diff --git a/e2e/fixtures.ts b/e2e/fixtures.ts
index 07e12e6..921d9a4 100644
--- a/e2e/fixtures.ts
+++ b/e2e/fixtures.ts
@@ -1,4 +1,4 @@
-import { test as base, expect } from "@playwright/test";
+import { test as base, expect, type Page } from "@playwright/test";
 import AxeBuilder from "@axe-core/playwright";
 
 export const test = base.extend<{ axeCheck: void }>({
@@ -10,3 +10,96 @@ export const test = base.extend<{ axeCheck: void }>({
 });
 
 export { expect } from "@playwright/test";
+
+const MOCK_USER_ID = "mock_user_123";
+const MOCK_SESSION_ID = "mock_session_456";
+
+function mockAuthRoutes(page: Page, authenticated = false) {
+  page.route(/\/auth\/register/, async (route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({
+        user: {
+          id: MOCK_USER_ID,
+          email: "mock@cartsnitch.test",
+          name: "Mock User",
+          emailVerified: true,
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+        },
+        session: {
+          id: MOCK_SESSION_ID,
+          userId: MOCK_USER_ID,
+          expiresAt: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000).toISOString(),
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+          ipAddress: null,
+          userAgent: null,
+        },
+      }),
+    });
+  });
+
+  page.route(/\/auth\/sign-in\/email/, async (route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({
+        user: {
+          id: MOCK_USER_ID,
+          email: "mock@cartsnitch.test",
+          name: "Mock User",
+          emailVerified: true,
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+        },
+        session: {
+          id: MOCK_SESSION_ID,
+          userId: MOCK_USER_ID,
+          expiresAt: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000).toISOString(),
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+          ipAddress: null,
+          userAgent: null,
+        },
+      }),
+    });
+  });
+
+  page.route(/\/auth\/session/, async (route) => {
+    if (authenticated) {
+      await route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({
+          session: {
+            id: MOCK_SESSION_ID,
+            userId: MOCK_USER_ID,
+            expiresAt: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000).toISOString(),
+            createdAt: new Date().toISOString(),
+            updatedAt: new Date().toISOString(),
+            ipAddress: null,
+            userAgent: null,
+          },
+          user: {
+            id: MOCK_USER_ID,
+            email: "mock@cartsnitch.test",
+            name: "Mock User",
+            emailVerified: true,
+            createdAt: new Date().toISOString(),
+            updatedAt: new Date().toISOString(),
+          },
+        }),
+      });
+    } else {
+      await route.fulfill({
+        status: 401,
+        contentType: "application/json",
+        body: JSON.stringify({ error: "Unauthorized" }),
+      });
+    }
+  });
+}
+
+export { mockAuthRoutes };
diff --git a/e2e/journeys/j1-registration-login.spec.ts b/e2e/journeys/j1-registration-login.spec.ts
index ec116ab..e860f4f 100644
--- a/e2e/journeys/j1-registration-login.spec.ts
+++ b/e2e/journeys/j1-registration-login.spec.ts
@@ -1,16 +1,17 @@
 import { test, expect } from '@playwright/test';
+import { mockAuthRoutes } from '../fixtures';
 
 const uniqueEmail = () => `betty+e2e-${Date.now()}@cartsnitch.test`;
 
 test.describe('J1: Registration and Login', () => {
   test('can register a new account and lands on dashboard', async ({ page }) => {
+    mockAuthRoutes(page, true);
     await page.goto('/register');
     await page.fill('[placeholder="Full Name"]', 'Betty Tester');
     await page.fill('[placeholder="Email"]', uniqueEmail());
     await page.fill('[placeholder="Password (min. 8 characters)"]', 'TestPass123!');
     await page.click('button[type="submit"]');
 
-    // With VITE_MOCK_AUTH=true the app navigates to "/" on success
     await expect(page).toHaveURL('http://localhost:5173/');
     await expect(page.getByRole('heading', { name: /cart/i })).toBeVisible();
   });
@@ -31,8 +32,8 @@ test.describe('J1: Registration and Login', () => {
   });
 
   test('can sign in with credentials and land on dashboard', async ({ page }) => {
-    // Register first so we have a real account
     const email = uniqueEmail();
+    mockAuthRoutes(page, true);
     await page.goto('/register');
     await page.fill('[placeholder="Full Name"]', 'Login Betty');
     await page.fill('[placeholder="Email"]', email);
@@ -40,11 +41,9 @@ test.describe('J1: Registration and Login', () => {
     await page.click('button[type="submit"]');
     await expect(page).toHaveURL('http://localhost:5173/');
 
-    // Sign out by clearing the mock session (reload with no session)
     await page.goto('/');
     await page.reload();
 
-    // Now sign in
     await page.goto('/login');
     await page.fill('[placeholder="Email"]', email);
     await page.fill('[placeholder="Password"]', 'TestPass123!');
diff --git a/playwright.config.ts b/playwright.config.ts
index b22d74a..a2d7b0b 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -9,7 +9,7 @@ export default defineConfig({
     },
   ],
   webServer: {
-    command: 'VITE_MOCK_AUTH=true npm run dev',
+    command: 'npm run dev',
     url: 'http://localhost:5173',
     reuseExistingServer: !process.env.CI,
   },