diff --git a/src/main/index.ts b/src/main/index.ts
index 8b9f58646..557b3d008 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -14,16 +14,10 @@ import {
   registerUpdaterHandlers,
 } from './handlers';
 import { getIdleTrayIcon } from './icons';
-import {
-  configureWindowEvents,
-  handleProtocolURL,
-  initializeAppLifecycle,
-  onFirstRunMaybe,
-} from './lifecycle';
+import { configureWindowEvents, initializeAppLifecycle, onFirstRunMaybe } from './lifecycle';
 import MenuBuilder from './menu';
 import { applyOzonePlatform } from './ozone';
 import AppUpdater from './updater';
-import { isDevMode } from './utils';
 
 // Runs at module load: the Ozone platform is read during app startup, so this
 // has to happen before `app.whenReady()` below.
@@ -48,10 +42,6 @@ const mb = menubar({
 const menuBuilder = new MenuBuilder(mb);
 const contextMenu = menuBuilder.buildMenu();
 
-// Register your app as the handler for a custom protocol
-const protocol = isDevMode() ? 'gitify-dev' : 'gitify';
-app.setAsDefaultProtocolClient(protocol);
-
 const appUpdater = new AppUpdater(mb, menuBuilder);
 
 app
@@ -59,7 +49,7 @@ app
   .then(async () => {
     await onFirstRunMaybe();
 
-    initializeAppLifecycle(mb, contextMenu, protocol);
+    initializeAppLifecycle(mb, contextMenu);
 
     // Configure window event handlers (Escape key, DevTools resize)
     configureWindowEvents(mb, menuBuilder);
@@ -75,9 +65,3 @@ app
   .catch((err) => {
     logError('main', 'Failed to initialize application', toError(err));
   });
-
-// Handle gitify:// custom protocol URL events for OAuth 2.0 callback
-app.on('open-url', (event, url) => {
-  event.preventDefault();
-  handleProtocolURL(mb, url, protocol);
-});
diff --git a/src/main/lifecycle/startup.test.ts b/src/main/lifecycle/startup.test.ts
index f81f9a66f..17ced7ae8 100644
--- a/src/main/lifecycle/startup.test.ts
+++ b/src/main/lifecycle/startup.test.ts
@@ -1,30 +1,19 @@
 import type { Menubar } from 'electron-menubar';
 
-import { EVENTS } from '../../shared/events';
-
-import { handleProtocolURL, initializeAppLifecycle } from './startup';
+import { initializeAppLifecycle } from './startup';
 
 const requestSingleInstanceLockMock = vi.fn(() => true);
-const appOnMock = vi.fn();
 const appQuitMock = vi.fn();
 
 vi.mock('electron', () => ({
   app: {
     requestSingleInstanceLock: () => requestSingleInstanceLockMock(),
-    on: (...a: unknown[]) => appOnMock(...a),
     quit: () => appQuitMock(),
-  } satisfies Pick<Electron.App, 'requestSingleInstanceLock' | 'on' | 'quit'>,
-}));
-
-const sendRendererEventMock = vi.fn();
-vi.mock('../events', () => ({
-  sendRendererEvent: (...a: unknown[]) => sendRendererEventMock(...a),
+  } satisfies Pick<Electron.App, 'requestSingleInstanceLock' | 'quit'>,
 }));
 
-const logInfoMock = vi.fn();
 const logWarnMock = vi.fn();
 vi.mock('../../shared/logger', () => ({
-  logInfo: (...a: unknown[]) => logInfoMock(...a),
   logWarn: (...a: unknown[]) => logWarnMock(...a),
 }));
 
@@ -46,7 +35,7 @@ describe('main/lifecycle/startup.ts', () => {
       const mb = createMb();
       const contextMenu = {} as Electron.Menu;
 
-      initializeAppLifecycle(mb as unknown as Menubar, contextMenu, 'gitify');
+      initializeAppLifecycle(mb as unknown as Menubar, contextMenu);
 
       expect(mb.on).toHaveBeenCalledWith('ready', expect.any(Function));
     });
@@ -56,7 +45,7 @@ describe('main/lifecycle/startup.ts', () => {
       const mb = createMb();
       const contextMenu = {} as Electron.Menu;
 
-      initializeAppLifecycle(mb as unknown as Menubar, contextMenu, 'gitify');
+      initializeAppLifecycle(mb as unknown as Menubar, contextMenu);
 
       expect(appQuitMock).toHaveBeenCalled();
       expect(logWarnMock).toHaveBeenCalled();
@@ -66,7 +55,7 @@ describe('main/lifecycle/startup.ts', () => {
       const mb = createMb();
       const contextMenu = {} as Electron.Menu;
 
-      initializeAppLifecycle(mb as unknown as Menubar, contextMenu, 'gitify');
+      initializeAppLifecycle(mb as unknown as Menubar, contextMenu);
 
       const readyHandler = (mb.on as unknown as ReturnType<typeof vi.fn>).mock.calls[0]?.[1];
       expect(readyHandler).toBeDefined();
@@ -75,19 +64,4 @@ describe('main/lifecycle/startup.ts', () => {
       expect(mb.setContextMenu).toHaveBeenCalledWith(contextMenu);
     });
   });
-
-  describe('handleProtocolURL', () => {
-    it('forwards matching protocol URL to renderer as AUTH_CALLBACK', () => {
-      const mb = createMb();
-      const url = 'gitify://callback?code=abc123';
-      handleProtocolURL(mb as unknown as Menubar, url, 'gitify');
-      expect(sendRendererEventMock).toHaveBeenCalledWith(mb, EVENTS.AUTH_CALLBACK, url);
-    });
-
-    it('ignores URLs that do not match the protocol', () => {
-      const mb = createMb();
-      handleProtocolURL(mb as unknown as Menubar, 'https://github.com', 'gitify');
-      expect(sendRendererEventMock).not.toHaveBeenCalled();
-    });
-  });
 });
diff --git a/src/main/lifecycle/startup.ts b/src/main/lifecycle/startup.ts
index e80a38f71..a7b4faa98 100644
--- a/src/main/lifecycle/startup.ts
+++ b/src/main/lifecycle/startup.ts
@@ -2,14 +2,11 @@ import { app } from 'electron';
 import type { Menubar } from 'electron-menubar';
 
 import { APPLICATION } from '../../shared/constants';
-import { EVENTS } from '../../shared/events';
-import { logInfo, logWarn } from '../../shared/logger';
-
-import { sendRendererEvent } from '../events';
+import { logWarn } from '../../shared/logger';
 
 /**
- * Set up core application lifecycle events including tray ready setup,
- * protocol URL handling, and single-instance enforcement.
+ * Set up core application lifecycle events: tray ready setup and
+ * single-instance enforcement.
  *
  * The tray's context-menu wiring (Linux `setContextMenu` vs macOS/Windows
  * right-click popup) and the macOS `setIgnoreDoubleClickEvents` default
@@ -18,60 +15,26 @@ import { sendRendererEvent } from '../events';
  *
  * @param mb - The menubar instance to attach lifecycle events to.
  * @param contextMenu - The tray context menu to attach via `mb.setContextMenu`.
- * @param protocol - The custom protocol string (e.g. 'gitify' or 'gitify-dev').
  */
-export function initializeAppLifecycle(
-  mb: Menubar,
-  contextMenu: Electron.Menu,
-  protocol: string,
-): void {
+export function initializeAppLifecycle(mb: Menubar, contextMenu: Electron.Menu): void {
   mb.on('ready', () => {
     mb.app.setAppUserModelId(APPLICATION.ID);
     mb.tray.setToolTip(APPLICATION.NAME);
     mb.setContextMenu(contextMenu);
   });
 
-  preventSecondInstance(mb, protocol);
-}
-
-/**
- * Handle a gitify:// protocol URL by forwarding it to the renderer process
- * as an AUTH_CALLBACK event.
- *
- * @param mb - The menubar instance to forward the event through.
- * @param url - The protocol URL to handle.
- * @param protocol - The custom protocol string to match.
- */
-export function handleProtocolURL(mb: Menubar, url: string, protocol: string): void {
-  if (url.startsWith(`${protocol}://`)) {
-    logInfo('main:handleUrl', `forwarding URL ${url} to renderer process`);
-    sendRendererEvent(mb, EVENTS.AUTH_CALLBACK, url);
-  }
+  preventSecondInstance();
 }
 
 /**
- * Enforce a single application instance. If a second instance is launched,
- * any protocol URL in the command line is forwarded to the existing instance.
- *
- * @param mb - The menubar instance to show when a second instance is detected.
- * @param protocol - The custom protocol string to extract from command line args.
+ * Enforce a single application instance. A second launch quits immediately so
+ * the already-running tray instance remains the only one.
  */
-function preventSecondInstance(mb: Menubar, protocol: string): void {
+function preventSecondInstance(): void {
   const gotTheLock = app.requestSingleInstanceLock();
 
   if (!gotTheLock) {
     logWarn('main:gotTheLock', 'Second instance detected, quitting');
     app.quit();
-    return;
   }
-
-  app.on('second-instance', (_event, commandLine) => {
-    logInfo('main:second-instance', 'Second instance was launched. Extracting command to forward');
-
-    const url = commandLine.find((arg) => arg.startsWith(`${protocol}://`));
-
-    if (url) {
-      handleProtocolURL(mb, url, protocol);
-    }
-  });
 }
diff --git a/src/preload/index.ts b/src/preload/index.ts
index f760cd767..b88db7a2a 100644
--- a/src/preload/index.ts
+++ b/src/preload/index.ts
@@ -245,16 +245,6 @@ export const api = {
     return onRendererEvent(EVENTS.SYSTEM_WAKE, () => callback());
   },
 
-  /**
-   * Register a callback invoked when the main process delivers an OAuth callback URL.
-   *
-   * @param callback - Called with the full callback URL (e.g. `gitify://oauth?code=...`).
-   * @returns A function that removes the listener.
-   */
-  onAuthCallback: (callback: (url: string) => void) => {
-    return onRendererEvent(EVENTS.AUTH_CALLBACK, (_, url) => callback(url));
-  },
-
   /**
    * Display a native OS notification.
    *
diff --git a/src/renderer/App.tsx b/src/renderer/App.tsx
index 19f4e11ef..29ae186fb 100644
--- a/src/renderer/App.tsx
+++ b/src/renderer/App.tsx
@@ -11,9 +11,9 @@ import { AccountScopesRoute } from './routes/AccountScopes';
 import { BitbucketLoginWithPersonalAccessTokenRoute } from './routes/bitbucket/LoginWithPersonalAccessToken';
 import { FiltersRoute } from './routes/Filters';
 import { GiteaLoginWithPersonalAccessTokenRoute } from './routes/gitea/LoginWithPersonalAccessToken';
+import { GitHubLoginWithCustomOAuthAppRoute } from './routes/github/LoginWithCustomOAuthApp';
 import { GitHubLoginWithDeviceFlowRoute } from './routes/github/LoginWithDeviceFlow';
 import { GitHubLoginWithCLIRoute } from './routes/github/LoginWithGitHubCLI';
-import { GitHubLoginWithOAuthAppRoute } from './routes/github/LoginWithOAuthApp';
 import { GitHubLoginWithPersonalAccessTokenRoute } from './routes/github/LoginWithPersonalAccessToken';
 import { GitLabLoginWithPersonalAccessTokenRoute } from './routes/gitlab/LoginWithPersonalAccessToken';
 import { LoginRoute } from './routes/Login';
@@ -108,7 +108,10 @@ export function App() {
                   element={<GitHubLoginWithPersonalAccessTokenRoute />}
                   path="/login/github/personal-access-token"
                 />
-                <Route element={<GitHubLoginWithOAuthAppRoute />} path="/login/github/oauth-app" />
+                <Route
+                  element={<GitHubLoginWithCustomOAuthAppRoute />}
+                  path="/login/github/custom-oauth-app"
+                />
                 <Route
                   element={<GiteaLoginWithPersonalAccessTokenRoute />}
                   path="/login/gitea/personal-access-token"
diff --git a/src/renderer/__helpers__/hook-mocks.ts b/src/renderer/__helpers__/hook-mocks.ts
index fcff10597..a99570529 100644
--- a/src/renderer/__helpers__/hook-mocks.ts
+++ b/src/renderer/__helpers__/hook-mocks.ts
@@ -52,7 +52,6 @@ function buildLoginsDefaults(): LoginsState {
     loginWithDeviceFlowPoll: vi.fn(),
     loginWithDeviceFlowComplete: vi.fn(),
     loginWithCli: vi.fn(),
-    loginWithOAuthApp: vi.fn(),
     loginWithPersonalAccessToken: vi.fn(),
     logoutFromAccount: vi.fn(),
   };
diff --git a/src/renderer/__helpers__/test-utils.tsx b/src/renderer/__helpers__/test-utils.tsx
index 53bf781fd..333e35ab0 100644
--- a/src/renderer/__helpers__/test-utils.tsx
+++ b/src/renderer/__helpers__/test-utils.tsx
@@ -47,7 +47,6 @@ const LOGIN_KEYS = [
   'loginWithDeviceFlowPoll',
   'loginWithDeviceFlowComplete',
   'loginWithCli',
-  'loginWithOAuthApp',
   'loginWithPersonalAccessToken',
   'logoutFromAccount',
 ] as const;
diff --git a/src/renderer/__helpers__/visual.setup.ts b/src/renderer/__helpers__/visual.setup.ts
index c6bda06ec..3ea8fd8e1 100644
--- a/src/renderer/__helpers__/visual.setup.ts
+++ b/src/renderer/__helpers__/visual.setup.ts
@@ -105,7 +105,6 @@ function createGitifyBridgeApi(): Window['gitify'] {
       useUnreadActiveIcon: vi.fn(),
     },
     notificationSoundPath: vi.fn(),
-    onAuthCallback: vi.fn(() => vi.fn()),
     onResetApp: vi.fn(() => vi.fn()),
     onSystemWake: vi.fn(() => vi.fn()),
     setAutoLaunch: vi.fn(),
diff --git a/src/renderer/__helpers__/vitest.setup.ts b/src/renderer/__helpers__/vitest.setup.ts
index 87d475fa6..7319d2bf4 100644
--- a/src/renderer/__helpers__/vitest.setup.ts
+++ b/src/renderer/__helpers__/vitest.setup.ts
@@ -114,7 +114,6 @@ function createGitifyBridgeApi(): Window['gitify'] {
       useUnreadActiveIcon: vi.fn(),
     },
     notificationSoundPath: vi.fn(),
-    onAuthCallback: vi.fn(() => vi.fn()),
     onResetApp: vi.fn(() => vi.fn()),
     onSystemWake: vi.fn(() => vi.fn()),
     setAutoLaunch: vi.fn(),
diff --git a/src/renderer/__mocks__/account-mocks.ts b/src/renderer/__mocks__/account-mocks.ts
index 5c87fd56c..6229c78ad 100644
--- a/src/renderer/__mocks__/account-mocks.ts
+++ b/src/renderer/__mocks__/account-mocks.ts
@@ -1,14 +1,21 @@
 import { Constants } from '../constants';
 
