From 4664b344e339107af43bb5936e88a3dab0e61c58 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 15 Aug 2025 16:24:10 +0800
Subject: [PATCH 01/20] feat: enhance locale handling with AsyncLocalStorage
 support for server-side requests

---
 .../request-handler/user-response.ts          |  7 ++-
 packages/qwik/src/core/use/use-locale.ts      | 45 +++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index f37ca8a8c17..a2445a560a9 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -13,6 +13,7 @@ import {
 } from './request-event';
 import { encoder } from './resolve-request-handlers';
 import type { QwikSerializer, ServerRequestEvent, StatusCodes } from './types';
+import { withLocale } from '@qwik.dev/core';
 // Import separately to avoid duplicate imports in the vite dev server
 import {
   AbortMessage,
@@ -64,8 +65,10 @@ export function runQwikRouter<T>(
     response: responsePromise,
     requestEv,
     completion: asyncStore
-      ? asyncStore.run(requestEv, runNext, requestEv, rebuildRouteInfo, resolve!)
-      : runNext(requestEv, rebuildRouteInfo, resolve!),
+      ? asyncStore.run(requestEv, () =>
+          withLocale(requestEv.locale(), () => runNext(requestEv, rebuildRouteInfo, resolve!))
+        )
+      : withLocale(requestEv.locale(), () => runNext(requestEv, rebuildRouteInfo, resolve!)),
   };
 }
 
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index 5e3efdddabb..90432ff61bf 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -11,6 +11,21 @@ let _locale: string | undefined = undefined;
  * @public
  */
 export function getLocale(defaultLocale?: string): string {
+  // Prefer per-request locale from AsyncLocalStorage if available (server-side)
+  try {
+    const asyncStore = (globalThis as any).qcAsyncRequestStore;
+    const ev = asyncStore?.getStore?.();
+    const evLocale = ev && typeof ev.locale === 'function' ? ev.locale : undefined;
+    if (evLocale) {
+      const l = evLocale();
+      if (l) {
+        return l;
+      }
+    }
+  } catch {
+    // ignore and fallback
+  }
+
   if (_locale === undefined) {
     const ctx = tryGetInvokeContext();
     if (ctx && ctx.$locale$) {
@@ -30,6 +45,24 @@ export function getLocale(defaultLocale?: string): string {
  * @public
  */
 export function withLocale<T>(locale: string, fn: () => T): T {
+  // If running on the server with AsyncLocalStorage, set locale on the current request
+  try {
+    const asyncStore = (globalThis as any).qcAsyncRequestStore;
+    const ev = asyncStore?.getStore?.();
+    const evLocale = ev && typeof ev.locale === 'function' ? ev.locale : undefined;
+    if (evLocale) {
+      const previous = evLocale();
+      try {
+        evLocale(locale);
+        return fn();
+      } finally {
+        evLocale(previous);
+      }
+    }
+  } catch {
+    // ignore and fallback
+  }
+
   const previousLang = _locale;
   try {
     _locale = locale;
@@ -48,5 +81,17 @@ export function withLocale<T>(locale: string, fn: () => T): T {
  * @public
  */
 export function setLocale(locale: string): void {
+  // On the server, prefer setting the locale on the per-request store
+  try {
+    const asyncStore = (globalThis as any).qcAsyncRequestStore;
+    const ev = asyncStore?.getStore?.();
+    const evLocale = ev && typeof ev.locale === 'function' ? ev.locale : undefined;
+    if (evLocale) {
+      evLocale(locale);
+      return;
+    }
+  } catch {
+    // ignore and fallback
+  }
   _locale = locale;
 }

From 90890c916349b35cf6988fec6089a2eff939da11 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 15 Aug 2025 16:43:52 +0800
Subject: [PATCH 02/20] add changeset

---
 .changeset/pretty-parents-draw.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 .changeset/pretty-parents-draw.md

diff --git a/.changeset/pretty-parents-draw.md b/.changeset/pretty-parents-draw.md
new file mode 100644
index 00000000000..5dc3372ef3f
--- /dev/null
+++ b/.changeset/pretty-parents-draw.md
@@ -0,0 +1,6 @@
+---
+'@qwik.dev/router': patch
+'@qwik.dev/core': patch
+---
+
+enhance locale handling with AsyncLocalStorage support for server-side requests

From 25d16481246dfcfdf4c421d290a8b58ed87deda6 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 15 Aug 2025 17:00:50 +0800
Subject: [PATCH 03/20] fix: improve locale handling in resolveHead function
 with AsyncLocalStorage support

---
 packages/qwik-router/src/runtime/src/head.ts | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index 6e2136cd43f..39d31bb6ce3 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -37,9 +37,10 @@ export const resolveHead = (
     }
     return data;
   }) as any as ResolveSyncValue;
+  const storeEv = (globalThis as any).qcAsyncRequestStore?.getStore?.();
   const headProps: DocumentHeadProps = {
     head,
-    withLocale: (fn) => withLocale(locale, fn),
+    withLocale: (fn) => (storeEv ? fn() : withLocale(locale, fn)),
     resolveValue: getData,
     ...routeLocation,
   };
@@ -50,7 +51,9 @@ export const resolveHead = (
       if (typeof contentModuleHead === 'function') {
         resolveDocumentHead(
           head,
-          withLocale(locale, () => contentModuleHead(headProps))
+          storeEv
+            ? contentModuleHead(headProps)
+            : withLocale(locale, () => contentModuleHead(headProps))
         );
       } else if (typeof contentModuleHead === 'object') {
         resolveDocumentHead(head, contentModuleHead);

From 0abc9d8e41a8a69d3642ea8eb12d2fc37c5a208a Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Sat, 16 Aug 2025 09:23:21 +0800
Subject: [PATCH 04/20] refactor: streamline locale handling with
 AsyncLocalStorage for server-side context

---
 .../request-handler/user-response.ts          | 10 +--
 packages/qwik/src/core/use/use-locale.ts      | 62 +++++++++++--------
 2 files changed, 40 insertions(+), 32 deletions(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index a2445a560a9..70c7b954980 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -64,11 +64,11 @@ export function runQwikRouter<T>(
   return {
     response: responsePromise,
     requestEv,
-    completion: asyncStore
-      ? asyncStore.run(requestEv, () =>
-          withLocale(requestEv.locale(), () => runNext(requestEv, rebuildRouteInfo, resolve!))
-        )
-      : withLocale(requestEv.locale(), () => runNext(requestEv, rebuildRouteInfo, resolve!)),
+    completion: withLocale(requestEv.locale(), () =>
+      asyncStore
+        ? asyncStore.run(requestEv, () => runNext(requestEv, rebuildRouteInfo, resolve!))
+        : runNext(requestEv, rebuildRouteInfo, resolve!)
+    ),
   };
 }
 
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index 90432ff61bf..ca711abfd06 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -1,7 +1,30 @@
 import { tryGetInvokeContext } from './use-core';
+import { isServer } from '@qwik.dev/core/build';
 
 let _locale: string | undefined = undefined;
 
