diff --git a/web/src/components/SessionFiles/DirectoryTree.tsx b/web/src/components/SessionFiles/DirectoryTree.tsx
index 80b1e532a2..4f282cb33d 100644
--- a/web/src/components/SessionFiles/DirectoryTree.tsx
+++ b/web/src/components/SessionFiles/DirectoryTree.tsx
@@ -1,4 +1,4 @@
-import { useCallback, useMemo, useState } from 'react'
+import { useCallback, useEffect, useMemo, useState } from 'react'
 import type { ApiClient } from '@/api/client'
 import { FileIcon } from '@/components/FileIcon'
 import { useSessionDirectory } from '@/hooks/queries/useSessionDirectory'
@@ -171,13 +171,40 @@ function DirectoryNode(props: {
     )
 }
 
+const STORAGE_KEY_PREFIX = 'hapi-dir-expanded-'
+
+function readExpanded(sessionId: string): Set<string> {
+    try {
+        const raw = sessionStorage.getItem(STORAGE_KEY_PREFIX + sessionId)
+        if (raw) {
+            const parsed = JSON.parse(raw)
+            if (Array.isArray(parsed)) return new Set(parsed as string[])
+        }
+    } catch {
+        // ignore
+    }
+    return new Set([''])
+}
+
+function writeExpanded(sessionId: string, expanded: Set<string>) {
+    try {
+        sessionStorage.setItem(STORAGE_KEY_PREFIX + sessionId, JSON.stringify([...expanded]))
+    } catch {
+        // ignore
+    }
+}
+
 export function DirectoryTree(props: {
     api: ApiClient | null
     sessionId: string
     rootLabel: string
     onOpenFile: (path: string) => void
 }) {
-    const [expanded, setExpanded] = useState<Set<string>>(() => new Set(['']))
+    const [expanded, setExpanded] = useState<Set<string>>(() => readExpanded(props.sessionId))
+
+    useEffect(() => {
+        writeExpanded(props.sessionId, expanded)
+    }, [props.sessionId, expanded])
 
     const handleToggle = useCallback((path: string) => {
         setExpanded((prev) => {
diff --git a/web/src/routes/sessions/files.tsx b/web/src/routes/sessions/files.tsx
index f8c698d76d..a77e05b7a3 100644
--- a/web/src/routes/sessions/files.tsx
+++ b/web/src/routes/sessions/files.tsx
@@ -1,4 +1,4 @@
-import { useCallback, useMemo, useState } from 'react'
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { useNavigate, useParams, useSearch } from '@tanstack/react-router'
 import type { FileSearchItem, GitFileStatus } from '@/types/api'
 import { FileIcon } from '@/components/FileIcon'
@@ -236,6 +236,8 @@ function FileListSkeleton(props: { label: string; rows?: number }) {
     )
 }
 
+const SCROLL_KEY_PREFIX = 'hapi-dir-scroll-'
+
 export default function FilesPage() {
     const { api } = useAppContext()
     const { t } = useTranslation()
@@ -246,10 +248,31 @@ export default function FilesPage() {
     const search = useSearch({ from: '/sessions/$sessionId/files' })
     const { session } = useSession(api, sessionId)
     const [searchQuery, setSearchQuery] = useState('')
+    const scrollRef = useRef<HTMLDivElement>(null)
 
     const initialTab = search.tab === 'directories' ? 'directories' : 'changes'
     const [activeTab, setActiveTab] = useState<'changes' | 'directories'>(initialTab)
 
+    useEffect(() => {
+        const el = scrollRef.current
+        if (!el) return
+        const key = SCROLL_KEY_PREFIX + sessionId
+        try {
+            const saved = sessionStorage.getItem(key)
+            if (saved !== null) el.scrollTop = Number(saved)
+        } catch {
+            // ignore
+        }
+        return () => {
+            try {
+                sessionStorage.setItem(key, String(el.scrollTop))
+            } catch {
+                // ignore
+            }
+        }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    }, [sessionId])
+
     const {
         status: gitStatus,
         error: gitError,
@@ -411,7 +434,7 @@ export default function FilesPage() {
                 </div>
             ) : null}
 
-            <div className="app-scroll-y flex-1 min-h-0">
+            <div ref={scrollRef} className="app-scroll-y flex-1 min-h-0">
                 <div className="mx-auto w-full max-w-content">
                     {showGitErrorBanner && activeTab === 'changes' ? (
                         <div className="border-b border-[var(--app-divider)] bg-amber-500/10 px-3 py-2 text-xs text-[var(--app-hint)]">
@@ -441,6 +464,7 @@ export default function FilesPage() {
                         )
                     ) : activeTab === 'directories' ? (
                         <DirectoryTree
+                            key={sessionId}
                             api={api}
                             sessionId={sessionId}
                             rootLabel={rootLabel}