-import type { Account, AccountNotifications, GitifyError, Hostname, Token } from '../types';
+import type {
+  Account,
+  AccountNotifications,
+  ClientID,
+  GitifyError,
+  Hostname,
+  Token,
+} from '../types';
 
 import { getRecommendedScopeNames } from '../utils/auth/scopes';
 import { mockGitifyUser } from './user-mocks';
 
-export const mockGitHubAppAccount: Account = {
+export const mockGitifyOAuthAppAccount: Account = {
   forge: 'github',
   platform: 'GitHub Cloud',
-  method: 'GitHub App',
+  method: 'Gitify OAuth App',
   token: 'token-987654321' as Token,
   hostname: Constants.GITHUB_HOSTNAME,
   user: mockGitifyUser,
@@ -37,12 +44,13 @@ export const mockGitHubCliAccount: Account = {
   scopes: ['gist', 'read:org', 'repo', 'workflow'],
 };
 
-export const mockOAuthAccount: Account = {
+export const mockCustomOAuthAppAccount: Account = {
   forge: 'github',
   platform: 'GitHub Enterprise Server',
-  method: 'OAuth App',
+  method: 'Custom OAuth App',
   token: 'token-1234568790' as Token,
   hostname: 'github.gitify.io' as Hostname,
+  clientId: 'CUSTOM_CLIENT_ID_123' as ClientID,
   user: mockGitifyUser,
   scopes: getRecommendedScopeNames(),
 };
diff --git a/src/renderer/__mocks__/notifications-mocks.ts b/src/renderer/__mocks__/notifications-mocks.ts
index 6f8d351a1..95560abc0 100644
--- a/src/renderer/__mocks__/notifications-mocks.ts
+++ b/src/renderer/__mocks__/notifications-mocks.ts
@@ -21,7 +21,7 @@ import {
 
 import {
   mockGiteaAccount,
-  mockGitHubAppAccount,
+  mockGitifyOAuthAppAccount,
   mockGitHubCloudAccount,
   mockGitHubEnterpriseServerAccount,
 } from './account-mocks';
@@ -332,7 +332,7 @@ export function mockPartialGitifyNotification(
   repository?: Partial<GitifyRepository>,
 ): GitifyNotification {
   const mockNotification: Partial<GitifyNotification> = {
-    account: mockGitHubAppAccount,
+    account: mockGitifyOAuthAppAccount,
     reason: {
       code: 'subscribed',
       title: 'Updated',
diff --git a/src/renderer/components/settings/AppearanceSettings.test.tsx b/src/renderer/components/settings/AppearanceSettings.test.tsx
index d776e334b..d7d5377dc 100644
--- a/src/renderer/components/settings/AppearanceSettings.test.tsx
+++ b/src/renderer/components/settings/AppearanceSettings.test.tsx
@@ -3,7 +3,7 @@ import userEvent from '@testing-library/user-event';
 
 import { renderWithProviders } from '../../__helpers__/test-utils';
 import {
-  mockGitHubAppAccount,
+  mockGitifyOAuthAppAccount,
   mockGitHubEnterpriseServerAccount,
 } from '../../__mocks__/account-mocks';
 
@@ -91,7 +91,7 @@ describe('renderer/components/settings/AppearanceSettings.tsx', () => {
   ] as const)('should toggle %s checkbox', async (testId, setting) => {
     await act(async () => {
       renderWithProviders(<AppearanceSettings />, {
-        accounts: [mockGitHubAppAccount],
+        accounts: [mockGitifyOAuthAppAccount],
       });
     });
 
@@ -135,7 +135,7 @@ describe('renderer/components/settings/AppearanceSettings.tsx', () => {
   it('reactively hides the account header checkbox when a second account is added', async () => {
     await act(async () => {
       renderWithProviders(<AppearanceSettings />, {
-        accounts: [mockGitHubAppAccount],
+        accounts: [mockGitifyOAuthAppAccount],
       });
     });
 
@@ -143,7 +143,7 @@ describe('renderer/components/settings/AppearanceSettings.tsx', () => {
 
     await act(async () => {
       useAccountsStore.setState({
-        accounts: [mockGitHubAppAccount, mockGitHubEnterpriseServerAccount],
+        accounts: [mockGitifyOAuthAppAccount, mockGitHubEnterpriseServerAccount],
       });
     });
 
diff --git a/src/renderer/hooks/useLogins.test.tsx b/src/renderer/hooks/useLogins.test.tsx
index 28f23fbfd..635034455 100644
--- a/src/renderer/hooks/useLogins.test.tsx
+++ b/src/renderer/hooks/useLogins.test.tsx
@@ -14,7 +14,7 @@ import { Constants } from '../constants';
 
 import { useAccountsStore } from '../stores';
 
-import type { ClientID, ClientSecret, Token } from '../types';
+import type { ClientID, Token } from '../types';
 import type { DeviceFlowSession } from '../utils/auth/types';
 
 import { getAdapter } from '../utils/forges/registry';
@@ -113,7 +113,7 @@ describe('renderer/hooks/useLogins.ts', () => {
     expect(pollSpy).toHaveBeenCalledWith('session');
   });
 
-  it('loginWithDeviceFlowComplete creates the account', async () => {
+  it('loginWithDeviceFlowComplete records the built-in Gitify OAuth App account', async () => {
     const { result } = renderLoginsHook();
 
     await act(async () => {
@@ -124,24 +124,36 @@ describe('renderer/hooks/useLogins.ts', () => {
       );
     });
 
-    expect(createAccountSpy).toHaveBeenCalledWith('GitHub App', 'token', 'github.com', 'github');
+    expect(createAccountSpy).toHaveBeenCalledWith(
+      'Gitify OAuth App',
+      'token',
+      'github.com',
+      'github',
+      undefined,
+      undefined,
+    );
   });
 
-  it('loginWithOAuthApp delegates to the forge adapter', async () => {
-    const adapter = getAdapter('github');
-    const oauthSpy = vi.spyOn(adapter.oauthWebApp!, 'performWebOAuth');
-
+  it('loginWithDeviceFlowComplete records a custom app client ID', async () => {
     const { result } = renderLoginsHook();
 
     await act(async () => {
-      void result.current.loginWithOAuthApp('github', {
-        clientId: 'id' as ClientID,
-        clientSecret: 'secret' as ClientSecret,
-        hostname: Constants.GITHUB_HOSTNAME,
-      });
+      await result.current.loginWithDeviceFlowComplete(
+        'github',
+        'token' as Token,
+        Constants.GITHUB_HOSTNAME,
+        'CUSTOM_CLIENT_ID_123' as ClientID,
+      );
     });
 
-    expect(oauthSpy).toHaveBeenCalled();
+    expect(createAccountSpy).toHaveBeenCalledWith(
+      'Custom OAuth App',
+      'token',
+      'github.com',
+      'github',
+      undefined,
+      'CUSTOM_CLIENT_ID_123',
+    );
   });
 
   it('loginWithDeviceFlowStart throws when the forge does not support device flow', async () => {
@@ -172,18 +184,6 @@ describe('renderer/hooks/useLogins.ts', () => {
     ).rejects.toThrow(/does not support device flow/);
   });
 
-  it('loginWithOAuthApp throws when the forge does not support OAuth app login', async () => {
-    const { result } = renderLoginsHook();
-
-    await expect(
-      result.current.loginWithOAuthApp('gitea', {
-        clientId: 'id' as ClientID,
-        clientSecret: 'secret' as ClientSecret,
-        hostname: Constants.GITHUB_HOSTNAME,
-      }),
-    ).rejects.toThrow(/OAuth app login is not supported for forge "gitea"/);
-  });
-
   it('logoutFromAccount calls removeAccountNotifications, removeAccount', async () => {
     useAccountsStore.setState({ accounts: [mockGitHubCloudAccount] });
 
diff --git a/src/renderer/hooks/useLogins.ts b/src/renderer/hooks/useLogins.ts
index 24ac225b4..e5fae7e03 100644
--- a/src/renderer/hooks/useLogins.ts
+++ b/src/renderer/hooks/useLogins.ts
@@ -4,10 +4,10 @@ import { useQueryClient } from '@tanstack/react-query';
 
 import { useAccountsStore } from '../stores';
 
-import type { Account, Forge, Hostname, Token } from '../types';
+import type { Account, ClientID, Forge, Hostname, Token } from '../types';
 import type {
+  AuthMethod,
   DeviceFlowSession,
-  LoginOAuthWebOptions,
   LoginPersonalAccessTokenOptions,
 } from '../utils/auth/types';
 
@@ -21,11 +21,16 @@ interface LoginsState {
     forge: Forge,
     hostname?: Hostname,
     scopes?: string[],
+    clientId?: ClientID,
   ) => Promise<DeviceFlowSession>;
   loginWithDeviceFlowPoll: (forge: Forge, session: DeviceFlowSession) => Promise<Token | null>;
-  loginWithDeviceFlowComplete: (forge: Forge, token: Token, hostname: Hostname) => Promise<void>;
+  loginWithDeviceFlowComplete: (
+    forge: Forge,
+    token: Token,
+    hostname: Hostname,
+    clientId?: ClientID,
+  ) => Promise<void>;
   loginWithCli: (forge: Forge, hostname: Hostname) => Promise<void>;
-  loginWithOAuthApp: (forge: Forge, data: LoginOAuthWebOptions) => Promise<void>;
   loginWithPersonalAccessToken: (data: LoginPersonalAccessTokenOptions) => Promise<void>;
   logoutFromAccount: (account: Account) => void;
 }
@@ -63,12 +68,12 @@ export const useLogins = (): LoginsState => {
    * Initiate an OAuth device-flow session for the given forge.
    */
   const loginWithDeviceFlowStart = useCallback(
-    async (forge: Forge, hostname?: Hostname, scopes?: string[]) => {
+    async (forge: Forge, hostname?: Hostname, scopes?: string[], clientId?: ClientID) => {
       const { deviceFlow } = getAdapter(forge);
       if (!deviceFlow) {
         throw new Error(`Device flow is not supported for forge "${forge}".`);
       }
-      return await deviceFlow.start(hostname, scopes);
+      return await deviceFlow.start(hostname, scopes, clientId);
     },
     [],
   );
@@ -88,19 +93,22 @@ export const useLogins = (): LoginsState => {
    * Finalise an OAuth device-flow session by recording the account.
    */
   const loginWithDeviceFlowComplete = useCallback(
-    async (forge: Forge, token: Token, hostname: Hostname) => {
-      const { deviceFlow } = getAdapter(forge);
+    async (forge: Forge, token: Token, hostname: Hostname, clientId?: ClientID) => {
+      const { deviceFlow, customOAuthApp } = getAdapter(forge);
       if (!deviceFlow) {
         throw new Error(`Forge "${forge}" does not support device flow.`);
       }
-      const method = deviceFlow.authMethod;
+      // A supplied client ID means the user authorized their own app; without
+      // one the flow used Gitify's preconfigured app.
+      const method: AuthMethod =
+        clientId && customOAuthApp ? customOAuthApp.authMethod : deviceFlow.authMethod;
 
       const existingAccount = accounts.find((a) => a.hostname === hostname && a.method === method);
       if (existingAccount) {
         removeAccountNotifications(existingAccount);
       }
 
-      await createAccount(method, token, hostname, forge);
+      await createAccount(method, token, hostname, forge, undefined, clientId);
     },
     [accounts, createAccount, removeAccountNotifications],
   );
@@ -135,31 +143,6 @@ export const useLogins = (): LoginsState => {
     [createAccountInStore, queryClient, removeAccountNotifications],
   );
 