+type LocaleStore = { locale: string | undefined };
+
+type LocaleAsyncStore = import('node:async_hooks').AsyncLocalStorage<LocaleStore>;
+
+let localAsyncStore: LocaleAsyncStore | undefined;
+
+if (isServer) {
+  try {
+    // Lazy import to avoid bundling for non-Node targets
+    import('node:async_hooks')
+      .then((module) => {
+        const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => LocaleAsyncStore;
+        localAsyncStore = new AsyncLocalStorage();
+      })
+      .catch(() => {
+        // ignore if AsyncLocalStorage is not available
+      });
+  } catch {
+    // ignore and fallback
+  }
+}
+
 /**
  * Retrieve the current locale.
  *
@@ -11,16 +34,12 @@ let _locale: string | undefined = undefined;
  * @public
  */
 export function getLocale(defaultLocale?: string): string {
-  // Prefer per-request locale from AsyncLocalStorage if available (server-side)
+  // Prefer per-request locale from local AsyncLocalStorage if available (server-side)
   try {
-    const asyncStore = (globalThis as any).qcAsyncRequestStore;
-    const ev = asyncStore?.getStore?.();
-    const evLocale = ev && typeof ev.locale === 'function' ? ev.locale : undefined;
-    if (evLocale) {
-      const l = evLocale();
-      if (l) {
-        return l;
-      }
+    const store = localAsyncStore?.getStore?.();
+    const l = store?.locale;
+    if (l) {
+      return l;
     }
   } catch {
     // ignore and fallback
@@ -45,19 +64,10 @@ export function getLocale(defaultLocale?: string): string {
  * @public
  */
 export function withLocale<T>(locale: string, fn: () => T): T {
-  // If running on the server with AsyncLocalStorage, set locale on the current request
+  // If running on the server with AsyncLocalStorage, set locale for this async context
   try {
-    const asyncStore = (globalThis as any).qcAsyncRequestStore;
-    const ev = asyncStore?.getStore?.();
-    const evLocale = ev && typeof ev.locale === 'function' ? ev.locale : undefined;
-    if (evLocale) {
-      const previous = evLocale();
-      try {
-        evLocale(locale);
-        return fn();
-      } finally {
-        evLocale(previous);
-      }
+    if (localAsyncStore?.run) {
+      return localAsyncStore.run({ locale }, fn);
     }
   } catch {
     // ignore and fallback
@@ -81,13 +91,11 @@ export function withLocale<T>(locale: string, fn: () => T): T {
  * @public
  */
 export function setLocale(locale: string): void {
-  // On the server, prefer setting the locale on the per-request store
+  // On the server, prefer setting the locale on the local per-request store
   try {
-    const asyncStore = (globalThis as any).qcAsyncRequestStore;
-    const ev = asyncStore?.getStore?.();
-    const evLocale = ev && typeof ev.locale === 'function' ? ev.locale : undefined;
-    if (evLocale) {
-      evLocale(locale);
+    const store = localAsyncStore?.getStore?.();
+    if (store) {
+      store.locale = locale;
       return;
     }
   } catch {

From 27dd79508e7322ab1dea943b79db373795e2c369 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Mon, 18 Aug 2025 09:40:45 +0800
Subject: [PATCH 05/20] refactor: remove unnecessary comment and simplify store
 retrieval in head.ts

---
 packages/qwik-router/src/runtime/src/head.ts | 2 +-
 packages/qwik/src/core/use/use-locale.ts     | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index 39d31bb6ce3..a347c43e396 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -37,7 +37,7 @@ export const resolveHead = (
     }
     return data;
   }) as any as ResolveSyncValue;
-  const storeEv = (globalThis as any).qcAsyncRequestStore?.getStore?.();
+  const storeEv = (globalThis as any).qcAsyncRequestStore;
   const headProps: DocumentHeadProps = {
     head,
     withLocale: (fn) => (storeEv ? fn() : withLocale(locale, fn)),
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index ca711abfd06..4aaf785795e 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -11,7 +11,6 @@ let localAsyncStore: LocaleAsyncStore | undefined;
 
 if (isServer) {
   try {
-    // Lazy import to avoid bundling for non-Node targets
     import('node:async_hooks')
       .then((module) => {
         const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => LocaleAsyncStore;

From 1c341e44bd4053581733234eaffd345f21d1bd09 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Tue, 19 Aug 2025 17:02:13 +0800
Subject: [PATCH 06/20] refactor: simplify AsyncLocalStorage usage and improve
 locale retrieval in use-locale.ts

---
 .../request-handler/user-response.ts          |  7 ++---
 packages/qwik-router/src/runtime/src/head.ts  |  2 +-
 packages/qwik/src/core/use/use-locale.ts      | 27 ++++++++-----------
 3 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index 70c7b954980..c3bb6e22012 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -64,10 +64,11 @@ export function runQwikRouter<T>(
   return {
     response: responsePromise,
     requestEv,
-    completion: withLocale(requestEv.locale(), () =>
+    completion: withLocale(
+      requestEv.locale(),
       asyncStore
-        ? asyncStore.run(requestEv, () => runNext(requestEv, rebuildRouteInfo, resolve!))
-        : runNext(requestEv, rebuildRouteInfo, resolve!)
+        ? () => asyncStore!.run(requestEv, runNext, requestEv, rebuildRouteInfo, resolve!)
+        : () => runNext(requestEv, rebuildRouteInfo, resolve!)
     ),
   };
 }
diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index a347c43e396..a712bc9110d 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -40,7 +40,7 @@ export const resolveHead = (
   const storeEv = (globalThis as any).qcAsyncRequestStore;
   const headProps: DocumentHeadProps = {
     head,
-    withLocale: (fn) => (storeEv ? fn() : withLocale(locale, fn)),
+    withLocale: storeEv ? (fn) => fn() : (fn) => withLocale(locale, fn),
     resolveValue: getData,
     ...routeLocation,
   };
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index 4aaf785795e..589529ad789 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -10,18 +10,14 @@ type LocaleAsyncStore = import('node:async_hooks').AsyncLocalStorage<LocaleStore
 let localAsyncStore: LocaleAsyncStore | undefined;
 
 if (isServer) {
-  try {
-    import('node:async_hooks')
-      .then((module) => {
-        const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => LocaleAsyncStore;
-        localAsyncStore = new AsyncLocalStorage();
-      })
-      .catch(() => {
-        // ignore if AsyncLocalStorage is not available
-      });
-  } catch {
-    // ignore and fallback
-  }
+  import('node:async_hooks')
+    .then((module) => {
+      const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => LocaleAsyncStore;
+      localAsyncStore = new AsyncLocalStorage();
+    })
+    .catch(() => {
+      // ignore if AsyncLocalStorage is not available
+    });
 }
 
 /**
@@ -35,10 +31,9 @@ if (isServer) {
 export function getLocale(defaultLocale?: string): string {
   // Prefer per-request locale from local AsyncLocalStorage if available (server-side)
   try {
-    const store = localAsyncStore?.getStore?.();
-    const l = store?.locale;
-    if (l) {
-      return l;
+    const locale = localAsyncStore?.getStore?.()?.locale;
+    if (locale) {
+      return locale;
     }
   } catch {
     // ignore and fallback

From 92d67daa6d61d3e5b3b8e8e49663e1c7988eba72 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Mon, 25 Aug 2025 13:42:18 +0800
Subject: [PATCH 07/20] refactor: unify AsyncLocalStorage usage across router
 middleware and improve request handling

---
 packages/qwik-router/global.d.ts              |  1 -
 .../request-handler/async-request-store.ts    | 11 ++++++++
 .../request-handler/request-event.ts          |  3 ++-
 .../request-handler/user-response.ts          |  4 ++-
 packages/qwik-router/src/runtime/src/head.ts  |  8 +++---
 .../src/runtime/src/server-functions.ts       |  3 ++-
 packages/qwik/src/core/use/use-locale.ts      | 25 ++++++++-----------
 7 files changed, 34 insertions(+), 21 deletions(-)
 create mode 100644 packages/qwik-router/src/middleware/request-handler/async-request-store.ts

diff --git a/packages/qwik-router/global.d.ts b/packages/qwik-router/global.d.ts
index 2f382a9ddcf..12b823070f8 100644
--- a/packages/qwik-router/global.d.ts
+++ b/packages/qwik-router/global.d.ts
@@ -6,7 +6,6 @@ type RequestEventInternal =
 type AsyncStore = import('node:async_hooks').AsyncLocalStorage<RequestEventInternal>;
 type SerializationStrategy = import('@qwik.dev/core/internal').SerializationStrategy;
 
