diff --git a/e2e/pages/ManageUsersPanel.ts b/e2e/pages/ManageUsersPanel.ts
new file mode 100644
index 0000000..40eafb0
--- /dev/null
+++ b/e2e/pages/ManageUsersPanel.ts
@@ -0,0 +1,109 @@
+import { type Page, type Locator } from '@playwright/test';
+import { BasePage, waitForVisible, waitForHidden } from '@levkin/playkit';
+
+export interface NewUserInput {
+  email: string;
+  password: string;
+  name: string;
+  isAdmin?: boolean;
+  hasWriteAccess?: boolean;
+}
+
+/**
+ * Page object for the "Manage Users" overlay content
+ * (`viewer-frontend/app/admin/users/ManageUsersContent.tsx`).
+ *
+ * Talks to the NextAuth-backed `/api/users` store — a separate account
+ * database from the FastAPI `/api/v1/users` store covered by
+ * `api.role-permissions.spec.ts`.
+ */
+export class ManageUsersPanel extends BasePage {
+  constructor(page: Page, baseUrl: string) {
+    super(page, baseUrl);
+  }
+
+  row(email: string): Locator {
+    return this.page.locator('tbody tr').filter({ hasText: email });
+  }
+
+  /** Scopes to the currently-open dialog matching a heading, to avoid
+   * ambiguous matches against hidden/portalled sibling dialogs. */
+  private dialog(headingText: string): Locator {
+    return this.page
+      .getByRole('dialog')
+      .filter({ has: this.page.getByRole('heading', { name: headingText, exact: true }) });
+  }
+
+  async createUser(input: NewUserInput): Promise<void> {
+    await this.click(this.page.getByRole('button', { name: 'Add User', exact: true }));
+    const dialog = this.dialog('Add New User');
+    await waitForVisible(dialog);
+    await this.fill(dialog.locator('#add-email'), input.email);
+    await this.fill(dialog.locator('#add-password'), input.password);
+    await this.fill(dialog.locator('#add-name'), input.name);
+    if (input.isAdmin) {
+      await this.click(dialog.locator('#add-role'));
+      await this.click(this.page.getByRole('option', { name: 'Admin', exact: true }));
+    }
+    if (input.hasWriteAccess) {
+      await this.click(dialog.locator('#add-write-access'));
+    }
+    await this.click(dialog.getByRole('button', { name: 'Create User', exact: true }));
+    await waitForVisible(this.row(input.email), { timeout: 15_000 });
+  }
+
+  async openEditDialog(email: string): Promise<void> {
+    await this.click(this.row(email).getByRole('button', { name: `Edit ${email}`, exact: true }));
+    await waitForVisible(this.dialog('Edit User'));
+  }
+
+  private async setCheckbox(locator: Locator, checked: boolean): Promise<void> {
+    const isChecked = await locator.isChecked();
+    if (isChecked !== checked) {
+      await this.click(locator);
+    }
+  }
+
+  async setActive(active: boolean): Promise<void> {
+    await this.setCheckbox(this.dialog('Edit User').locator('#edit-active'), active);
+  }
+
+  async setWriteAccess(enabled: boolean): Promise<void> {
+    await this.setCheckbox(this.dialog('Edit User').locator('#edit-write-access'), enabled);
+  }
+
+  async saveEdit(): Promise<void> {
+    const dialog = this.dialog('Edit User');
+    await this.click(dialog.getByRole('button', { name: 'Save Changes', exact: true }));
+    await waitForHidden(dialog);
+  }
+
+  /** Clicks the row's delete/deactivate icon and confirms in the dialog.