-  /**
-   * Login with a custom OAuth app on the given forge.
-   */
-  const loginWithOAuthApp = useCallback(
-    async (forge: Forge, data: LoginOAuthWebOptions) => {
-      const { oauthWebApp } = getAdapter(forge);
-      if (!oauthWebApp) {
-        throw new Error(`OAuth app login is not supported for forge "${forge}".`);
-      }
-
-      const { authOptions, authCode } = await oauthWebApp.performWebOAuth(data);
-      const token = await oauthWebApp.exchangeAuthCodeForToken(authCode, authOptions);
-
-      const existingAccount = accounts.find(
-        (a) => a.hostname === authOptions.hostname && a.method === 'OAuth App',
-      );
-      if (existingAccount) {
-        removeAccountNotifications(existingAccount);
-      }
-
-      await createAccount('OAuth App', token, authOptions.hostname, forge);
-    },
-    [accounts, createAccount, removeAccountNotifications],
-  );
-
   /**
    * Login with Personal Access Token (PAT).
    */
@@ -203,7 +186,6 @@ export const useLogins = (): LoginsState => {
     loginWithDeviceFlowPoll,
     loginWithDeviceFlowComplete,
     loginWithCli,
-    loginWithOAuthApp,
     loginWithPersonalAccessToken,
     logoutFromAccount,
   };
diff --git a/src/renderer/routes/AccountScopes.test.tsx b/src/renderer/routes/AccountScopes.test.tsx
index 9a0677bed..9754f6dee 100644
--- a/src/renderer/routes/AccountScopes.test.tsx
+++ b/src/renderer/routes/AccountScopes.test.tsx
@@ -3,9 +3,9 @@ import userEvent from '@testing-library/user-event';
 
 import { renderWithProviders } from '../__helpers__/test-utils';
 import {
-  mockGitHubAppAccount,
+  mockGitifyOAuthAppAccount,
   mockGitHubCliAccount,
-  mockOAuthAccount,
+  mockCustomOAuthAppAccount,
   mockPersonalAccessTokenAccount,
 } from '../__mocks__/account-mocks';
 
@@ -19,7 +19,7 @@ const navigateMock = vi.fn();
 // Mutable variable — individual tests reassign this before rendering to simulate
 // different account states without needing vi.doMock.
 let mockLocationAccount: Account = {
-  ...mockGitHubAppAccount,
+  ...mockGitifyOAuthAppAccount,
   scopes: ['read:user', 'notifications', 'repo'],
 };
 
@@ -35,7 +35,7 @@ vi.mock('react-router-dom', async (importActual) => {
 describe('renderer/routes/AccountScopes.tsx', () => {
   beforeEach(() => {
     mockLocationAccount = {
-      ...mockGitHubAppAccount,
+      ...mockGitifyOAuthAppAccount,
       scopes: ['read:user', 'notifications', 'repo'],
     };
   });
@@ -97,7 +97,7 @@ describe('renderer/routes/AccountScopes.tsx', () => {
 
   it('should show all-granted status when account has public_repo instead of repo', async () => {
     mockLocationAccount = {
-      ...mockGitHubAppAccount,
+      ...mockGitifyOAuthAppAccount,
       scopes: ['read:user', 'notifications', 'public_repo'],
     };
 
@@ -112,7 +112,7 @@ describe('renderer/routes/AccountScopes.tsx', () => {
 
   it('should show missing indicator when neither repo nor public_repo is granted', async () => {
     mockLocationAccount = {
-      ...mockGitHubAppAccount,
+      ...mockGitifyOAuthAppAccount,
       scopes: ['read:user', 'notifications'],
     };
 
@@ -128,7 +128,7 @@ describe('renderer/routes/AccountScopes.tsx', () => {
 
   it('should show missing indicator when notifications scope is absent', async () => {
     mockLocationAccount = {
-      ...mockGitHubAppAccount,
+      ...mockGitifyOAuthAppAccount,
       scopes: ['read:user', 'repo'],
     };
 
@@ -142,7 +142,7 @@ describe('renderer/routes/AccountScopes.tsx', () => {
 
   it('should show extra scopes when token has additional permissions', async () => {
     mockLocationAccount = {
-      ...mockGitHubAppAccount,
+      ...mockGitifyOAuthAppAccount,
       scopes: ['read:user', 'notifications', 'repo', 'write:packages', 'read:org'],
     };
 
@@ -156,7 +156,7 @@ describe('renderer/routes/AccountScopes.tsx', () => {
   });
 
   it('should show no-scopes message when scopes are not loaded', async () => {
-    mockLocationAccount = { ...mockGitHubAppAccount, scopes: undefined };
+    mockLocationAccount = { ...mockGitifyOAuthAppAccount, scopes: undefined };
 
     await act(async () => {
       renderWithProviders(<AccountScopesRoute />);
@@ -191,8 +191,8 @@ describe('renderer/routes/AccountScopes.tsx', () => {
 
   describe('all auth methods show permissions button', () => {
     it.each([
-      ['GitHub App', mockGitHubAppAccount],
-      ['OAuth App', mockOAuthAccount],
+      ['Gitify OAuth App', mockGitifyOAuthAppAccount],
+      ['Custom OAuth App', mockCustomOAuthAppAccount],
       ['Personal Access Token', mockPersonalAccessTokenAccount],
     ])('%s account has a permissions button', async (_method, account) => {
       mockLocationAccount = {
diff --git a/src/renderer/routes/Accounts.test.tsx b/src/renderer/routes/Accounts.test.tsx
index 5ff682381..fdf784e2c 100644
--- a/src/renderer/routes/Accounts.test.tsx
+++ b/src/renderer/routes/Accounts.test.tsx
@@ -4,8 +4,8 @@ import userEvent from '@testing-library/user-event';
 import { navigateMock, renderWithProviders } from '../__helpers__/test-utils';
 import {
   mockGiteaAccount,
-  mockGitHubAppAccount,
-  mockOAuthAccount,
+  mockGitifyOAuthAppAccount,
+  mockCustomOAuthAppAccount,
   mockPersonalAccessTokenAccount,
 } from '../__mocks__/account-mocks';
 
@@ -30,7 +30,11 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should render itself & its children', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockPersonalAccessTokenAccount, mockOAuthAccount, mockGitHubAppAccount],
+          accounts: [
+            mockPersonalAccessTokenAccount,
+            mockCustomOAuthAppAccount,
+            mockGitifyOAuthAppAccount,
+          ],
         });
       });
 
@@ -241,8 +245,8 @@ describe('renderer/routes/Accounts.tsx', () => {
               ...mockPersonalAccessTokenAccount,
               scopes: ['read:user', 'notifications'],
             },
-            mockOAuthAccount,
-            mockGitHubAppAccount,
+            mockCustomOAuthAppAccount,
+            mockGitifyOAuthAppAccount,
           ],
         });
       });
@@ -266,7 +270,11 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should set account as primary account', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockPersonalAccessTokenAccount, mockOAuthAccount, mockGitHubAppAccount],
+          accounts: [
+            mockPersonalAccessTokenAccount,
+            mockCustomOAuthAppAccount,
+            mockGitifyOAuthAppAccount,
+          ],
         });
       });
 
@@ -276,7 +284,7 @@ describe('renderer/routes/Accounts.tsx', () => {
 
       await userEvent.click(screen.getAllByTestId('account-set-primary')[1]);
 
-      expect(useAccountsStore.getState().accounts[0]).toBe(mockOAuthAccount);
+      expect(useAccountsStore.getState().accounts[0]).toBe(mockCustomOAuthAppAccount);
       expect(navigateMock).toHaveBeenCalledWith('/accounts', { replace: true });
     });
 
@@ -318,7 +326,11 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should show view-scopes button for all auth methods', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockPersonalAccessTokenAccount, mockOAuthAccount, mockGitHubAppAccount],
+          accounts: [
+            mockPersonalAccessTokenAccount,
+            mockCustomOAuthAppAccount,
+            mockGitifyOAuthAppAccount,
+          ],
         });
       });
 
@@ -344,7 +356,7 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should show github login methods after selecting GitHub forge', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockOAuthAccount],
+          accounts: [mockCustomOAuthAppAccount],
         });
       });
 
@@ -367,7 +379,7 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should show login with personal access token after selecting GitHub forge', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockOAuthAccount],
+          accounts: [mockCustomOAuthAppAccount],
         });
       });
 
@@ -384,7 +396,7 @@ describe('renderer/routes/Accounts.tsx', () => {
       });
     });
 
-    it('should show login with oauth app after selecting GitHub forge', async () => {
+    it('should show login with a custom OAuth app after selecting GitHub forge', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
           accounts: [mockPersonalAccessTokenAccount],
@@ -394,12 +406,14 @@ describe('renderer/routes/Accounts.tsx', () => {
       await userEvent.click(screen.getByTestId('account-add-new'));
       await userEvent.click(screen.getByTestId('account-add-forge-github'));
 
-      expect(screen.getByTestId('account-add-oauth-app')).toHaveTextContent('OAuth App');
+      expect(screen.getByTestId('account-add-custom-oauth-app')).toHaveTextContent(
+        'Custom OAuth App',
+      );
 
-      await userEvent.click(screen.getByTestId('account-add-oauth-app'));
+      await userEvent.click(screen.getByTestId('account-add-custom-oauth-app'));
 
       expect(navigateMock).toHaveBeenCalledTimes(1);
-      expect(navigateMock).toHaveBeenCalledWith('/login/github/oauth-app', {
+      expect(navigateMock).toHaveBeenCalledWith('/login/github/custom-oauth-app', {
         replace: true,
       });
     });
@@ -407,7 +421,7 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should navigate directly to gitea login (single method forge)', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockOAuthAccount],
+          accounts: [mockCustomOAuthAppAccount],
         });
       });
 
@@ -426,7 +440,7 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should navigate directly to bitbucket login (single method forge)', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockOAuthAccount],
+          accounts: [mockCustomOAuthAppAccount],
         });
       });
 
@@ -472,10 +486,10 @@ describe('renderer/routes/Accounts.tsx', () => {
     it('should re-authenticate a github app account', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockGitHubAppAccount],
+          accounts: [mockGitifyOAuthAppAccount],
           notifications: [
             {
-              account: mockGitHubAppAccount,
+              account: mockGitifyOAuthAppAccount,
               notifications: [],
               error: Errors.BAD_CREDENTIALS,
             },
@@ -488,17 +502,17 @@ describe('renderer/routes/Accounts.tsx', () => {
       expect(navigateMock).toHaveBeenCalledTimes(1);
       expect(navigateMock).toHaveBeenCalledWith('/login/github/device-flow', {
         replace: true,
-        state: { account: mockGitHubAppAccount },
+        state: { account: mockGitifyOAuthAppAccount },
       });
     });
 
-    it('should re-authenticate an oauth app account', async () => {
+    it('should re-authenticate a custom OAuth app account', async () => {
       await act(async () => {
         renderWithProviders(<AccountsRoute />, {
-          accounts: [mockOAuthAccount],
+          accounts: [mockCustomOAuthAppAccount],
           notifications: [
             {
-              account: mockOAuthAccount,
+              account: mockCustomOAuthAppAccount,
               notifications: [],
               error: Errors.BAD_CREDENTIALS,
             },
@@ -509,9 +523,9 @@ describe('renderer/routes/Accounts.tsx', () => {
       await userEvent.click(screen.getByTestId('account-reauthenticate'));
 
       expect(navigateMock).toHaveBeenCalledTimes(1);
-      expect(navigateMock).toHaveBeenCalledWith('/login/github/oauth-app', {
+      expect(navigateMock).toHaveBeenCalledWith('/login/github/custom-oauth-app', {
         replace: true,
-        state: { account: mockOAuthAccount },
+        state: { account: mockCustomOAuthAppAccount },
       });
     });
 
@@ -540,10 +554,10 @@ describe('renderer/routes/Accounts.tsx', () => {
 
     it('should log and skip re-authenticate when no login method matches', async () => {
       const rendererLogErrorSpy = vi.spyOn(logger, 'rendererLogError').mockImplementation(vi.fn());
-      // Gitea only registers PAT — a GitHub App method has no matching loginMethod.
+      // Gitea only registers PAT — a Custom OAuth App method has no matching loginMethod.
       const unsupportedAccount = {
         ...mockGiteaAccount,
-        method: 'GitHub App' as const,
+        method: 'Custom OAuth App' as const,
       };
 
       await act(async () => {
diff --git a/src/renderer/routes/Login.test.tsx b/src/renderer/routes/Login.test.tsx
index f907c2747..55db58e0a 100644
--- a/src/renderer/routes/Login.test.tsx
+++ b/src/renderer/routes/Login.test.tsx
@@ -31,7 +31,7 @@ describe('renderer/routes/Login.tsx', () => {
   it.each([
     ['login-github', '/login/github/device-flow'],
     ['login-pat', '/login/github/personal-access-token'],
-    ['login-oauth-app', '/login/github/oauth-app'],
+    ['login-custom-oauth-app', '/login/github/custom-oauth-app'],
   ])('navigates %s', async (testId, route) => {
     renderWithProviders(<LoginRoute />);
 