-declare var qcAsyncRequestStore: AsyncStore | undefined;
 declare var _qwikActionsMap: Map<string, ActionInternal> | undefined;
 
 /** @deprecated Will be removed in v3 */
diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
new file mode 100644
index 00000000000..fd34f6ae826
--- /dev/null
+++ b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
@@ -0,0 +1,11 @@
+import type { RequestEventInternal } from './request-event';
+import type { AsyncLocalStorage } from 'node:async_hooks';
+
+export type AsyncStore = AsyncLocalStorage<RequestEventInternal>;
+
+// Qwik Core will also be using the async store if this is present
+export let asyncRequestStore: AsyncStore | undefined;
+
+export const setAsyncRequestStore = (store: AsyncStore | undefined) => {
+  asyncRequestStore = store;
+};
diff --git a/packages/qwik-router/src/middleware/request-handler/request-event.ts b/packages/qwik-router/src/middleware/request-handler/request-event.ts
index 9cdadfe9055..42096286bd7 100644
--- a/packages/qwik-router/src/middleware/request-handler/request-event.ts
+++ b/packages/qwik-router/src/middleware/request-handler/request-event.ts
@@ -20,6 +20,7 @@ import {
   RewriteMessage,
 } from '@qwik.dev/router/middleware/request-handler';
 import { encoder, getRouteLoaderPromise } from './resolve-request-handlers';
+import { asyncRequestStore } from './async-request-store';
 import type {
   CacheControl,
   CacheControlTarget,
@@ -83,7 +84,7 @@ export function createRequestEvent(
 
     while (routeModuleIndex < requestHandlers.length) {
       const moduleRequestHandler = requestHandlers[routeModuleIndex];
-      const asyncStore = globalThis.qcAsyncRequestStore;
+      const asyncStore = asyncRequestStore;
       const result = asyncStore?.run
         ? asyncStore.run(requestEv, moduleRequestHandler, requestEv)
         : moduleRequestHandler(requestEv);
diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index c3bb6e22012..f94450d61af 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -14,6 +14,8 @@ import {
 import { encoder } from './resolve-request-handlers';
 import type { QwikSerializer, ServerRequestEvent, StatusCodes } from './types';
 import { withLocale } from '@qwik.dev/core';
+import { setAsyncRequestStore } from './async-request-store';
+import type { AsyncStore } from './async-request-store';
 // Import separately to avoid duplicate imports in the vite dev server
 import {
   AbortMessage,
@@ -33,7 +35,7 @@ import('node:async_hooks')
   .then((module) => {
     const AsyncLocalStorage = module.AsyncLocalStorage;
     asyncStore = new AsyncLocalStorage<RequestEventInternal>();
-    globalThis.qcAsyncRequestStore = asyncStore;
+    setAsyncRequestStore(asyncStore);
   })
   .catch((err) => {
     console.warn(
diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index a712bc9110d..ab4d7d696aa 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -13,6 +13,7 @@ import type {
   ActionInternal,
 } from './types';
 import { isPromise } from './utils';
+import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
 
 export const resolveHead = (
   endpoint: EndpointResponse | ClientPageData,
@@ -37,10 +38,11 @@ export const resolveHead = (
     }
     return data;
   }) as any as ResolveSyncValue;
-  const storeEv = (globalThis as any).qcAsyncRequestStore;
+  // Qwik Core will also be using the async store if this is present
+  const hasAsyncStore = asyncRequestStore;
   const headProps: DocumentHeadProps = {
     head,
-    withLocale: storeEv ? (fn) => fn() : (fn) => withLocale(locale, fn),
+    withLocale: hasAsyncStore ? (fn) => fn() : (fn) => withLocale(locale, fn),
     resolveValue: getData,
     ...routeLocation,
   };
@@ -51,7 +53,7 @@ export const resolveHead = (
       if (typeof contentModuleHead === 'function') {
         resolveDocumentHead(
           head,
-          storeEv
+          hasAsyncStore
             ? contentModuleHead(headProps)
             : withLocale(locale, () => contentModuleHead(headProps))
         );
diff --git a/packages/qwik-router/src/runtime/src/server-functions.ts b/packages/qwik-router/src/runtime/src/server-functions.ts
index fafddd70ab2..3ba57ada274 100644
--- a/packages/qwik-router/src/runtime/src/server-functions.ts
+++ b/packages/qwik-router/src/runtime/src/server-functions.ts
@@ -65,6 +65,7 @@ import { useAction, useLocation, useQwikRouterEnv } from './use-functions';
 
 import type { FormSubmitCompletedDetail } from './form-component';
 import { deepFreeze } from './utils';
+import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
 
 /** @internal */
 export const routeActionQrl = ((
@@ -420,7 +421,7 @@ export const serverQrl = <T extends ServerFunction>(
 
       if (isServer) {
         // Running during SSR, we can call the function directly
-        let requestEvent = globalThis.qcAsyncRequestStore?.getStore() as RequestEvent | undefined;
+        let requestEvent = asyncRequestStore?.getStore() as RequestEvent | undefined;
 
         if (!requestEvent) {
           const contexts = [useQwikRouterEnv()?.ev, this, _getContextEvent()] as RequestEvent[];
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index 589529ad789..81a3cd6f106 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -1,18 +1,17 @@
 import { tryGetInvokeContext } from './use-core';
 import { isServer } from '@qwik.dev/core/build';
+import type { AsyncLocalStorage } from 'node:async_hooks';
 
 let _locale: string | undefined = undefined;
 
-type LocaleStore = { locale: string | undefined };
-
-type LocaleAsyncStore = import('node:async_hooks').AsyncLocalStorage<LocaleStore>;
-
-let localAsyncStore: LocaleAsyncStore | undefined;
+let localAsyncStore: AsyncLocalStorage<{ locale?: string }> | undefined;
 
 if (isServer) {
   import('node:async_hooks')
     .then((module) => {
-      const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => LocaleAsyncStore;
+      const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => AsyncLocalStorage<{
+        locale?: string;
+      }>;
       localAsyncStore = new AsyncLocalStorage();
     })
     .catch(() => {
@@ -30,13 +29,11 @@ if (isServer) {
  */
 export function getLocale(defaultLocale?: string): string {
   // Prefer per-request locale from local AsyncLocalStorage if available (server-side)
-  try {
-    const locale = localAsyncStore?.getStore?.()?.locale;
+  if (localAsyncStore) {
+    const locale = localAsyncStore.getStore()?.locale;
     if (locale) {
       return locale;
     }
-  } catch {
-    // ignore and fallback
   }
 
   if (_locale === undefined) {
@@ -60,7 +57,7 @@ export function getLocale(defaultLocale?: string): string {
 export function withLocale<T>(locale: string, fn: () => T): T {
   // If running on the server with AsyncLocalStorage, set locale for this async context
   try {
-    if (localAsyncStore?.run) {
+    if (localAsyncStore) {
       return localAsyncStore.run({ locale }, fn);
     }
   } catch {
@@ -87,9 +84,9 @@ export function withLocale<T>(locale: string, fn: () => T): T {
 export function setLocale(locale: string): void {
   // On the server, prefer setting the locale on the local per-request store
   try {
-    const store = localAsyncStore?.getStore?.();
-    if (store) {
-      store.locale = locale;
+    if (localAsyncStore && localAsyncStore.getStore) {
+      const store = localAsyncStore.getStore();
+      store!.locale = locale;
       return;
     }
   } catch {

