fix(tanstack-react-start): Apply response headers

.changeset/puny-brooms-grab.md

@@ -0,0 +1,5 @@
+---
+'@clerk/tanstack-react-start': patch
+---
+
+Apply Clerk response headers

integration/tests/tanstack-start/basic.test.ts

@@ -71,5 +71,15 @@ testAgainstRunningApps({ withEnv: [appConfigs.envs.withEmailCodes] })(
 
       expect(clerkInitialState !== undefined).toBeTruthy();
     });
+
+    test('clerk handler sets headers', async ({ page, context }) => {
+      const u = createTestUtils({ app, page, context });
+      const r = await u.po.signIn.goTo();
+
+      expect(r.headers()).toContain({
+        'x-clerk-auth-reason': 'session-token-and-uat-missing',
+        'x-clerk-auth-status': 'signed-out',
+      });
+    });
   },
 );

packages/tanstack-react-start/src/server/middlewareHandler.ts

@@ -24,11 +24,16 @@ export function createClerkHandler<TRouter extends AnyRouter>(
 
         const requestState = await authenticateRequest(request, loadedOptions);
 
-        const clerkInitialState = getResponseClerkState(requestState, loadedOptions);
+        const { clerkInitialState, headers } = getResponseClerkState(requestState, loadedOptions);
 
         // Merging the TanStack router context with the Clerk context and loading the router
         router.update({
-          context: { ...router.options.context, ...clerkInitialState },
+          context: { ...router.options.context, clerkInitialState },
+        });
+
+        // Adding the Clerk response headers to the response
+        headers.forEach((value, key) => {
+          responseHeaders.set(key, value);
         });
 
         await router.load();