diff --git a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-dark-classic-chromium-linux.png b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-dark-classic-chromium-linux.png
index caea7edd6..d710632b4 100644
Binary files a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-dark-classic-chromium-linux.png and b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-dark-classic-chromium-linux.png differ
diff --git a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-custom-oauth-app-dark-classic-chromium-linux.png b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-custom-oauth-app-dark-classic-chromium-linux.png
new file mode 100644
index 000000000..b65724cd4
Binary files /dev/null and b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-custom-oauth-app-dark-classic-chromium-linux.png differ
diff --git a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-custom-oauth-app-light-classic-chromium-linux.png b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-custom-oauth-app-light-classic-chromium-linux.png
new file mode 100644
index 000000000..e30e7e1f2
Binary files /dev/null and b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-custom-oauth-app-light-classic-chromium-linux.png differ
diff --git a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-oauth-app-dark-classic-chromium-linux.png b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-oauth-app-dark-classic-chromium-linux.png
deleted file mode 100644
index c4179a24e..000000000
Binary files a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-oauth-app-dark-classic-chromium-linux.png and /dev/null differ
diff --git a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-oauth-app-light-classic-chromium-linux.png b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-oauth-app-light-classic-chromium-linux.png
deleted file mode 100644
index cc534051b..000000000
Binary files a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-github-oauth-app-light-classic-chromium-linux.png and /dev/null differ
diff --git a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-light-classic-chromium-linux.png b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-light-classic-chromium-linux.png
index cb7b1528c..fbc85fc59 100644
Binary files a/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-light-classic-chromium-linux.png and b/src/renderer/routes/__screenshots__/routes.visual.test.tsx/login-light-classic-chromium-linux.png differ
diff --git a/src/renderer/routes/__snapshots__/Login.test.tsx.snap b/src/renderer/routes/__snapshots__/Login.test.tsx.snap
index e4af27471..da70146dd 100644
--- a/src/renderer/routes/__snapshots__/Login.test.tsx.snap
+++ b/src/renderer/routes/__snapshots__/Login.test.tsx.snap
@@ -364,7 +364,7 @@ exports[`renderer/routes/Login.tsx > should render itself & its children 1`] = `
             data-component="Button"
             data-loading="false"
             data-size="medium"
-            data-testid="login-oauth-app"
+            data-testid="login-custom-oauth-app"
             data-variant="invisible"
             type="button"
           >
@@ -399,7 +399,7 @@ exports[`renderer/routes/Login.tsx > should render itself & its children 1`] = `
                 class="prc-Button-Label-FWkx3"
                 data-component="text"
               >
-                OAuth App
+                Custom OAuth App
               </span>
             </span>
           </button>
diff --git a/src/renderer/routes/github/LoginWithDeviceFlow.test.tsx b/src/renderer/routes/github/DeviceFlowAuthorize.test.tsx
similarity index 82%
rename from src/renderer/routes/github/LoginWithDeviceFlow.test.tsx
rename to src/renderer/routes/github/DeviceFlowAuthorize.test.tsx
index 8b42a6158..91f989d20 100644
--- a/src/renderer/routes/github/LoginWithDeviceFlow.test.tsx
+++ b/src/renderer/routes/github/DeviceFlowAuthorize.test.tsx
@@ -2,15 +2,15 @@ import { screen, waitFor } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 
 import { navigateMock, renderWithProviders } from '../../__helpers__/test-utils';
-import { mockGitHubAppAccount } from '../../__mocks__/account-mocks';
+import { mockGitifyOAuthAppAccount } from '../../__mocks__/account-mocks';
 
-import type { Hostname } from '../../types';
+import type { ClientID, Hostname } from '../../types';
 
 import * as logger from '../../utils/core/logger';
 import * as comms from '../../utils/system/comms';
-import { GitHubLoginWithDeviceFlowRoute } from './LoginWithDeviceFlow';
+import { GitHubDeviceFlowAuthorize } from './DeviceFlowAuthorize';
 
-describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
+describe('renderer/routes/github/DeviceFlowAuthorize.tsx', () => {
   const copyToClipboardSpy = vi.spyOn(comms, 'copyToClipboard').mockResolvedValue();
   const openExternalLinkSpy = vi.spyOn(comms, 'openExternalLink').mockImplementation(vi.fn());
 
@@ -25,7 +25,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
@@ -48,17 +48,18 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
     await userEvent.click(screen.getByTestId('device-scope-public'));
 
-    expect(loginWithDeviceFlowStartMock).toHaveBeenCalledWith('github', undefined, [
-      'notifications',
-      'read:user',
-      'public_repo',
-    ]);
+    expect(loginWithDeviceFlowStartMock).toHaveBeenCalledWith(
+      'github',
+      'github.com',
+      ['notifications', 'read:user', 'public_repo'],
+      undefined,
+    );
 
     await screen.findByTestId('device-user-code');
     expect(screen.getByTestId('open-browser-button')).toBeInTheDocument();
@@ -79,17 +80,18 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
     await userEvent.click(screen.getByTestId('device-scope-full'));
 
-    expect(loginWithDeviceFlowStartMock).toHaveBeenCalledWith('github', undefined, [
-      'notifications',
-      'read:user',
-      'repo',
-    ]);
+    expect(loginWithDeviceFlowStartMock).toHaveBeenCalledWith(
+      'github',
+      'github.com',
+      ['notifications', 'read:user', 'repo'],
+      undefined,
+    );
 
     await screen.findByTestId('device-user-code');
   });
@@ -105,7 +107,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
@@ -128,7 +130,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
@@ -157,7 +159,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
@@ -176,7 +178,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
     const rendererLogErrorSpy = vi.spyOn(logger, 'rendererLogError').mockImplementation(vi.fn());
     const loginWithDeviceFlowStartMock = vi.fn().mockRejectedValueOnce(new Error('Network error'));
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
@@ -197,7 +199,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
     });
 
@@ -219,7 +221,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
     const loginWithDeviceFlowPollMock = vi.fn().mockResolvedValueOnce('access-token');
     const loginWithDeviceFlowCompleteMock = vi.fn().mockResolvedValueOnce(undefined);
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
       loginWithDeviceFlowPoll: loginWithDeviceFlowPollMock,
       loginWithDeviceFlowComplete: loginWithDeviceFlowCompleteMock,
@@ -234,6 +236,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
         'github',
         'access-token',
         'github.com',
+        undefined,
       );
       expect(navigateMock).toHaveBeenCalledWith('/');
     });
@@ -254,7 +257,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       .fn()
       .mockRejectedValueOnce(new Error('authorization denied'));
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
       loginWithDeviceFlowPoll: loginWithDeviceFlowPollMock,
     });
@@ -281,7 +284,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
     });
     const loginWithDeviceFlowPollMock = vi.fn();
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
       loginWithDeviceFlowPoll: loginWithDeviceFlowPollMock,
     });
@@ -306,7 +309,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       expiresAt: Date.now() + 900000,
     });
 
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />, {
+    renderWithProviders(<GitHubDeviceFlowAuthorize />, {
       loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
       loginWithDeviceFlowPoll: vi.fn().mockResolvedValueOnce(null),
       initialEntries: [
@@ -314,7 +317,7 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
           pathname: '/login/github/device-flow',
           state: {
             account: {
-              ...mockGitHubAppAccount,
+              ...mockGitifyOAuthAppAccount,
               hostname: 'github.enterprise.example' as Hostname,
             },
           },
@@ -328,11 +331,41 @@ describe('renderer/routes/github/LoginWithDeviceFlow.tsx', () => {
       'github',
       'github.enterprise.example',
       ['notifications', 'read:user', 'repo'],
+      undefined,
+    );
+  });
+
+  it('threads a custom client ID and hostname through the device flow', async () => {
+    const loginWithDeviceFlowStartMock = vi.fn().mockResolvedValueOnce({
+      hostname: 'github.example.com',
+      clientId: 'CUSTOM_CLIENT_ID_123',
+      deviceCode: 'device-code',
+      userCode: 'USER-1234',
+      verificationUri: 'https://github.example.com/login/device',
+      intervalSeconds: 5,
+      expiresAt: Date.now() + 900000,
+    });
+
+    renderWithProviders(
+      <GitHubDeviceFlowAuthorize
+        clientId={'CUSTOM_CLIENT_ID_123' as ClientID}
+        hostname={'github.example.com' as Hostname}
+      />,
+      { loginWithDeviceFlowStart: loginWithDeviceFlowStartMock },
+    );
+
+    await userEvent.click(screen.getByTestId('device-scope-full'));
+
+    expect(loginWithDeviceFlowStartMock).toHaveBeenCalledWith(
+      'github',
+      'github.example.com',
+      ['notifications', 'read:user', 'repo'],
+      'CUSTOM_CLIENT_ID_123',
     );
   });
 
   it('should open the revoke-access developer settings link', async () => {
-    renderWithProviders(<GitHubLoginWithDeviceFlowRoute />);
+    renderWithProviders(<GitHubDeviceFlowAuthorize />);
 
     await userEvent.click(screen.getByTitle('GitHub → Developer Settings'));
 