From 559b9f381f4bb7196ced25407677dcea940cf942 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Tue, 26 Aug 2025 10:24:03 +0800
Subject: [PATCH 08/20] refactor: streamline AsyncLocalStorage usage in locale
 functions and improve code clarity

---
 packages/qwik-router/src/runtime/src/head.ts |  3 +--
 packages/qwik/src/core/use/use-locale.ts     | 22 ++++++--------------
 2 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index ab4d7d696aa..dd8ec4c5661 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -13,7 +13,7 @@ import type {
   ActionInternal,
 } from './types';
 import { isPromise } from './utils';
-import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
+import { asyncRequestStore as hasAsyncStore } from '../../middleware/request-handler/async-request-store';
 
 export const resolveHead = (
   endpoint: EndpointResponse | ClientPageData,
@@ -39,7 +39,6 @@ export const resolveHead = (
     return data;
   }) as any as ResolveSyncValue;
   // Qwik Core will also be using the async store if this is present
-  const hasAsyncStore = asyncRequestStore;
   const headProps: DocumentHeadProps = {
     head,
     withLocale: hasAsyncStore ? (fn) => fn() : (fn) => withLocale(locale, fn),
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index 81a3cd6f106..83d545f8f3f 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -55,13 +55,8 @@ export function getLocale(defaultLocale?: string): string {
  * @public
  */
 export function withLocale<T>(locale: string, fn: () => T): T {
-  // If running on the server with AsyncLocalStorage, set locale for this async context
-  try {
-    if (localAsyncStore) {
-      return localAsyncStore.run({ locale }, fn);
-    }
-  } catch {
-    // ignore and fallback
+  if (localAsyncStore) {
+    return localAsyncStore.run({ locale }, fn);
   }
 
   const previousLang = _locale;
@@ -82,15 +77,10 @@ export function withLocale<T>(locale: string, fn: () => T): T {
  * @public
  */
 export function setLocale(locale: string): void {
-  // On the server, prefer setting the locale on the local per-request store
-  try {
-    if (localAsyncStore && localAsyncStore.getStore) {
-      const store = localAsyncStore.getStore();
-      store!.locale = locale;
-      return;
-    }
-  } catch {
-    // ignore and fallback
+  if (localAsyncStore && localAsyncStore.getStore) {
+    const store = localAsyncStore.getStore();
+    store!.locale = locale;
+    return;
   }
   _locale = locale;
 }

From 0e148b711fc8dc3e45b8c284478e502084e7e158 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Tue, 26 Aug 2025 14:21:01 +0800
Subject: [PATCH 09/20] refactor: simplify AsyncLocalStorage usage and improve
 locale retrieval in use-locale.ts

---
 packages/qwik-router/global.d.ts                      |  2 ++
 .../middleware/request-handler/async-request-store.ts |  4 ++--
 .../src/middleware/request-handler/user-response.ts   | 11 +++++------
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/packages/qwik-router/global.d.ts b/packages/qwik-router/global.d.ts
index 12b823070f8..ac5e1996356 100644
--- a/packages/qwik-router/global.d.ts
+++ b/packages/qwik-router/global.d.ts
@@ -6,6 +6,8 @@ type RequestEventInternal =
 type AsyncStore = import('node:async_hooks').AsyncLocalStorage<RequestEventInternal>;
 type SerializationStrategy = import('@qwik.dev/core/internal').SerializationStrategy;
 
+declare var qcAsyncRequestStore: AsyncStore | undefined;
+
 declare var _qwikActionsMap: Map<string, ActionInternal> | undefined;
 
 /** @deprecated Will be removed in v3 */
diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
index fd34f6ae826..72b87db8203 100644
--- a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
+++ b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
@@ -4,8 +4,8 @@ import type { AsyncLocalStorage } from 'node:async_hooks';
 export type AsyncStore = AsyncLocalStorage<RequestEventInternal>;
 
 // Qwik Core will also be using the async store if this is present
-export let asyncRequestStore: AsyncStore | undefined;
+export const asyncRequestStore: AsyncStore | undefined = globalThis.qcAsyncRequestStore;
 
 export const setAsyncRequestStore = (store: AsyncStore | undefined) => {
-  asyncRequestStore = store;
+  globalThis.qcAsyncRequestStore = store;
 };
diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index f94450d61af..d7c5c311207 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -14,8 +14,7 @@ import {
 import { encoder } from './resolve-request-handlers';
 import type { QwikSerializer, ServerRequestEvent, StatusCodes } from './types';
 import { withLocale } from '@qwik.dev/core';
-import { setAsyncRequestStore } from './async-request-store';
-import type { AsyncStore } from './async-request-store';
+import { setAsyncRequestStore, asyncRequestStore } from './async-request-store';
 // Import separately to avoid duplicate imports in the vite dev server
 import {
   AbortMessage,
@@ -30,11 +29,11 @@ export interface QwikRouterRun<T> {
   completion: Promise<unknown>;
 }
 
-let asyncStore: AsyncStore | undefined;
 import('node:async_hooks')
   .then((module) => {
     const AsyncLocalStorage = module.AsyncLocalStorage;
-    asyncStore = new AsyncLocalStorage<RequestEventInternal>();
+    const asyncStore = new AsyncLocalStorage<RequestEventInternal>();
+    console.log('AsyncLocalStorage', asyncStore);
     setAsyncRequestStore(asyncStore);
   })
   .catch((err) => {
@@ -68,8 +67,8 @@ export function runQwikRouter<T>(
     requestEv,
     completion: withLocale(
       requestEv.locale(),
-      asyncStore
-        ? () => asyncStore!.run(requestEv, runNext, requestEv, rebuildRouteInfo, resolve!)
+      asyncRequestStore
+        ? () => asyncRequestStore!.run(requestEv, runNext, requestEv, rebuildRouteInfo, resolve!)
         : () => runNext(requestEv, rebuildRouteInfo, resolve!)
     ),
   };

From c1c07c65fde33ddc4c4bf4eb72381dd2afeb0938 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Tue, 26 Aug 2025 14:24:56 +0800
Subject: [PATCH 10/20] refactor: remove debug log for AsyncLocalStorage in
 user-response.ts

---
 .../qwik-router/src/middleware/request-handler/user-response.ts  | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index d7c5c311207..39100b1e469 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -33,7 +33,6 @@ import('node:async_hooks')
   .then((module) => {
     const AsyncLocalStorage = module.AsyncLocalStorage;
     const asyncStore = new AsyncLocalStorage<RequestEventInternal>();
-    console.log('AsyncLocalStorage', asyncStore);
     setAsyncRequestStore(asyncStore);
   })
   .catch((err) => {

From 888e4df54f10791b91f8b16e581469fd653f42c6 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Tue, 9 Sep 2025 16:08:14 +0800
Subject: [PATCH 11/20] refactor: enhance AsyncLocalStorage integration in
 request handling and locale management

---
 .../request-handler/async-request-store.ts       | 13 +++++++++++++
 .../middleware/request-handler/user-response.ts  | 15 +--------------
 packages/qwik/src/core/use/use-locale.ts         | 16 ++++++----------
 3 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
index 72b87db8203..f286631064f 100644
--- a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
+++ b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
@@ -9,3 +9,16 @@ export const asyncRequestStore: AsyncStore | undefined = globalThis.qcAsyncReque
 export const setAsyncRequestStore = (store: AsyncStore | undefined) => {
   globalThis.qcAsyncRequestStore = store;
 };
+
+import('node:async_hooks')
+  .then((module) => {
+    const AsyncLocalStorage = module.AsyncLocalStorage;
+    const asyncStore = new AsyncLocalStorage<RequestEventInternal>();
+    setAsyncRequestStore(asyncStore);
+  })
+  .catch((err) => {
+    console.warn(
+      'AsyncLocalStorage not available, continuing without it. This might impact concurrent server calls.',
+      err
+    );
+  });
diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index 39100b1e469..b431aa97319 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -14,7 +14,7 @@ import {
 import { encoder } from './resolve-request-handlers';
 import type { QwikSerializer, ServerRequestEvent, StatusCodes } from './types';
 import { withLocale } from '@qwik.dev/core';
-import { setAsyncRequestStore, asyncRequestStore } from './async-request-store';
+import { asyncRequestStore } from './async-request-store';
 // Import separately to avoid duplicate imports in the vite dev server
 import {
   AbortMessage,
@@ -29,19 +29,6 @@ export interface QwikRouterRun<T> {
   completion: Promise<unknown>;
 }
 
