diff --git a/CLAUDE.md b/CLAUDE.md
index f08dbb8..1f09a8f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -219,6 +219,7 @@ Write tests first or alongside features. Tests serve as living documentation of
 - Config: `playwright.config.ts` (Chromium only, builds + previews app on port 4173)
 - Test database: `./data/test-crumbs.db` (cleaned via `global-setup.ts`)
 - Auth fixture: `tests/e2e/helpers/fixtures.ts` provides `authenticatedPage` (handles setup/login race conditions across parallel workers)
+- **Shared login state**: `tests/e2e/auth.setup.ts` (project `login-state`) logs in once and saves the admin session cookie to `data/test-storage-state.json`; the `app` project loads it into every context so tests start authenticated instead of submitting the login form each time. A spec that needs an anonymous baseline opts out with `test.use({ storageState: { cookies: [], origins: [] } })` (see `pwa.spec.ts`, `mcp.spec.ts`). Never write a test that revokes or logs out the admin's own session — it would break every test in other workers
 - Auth tests use `test.describe.serial` because they depend on sequential database state
 - **Offline/online tests**: After `setOffline(false)`, always manually dispatch the `online` event via `page.evaluate(() => window.dispatchEvent(new Event('online')))` — Playwright doesn't reliably emit it in headless/CI environments, causing flaky `waitForResponse` timeouts
 
diff --git a/playwright.config.ts b/playwright.config.ts
index 7d942cc..aa0f1bb 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -1,4 +1,5 @@
 import { defineConfig, devices } from '@playwright/test';
+import { STORAGE_STATE_FILE } from './tests/e2e/global-setup';
 
 export default defineConfig({
 	testDir: './tests/e2e',
@@ -22,10 +23,20 @@ export default defineConfig({
 			use: { ...devices['Desktop Chrome'] }
 		},
 		{
-			name: 'app',
-			testIgnore: 'auth.spec.ts',
+			// Logs in once and saves the session cookie for the `app` project.
+			name: 'login-state',
+			testMatch: 'auth.setup.ts',
 			dependencies: ['auth-setup'],
 			use: { ...devices['Desktop Chrome'] }
+		},
+		{
+			name: 'app',
+			testIgnore: ['auth.spec.ts', 'auth.setup.ts'],
+			dependencies: ['login-state'],
+			// Every context starts with the admin already logged in. Specs that
+			// need an unauthenticated baseline opt out with
+			// `test.use({ storageState: { cookies: [], origins: [] } })`.
+			use: { ...devices['Desktop Chrome'], storageState: STORAGE_STATE_FILE }
 		}
 	],
 	webServer: {
diff --git a/tests/e2e/auth.setup.ts b/tests/e2e/auth.setup.ts
new file mode 100644
index 0000000..50ced7b
--- /dev/null
+++ b/tests/e2e/auth.setup.ts
@@ -0,0 +1,18 @@
+import { test as setup } from '@playwright/test';
+import { setupAndLogin } from './helpers/fixtures';
+import { STORAGE_STATE_FILE } from './global-setup';
+
+/**
+ * Log in as the admin once and persist the session cookie. The `app` project
+ * loads this storage state into every browser context, so tests start already
+ * authenticated instead of each one submitting the login form (~0.8s per test,
+ * roughly half of a typical test's duration).
+ *
+ * The admin's own session is never revoked by any test: admin-users only
+ * resets/revokes victim accounts, and auth.spec's logout scenario runs in the
+ * auth-setup project with its own context before this setup executes.
+ */
+setup('authenticate as admin and save storage state', async ({ page }) => {
+	await setupAndLogin(page);
+	await page.context().storageState({ path: STORAGE_STATE_FILE });
+});
diff --git a/tests/e2e/global-setup.ts b/tests/e2e/global-setup.ts
index 7139a3b..889fd9d 100644
--- a/tests/e2e/global-setup.ts
+++ b/tests/e2e/global-setup.ts
@@ -2,6 +2,8 @@ import { writeFileSync } from 'fs';
 import { randomUUID } from 'crypto';
 
 export const TEST_CREDENTIALS_FILE = './data/test-credentials.json';
+/** Admin session cookie captured by auth.setup.ts and shared by the `app` project. */
+export const STORAGE_STATE_FILE = './data/test-storage-state.json';
 
 export default function globalSetup() {
 	// The test database is wiped before the webServer starts (see the
diff --git a/tests/e2e/mcp.spec.ts b/tests/e2e/mcp.spec.ts
index 5f972c1..12ca86f 100644
--- a/tests/e2e/mcp.spec.ts
+++ b/tests/e2e/mcp.spec.ts
@@ -9,6 +9,10 @@ import { setupAndLogin } from './helpers/fixtures.js';
  * 3. Test tool invocations via JSON-RPC over Streamable HTTP
  */
 
+// Start unauthenticated: the "rejects requests without API key" scenario must
+// not carry the shared admin session cookie, and the apiKey fixture logs in itself.
+base.use({ storageState: { cookies: [], origins: [] } });
+
 const test = base.extend<{ apiKey: string }>({
 	apiKey: async ({ page }, use) => {
 		await setupAndLogin(page);
diff --git a/tests/e2e/pwa.spec.ts b/tests/e2e/pwa.spec.ts
index 32d9d02..57e2b43 100644
--- a/tests/e2e/pwa.spec.ts
+++ b/tests/e2e/pwa.spec.ts
@@ -1,5 +1,9 @@
 import { test, expect } from '@playwright/test';
 
+// These scenarios describe what an anonymous visitor receives, so drop the
+// shared admin session the `app` project injects.
+test.use({ storageState: { cookies: [], origins: [] } });
+
 test.describe('PWA', () => {
 	test('Scenario: Web manifest provides correct app metadata', async ({ page }) => {
 		// When the browser requests the web manifest