diff --git a/src/renderer/routes/github/DeviceFlowAuthorize.tsx b/src/renderer/routes/github/DeviceFlowAuthorize.tsx
new file mode 100644
index 000000000..eac8ffe0a
--- /dev/null
+++ b/src/renderer/routes/github/DeviceFlowAuthorize.tsx
@@ -0,0 +1,384 @@
+import { type ReactNode, useCallback, useEffect, useState } from 'react';
+import { useLocation, useNavigate } from 'react-router-dom';
+
+import {
+  CheckCircleFillIcon,
+  CopyIcon,
+  GlobeIcon,
+  LinkIcon,
+  SignInIcon,
+  SyncIcon,
+} from '@primer/octicons-react';
+import { Banner, Button, Heading, IconButton, Stack, Text } from '@primer/react';
+
+import { Constants } from '../../constants';
+
+import { useLogins } from '../../hooks/useLogins';
+
+import { Contents } from '../../components/layout/Contents';
+import { Page } from '../../components/layout/Page';
+import { Footer } from '../../components/primitives/Footer';
+import { Header } from '../../components/primitives/Header';
+
+import type { Account, ClientID, Forge, Hostname, Link } from '../../types';
+import type { DeviceFlowSession } from '../../utils/auth/types';
+
+import { getAlternateScopeNames, getRecommendedScopeNames } from '../../utils/auth/scopes';
+import { rendererLogError, toError } from '../../utils/core/logger';
+import { describeDeviceFlowStartError } from '../../utils/forges/github/flows';
+import { getAdapter } from '../../utils/forges/registry';
+import { copyToClipboard, openExternalLink } from '../../utils/system/comms';
+
+interface LocationState {
+  account?: Account;
+}
+
+interface GitHubDeviceFlowAuthorizeProps {
+  /** OAuth app client ID to authorize; omit to use Gitify's preconfigured app. */
+  clientId?: ClientID;
+  /** Hostname to authenticate against; defaults to the re-auth account or GitHub.com. */
+  hostname?: Hostname;
+  /** Page heading; defaults to authorizing Gitify's preconfigured app. */
+  title?: string;
+}
+
+type ScopeChoice = 'public' | 'full';
+
+export function GitHubDeviceFlowAuthorize({
+  clientId,
+  hostname,
+  title,
+}: GitHubDeviceFlowAuthorizeProps) {
+  const navigate = useNavigate();
+  const location = useLocation();
+  const { account: reAuthAccount } = (location.state ?? {}) as LocationState;
+
+  const forge: Forge = 'github';
+
+  const resolvedHostname = (hostname ??
+    reAuthAccount?.hostname ??
+    Constants.GITHUB_HOSTNAME) as Hostname;
+
+  const { loginWithDeviceFlowStart, loginWithDeviceFlowPoll, loginWithDeviceFlowComplete } =
+    useLogins();
+
+  const [session, setSession] = useState<DeviceFlowSession | null>(null);
+  const [isPolling, setIsPolling] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [scopeChoice, setScopeChoice] = useState<ScopeChoice | null>(null);
+
+  // Initialize device flow session, copy code, and open browser
+  useEffect(() => {
+    const initializeDeviceFlow = async () => {
+      try {
+        const scopes =
+          scopeChoice === 'public' ? getAlternateScopeNames() : getRecommendedScopeNames();
+
+        const newSession = await loginWithDeviceFlowStart(
+          forge,
+          resolvedHostname,
+          scopes,
+          clientId,
+        );
+        setSession(newSession);
+
+        // Auto-copy the user code to clipboard
+        await copyToClipboard(newSession.userCode);
+
+        // Auto-open the verification URL in the browser
+        openExternalLink(newSession.verificationUri as Link);
+      } catch (err) {
+        rendererLogError('LoginWithDeviceFlow', 'Failed to start device flow', toError(err));
+        setError(
+          describeDeviceFlowStartError(err, resolvedHostname, clientId) ??
+            'Failed to start authentication. Please try again.',
+        );
+      }
+    };
+
+    if (scopeChoice) {
+      void initializeDeviceFlow();
+    }
+  }, [loginWithDeviceFlowStart, resolvedHostname, clientId, scopeChoice, forge]);
+
+  // Poll for device flow completion
+  useEffect(() => {
+    if (!session) {
+      return;
+    }
+
+    let isActive = true;
+    let timeoutId: NodeJS.Timeout | null = null;
+
+    const startPolling = async () => {
+      setIsPolling(true);
+
+      const poll = async (): Promise<void> => {
+        if (!isActive || Date.now() >= session.expiresAt) {
+          if (isActive) {
+            setError('Device code expired. Please start again.');
+          }
+          return;
+        }
+
+        const token = await loginWithDeviceFlowPoll(forge, session);
+
+        if (token && isActive) {
+          await loginWithDeviceFlowComplete(forge, token, session.hostname, clientId);
+          void navigate('/');
+          return;
+        }
+
+        const intervalMs = Math.max(5000, session.intervalSeconds * 1000);
+        await new Promise((resolve) => {
+          timeoutId = setTimeout(resolve, intervalMs);
+        });
+        await poll();
+      };
+
+      try {
+        await poll();
+      } catch (err) {
+        if (isActive) {
+          rendererLogError('LoginWithDeviceFlow', 'Failed to poll device flow', toError(err));
+          setError('Authentication failed. Please try again.');
+        }
+      } finally {
+        if (isActive) {
+          setIsPolling(false);
+        }
+      }
+    };
+
+    void startPolling();
+
+    return () => {
+      isActive = false;
+      if (timeoutId) {
+        clearTimeout(timeoutId);
+      }
+    };
+    // oxlint-disable-next-line react/exhaustive-deps -- navigate is stable
+  }, [session, loginWithDeviceFlowPoll, loginWithDeviceFlowComplete, clientId, forge]);
+
+  const handleCopyUserCode = useCallback(async () => {
+    if (session?.userCode) {
+      await copyToClipboard(session.userCode);
+    }
+  }, [session?.userCode]);
+
+  const handleOpenBrowser = useCallback(() => {
+    if (session?.verificationUri) {
+      openExternalLink(session.verificationUri as Link);
+    }
+  }, [session?.verificationUri]);
+
+  const handleCopyVerificationLink = useCallback(async () => {
+    if (session?.verificationUri) {
+      await copyToClipboard(session.verificationUri);
+    }
+  }, [session?.verificationUri]);
+
+  // Render UI states as separate functions for clarity
+  const renderSessionUI = () => {
+    if (!session) {
+      return null;
+    }
+
+    return (
+      <Stack direction="vertical" gap="normal">
+        <Heading as="h3">
+          Authorize the app <Text as="span">using this code.</Text>
+        </Heading>
+
+        <Stack align="center" direction="horizontal" gap="condensed">
+          <Text
+            as="div"
+            data-testid="device-user-code"
+            style={{
+              fontSize: '32px',
+              fontWeight: 'bold',
+              fontFamily: 'monospace',
+              letterSpacing: '0.05em',
+            }}
+          >
+            {session.userCode}
+          </Text>
+          <IconButton
+            aria-label="Copy device code"
+            data-testid="copy-device-code"
+            icon={CopyIcon}
+            onClick={handleCopyUserCode}
+            size="small"
+            variant="invisible"
+          />
+        </Stack>
+
+        <Stack direction="vertical" gap="condensed">
+          <Stack align="center" direction="horizontal" gap="condensed">
+            <CheckCircleFillIcon size={16} />
+            <Text size="small">Code copied to clipboard</Text>
+          </Stack>
+
+          <Stack align="center" direction="horizontal" gap="condensed">
+            <GlobeIcon size={16} />
+            <Text size="small">
+              Opened{' '}
+              {session.hostname === Constants.GITHUB_HOSTNAME ? 'GitHub.com' : session.hostname}
+            </Text>
+          </Stack>
+
+          <Stack align="center" direction="horizontal" gap="condensed">
+            <SyncIcon className={isPolling ? 'animate-spin' : 'opacity-30'} size={16} />
+            <Text size="small">Waiting for authorization...</Text>
+          </Stack>
+        </Stack>
+      </Stack>
+    );
+  };
+
+  const renderScopeChoiceUI = () => (
+    <Stack direction="vertical" gap="normal">
+      <Text as="p">Receive notifications for:</Text>
+
+      <Stack align="center" direction="vertical">
+        <Button
+          block
+          data-testid="device-scope-full"
+          labelWrap
+          onClick={() => setScopeChoice('full')}
+          variant="primary"
+        >
+          <Stack gap="none">
+            <Text as="strong">Public and Private</Text>
+            <Text size="small">Best experience, but requires broader permissions.</Text>
+            <Text as="em" size="small">
+              Scopes: {getRecommendedScopeNames().join(', ')}
+            </Text>
+          </Stack>
+        </Button>
+
+        <Button
+          block
+          data-testid="device-scope-public"
+          labelWrap
+          onClick={() => setScopeChoice('public')}
+        >
+          <Stack gap="none">
+            <Text>Public</Text>
+            <Text size="small">Limited experience with least privilege permissions.</Text>
+            <Text as="em" size="small">
+              Scopes: {getAlternateScopeNames().join(', ')}
+            </Text>
+          </Stack>
+        </Button>
+
+        {(() => {
+          const adapter = getAdapter(forge);
+          const revokeUrl = adapter.deviceFlow?.getRevokeAccessUrl(resolvedHostname, clientId);
+          if (!revokeUrl) {
+            return null;
+          }
+          const label = `${adapter.displayName} → Developer Settings`;
+          return (
+            <Stack gap="none">
+              <Text as="em" size="small">
+                {clientId
+                  ? "Note: to change previously granted permissions, revoke your app's access at"
+                  : "Note: to change previously granted permissions, revoke Gitify's access at"}{' '}
+                <button
+                  className="text-gitify-link cursor-pointer"
+                  onClick={() => openExternalLink(revokeUrl)}
+                  title={label}
+                  type="button"
+                >
+                  {label}
+                </button>
+                {', then re-authorize above.'}
+              </Text>
+            </Stack>
+          );
+        })()}
+      </Stack>
+    </Stack>
+  );
+
+  const renderInitializingUI = () => (
+    <Stack align="center" direction="vertical" gap="normal">
+      <IconButton
+        aria-label="Initializing"
+        className={'animate-spin'}
+        icon={SyncIcon}
+        size="large"
+        variant="invisible"
+      />
+      <Text>Initializing authentication...</Text>
+    </Stack>
+  );
+
+  let mainContent: ReactNode;
+  if (session) {
+    mainContent = renderSessionUI();
+  } else if (!scopeChoice) {
+    mainContent = renderScopeChoiceUI();
+  } else {
+    mainContent = renderInitializingUI();
+  }
+
+  return (
+    <Page testId="Login With Device Flow">
+      <Header icon={SignInIcon}>{title ?? 'Authorize with GitHub'}</Header>
+
+      <Contents scrollFade>
+        {error && (
+          <Banner
+            data-testid="login-errors"
+            description={
+              <Text color="danger.fg">
+                <Stack direction="vertical" gap="condensed">
+                  <Text>{error}</Text>
+                </Stack>
+              </Text>
+            }
+            hideTitle
+            title="Login errors"
+            variant="critical"
+          />
+        )}
+        {mainContent}
+      </Contents>
+
+      {session ? (
+        <Footer justify="space-between">
+          <Button
+            data-testid="open-browser-button"
+            leadingVisual={GlobeIcon}
+            onClick={handleOpenBrowser}
+            variant="primary"
+          >
+            Open {session.hostname === Constants.GITHUB_HOSTNAME ? 'GitHub.com' : session.hostname}
+          </Button>
+          <Stack direction="horizontal" gap="condensed">
+            <Button
+              data-testid="copy-link-button"
+              leadingVisual={LinkIcon}
+              onClick={handleCopyVerificationLink}
+              variant="default"
+            >
+              Copy link
+            </Button>
+            <Button data-testid="cancel-button" onClick={() => navigate(-1)} variant="default">
+              Cancel
+            </Button>
+          </Stack>
+        </Footer>
+      ) : (
+        <Footer justify="end">
+          <Button data-testid="cancel-button" onClick={() => navigate(-1)} variant="default">
+            Cancel
+          </Button>
+        </Footer>
+      )}
+    </Page>
+  );
+}
diff --git a/src/renderer/routes/github/LoginWithCustomOAuthApp.test.tsx b/src/renderer/routes/github/LoginWithCustomOAuthApp.test.tsx
new file mode 100644
index 000000000..0987888e6
--- /dev/null
+++ b/src/renderer/routes/github/LoginWithCustomOAuthApp.test.tsx
@@ -0,0 +1,104 @@
+import { screen, waitFor } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+
+import { renderWithProviders } from '../../__helpers__/test-utils';
+import { mockCustomOAuthAppAccount } from '../../__mocks__/account-mocks';
+
+import * as comms from '../../utils/system/comms';
+import { GitHubLoginWithCustomOAuthAppRoute } from './LoginWithCustomOAuthApp';
+
+describe('renderer/routes/github/LoginWithCustomOAuthApp.tsx', () => {
+  const copyToClipboardSpy = vi.spyOn(comms, 'copyToClipboard').mockResolvedValue();
+  const openExternalLinkSpy = vi.spyOn(comms, 'openExternalLink').mockImplementation(vi.fn());
+
+  const session = {
+    hostname: 'github.example.com',
+    clientId: 'CUSTOM_CLIENT_ID_123',
+    deviceCode: 'device-code',
+    userCode: 'USER-1234',
+    verificationUri: 'https://github.example.com/login/device',
+    intervalSeconds: 5,
+    expiresAt: Date.now() + 900000,
+  };
+
+  it('collects a hostname and client ID, and no client secret', () => {
+    renderWithProviders(<GitHubLoginWithCustomOAuthAppRoute />);
+
+    expect(screen.getByTestId('login-hostname')).toBeInTheDocument();
+    expect(screen.getByTestId('login-clientId')).toBeInTheDocument();
+    expect(screen.queryByTestId('login-clientSecret')).not.toBeInTheDocument();
+  });
+
+  it('shows validation errors for an invalid hostname and client ID', async () => {
+    renderWithProviders(<GitHubLoginWithCustomOAuthAppRoute />);
+
+    const hostname = screen.getByTestId('login-hostname');
+    await userEvent.clear(hostname);
+    await userEvent.type(hostname, 'test');
+    await userEvent.type(screen.getByTestId('login-clientId'), 'short');
+
+    await userEvent.click(screen.getByTestId('login-submit'));
+
+    expect(screen.getByText('Hostname format is invalid')).toBeInTheDocument();
+    expect(screen.getByText('Client ID format is invalid')).toBeInTheDocument();
+    // Still on the credentials step — the device flow was not started.
+    expect(screen.getByTestId('login-submit')).toBeInTheDocument();
+  });
+
+  it('reuses the scope step and starts the device flow with the supplied credentials', async () => {
+    const loginWithDeviceFlowStartMock = vi.fn().mockResolvedValueOnce(session);
+
+    renderWithProviders(<GitHubLoginWithCustomOAuthAppRoute />, {
+      loginWithDeviceFlowStart: loginWithDeviceFlowStartMock,
+      loginWithDeviceFlowPoll: vi.fn().mockResolvedValue(null),