-import('node:async_hooks')
-  .then((module) => {
-    const AsyncLocalStorage = module.AsyncLocalStorage;
-    const asyncStore = new AsyncLocalStorage<RequestEventInternal>();
-    setAsyncRequestStore(asyncStore);
-  })
-  .catch((err) => {
-    console.warn(
-      'AsyncLocalStorage not available, continuing without it. This might impact concurrent server calls.',
-      err
-    );
-  });
-
 export function runQwikRouter<T>(
   serverRequestEv: ServerRequestEvent<T>,
   loadedRoute: LoadedRoute | null,
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index 83d545f8f3f..ab7ec99318e 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -4,15 +4,12 @@ import type { AsyncLocalStorage } from 'node:async_hooks';
 
 let _locale: string | undefined = undefined;
 
-let localAsyncStore: AsyncLocalStorage<{ locale?: string }> | undefined;
+let localAsyncStore: AsyncLocalStorage<string> | undefined;
 
 if (isServer) {
   import('node:async_hooks')
     .then((module) => {
-      const AsyncLocalStorage = module.AsyncLocalStorage as unknown as new () => AsyncLocalStorage<{
-        locale?: string;
-      }>;
-      localAsyncStore = new AsyncLocalStorage();
+      localAsyncStore = new module.AsyncLocalStorage();
     })
     .catch(() => {
       // ignore if AsyncLocalStorage is not available
@@ -30,7 +27,7 @@ if (isServer) {
 export function getLocale(defaultLocale?: string): string {
   // Prefer per-request locale from local AsyncLocalStorage if available (server-side)
   if (localAsyncStore) {
-    const locale = localAsyncStore.getStore()?.locale;
+    const locale = localAsyncStore.getStore();
     if (locale) {
       return locale;
     }
@@ -56,7 +53,7 @@ export function getLocale(defaultLocale?: string): string {
  */
 export function withLocale<T>(locale: string, fn: () => T): T {
   if (localAsyncStore) {
-    return localAsyncStore.run({ locale }, fn);
+    return localAsyncStore.run(locale, fn);
   }
 
   const previousLang = _locale;
@@ -77,9 +74,8 @@ export function withLocale<T>(locale: string, fn: () => T): T {
  * @public
  */
 export function setLocale(locale: string): void {
-  if (localAsyncStore && localAsyncStore.getStore) {
-    const store = localAsyncStore.getStore();
-    store!.locale = locale;
+  if (isServer) {
+    // ignore on server; use withLocale() within a request scope instead
     return;
   }
   _locale = locale;

From 1609ffd5b30e997030f1a5e8e6d362f8621e2fbb Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Wed, 10 Sep 2025 18:43:12 +0800
Subject: [PATCH 12/20] refactor: remove server-side check in setLocale and
 update asyncRequestStore initialization

---
 packages/qwik-router/global.d.ts                    |  2 --
 .../request-handler/async-request-store.ts          | 13 ++++---------
 packages/qwik/src/core/use/use-locale.ts            |  4 ----
 3 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/packages/qwik-router/global.d.ts b/packages/qwik-router/global.d.ts
index ac5e1996356..12b823070f8 100644
--- a/packages/qwik-router/global.d.ts
+++ b/packages/qwik-router/global.d.ts
@@ -6,8 +6,6 @@ type RequestEventInternal =
 type AsyncStore = import('node:async_hooks').AsyncLocalStorage<RequestEventInternal>;
 type SerializationStrategy = import('@qwik.dev/core/internal').SerializationStrategy;
 
-declare var qcAsyncRequestStore: AsyncStore | undefined;
-
 declare var _qwikActionsMap: Map<string, ActionInternal> | undefined;
 
 /** @deprecated Will be removed in v3 */
diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
index f286631064f..1f0d5b38e87 100644
--- a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
+++ b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
@@ -3,18 +3,10 @@ import type { AsyncLocalStorage } from 'node:async_hooks';
 
 export type AsyncStore = AsyncLocalStorage<RequestEventInternal>;
 
-// Qwik Core will also be using the async store if this is present
-export const asyncRequestStore: AsyncStore | undefined = globalThis.qcAsyncRequestStore;
-
-export const setAsyncRequestStore = (store: AsyncStore | undefined) => {
-  globalThis.qcAsyncRequestStore = store;
-};
-
 import('node:async_hooks')
   .then((module) => {
     const AsyncLocalStorage = module.AsyncLocalStorage;
-    const asyncStore = new AsyncLocalStorage<RequestEventInternal>();
-    setAsyncRequestStore(asyncStore);
+    asyncRequestStore = new AsyncLocalStorage<RequestEventInternal>();
   })
   .catch((err) => {
     console.warn(
@@ -22,3 +14,6 @@ import('node:async_hooks')
       err
     );
   });
+
+// Qwik Core will also be using the async store if this is present
+export let asyncRequestStore: AsyncStore | undefined = undefined;
diff --git a/packages/qwik/src/core/use/use-locale.ts b/packages/qwik/src/core/use/use-locale.ts
index ab7ec99318e..da62788cc33 100644
--- a/packages/qwik/src/core/use/use-locale.ts
+++ b/packages/qwik/src/core/use/use-locale.ts
@@ -74,9 +74,5 @@ export function withLocale<T>(locale: string, fn: () => T): T {
  * @public
  */
 export function setLocale(locale: string): void {
-  if (isServer) {
-    // ignore on server; use withLocale() within a request scope instead
-    return;
-  }
   _locale = locale;
 }

From ef7579846f77adb499e1c9b1c9a6221ad93470b7 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Wed, 10 Sep 2025 18:56:45 +0800
Subject: [PATCH 13/20] refactor: optimize AsyncLocalStorage handling in locale
 functions and enhance code organization

---
 .../src/routes/locale-concurrent/index.tsx    | 67 +++++++++++++++++++
 .../e2e/qwikrouter/locale-concurrent.e2e.ts   | 37 ++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 starters/apps/qwikrouter-test/src/routes/locale-concurrent/index.tsx
 create mode 100644 starters/e2e/qwikrouter/locale-concurrent.e2e.ts

