					</Button>
+				)}
+			</header>
+
+			{/* List */}
+			<div className="flex-1 overflow-y-auto">
+				{loading && (
+					<div className="flex items-center justify-center h-32 text-xs text-muted-foreground">
+						Loading...
+					</div>
+				)}
+
+				{!loading && sessions.length === 0 && (
+					<div className="flex items-center justify-center h-32 text-xs text-muted-foreground">
+						No history yet
+					</div>
+				)}
+
+				{sessions.map((session) => (
+					<div
+						key={session.id}
+						role="button"
+						tabIndex={0}
+						onClick={() => onSelect(session.id)}
+						onKeyDown={(e) => e.key === 'Enter' && onSelect(session.id)}
+						className="w-full text-left px-3 py-2.5 border-b hover:bg-muted/50 transition-colors cursor-pointer flex items-start gap-2 group"
+					>
+						{/* Status icon */}
+						{session.status === 'completed' ? (
+							<CheckCircle className="size-3.5 text-green-500 shrink-0 mt-0.5" />
+						) : (
+							<XCircle className="size-3.5 text-destructive shrink-0 mt-0.5" />
+						)}
+
+						{/* Content */}
+						<div className="flex-1 min-w-0">
+							<p className="text-xs font-medium truncate">{session.task}</p>
+							<p className="text-[10px] text-muted-foreground mt-0.5">
+								{timeAgo(session.createdAt)} · {session.history.length} steps
+							</p>
+						</div>
+
+						{/* Delete */}
+						<button
+							type="button"
+							onClick={(e) => handleDelete(e, session.id)}
+							className="opacity-0 group-hover:opacity-100 transition-opacity p-1 hover:text-destructive cursor-pointer shrink-0"
+						>
+							<Trash2 className="size-3" />
+						</button>
+					</div>
+				))}
+			</div>
+		</div>
+	)
+}

packages/extension/src/lib/db.ts

@@ -0,0 +1,70 @@
+import type { HistoricalEvent } from '@page-agent/core'
+import { type DBSchema, type IDBPDatabase, openDB } from 'idb'
+
+const DB_NAME = 'page-agent-ext'
+const DB_VERSION = 1
+
+export interface SessionRecord {
+	id: string
+	task: string
+	history: HistoricalEvent[]
+	status: 'completed' | 'error'
+	createdAt: number
+}
+
+interface PageAgentDB extends DBSchema {
+	sessions: {
+		key: string
+		value: SessionRecord
+		indexes: { 'by-created': number }
+	}
+}
+
+let dbPromise: Promise<IDBPDatabase<PageAgentDB>> | null = null
+
+function getDB() {
+	if (!dbPromise) {
+		dbPromise = openDB<PageAgentDB>(DB_NAME, DB_VERSION, {
+			upgrade(db) {
+				const store = db.createObjectStore('sessions', { keyPath: 'id' })
+				store.createIndex('by-created', 'createdAt')
+			},
+		})
+	}
+	return dbPromise
+}
+
+export async function saveSession(
+	session: Omit<SessionRecord, 'id' | 'createdAt'>
+): Promise<SessionRecord> {
+	const db = await getDB()
+	const record: SessionRecord = {
+		...session,
+		id: crypto.randomUUID(),
+		createdAt: Date.now(),
+	}
+	await db.put('sessions', record)
+	return record
+}
+
+/** List sessions, newest first */
+export async function listSessions(): Promise<SessionRecord[]> {
+	const db = await getDB()
+	const all = await db.getAllFromIndex('sessions', 'by-created')
+	return all.reverse()
+}
+
+export async function getSession(id: string): Promise<SessionRecord | undefined> {
+	const db = await getDB()
+	return db.get('sessions', id)
+}
+
+export async function deleteSession(id: string): Promise<void> {
+	const db = await getDB()
+	await db.delete('sessions', id)
+}
+
+export async function clearSessions(): Promise<void> {
+	const db = await getDB()
+	await db.clear('sessions')
+}