+    });
+
+    const hostname = screen.getByTestId('login-hostname');
+    await userEvent.clear(hostname);
+    await userEvent.type(hostname, 'github.example.com');
+    await userEvent.type(screen.getByTestId('login-clientId'), 'CUSTOM_CLIENT_ID_123');
+
+    await userEvent.click(screen.getByTestId('login-submit'));
+
+    // The shared public/recommended scope step is shown before the session starts.
+    expect(screen.getByTestId('device-scope-full')).toBeInTheDocument();
+    await userEvent.click(screen.getByTestId('device-scope-full'));
+
+    await waitFor(() => {
+      expect(loginWithDeviceFlowStartMock).toHaveBeenCalledWith(
+        'github',
+        'github.example.com',
+        ['notifications', 'read:user', 'repo'],
+        'CUSTOM_CLIENT_ID_123',
+      );
+    });
+
+    await screen.findByTestId('device-user-code');
+    expect(copyToClipboardSpy).toHaveBeenCalledWith('USER-1234');
+  });
+
+  it('opens the OAuth app registration page without a callback URL', async () => {
+    renderWithProviders(<GitHubLoginWithCustomOAuthAppRoute />);
+
+    await userEvent.click(screen.getByTestId('login-create-oauth-app'));
+
+    expect(openExternalLinkSpy).toHaveBeenCalledWith(
+      expect.stringContaining('https://github.com/settings/applications/new'),
+    );
+    expect(openExternalLinkSpy).not.toHaveBeenCalledWith(expect.stringContaining('callback_url'));
+  });
+
+  it('prefills the hostname and client ID from the re-auth account', () => {
+    renderWithProviders(<GitHubLoginWithCustomOAuthAppRoute />, {
+      initialEntries: [
+        {
+          pathname: '/login/github/custom-oauth-app',
+          state: { account: mockCustomOAuthAppAccount },
+        },
+      ],
+    });
+
+    expect(screen.getByTestId('login-hostname')).toHaveValue('github.gitify.io');
+    expect(screen.getByTestId('login-clientId')).toHaveValue('CUSTOM_CLIENT_ID_123');
+  });
+});
diff --git a/src/renderer/routes/github/LoginWithCustomOAuthApp.tsx b/src/renderer/routes/github/LoginWithCustomOAuthApp.tsx
new file mode 100644
index 000000000..ab41e6e4d
--- /dev/null
+++ b/src/renderer/routes/github/LoginWithCustomOAuthApp.tsx
@@ -0,0 +1,164 @@
+import { useState } from 'react';
+import { useLocation } from 'react-router-dom';
+
+import { BookIcon, PersonIcon } from '@primer/octicons-react';
+import { Button, FormControl, Stack, Text, TextInput, Tooltip } from '@primer/react';
+
+import { Constants } from '../../constants';
+
+import { Contents } from '../../components/layout/Contents';
+import { Page } from '../../components/layout/Page';
+import { Footer } from '../../components/primitives/Footer';
+import { Header } from '../../components/primitives/Header';
+
+import type { Account, ClientID, Forge, Hostname } from '../../types';
+
+import {
+  type CustomOAuthAppFormData,
+  type CustomOAuthAppFormErrors,
+  validateCustomOAuthAppForm,
+} from '../../utils/auth/loginValidation';
+import { getAdapter } from '../../utils/forges/registry';
+import { openExternalLink } from '../../utils/system/comms';
+import { GitHubDeviceFlowAuthorize } from './DeviceFlowAuthorize';
+
+interface LocationState {
+  account?: Account;
+}
+
+/**
+ * Sign in with a user-supplied GitHub OAuth app.
+ *
+ * Collects the app's hostname and client ID (a public identifier — never a
+ * secret), then hands off to the shared device-flow authorization UI.
+ */
+export function GitHubLoginWithCustomOAuthAppRoute() {
+  const location = useLocation();
+  const { account: reAuthAccount } = (location.state ?? {}) as LocationState;
+
+  const forge: Forge = 'github';
+
+  const [formData, setFormData] = useState<CustomOAuthAppFormData>({
+    hostname: (reAuthAccount?.hostname ?? Constants.GITHUB_HOSTNAME) as Hostname,
+    clientId: (reAuthAccount?.clientId ?? '') as ClientID,
+  });
+  const [errors, setErrors] = useState<CustomOAuthAppFormErrors>({});
+  const [credentials, setCredentials] = useState<CustomOAuthAppFormData | null>(null);
+
+  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const { name, value } = e.target;
+    setFormData((prev) => ({ ...prev, [name]: value }));
+  };
+
+  const handleSubmit = () => {
+    const newErrors = validateCustomOAuthAppForm(formData, forge);
+
+    setErrors(newErrors);
+
+    if (!newErrors.hostname && !newErrors.clientId) {
+      setCredentials(formData);
+    }
+  };
+
+  if (credentials) {
+    return (
+      <GitHubDeviceFlowAuthorize
+        clientId={credentials.clientId}
+        hostname={credentials.hostname}
+        title="Authorize with your OAuth app"
+      />
+    );
+  }
+
+  return (
+    <Page testId="Login With Custom OAuth App">
+      <Header icon={PersonIcon}>Login with Custom OAuth App</Header>
+
+      <Contents scrollFade>
+        <Stack direction="vertical" gap="normal">
+          <Text as="p" size="small">
+            Authorize Gitify with your own GitHub OAuth app. Create an app, enable its device flow,
+            then paste its client ID below.
+          </Text>
+
+          <FormControl required>
+            <FormControl.Label>Hostname</FormControl.Label>
+            <FormControl.Caption>
+              <Text as="i">Change only if you are using GitHub Enterprise Server</Text>
+            </FormControl.Caption>
+            <TextInput
+              aria-invalid={errors.hostname ? 'true' : 'false'}
+              block
+              className={
+                errors.hostname
+                  ? 'border-gitify-textInput-error'
+                  : 'border-gitify-textInput-default'
+              }
+              data-testid="login-hostname"
+              name="hostname"
+              onChange={handleInputChange}
+              placeholder="github.com"
+              value={formData.hostname}
+            />
+            {errors.hostname && (
+              <FormControl.Validation variant="error">{errors.hostname}</FormControl.Validation>
+            )}
+          </FormControl>
+
+          <Stack align="center" direction="horizontal" gap="condensed">
+            <Button
+              data-testid="login-create-oauth-app"
+              disabled={!formData.hostname}
+              leadingVisual={PersonIcon}
+              onClick={() => {
+                const url = getAdapter(forge).customOAuthApp?.getNewOAuthAppUrl(formData.hostname);
+                if (url) {
+                  openExternalLink(url);
+                }
+              }}
+              size="small"
+            >
+              Create new OAuth app
+            </Button>
+            <Text className="text-xs">
+              and enable its <Text as="i">device flow</Text>, then use its client ID below.
+            </Text>
+          </Stack>
+
+          <FormControl required>
+            <FormControl.Label>Client ID</FormControl.Label>
+            <TextInput
+              aria-invalid={errors.clientId ? 'true' : 'false'}
+              block
+              data-testid="login-clientId"
+              name="clientId"
+              onChange={handleInputChange}
+              placeholder="Your generated client ID (20 characters)"
+              value={formData.clientId}
+            />
+            {errors.clientId && (
+              <FormControl.Validation variant="error">{errors.clientId}</FormControl.Validation>
+            )}
+          </FormControl>
+        </Stack>
+      </Contents>
+
+      <Footer justify="space-between">
+        <Tooltip text="GitHub documentation">
+          <Button
+            data-testid="login-docs"
+            leadingVisual={BookIcon}
+            onClick={() => openExternalLink(Constants.GITHUB_DOCS.OAUTH_URL)}
+            size="small"
+          >
+            Docs
+          </Button>
+        </Tooltip>
+
+        <Button data-testid="login-submit" onClick={handleSubmit} variant="primary">
+          Continue
+        </Button>
+      </Footer>
+    </Page>
+  );
+}
diff --git a/src/renderer/routes/github/LoginWithDeviceFlow.tsx b/src/renderer/routes/github/LoginWithDeviceFlow.tsx
index eca790539..2d7bd7ae5 100644
--- a/src/renderer/routes/github/LoginWithDeviceFlow.tsx
+++ b/src/renderer/routes/github/LoginWithDeviceFlow.tsx
@@ -1,358 +1,12 @@
-import { type ReactNode, useCallback, useEffect, useState } from 'react';
-import { useLocation, useNavigate } from 'react-router-dom';
-
-import {
-  CheckCircleFillIcon,
-  CopyIcon,
-  GlobeIcon,
-  LinkIcon,
-  SignInIcon,
-  SyncIcon,
-} from '@primer/octicons-react';
-import { Banner, Button, Heading, IconButton, Stack, Text } from '@primer/react';
-
-import { Constants } from '../../constants';
-
-import { useLogins } from '../../hooks/useLogins';
-
-import { Contents } from '../../components/layout/Contents';
-import { Page } from '../../components/layout/Page';
-import { Footer } from '../../components/primitives/Footer';
-import { Header } from '../../components/primitives/Header';
-
-import type { Account, Forge, Hostname, Link } from '../../types';
-import type { DeviceFlowSession } from '../../utils/auth/types';
-
-import { getAlternateScopeNames, getRecommendedScopeNames } from '../../utils/auth/scopes';
-import { rendererLogError, toError } from '../../utils/core/logger';
-import { getAdapter } from '../../utils/forges/registry';
-import { copyToClipboard, openExternalLink } from '../../utils/system/comms';
-
-interface LocationState {
-  account?: Account;
-}
-
-type ScopeChoice = 'public' | 'full';
-
+import { GitHubDeviceFlowAuthorize } from './DeviceFlowAuthorize';
+
+/**
+ * Route element for `/login/github/device-flow`.
+ *
+ * Authorizes Gitify's preconfigured OAuth app on GitHub.com. A user-supplied
+ * custom app uses the `/login/github/custom-oauth-app` route instead, which
+ * composes the same `GitHubDeviceFlowAuthorize` UI with its own client ID.
+ */
 export function GitHubLoginWithDeviceFlowRoute() {
-  const navigate = useNavigate();
-  const location = useLocation();
-  const { account: reAuthAccount } = (location.state ?? {}) as LocationState;
-
-  const forge: Forge = 'github';
-
-  const { loginWithDeviceFlowStart, loginWithDeviceFlowPoll, loginWithDeviceFlowComplete } =
-    useLogins();
-
-  const [session, setSession] = useState<DeviceFlowSession | null>(null);
-  const [isPolling, setIsPolling] = useState(false);
-  const [error, setError] = useState<string | null>(null);
-  const [scopeChoice, setScopeChoice] = useState<ScopeChoice | null>(null);
-
-  // Initialize device flow session, copy code, and open browser
-  useEffect(() => {
-    const initializeDeviceFlow = async () => {
-      try {
-        const scopes =
-          scopeChoice === 'public' ? getAlternateScopeNames() : getRecommendedScopeNames();
-
-        const newSession = await loginWithDeviceFlowStart(forge, reAuthAccount?.hostname, scopes);
-        setSession(newSession);
-
-        // Auto-copy the user code to clipboard
-        await copyToClipboard(newSession.userCode);
-
-        // Auto-open the verification URL in the browser
-        openExternalLink(newSession.verificationUri as Link);
-      } catch (err) {
-        rendererLogError('LoginWithDeviceFlow', 'Failed to start device flow', toError(err));
-        setError('Failed to start authentication. Please try again.');
-      }
-    };
-
-    if (scopeChoice) {
-      void initializeDeviceFlow();
-    }
-  }, [loginWithDeviceFlowStart, reAuthAccount, scopeChoice, forge]);
-
-  // Poll for device flow completion
-  useEffect(() => {
-    if (!session) {
-      return;
-    }
-
-    let isActive = true;
-    let timeoutId: NodeJS.Timeout | null = null;
-
-    const startPolling = async () => {
-      setIsPolling(true);
-
-      const poll = async (): Promise<void> => {
-        if (!isActive || Date.now() >= session.expiresAt) {
-          if (isActive) {
-            setError('Device code expired. Please start again.');
-          }
-          return;
-        }
-
-        const token = await loginWithDeviceFlowPoll(forge, session);
-
-        if (token && isActive) {
-          await loginWithDeviceFlowComplete(forge, token, session.hostname);
-          void navigate('/');
-          return;
-        }
-
-        const intervalMs = Math.max(5000, session.intervalSeconds * 1000);
-        await new Promise((resolve) => {
-          timeoutId = setTimeout(resolve, intervalMs);
-        });
-        await poll();
-      };
-
-      try {
-        await poll();
-      } catch (err) {
-        if (isActive) {
-          rendererLogError('LoginWithDeviceFlow', 'Failed to poll device flow', toError(err));
-          setError('Authentication failed. Please try again.');
-        }
-      } finally {
-        if (isActive) {
-          setIsPolling(false);
-        }
-      }
-    };
-
-    void startPolling();
-
-    return () => {
-      isActive = false;
-      if (timeoutId) {
-        clearTimeout(timeoutId);
-      }
-    };
-    // oxlint-disable-next-line react/exhaustive-deps -- navigate is stable
-  }, [session, loginWithDeviceFlowPoll, loginWithDeviceFlowComplete, forge]);
-
-  const handleCopyUserCode = useCallback(async () => {
-    if (session?.userCode) {
-      await copyToClipboard(session.userCode);
-    }
-  }, [session?.userCode]);
-
-  const handleOpenBrowser = useCallback(() => {
-    if (session?.verificationUri) {
-      openExternalLink(session.verificationUri as Link);
-    }
-  }, [session?.verificationUri]);
-
-  const handleCopyVerificationLink = useCallback(async () => {
-    if (session?.verificationUri) {
-      await copyToClipboard(session.verificationUri);
-    }
-  }, [session?.verificationUri]);
-
-  // Render UI states as separate functions for clarity
-  const renderSessionUI = () => {
-    if (!session) {
-      return null;
-    }
-
-    return (
-      <Stack direction="vertical" gap="normal">
-        <Heading as="h3">
-          Authorize the app <Text as="span">using this code.</Text>
-        </Heading>
-
-        <Stack align="center" direction="horizontal" gap="condensed">
-          <Text
-            as="div"
-            data-testid="device-user-code"
-            style={{
-              fontSize: '32px',
-              fontWeight: 'bold',
-              fontFamily: 'monospace',
-              letterSpacing: '0.05em',
-            }}
-          >
-            {session.userCode}
-          </Text>
-          <IconButton
-            aria-label="Copy device code"
-            data-testid="copy-device-code"
-            icon={CopyIcon}
-            onClick={handleCopyUserCode}
-            size="small"
-            variant="invisible"
-          />
-        </Stack>
-
-        <Stack direction="vertical" gap="condensed">
-          <Stack align="center" direction="horizontal" gap="condensed">
-            <CheckCircleFillIcon size={16} />
-            <Text size="small">Code copied to clipboard</Text>
-          </Stack>
-
-          <Stack align="center" direction="horizontal" gap="condensed">
-            <GlobeIcon size={16} />
-            <Text size="small">
-              Opened{' '}
-              {session.hostname === Constants.GITHUB_HOSTNAME ? 'GitHub.com' : session.hostname}
-            </Text>
-          </Stack>
-
-          <Stack align="center" direction="horizontal" gap="condensed">