diff --git a/starters/apps/qwikrouter-test/src/routes/locale-concurrent/index.tsx b/starters/apps/qwikrouter-test/src/routes/locale-concurrent/index.tsx
new file mode 100644
index 00000000000..e0d9c011ce0
--- /dev/null
+++ b/starters/apps/qwikrouter-test/src/routes/locale-concurrent/index.tsx
@@ -0,0 +1,67 @@
+import { component$, Resource, getLocale } from "@qwik.dev/core";
+import type { RequestHandler } from "@qwik.dev/router";
+import { routeLoader$ } from "@qwik.dev/router";
+
+// Simple in-memory barrier to coordinate two concurrent requests in tests.
+type Barrier = {
+  waiters: Set<string>;
+  promise?: Promise<void>;
+  resolve?: () => void;
+};
+
+const barriers = new Map<string, Barrier>();
+
+function getBarrier(group: string): Barrier {
+  let b = barriers.get(group);
+  if (!b) {
+    b = { waiters: new Set() };
+    barriers.set(group, b);
+  }
+  return b;
+}
+
+function waitForBoth(group: string, id: string) {
+  const barrier = getBarrier(group);
+  if (!barrier.promise) {
+    barrier.promise = new Promise<void>(
+      (resolve) => (barrier.resolve = resolve),
+    );
+  }
+  barrier.waiters.add(id);
+  if (barrier.waiters.size >= 2) {
+    barrier.resolve?.();
+  }
+  return barrier.promise!;
+}
+
+export const onRequest: RequestHandler = ({ url, locale }) => {
+  const qpLocale = url.searchParams.get("locale");
+  if (qpLocale) {
+    locale(qpLocale);
+  }
+};
+
+export const useBarrier = routeLoader$(({ url }) => {
+  const group = url.searchParams.get("group") || "default";
+  const id = url.searchParams.get("id") || Math.random().toString(36).slice(2);
+  return waitForBoth(group, id).then(() => ({ done: true }));
+});
+
+export default component$(() => {
+  const barrier = useBarrier();
+  return (
+    <section>
+      <p>
+        Before barrier locale: <span class="locale-before">{getLocale()}</span>
+      </p>
+      <Resource
+        value={barrier}
+        onResolved={() => (
+          <p>
+            After barrier locale: <span class="locale">{getLocale()}</span>
+          </p>
+        )}
+      />
+    </section>
+  );
+});
diff --git a/starters/e2e/qwikrouter/locale-concurrent.e2e.ts b/starters/e2e/qwikrouter/locale-concurrent.e2e.ts
new file mode 100644
index 00000000000..199ee98f42a
--- /dev/null
+++ b/starters/e2e/qwikrouter/locale-concurrent.e2e.ts
@@ -0,0 +1,37 @@
+import { expect, test } from "@playwright/test";
+
+// This test ensures asyncRequestStore locale isolation across concurrent requests.
+// It triggers two concurrent server renders to the same route with different locales,
+// and uses a server-side barrier so the page reveals the locale only after both renders started.
+
+test.describe("Qwik Router concurrent locale", () => {
+  test("should isolate locale per concurrent request", async ({ browser }) => {
+    const ctx1 = await browser.newContext();
+    const ctx2 = await browser.newContext();
+
+    const page1 = await ctx1.newPage();
+    const page2 = await ctx2.newPage();
+
+    const url1 =
+      "/qwikrouter-test/locale-concurrent?group=g&id=one&locale=en-US";
+    const url2 =
+      "/qwikrouter-test/locale-concurrent?group=g&id=two&locale=fr-FR";
+
+    // Start both navigations without waiting them to finish
+    const nav1 = page1.goto(url1);
+    const nav2 = page2.goto(url2);
+
+    await Promise.all([nav1, nav2]);
+
+    // Before barrier render, locale is already set and visible in first block
+    await expect(page1.locator(".locale-before")).toHaveText("en-US");
+    await expect(page2.locator(".locale-before")).toHaveText("fr-FR");
+
+    // After barrier releases, the bottom content renders and must preserve each locale
+    await expect(page1.locator(".locale")).toHaveText("en-US");
+    await expect(page2.locator(".locale")).toHaveText("fr-FR");
+
+    await ctx1.close();
+    await ctx2.close();
+  });
+});

From 1293991437efdfd8038ceabea3158293ce4e20e9 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Thu, 25 Sep 2025 17:04:29 +0800
Subject: [PATCH 14/20] refactor: add server-side check for AsyncLocalStorage
 initialization in async-request-store

---
 .../request-handler/async-request-store.ts    | 25 +++++++++++--------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
index 1f0d5b38e87..e72ff3b538f 100644
--- a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
+++ b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
@@ -1,19 +1,22 @@
+import { isServer } from 'packages/qwik/dist';
 import type { RequestEventInternal } from './request-event';
 import type { AsyncLocalStorage } from 'node:async_hooks';
 
 export type AsyncStore = AsyncLocalStorage<RequestEventInternal>;
 
-import('node:async_hooks')
-  .then((module) => {
-    const AsyncLocalStorage = module.AsyncLocalStorage;
-    asyncRequestStore = new AsyncLocalStorage<RequestEventInternal>();
-  })
-  .catch((err) => {
-    console.warn(
-      'AsyncLocalStorage not available, continuing without it. This might impact concurrent server calls.',
-      err
-    );
-  });
+if (isServer) {
+  import('node:async_hooks')
+    .then((module) => {
+      const AsyncLocalStorage = module.AsyncLocalStorage;
+      asyncRequestStore = new AsyncLocalStorage<RequestEventInternal>();
+    })
+    .catch((err) => {
+      console.warn(
+        'AsyncLocalStorage not available, continuing without it. This might impact concurrent server calls.',
+        err
+      );
+    });
+}
 
 // Qwik Core will also be using the async store if this is present
 export let asyncRequestStore: AsyncStore | undefined = undefined;

From e97bc4066b2ff58635fc56f6ae1525854a7614a9 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 26 Sep 2025 14:50:52 +0800
Subject: [PATCH 15/20] refactor: update import paths for core modules in
 async-request-store and server-functions

---
 .../src/middleware/request-handler/async-request-store.ts       | 2 +-
 packages/qwik-router/src/runtime/src/server-functions.ts        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
index e72ff3b538f..bf05e191813 100644
--- a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
+++ b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
@@ -1,4 +1,4 @@
-import { isServer } from 'packages/qwik/dist';
+import { isServer } from '@qwik.dev/core';
 import type { RequestEventInternal } from './request-event';
 import type { AsyncLocalStorage } from 'node:async_hooks';
 
diff --git a/packages/qwik-router/src/runtime/src/server-functions.ts b/packages/qwik-router/src/runtime/src/server-functions.ts
index 3ba57ada274..32cf842d7e5 100644
--- a/packages/qwik-router/src/runtime/src/server-functions.ts
+++ b/packages/qwik-router/src/runtime/src/server-functions.ts
@@ -64,8 +64,8 @@ import type {
 import { useAction, useLocation, useQwikRouterEnv } from './use-functions';
 
 import type { FormSubmitCompletedDetail } from './form-component';
-import { deepFreeze } from './utils';
 import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
+import { deepFreeze } from './deepFreeze';
 
 /** @internal */
 export const routeActionQrl = ((

From e1bd82c51faeabf4a00d77c43c676f7a1193f55e Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 26 Sep 2025 15:30:57 +0800
Subject: [PATCH 16/20] refactor(router): improve plugin retrieval logic in
 Vite adapter

---
 packages/qwik-router/src/adapters/shared/vite/index.ts | 5 ++---
 packages/qwik-router/src/buildtime/vite/plugin.ts      | 3 ++-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/qwik-router/src/adapters/shared/vite/index.ts b/packages/qwik-router/src/adapters/shared/vite/index.ts
index 708e54926b4..c6f1dc62991 100644
--- a/packages/qwik-router/src/adapters/shared/vite/index.ts
+++ b/packages/qwik-router/src/adapters/shared/vite/index.ts
@@ -48,9 +48,8 @@ export function viteAdapter(opts: ViteAdapterPluginOptions) {
         if (!qwikRouterPlugin) {
           throw new Error('Missing vite-plugin-qwik-router');
         }
-        qwikVitePlugin = config.plugins.find(
-          (p) => p.name === 'vite-plugin-qwik'
-        ) as QwikVitePlugin;
+        const foundQwikPlugin = config.plugins.find((p) => p.name === 'vite-plugin-qwik');
+        qwikVitePlugin = foundQwikPlugin as QwikVitePlugin;
         if (!qwikVitePlugin) {
           throw new Error('Missing vite-plugin-qwik');
         }
diff --git a/packages/qwik-router/src/buildtime/vite/plugin.ts b/packages/qwik-router/src/buildtime/vite/plugin.ts
index 19d2babf251..4569d74bfc2 100644
--- a/packages/qwik-router/src/buildtime/vite/plugin.ts
+++ b/packages/qwik-router/src/buildtime/vite/plugin.ts
@@ -134,7 +134,8 @@ function qwikRouterPlugin(userOpts?: QwikRouterVitePluginOptions): any {
 
       mdxTransform = await createMdxTransformer(ctx);
 