+   * Hard-deletes if the account has no related records, otherwise the
+   * backend soft-deactivates it — either way `isActive` ends up false. */
+  async deleteUser(email: string): Promise<void> {
+    await this.click(
+      this.row(email).getByRole('button', { name: `Deactivate ${email}`, exact: true }),
+    );
+    const dialog = this.dialog('Delete User');
+    await waitForVisible(dialog);
+    await this.click(dialog.getByRole('button', { name: 'Delete', exact: true }));
+    await waitForHidden(dialog);
+  }
+
+  async statusBadgeText(email: string): Promise<string> {
+    return (await this.row(email).locator('td').nth(2).innerText()).trim();
+  }
+
+  async roleBadgeText(email: string): Promise<string> {
+    return (await this.row(email).locator('td').nth(3).innerText()).trim();
+  }
+
+  async writeAccessText(email: string): Promise<string> {
+    return (await this.row(email).locator('td').nth(4).innerText()).trim();
+  }
+
+  async waitForRowGone(email: string, timeout = 15_000): Promise<void> {
+    await waitForHidden(this.row(email), { timeout });
+  }
+}
diff --git a/e2e/tests/admin.manage-users-actions.spec.ts b/e2e/tests/admin.manage-users-actions.spec.ts
new file mode 100644
index 0000000..55fb5b2
--- /dev/null
+++ b/e2e/tests/admin.manage-users-actions.spec.ts
@@ -0,0 +1,153 @@
+import type { Page } from '@playwright/test';
+import { test, expect } from '../fixtures';
+import { LoginPage } from '../pages/LoginPage';
+
+/**
+ * Real Manage Users CRUD through the admin UI (`admin.manage-users.spec.ts`
+ * only opens/closes the panel — it never exercises create/edit/delete), plus
+ * a causal cross-session check: an admin deactivating a user immediately
+ * signs that user out of their *already open* session, because the NextAuth
+ * `jwt` callback re-checks `isActive` from the DB on every request (see
+ * `viewer-frontend/app/api/auth/[...nextauth]/route.ts`, issue #57 fix).
+ *
+ * punimtagdev shares its Postgres DB with MirrorMatch and reuses the same
+ * pre-seeded accounts as other specs (E2E_ADMIN_EMAIL, E2E_VIEWER_EMAIL), so
+ * every test here creates its own disposable `e2e-manage-test-*` account and
+ * deletes it in a `finally`, regardless of outcome.
+ */
+function throwawayEmail(tag: string): string {
+  return `e2e-manage-test-${tag}-${Date.now()}@e2e.invalid`;
+}
+
+const THROWAWAY_PASSWORD = 'E2eThrowaway!123';
+
+interface AdminUser {
+  id: number;
+  email: string;
+}
+
+/** Best-effort cleanup — looks the account up by email since we may not
+ * have its id if the test failed before/during creation. */
+async function deleteUserByEmail(page: Page, baseUrl: string, email: string): Promise<void> {
+  const res = await page.request.get(`${baseUrl}/api/users?status=all`);
+  if (!res.ok()) return;
+  const body = (await res.json()) as { users?: AdminUser[] };
+  const match = body.users?.find((u) => u.email === email);
+  if (match) {
+    await page.request.delete(`${baseUrl}/api/users/${match.id}`);
+  }
+}
+
+test.describe('admin manage users: create/edit/delete @smoke', () => {
+  test('admin can create, edit, and delete a user through the panel', async ({
+    page,
+    playkitConfig,
+    loginPage,
+    accountMenu,
+    manageUsersPanel,
+    e2eCredentials,
+    timings,
+  }) => {
+    test.skip(!e2eCredentials, 'E2E_ADMIN_EMAIL/PASSWORD required (admin user)');
+    const email = throwawayEmail('crud');
+
+    try {
+      await loginPage.openLogin();
+      await loginPage.signIn(e2eCredentials!.email, e2eCredentials!.password);
+      await page.waitForURL((url) => !url.pathname.includes('/login'), { timeout: 30_000 });
+      await page.getByLabel('Account menu').waitFor({ state: 'visible', timeout: 30_000 });
+
+      await accountMenu.openManageUsers();
+
+      await timings.measure('create_user', () =>
+        manageUsersPanel.createUser({ email, password: THROWAWAY_PASSWORD, name: 'E2E Throwaway' }),
+      );