-            <SyncIcon className={isPolling ? 'animate-spin' : 'opacity-30'} size={16} />
-            <Text size="small">Waiting for authorization...</Text>
-          </Stack>
-        </Stack>
-      </Stack>
-    );
-  };
-
-  const renderScopeChoiceUI = () => (
-    <Stack direction="vertical" gap="normal">
-      <Text as="p">Receive notifications for:</Text>
-
-      <Stack align="center" direction="vertical">
-        <Button
-          block
-          data-testid="device-scope-full"
-          labelWrap
-          onClick={() => setScopeChoice('full')}
-          variant="primary"
-        >
-          <Stack gap="none">
-            <Text as="strong">Public and Private</Text>
-            <Text size="small">Best experience, but requires broader permissions.</Text>
-            <Text as="em" size="small">
-              Scopes: {getRecommendedScopeNames().join(', ')}
-            </Text>
-          </Stack>
-        </Button>
-
-        <Button
-          block
-          data-testid="device-scope-public"
-          labelWrap
-          onClick={() => setScopeChoice('public')}
-        >
-          <Stack gap="none">
-            <Text>Public</Text>
-            <Text size="small">Limited experience with least privilege permissions.</Text>
-            <Text as="em" size="small">
-              Scopes: {getAlternateScopeNames().join(', ')}
-            </Text>
-          </Stack>
-        </Button>
-
-        {(() => {
-          const adapter = getAdapter(forge);
-          const revokeUrl = adapter.deviceFlow?.getRevokeAccessUrl(
-            (reAuthAccount?.hostname ?? Constants.GITHUB_HOSTNAME) as Hostname,
-          );
-          if (!revokeUrl) {
-            return null;
-          }
-          const label = `${adapter.displayName} → Developer Settings`;
-          return (
-            <Stack gap="none">
-              <Text as="em" size="small">
-                Note: to change previously granted permissions, revoke Gitify's access at{' '}
-                <button
-                  className="text-gitify-link cursor-pointer"
-                  onClick={() => openExternalLink(revokeUrl)}
-                  title={label}
-                  type="button"
-                >
-                  {label}
-                </button>
-                {', then re-authorize above.'}
-              </Text>
-            </Stack>
-          );
-        })()}
-      </Stack>
-    </Stack>
-  );
-
-  const renderInitializingUI = () => (
-    <Stack align="center" direction="vertical" gap="normal">
-      <IconButton
-        aria-label="Initializing"
-        className={'animate-spin'}
-        icon={SyncIcon}
-        size="large"
-        variant="invisible"
-      />
-      <Text>Initializing authentication...</Text>
-    </Stack>
-  );
-
-  let mainContent: ReactNode;
-  if (session) {
-    mainContent = renderSessionUI();
-  } else if (!scopeChoice) {
-    mainContent = renderScopeChoiceUI();
-  } else {
-    mainContent = renderInitializingUI();
-  }
-
-  return (
-    <Page testId="Login With Device Flow">
-      <Header icon={SignInIcon}>Authorize with GitHub</Header>
-
-      <Contents scrollFade>
-        {error && (
-          <Banner
-            data-testid="login-errors"
-            description={
-              <Text color="danger.fg">
-                <Stack direction="vertical" gap="condensed">
-                  <Text>{error}</Text>
-                </Stack>
-              </Text>
-            }
-            hideTitle
-            title="Login errors"
-            variant="critical"
-          />
-        )}
-        {mainContent}
-      </Contents>
-
-      {session ? (
-        <Footer justify="space-between">
-          <Button
-            data-testid="open-browser-button"
-            leadingVisual={GlobeIcon}
-            onClick={handleOpenBrowser}
-            variant="primary"
-          >
-            Open {session.hostname === Constants.GITHUB_HOSTNAME ? 'GitHub.com' : session.hostname}
-          </Button>
-          <Stack direction="horizontal" gap="condensed">
-            <Button
-              data-testid="copy-link-button"
-              leadingVisual={LinkIcon}
-              onClick={handleCopyVerificationLink}
-              variant="default"
-            >
-              Copy link
-            </Button>
-            <Button data-testid="cancel-button" onClick={() => navigate(-1)} variant="default">
-              Cancel
-            </Button>
-          </Stack>
-        </Footer>
-      ) : (
-        <Footer justify="end">
-          <Button data-testid="cancel-button" onClick={() => navigate(-1)} variant="default">
-            Cancel
-          </Button>
-        </Footer>
-      )}
-    </Page>
-  );
+  return <GitHubDeviceFlowAuthorize />;
 }
diff --git a/src/renderer/routes/github/LoginWithOAuthApp.test.tsx b/src/renderer/routes/github/LoginWithOAuthApp.test.tsx
deleted file mode 100644
index c6aa28793..000000000
--- a/src/renderer/routes/github/LoginWithOAuthApp.test.tsx
+++ /dev/null
@@ -1,145 +0,0 @@
-import { screen, waitFor } from '@testing-library/react';
-import userEvent from '@testing-library/user-event';
-
-import { navigateMock, renderWithProviders } from '../../__helpers__/test-utils';
-
-import * as logger from '../../utils/core/logger';
-import * as comms from '../../utils/system/comms';
-import { GitHubLoginWithOAuthAppRoute } from './LoginWithOAuthApp';
-
-describe('renderer/routes/github/LoginWithOAuthApp.tsx', () => {
-  const loginWithOAuthAppMock = vi.fn();
-
-  const openExternalLinkSpy = vi.spyOn(comms, 'openExternalLink').mockImplementation(vi.fn());
-
-  it('renders correctly', () => {
-    const tree = renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-    expect(tree.container).toMatchSnapshot();
-  });
-
-  it('let us go back', async () => {
-    renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-    await userEvent.click(screen.getByTestId('header-nav-back'));
-
-    expect(navigateMock).toHaveBeenCalledTimes(1);
-    expect(navigateMock).toHaveBeenCalledWith(-1);
-  });
-
-  describe("'Create new OAuth App' button", () => {
-    it('should be disabled if no hostname configured', async () => {
-      renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-      await userEvent.clear(screen.getByTestId('login-hostname'));
-
-      await userEvent.click(screen.getByTestId('login-create-oauth-app'));
-
-      expect(openExternalLinkSpy).toHaveBeenCalledTimes(0);
-    });
-
-    it('should open in browser if hostname configured', async () => {
-      renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-      const hostname = screen.getByTestId('login-hostname');
-      await userEvent.clear(hostname);
-      await userEvent.type(hostname, 'company.github.com');
-
-      await userEvent.click(screen.getByTestId('login-create-oauth-app'));
-
-      expect(openExternalLinkSpy).toHaveBeenCalledTimes(1);
-    });
-  });
-
-  it('should login using a token - success', async () => {
-    loginWithOAuthAppMock.mockResolvedValueOnce(null);
-
-    renderWithProviders(<GitHubLoginWithOAuthAppRoute />, {
-      loginWithOAuthApp: loginWithOAuthAppMock,
-    });
-
-    const hostname = screen.getByTestId('login-hostname');
-    await userEvent.clear(hostname);
-    await userEvent.type(hostname, 'github.com');
-
-    await userEvent.type(screen.getByTestId('login-clientId'), '1234567890_ASDFGHJKL');
-
-    await userEvent.type(
-      screen.getByTestId('login-clientSecret'),
-      '1234567890_asdfghjklPOIUYTREWQ0987654321',
-    );
-
-    await userEvent.click(screen.getByTestId('login-submit'));
-
-    expect(loginWithOAuthAppMock).toHaveBeenCalledTimes(1);
-    expect(navigateMock).toHaveBeenCalledTimes(1);
-    expect(navigateMock).toHaveBeenCalledWith('/');
-  });
-
-  it('should login using a token - failure', async () => {
-    const rendererLogErrorSpy = vi.spyOn(logger, 'rendererLogError').mockImplementation(vi.fn());
-    loginWithOAuthAppMock.mockRejectedValueOnce(null);
-
-    renderWithProviders(<GitHubLoginWithOAuthAppRoute />, {
-      loginWithOAuthApp: loginWithOAuthAppMock,
-    });
-
-    const hostname = screen.getByTestId('login-hostname');
-    await userEvent.clear(hostname);
-    await userEvent.type(hostname, 'github.com');
-
-    await userEvent.type(screen.getByTestId('login-clientId'), '1234567890_ASDFGHJKL');
-
-    await userEvent.type(
-      screen.getByTestId('login-clientSecret'),
-      '1234567890_asdfghjklPOIUYTREWQ0987654321',
-    );
-
-    await userEvent.click(screen.getByTestId('login-submit'));
-
-    await waitFor(() => {
-      expect(loginWithOAuthAppMock).toHaveBeenCalledTimes(1);
-      expect(navigateMock).toHaveBeenCalledTimes(0);
-      expect(rendererLogErrorSpy).toHaveBeenCalledTimes(1);
-    });
-  });
-
-  it('should render the form with errors', async () => {
-    renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-    const hostname = screen.getByTestId('login-hostname');
-    await userEvent.clear(hostname);
-    await userEvent.type(hostname, 'test');
-
-    await userEvent.type(screen.getByTestId('login-clientId'), '123');
-
-    await userEvent.type(screen.getByTestId('login-clientSecret'), 'abc');
-
-    await userEvent.click(screen.getByTestId('login-submit'));
-
-    expect(screen.getByText('Hostname format is invalid')).toBeInTheDocument();
-    expect(screen.getByText('Client ID format is invalid')).toBeInTheDocument();
-    expect(screen.getByText('Client Secret format is invalid')).toBeInTheDocument();
-  });
-
-  it('should open help docs in the browser', async () => {
-    renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-    await userEvent.click(screen.getByTestId('login-docs'));
-
-    expect(openExternalLinkSpy).toHaveBeenCalledTimes(1);
-  });
-
-  it('should toggle client secret visibility', async () => {
-    renderWithProviders(<GitHubLoginWithOAuthAppRoute />);
-
-    const secretInput = screen.getByTestId('login-clientSecret');
-    expect(secretInput).toHaveAttribute('type', 'password');
-
-    await userEvent.click(screen.getByLabelText('Show token'));
-    expect(secretInput).toHaveAttribute('type', 'text');
-
-    await userEvent.click(screen.getByLabelText('Hide token'));
-    expect(secretInput).toHaveAttribute('type', 'password');
-  });
-});
diff --git a/src/renderer/routes/github/LoginWithOAuthApp.tsx b/src/renderer/routes/github/LoginWithOAuthApp.tsx
deleted file mode 100644
index 6f12e5e88..000000000
--- a/src/renderer/routes/github/LoginWithOAuthApp.tsx
+++ /dev/null
@@ -1,216 +0,0 @@
-import { useCallback, useState } from 'react';
-import { useLocation, useNavigate } from 'react-router-dom';
-
-import { BookIcon, EyeClosedIcon, EyeIcon, PersonIcon, SignInIcon } from '@primer/octicons-react';
-import { Banner, Button, FormControl, Stack, Text, TextInput, Tooltip } from '@primer/react';
-
-import { Constants } from '../../constants';
-
-import { useLogins } from '../../hooks/useLogins';
-
-import { Contents } from '../../components/layout/Contents';
-import { Page } from '../../components/layout/Page';
-import { Footer } from '../../components/primitives/Footer';
-import { Header } from '../../components/primitives/Header';
-
-import type { Account, ClientID, ClientSecret, Forge } from '../../types';
-
-import {
-  type OAuthAppFormData,
-  type OAuthAppFormErrors,
-  validateOAuthAppForm,
-} from '../../utils/auth/loginValidation';
-import { rendererLogError, toError } from '../../utils/core/logger';
-import { getAdapter } from '../../utils/forges/registry';
-import { openExternalLink } from '../../utils/system/comms';
-
-interface LocationState {
-  account?: Account;
-}
-
-export function GitHubLoginWithOAuthAppRoute() {
-  const navigate = useNavigate();
-  const location = useLocation();
-  const { account: reAuthAccount } = (location.state ?? {}) as LocationState;
-
-  const forge: Forge = 'github';
-
-  const { loginWithOAuthApp } = useLogins();
-
-  const [shouldMaskClientSecret, setShouldMaskClientSecret] = useState(true);
-  const [isVerifyingCredentials, setIsVerifyingCredentials] = useState(false);
-
-  const [formData, setFormData] = useState({
-    hostname: reAuthAccount?.hostname ?? Constants.GITHUB_HOSTNAME,
-    clientId: '' as ClientID,
-    clientSecret: '' as ClientSecret,
-  } as OAuthAppFormData);
-
-  const [errors, setErrors] = useState({} as OAuthAppFormErrors);
-
-  const handleSubmit = async () => {
-    setIsVerifyingCredentials(true);
-
-    const newErrors = validateOAuthAppForm(formData, forge);
-
-    setErrors(newErrors);
-
-    if (!newErrors.hostname && !newErrors.clientId && !newErrors.clientSecret) {
-      await verifyLoginCredentials(formData);
-    }
-    setIsVerifyingCredentials(false);
-  };
-
-  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
-    const { name, value } = e.target;
-    setFormData({
-      ...formData,
-      [name]: value,
-    });
-  };
-
-  const verifyLoginCredentials = useCallback(
-    async (data: OAuthAppFormData) => {
-      try {
-        await loginWithOAuthApp(forge, data);
-        void navigate('/');
-      } catch (err) {
-        rendererLogError('loginWithOAuthApp', 'Failed to login with OAuth App', toError(err));
-        setErrors({
-          invalidCredentialsForHost: `Failed to validate provided Client ID and Secret against ${data.hostname}`,
-        });
-      }
-    },
-    // oxlint-disable-next-line react/exhaustive-deps -- navigate is stable
-    [loginWithOAuthApp, forge],
-  );
-
-  return (
-    <Page testId="Login With OAuth App">
-      <Header icon={PersonIcon}>Login with OAuth App</Header>
-
-      <Contents scrollFade>
-        {errors.invalidCredentialsForHost && (
-          <Banner
-            data-testid="login-errors"
-            description={
-              <Text color="danger.fg">
-                <Stack direction="vertical" gap="condensed">
-                  <Text>{errors.invalidCredentialsForHost}</Text>
-                </Stack>
-              </Text>
-            }
-            hideTitle
-            title="Validation errors"
-            variant="critical"
-          />
-        )}
-        <Stack direction="vertical" gap="normal">
-          <FormControl required>
-            <FormControl.Label>Hostname</FormControl.Label>
-            <FormControl.Caption>
-              <Text as="i">Change only if you are using GitHub Enterprise Server</Text>
-            </FormControl.Caption>
-            <TextInput
-              aria-invalid={errors.hostname ? 'true' : 'false'}
-              block
-              className={
-                errors.hostname
-                  ? 'border-gitify-textInput-error'
-                  : 'border-gitify-textInput-default'
-              }
-              data-testid="login-hostname"
-              name="hostname"
-              onChange={handleInputChange}
-              placeholder="github.com"
-              value={formData.hostname}
-            />
-            {errors.hostname && (
-              <FormControl.Validation variant="error">{errors.hostname}</FormControl.Validation>
-            )}
-          </FormControl>
-          <Stack align="center" direction="horizontal" gap="condensed">
-            <Button