-      qwikPlugin = config.plugins.find((p) => p.name === 'vite-plugin-qwik') as QwikVitePlugin;
+      const foundPlugin = config.plugins.find((p) => p.name === 'vite-plugin-qwik');
+      qwikPlugin = foundPlugin as QwikVitePlugin;
       if (!qwikPlugin) {
         throw new Error('Missing vite-plugin-qwik');
       }

From 412a0e3168162bd8d7920e8635d967ed61dfb93d Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 26 Sep 2025 15:41:20 +0800
Subject: [PATCH 17/20] refactor(router): unify plugin retrieval logic in Vite
 adapter and buildtime plugin

---
 packages/qwik-router/src/adapters/shared/vite/index.ts | 5 +++--
 packages/qwik-router/src/buildtime/vite/plugin.ts      | 6 +++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/qwik-router/src/adapters/shared/vite/index.ts b/packages/qwik-router/src/adapters/shared/vite/index.ts
index c6f1dc62991..e2ff36a3b70 100644
--- a/packages/qwik-router/src/adapters/shared/vite/index.ts
+++ b/packages/qwik-router/src/adapters/shared/vite/index.ts
@@ -48,8 +48,9 @@ export function viteAdapter(opts: ViteAdapterPluginOptions) {
         if (!qwikRouterPlugin) {
           throw new Error('Missing vite-plugin-qwik-router');
         }
-        const foundQwikPlugin = config.plugins.find((p) => p.name === 'vite-plugin-qwik');
-        qwikVitePlugin = foundQwikPlugin as QwikVitePlugin;
+        qwikVitePlugin = config.plugins.find(
+          (p) => p.name === 'vite-plugin-qwik'
+        ) as any as QwikVitePlugin;
         if (!qwikVitePlugin) {
           throw new Error('Missing vite-plugin-qwik');
         }
diff --git a/packages/qwik-router/src/buildtime/vite/plugin.ts b/packages/qwik-router/src/buildtime/vite/plugin.ts
index 4569d74bfc2..3c5e106c388 100644
--- a/packages/qwik-router/src/buildtime/vite/plugin.ts
+++ b/packages/qwik-router/src/buildtime/vite/plugin.ts
@@ -133,9 +133,9 @@ function qwikRouterPlugin(userOpts?: QwikRouterVitePluginOptions): any {
       await validatePlugin(ctx.opts);
 
       mdxTransform = await createMdxTransformer(ctx);
-
-      const foundPlugin = config.plugins.find((p) => p.name === 'vite-plugin-qwik');
-      qwikPlugin = foundPlugin as QwikVitePlugin;
+      qwikPlugin = config.plugins.find(
+        (p) => p.name === 'vite-plugin-qwik'
+      ) as any as QwikVitePlugin;
       if (!qwikPlugin) {
         throw new Error('Missing vite-plugin-qwik');
       }

From bd3925a41b8041baeca6a88d1b2a4aa317217e0b Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 26 Sep 2025 15:54:45 +0800
Subject: [PATCH 18/20] refactor(router): add double type assertion to avoid
 TypeScript stack depth error in plugin retrieval

---
 packages/qwik-router/src/adapters/shared/vite/index.ts | 2 ++
 packages/qwik-router/src/buildtime/vite/plugin.ts      | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/packages/qwik-router/src/adapters/shared/vite/index.ts b/packages/qwik-router/src/adapters/shared/vite/index.ts
index e2ff36a3b70..8debe3c08b0 100644
--- a/packages/qwik-router/src/adapters/shared/vite/index.ts
+++ b/packages/qwik-router/src/adapters/shared/vite/index.ts
@@ -48,6 +48,8 @@ export function viteAdapter(opts: ViteAdapterPluginOptions) {
         if (!qwikRouterPlugin) {
           throw new Error('Missing vite-plugin-qwik-router');
         }
+        // Use double type assertion to avoid TS "Excessive stack depth comparing types" error
+        // when comparing QwikVitePlugin with Plugin types
         qwikVitePlugin = config.plugins.find(
           (p) => p.name === 'vite-plugin-qwik'
         ) as any as QwikVitePlugin;
diff --git a/packages/qwik-router/src/buildtime/vite/plugin.ts b/packages/qwik-router/src/buildtime/vite/plugin.ts
index 3c5e106c388..79a23097022 100644
--- a/packages/qwik-router/src/buildtime/vite/plugin.ts
+++ b/packages/qwik-router/src/buildtime/vite/plugin.ts
@@ -133,6 +133,8 @@ function qwikRouterPlugin(userOpts?: QwikRouterVitePluginOptions): any {
       await validatePlugin(ctx.opts);
 
       mdxTransform = await createMdxTransformer(ctx);
+      // Use double type assertion to avoid TS "Excessive stack depth comparing types" error
+      // when comparing QwikVitePlugin with Plugin types
       qwikPlugin = config.plugins.find(
         (p) => p.name === 'vite-plugin-qwik'
       ) as any as QwikVitePlugin;

From f815a3279eec6a079cf075faa65a9002cd4e7b51 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Fri, 26 Sep 2025 16:41:12 +0800
Subject: [PATCH 19/20] refactor(router): enhance head resolution logic to
 support async request store

---
 packages/qwik-router/src/runtime/src/head.ts | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index fdb00342d15..ec3edf63565 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -14,6 +14,7 @@ import type {
   ContentModuleHead,
 } from './types';
 import { isPromise } from './utils';
+import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
 
 export const resolveHead = (
   endpoint: EndpointResponse | ClientPageData,
@@ -53,18 +54,25 @@ export const resolveHead = (
     }
   }
   if (fns.length) {
+    const hasAsyncStore = !!asyncRequestStore;
     const headProps: DocumentHeadProps = {
       head,
-      withLocale: (fn) => withLocale(locale, fn),
+      withLocale: hasAsyncStore ? (fn) => fn() : (fn) => withLocale(locale, fn),
       resolveValue: getData,
       ...routeLocation,
     };
 
-    withLocale(locale, () => {
+    if (hasAsyncStore) {
       for (const fn of fns) {
         resolveDocumentHead(head, fn(headProps));
       }
-    });
+    } else {
+      withLocale(locale, () => {
+        for (const fn of fns) {
+          resolveDocumentHead(head, fn(headProps));
+        }
+      });
+    }
   }
 
   return head;

From a50d819bb324f652ff8573320e16ae1a7250ca31 Mon Sep 17 00:00:00 2001
From: Jerry_Wu <409187100@qq.com>
Date: Sun, 28 Sep 2025 15:27:23 +0800
Subject: [PATCH 20/20] refactor(router): replace asyncRequestStore with global
 qcAsyncRequestStore for improved async handling