+      expect(await manageUsersPanel.statusBadgeText(email)).toMatch(/active/i);
+      expect(await manageUsersPanel.roleBadgeText(email)).toMatch(/user/i);
+      expect(await manageUsersPanel.writeAccessText(email)).toMatch(/no/i);
+
+      await timings.measure('edit_user', async () => {
+        await manageUsersPanel.openEditDialog(email);
+        await manageUsersPanel.setWriteAccess(true);
+        await manageUsersPanel.saveEdit();
+      });
+      expect(await manageUsersPanel.writeAccessText(email)).toMatch(/yes/i);
+
+      await timings.measure('delete_user', () => manageUsersPanel.deleteUser(email));
+      await manageUsersPanel.waitForRowGone(email);
+
+      await accountMenu.closeManageUsers();
+    } finally {
+      await deleteUserByEmail(page, playkitConfig.baseUrl, email).catch(() => undefined);
+    }
+  });
+});
+
+test.describe('admin manage users: causal cross-session effect @smoke', () => {
+  test('deactivating a user via admin UI immediately revokes their open session', async ({
+    browser,
+    page,
+    playkitConfig,
+    loginPage,
+    accountMenu,
+    manageUsersPanel,
+    e2eCredentials,
+    timings,
+  }) => {
+    test.skip(!e2eCredentials, 'E2E_ADMIN_EMAIL/PASSWORD required (admin user)');
+    const email = throwawayEmail('deactivate');
+    let userContext: import('@playwright/test').BrowserContext | undefined;
+
+    try {
+      await loginPage.openLogin();
+      await loginPage.signIn(e2eCredentials!.email, e2eCredentials!.password);
+      await page.waitForURL((url) => !url.pathname.includes('/login'), { timeout: 30_000 });
+      await page.getByLabel('Account menu').waitFor({ state: 'visible', timeout: 30_000 });
+
+      await accountMenu.openManageUsers();
+      await timings.measure('create_throwaway', () =>
+        manageUsersPanel.createUser({ email, password: THROWAWAY_PASSWORD, name: 'E2E Throwaway' }),
+      );
+      await accountMenu.closeManageUsers();
+
+      // Independent second session/actor — the throwaway user, logged in
+      // for real, concurrently with the admin.
+      userContext = await browser.newContext();
+      const userPage = await userContext.newPage();
+      const userLogin = new LoginPage(userPage, playkitConfig.baseUrl);
+
+      await timings.measure('throwaway_login', async () => {
+        await userLogin.openLogin();
+        await userLogin.signIn(email, THROWAWAY_PASSWORD);
+        await userPage.waitForURL((url) => !url.pathname.includes('/login'), { timeout: 30_000 });
+        await userPage.getByLabel('Account menu').waitFor({ state: 'visible', timeout: 30_000 });
+      });
+
+      const preRes = await userPage.request.get(`${playkitConfig.baseUrl}/api/auth/session`);
+      const preBody = await preRes.json();
+      expect(preBody?.user?.email).toBe(email);
+
+      // Admin deactivates the throwaway user. The throwaway user's session
+      // is never touched directly — no sign-out, no reload triggered by us.
+      await accountMenu.openManageUsers();
+      await timings.measure('deactivate_user', async () => {
+        await manageUsersPanel.openEditDialog(email);
+        await manageUsersPanel.setActive(false);
+        await manageUsersPanel.saveEdit();
+      });
+      expect(await manageUsersPanel.statusBadgeText(email)).toMatch(/inactive/i);
+      await accountMenu.closeManageUsers();
+
+      // The already-open session must now read as signed-out: the jwt
+      // callback re-checks `isActive` against the DB on every request.
+      await timings.measure('session_revoked', async () => {
+        const postRes = await userPage.request.get(`${playkitConfig.baseUrl}/api/auth/session`);
+        const postBody = await postRes.json();
+        expect(postBody?.user).toBeFalsy();
+      });
+    } finally {
+      await userContext?.close();
+      await deleteUserByEmail(page, playkitConfig.baseUrl, email).catch(() => undefined);
+    }
+  });
+});