---
 packages/qwik-router/global.d.ts              |  2 +-
 .../request-handler/async-request-store.ts    | 22 -------------------
 .../request-handler/request-event.ts          |  4 ++--
 .../request-handler/user-response.ts          | 18 ++++++++++++---
 packages/qwik-router/src/runtime/src/head.ts  | 14 +++---------
 .../src/runtime/src/server-functions.ts       |  3 +--
 6 files changed, 22 insertions(+), 41 deletions(-)
 delete mode 100644 packages/qwik-router/src/middleware/request-handler/async-request-store.ts

diff --git a/packages/qwik-router/global.d.ts b/packages/qwik-router/global.d.ts
index c94b51763b8..cc81dcec280 100644
--- a/packages/qwik-router/global.d.ts
+++ b/packages/qwik-router/global.d.ts
@@ -5,7 +5,7 @@ type RequestEventInternal =
   import('./middleware/request-handler/request-event').RequestEventInternal;
 type AsyncStore = import('node:async_hooks').AsyncLocalStorage<RequestEventInternal>;
 type SerializationStrategy = import('@qwik.dev/core/internal').SerializationStrategy;
-
+declare var qcAsyncRequestStore: AsyncStore | undefined;
 declare var _qwikActionsMap: Map<string, ActionInternal> | undefined;
 
 type ExperimentalFeatures = import('@qwik.dev/core/optimizer').ExperimentalFeatures;
diff --git a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts b/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
deleted file mode 100644
index bf05e191813..00000000000
--- a/packages/qwik-router/src/middleware/request-handler/async-request-store.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-import { isServer } from '@qwik.dev/core';
-import type { RequestEventInternal } from './request-event';
-import type { AsyncLocalStorage } from 'node:async_hooks';
-
-export type AsyncStore = AsyncLocalStorage<RequestEventInternal>;
-
-if (isServer) {
-  import('node:async_hooks')
-    .then((module) => {
-      const AsyncLocalStorage = module.AsyncLocalStorage;
-      asyncRequestStore = new AsyncLocalStorage<RequestEventInternal>();
-    })
-    .catch((err) => {
-      console.warn(
-        'AsyncLocalStorage not available, continuing without it. This might impact concurrent server calls.',
-        err
-      );
-    });
-}
-
-// Qwik Core will also be using the async store if this is present
-export let asyncRequestStore: AsyncStore | undefined = undefined;
diff --git a/packages/qwik-router/src/middleware/request-handler/request-event.ts b/packages/qwik-router/src/middleware/request-handler/request-event.ts
index 00a79bfd30e..8b36afd4a92 100644
--- a/packages/qwik-router/src/middleware/request-handler/request-event.ts
+++ b/packages/qwik-router/src/middleware/request-handler/request-event.ts
@@ -20,7 +20,7 @@ import {
   RewriteMessage,
 } from '@qwik.dev/router/middleware/request-handler';
 import { encoder, getRouteLoaderPromise } from './resolve-request-handlers';
-import { asyncRequestStore } from './async-request-store';
+
 import type {
   CacheControl,
   CacheControlTarget,
@@ -81,7 +81,7 @@ export function createRequestEvent(
 
     while (routeModuleIndex < requestHandlers.length) {
       const moduleRequestHandler = requestHandlers[routeModuleIndex];
-      const asyncStore = asyncRequestStore;
+      const asyncStore = globalThis.qcAsyncRequestStore;
       const result = asyncStore?.run
         ? asyncStore.run(requestEv, moduleRequestHandler, requestEv)
         : moduleRequestHandler(requestEv);
diff --git a/packages/qwik-router/src/middleware/request-handler/user-response.ts b/packages/qwik-router/src/middleware/request-handler/user-response.ts
index 11d031f5529..f43f0e6564e 100644
--- a/packages/qwik-router/src/middleware/request-handler/user-response.ts
+++ b/packages/qwik-router/src/middleware/request-handler/user-response.ts
@@ -9,7 +9,6 @@ import { getErrorHtml } from './error-handler';
 import { createRequestEvent, getRequestMode, type RequestEventInternal } from './request-event';
 import { encoder } from './resolve-request-handlers';
 import { withLocale } from '@qwik.dev/core';
-import { asyncRequestStore } from './async-request-store';
 import type { ServerRequestEvent, StatusCodes } from './types';
 // Import separately to avoid duplicate imports in the vite dev server
 import {
@@ -19,6 +18,19 @@ import {
   ServerError,
 } from '@qwik.dev/router/middleware/request-handler';
 
+let asyncStore: AsyncStore | undefined;
+import('node:async_hooks')
+  .then((module) => {
+    const AsyncLocalStorage = module.AsyncLocalStorage;
+    asyncStore = new AsyncLocalStorage<RequestEventInternal>();
+    globalThis.qcAsyncRequestStore = asyncStore;
+  })
+  .catch((err) => {
+    console.warn(
+      'AsyncLocalStorage not available, continuing without it. This might impact concurrent server calls.',
+      err
+    );
+  });
 export interface QwikRouterRun<T> {
   response: Promise<T | null>;
   requestEv: RequestEvent;
@@ -47,8 +59,8 @@ export function runQwikRouter<T>(
     requestEv,
     completion: withLocale(
       requestEv.locale(),
-      asyncRequestStore
-        ? () => asyncRequestStore!.run(requestEv, runNext, requestEv, rebuildRouteInfo, resolve!)
+      asyncStore
+        ? () => asyncStore!.run(requestEv, runNext, requestEv, rebuildRouteInfo, resolve!)
         : () => runNext(requestEv, rebuildRouteInfo, resolve!)
     ),
   };
diff --git a/packages/qwik-router/src/runtime/src/head.ts b/packages/qwik-router/src/runtime/src/head.ts
index ec3edf63565..fdb00342d15 100644
--- a/packages/qwik-router/src/runtime/src/head.ts
+++ b/packages/qwik-router/src/runtime/src/head.ts
@@ -14,7 +14,6 @@ import type {
   ContentModuleHead,
 } from './types';
 import { isPromise } from './utils';
-import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
 
 export const resolveHead = (
   endpoint: EndpointResponse | ClientPageData,
@@ -54,25 +53,18 @@ export const resolveHead = (
     }
   }
   if (fns.length) {
-    const hasAsyncStore = !!asyncRequestStore;
     const headProps: DocumentHeadProps = {
       head,
-      withLocale: hasAsyncStore ? (fn) => fn() : (fn) => withLocale(locale, fn),
+      withLocale: (fn) => withLocale(locale, fn),
       resolveValue: getData,
       ...routeLocation,
     };
 
-    if (hasAsyncStore) {
+    withLocale(locale, () => {
       for (const fn of fns) {
         resolveDocumentHead(head, fn(headProps));
       }
-    } else {
-      withLocale(locale, () => {
-        for (const fn of fns) {
-          resolveDocumentHead(head, fn(headProps));
-        }
-      });
-    }
+    });
   }
 
   return head;
diff --git a/packages/qwik-router/src/runtime/src/server-functions.ts b/packages/qwik-router/src/runtime/src/server-functions.ts
index 32cf842d7e5..323486d30a1 100644
--- a/packages/qwik-router/src/runtime/src/server-functions.ts
+++ b/packages/qwik-router/src/runtime/src/server-functions.ts
@@ -64,7 +64,6 @@ import type {
 import { useAction, useLocation, useQwikRouterEnv } from './use-functions';
 
 import type { FormSubmitCompletedDetail } from './form-component';
-import { asyncRequestStore } from '../../middleware/request-handler/async-request-store';
 import { deepFreeze } from './deepFreeze';
 
 /** @internal */
@@ -421,7 +420,7 @@ export const serverQrl = <T extends ServerFunction>(
 
       if (isServer) {
         // Running during SSR, we can call the function directly
-        let requestEvent = asyncRequestStore?.getStore() as RequestEvent | undefined;
+        let requestEvent = globalThis.qcAsyncRequestStore?.getStore() as RequestEvent | undefined;
 
         if (!requestEvent) {
           const contexts = [useQwikRouterEnv()?.ev, this, _getContextEvent()] as RequestEvent[];