-              data-testid="login-create-oauth-app"
-              disabled={!formData.hostname}
-              leadingVisual={PersonIcon}
-              onClick={() => {
-                const url = getAdapter(forge).oauthWebApp?.getNewOAuthAppUrl(formData.hostname);
-                if (url) {
-                  openExternalLink(url);
-                }
-              }}
-              size="small"
-            >
-              Create new OAuth App
-            </Button>
-            <Text className="text-xs">
-              and use your <Text as="i">client id & secret</Text> below.
-            </Text>
-          </Stack>
-          <FormControl required>
-            <FormControl.Label>Client ID</FormControl.Label>
-            <TextInput
-              aria-invalid={errors.clientId ? 'true' : 'false'}
-              block
-              data-testid="login-clientId"
-              name="clientId"
-              onChange={handleInputChange}
-              placeholder="Your generated client id (20 characters)"
-              value={formData.clientId}
-            />
-            {errors.clientId && (
-              <FormControl.Validation variant="error">{errors.clientId}</FormControl.Validation>
-            )}
-          </FormControl>
-          <FormControl required>
-            <FormControl.Label>Client Secret</FormControl.Label>
-            <TextInput
-              aria-invalid={errors.clientSecret ? 'true' : 'false'}
-              block
-              data-testid="login-clientSecret"
-              name="clientSecret"
-              onChange={handleInputChange}
-              placeholder="Your generated client secret (40 characters)"
-              trailingAction={
-                <TextInput.Action
-                  aria-label={shouldMaskClientSecret ? 'Show token' : 'Hide token'}
-                  icon={shouldMaskClientSecret ? EyeIcon : EyeClosedIcon}
-                  onClick={() => setShouldMaskClientSecret(!shouldMaskClientSecret)}
-                />
-              }
-              type={shouldMaskClientSecret ? 'password' : 'text'}
-              value={formData.clientSecret}
-            />
-            {errors.clientSecret && (
-              <FormControl.Validation variant="error">{errors.clientSecret}</FormControl.Validation>
-            )}
-          </FormControl>
-        </Stack>
-      </Contents>
-
-      <Footer justify="space-between">
-        <Tooltip text="GitHub documentation">
-          <Button
-            data-testid="login-docs"
-            leadingVisual={BookIcon}
-            onClick={() => openExternalLink(Constants.GITHUB_DOCS.OAUTH_URL)}
-            size="small"
-          >
-            Docs
-          </Button>
-        </Tooltip>
-
-        <Button
-          data-testid="login-submit"
-          leadingVisual={SignInIcon}
-          loading={isVerifyingCredentials}
-          onClick={handleSubmit}
-          variant="primary"
-        >
-          Login
-        </Button>
-      </Footer>
-    </Page>
-  );
-}
diff --git a/src/renderer/routes/github/__snapshots__/LoginWithOAuthApp.test.tsx.snap b/src/renderer/routes/github/__snapshots__/LoginWithOAuthApp.test.tsx.snap
deleted file mode 100644
index 1e0136890..000000000
--- a/src/renderer/routes/github/__snapshots__/LoginWithOAuthApp.test.tsx.snap
+++ /dev/null
@@ -1,487 +0,0 @@
-// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
-
-exports[`renderer/routes/github/LoginWithOAuthApp.tsx > renders correctly 1`] = `
-<div>
-  <div
-    class="flex flex-col h-screen"
-    data-testid="Login With OAuth App"
-  >
-    <div
-      class="pl-4 pr-5 pt-3 pb-1"
-    >
-      <div
-        class="prc-Stack-Stack-UQ9k6"
-        data-align="stretch"
-        data-component="Stack"
-        data-direction="horizontal"
-        data-justify="space-between"
-        data-padding="none"
-        data-wrap="nowrap"
-      >
-        <button
-          aria-labelledby="Go Back"
-          class="prc-Button-ButtonBase-9n-Xk prc-Button-IconButton-fyge7"
-          data-component="IconButton"
-          data-loading="false"
-          data-no-visuals="true"
-          data-size="medium"
-          data-testid="header-nav-back"
-          data-variant="invisible"
-          type="button"
-        >
-          <svg
-            aria-hidden="true"
-            class="octicon octicon-arrow-left"
-            data-component="Octicon"
-            display="inline-block"
-            fill="currentColor"
-            focusable="false"
-            height="16"
-            overflow="visible"
-            style="vertical-align: text-bottom;"
-            viewBox="0 0 16 16"
-            width="16"
-          >
-            <path
-              d="M7.78 12.53a.75.75 0 0 1-1.06 0L2.47 8.28a.75.75 0 0 1 0-1.06l4.25-4.25a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L4.81 7h7.44a.75.75 0 0 1 0 1.5H4.81l2.97 2.97a.75.75 0 0 1 0 1.06Z"
-            />
-          </svg>
-        </button>
-        <legend>
-          <div
-            class="mb-2"
-          >
-            <div
-              class="prc-Stack-Stack-UQ9k6"
-              data-align="center"
-              data-component="Stack"
-              data-direction="horizontal"
-              data-gap="condensed"
-              data-justify="start"
-              data-padding="none"
-              data-wrap="nowrap"
-              id="title-login-with-oauth-app"
-            >
-              <svg
-                aria-hidden="true"
-                class="octicon octicon-person"
-                data-component="Octicon"
-                display="inline-block"
-                fill="currentColor"
-                focusable="false"
-                height="16"
-                overflow="visible"
-                style="vertical-align: text-bottom;"
-                viewBox="0 0 16 16"
-                width="16"
-              >
-                <path
-                  d="M10.561 8.073a6.005 6.005 0 0 1 3.432 5.142.75.75 0 1 1-1.498.07 4.5 4.5 0 0 0-8.99 0 .75.75 0 0 1-1.498-.07 6.004 6.004 0 0 1 3.431-5.142 3.999 3.999 0 1 1 5.123 0ZM10.5 5a2.5 2.5 0 1 0-5 0 2.5 2.5 0 0 0 5 0Z"
-                />
-              </svg>
-              <h4
-                class="prc-Heading-Heading-MtWFE"
-                data-component="Heading"
-              >
-                Login with OAuth App
-              </h4>
-            </div>
-          </div>
-        </legend>
-      </div>
-    </div>
-    <div
-      class="grow overflow-x-hidden overflow-y-auto px-5 gitify-scroll-fade"
-    >
-      <div
-        class="prc-Stack-Stack-UQ9k6"
-        data-align="stretch"
-        data-component="Stack"
-        data-direction="vertical"
-        data-gap="normal"
-        data-justify="start"
-        data-padding="none"
-        data-wrap="nowrap"
-      >
-        <div
-          class="prc-FormControl-ControlVerticalLayout-8YotI"
-          data-component="FormControl"
-          data-has-label=""
-        >
-          <label
-            class="prc-components-Label-2mrqP"
-            data-component="FormControl.Label"
-            for="_r_1_"
-            id="_r_1_-label"
-          >
-            <span
-              class="prc-components-RequiredText-7UsHS"
-            >
-              <span>
-                Hostname
-              </span>
-              <span>
-                *
-              </span>
-            </span>
-          </label>
-          <span
-            aria-busy="false"
-            class="border-gitify-textInput-default TextInput-wrapper prc-components-TextInputWrapper-Hpdqi prc-components-TextInputBaseWrapper-wY-n0"
-            data-block="true"
-            data-component="TextInput"
-            data-no-leading-visual="true"
-            data-no-trailing-action="true"
-            data-no-trailing-visual="true"
-          >
-            <input
-              aria-describedby="_r_1_-caption"
-              aria-invalid="false"
-              aria-required="true"
-              class="prc-components-Input-IwWrt"
-              data-component="input"
-              data-testid="login-hostname"
-              id="_r_1_"
-              name="hostname"
-              placeholder="github.com"
-              type="text"
-              value="github.com"
-            />
-          </span>
-          <span
-            class="prc-FormControl-Caption-GNJPU prc-Text-Text-9mHv3"
-            data-component="FormControl.Caption"
-            id="_r_1_-caption"
-          >
-            <i
-              class="prc-Text-Text-9mHv3"
-              data-component="Text"
-            >
-              Change only if you are using GitHub Enterprise Server
-            </i>
-          </span>
-        </div>
-        <div
-          class="prc-Stack-Stack-UQ9k6"
-          data-align="center"
-          data-component="Stack"
-          data-direction="horizontal"
-          data-gap="condensed"
-          data-justify="start"
-          data-padding="none"
-          data-wrap="nowrap"
-        >
-          <button
-            class="prc-Button-ButtonBase-9n-Xk"
-            data-component="Button"
-            data-loading="false"
-            data-size="small"
-            data-testid="login-create-oauth-app"
-            data-variant="default"
-            type="button"
-          >
-            <span
-              class="prc-Button-ButtonContent-Iohp5"
-              data-align="center"
-              data-component="buttonContent"
-            >
-              <span
-                class="prc-Button-Visual-YNt2F prc-Button-LeadingVisual-UySKu prc-Button-VisualWrap-E4cnq"
-                data-component="leadingVisual"
-              >
-                <svg
-                  aria-hidden="true"
-                  class="octicon octicon-person"
-                  data-component="Octicon"
-                  display="inline-block"
-                  fill="currentColor"
-                  focusable="false"
-                  height="16"
-                  overflow="visible"
-                  style="vertical-align: text-bottom;"
-                  viewBox="0 0 16 16"
-                  width="16"
-                >
-                  <path
-                    d="M10.561 8.073a6.005 6.005 0 0 1 3.432 5.142.75.75 0 1 1-1.498.07 4.5 4.5 0 0 0-8.99 0 .75.75 0 0 1-1.498-.07 6.004 6.004 0 0 1 3.431-5.142 3.999 3.999 0 1 1 5.123 0ZM10.5 5a2.5 2.5 0 1 0-5 0 2.5 2.5 0 0 0 5 0Z"
-                  />
-                </svg>
-              </span>
-              <span
-                class="prc-Button-Label-FWkx3"
-                data-component="text"
-              >
-                Create new OAuth App
-              </span>
-            </span>
-          </button>
-          <span
-            class="text-xs prc-Text-Text-9mHv3"
-            data-component="Text"
-          >
-            and use your 
-            <i
-              class="prc-Text-Text-9mHv3"
-              data-component="Text"
-            >
-              client id & secret
-            </i>
-             below.
-          </span>
-        </div>
-        <div
-          class="prc-FormControl-ControlVerticalLayout-8YotI"
-          data-component="FormControl"
-          data-has-label=""
-        >
-          <label
-            class="prc-components-Label-2mrqP"
-            data-component="FormControl.Label"
-            for="_r_8_"
-            id="_r_8_-label"
-          >
-            <span
-              class="prc-components-RequiredText-7UsHS"
-            >
-              <span>
-                Client ID
-              </span>
-              <span>
-                *
-              </span>
-            </span>
-          </label>
-          <span
-            aria-busy="false"
-            class="TextInput-wrapper prc-components-TextInputWrapper-Hpdqi prc-components-TextInputBaseWrapper-wY-n0"
-            data-block="true"
-            data-component="TextInput"
-            data-no-leading-visual="true"
-            data-no-trailing-action="true"
-            data-no-trailing-visual="true"
-          >
-            <input
-              aria-invalid="false"
-              aria-required="true"
-              class="prc-components-Input-IwWrt"
-              data-component="input"
-              data-testid="login-clientId"
-              id="_r_8_"
-              name="clientId"
-              placeholder="Your generated client id (20 characters)"
-              type="text"
-              value=""
-            />
-          </span>
-        </div>
-        <div
-          class="prc-FormControl-ControlVerticalLayout-8YotI"
-          data-component="FormControl"
-          data-has-label=""
-        >
-          <label
-            class="prc-components-Label-2mrqP"
-            data-component="FormControl.Label"
-            for="_r_e_"
-            id="_r_e_-label"
-          >
-            <span
-              class="prc-components-RequiredText-7UsHS"
-            >
-              <span>
-                Client Secret
-              </span>
-              <span>
-                *
-              </span>
-            </span>
-          </label>
-          <span
-            aria-busy="false"
-            class="TextInput-wrapper prc-components-TextInputWrapper-Hpdqi prc-components-TextInputBaseWrapper-wY-n0"
-            data-block="true"
-            data-component="TextInput"
-            data-no-leading-visual="true"
-            data-no-trailing-visual="true"
-            data-trailing-action="true"
-          >
-            <input
-              aria-invalid="false"
-              aria-required="true"
-              class="prc-components-Input-IwWrt"
-              data-component="input"
-              data-testid="login-clientSecret"
-              id="_r_e_"
-              name="clientSecret"
-              placeholder="Your generated client secret (40 characters)"
-              type="password"
-              value=""
-            />
-            <span
-              class="TextInput-action prc-components-TextInputAction-CjGDX"
-              data-component="TextInput.Action"
-            >
-              <button
-                aria-labelledby="_r_k_"
-                class="prc-Button-ButtonBase-9n-Xk prc-components-Invisible-bKOcl prc-Button-IconButton-fyge7"
-                data-component="IconButton"
-                data-loading="false"
-                data-no-visuals="true"
-                data-size="small"
-                data-variant="invisible"
-                type="button"
-              >
-                <svg
-                  aria-hidden="true"
-                  class="octicon octicon-eye"
-                  data-component="Octicon"
-                  display="inline-block"
-                  fill="currentColor"
-                  focusable="false"
-                  height="16"
-                  overflow="visible"
-                  style="vertical-align: text-bottom;"
-                  viewBox="0 0 16 16"
-                  width="16"
-                >
-                  <path
-                    d="M8 2c1.981 0 3.671.992 4.933 2.078 1.27 1.091 2.187 2.345 2.637 3.023a1.62 1.62 0 0 1 0 1.798c-.45.678-1.367 1.932-2.637 3.023C11.67 13.008 9.981 14 8 14c-1.981 0-3.671-.992-4.933-2.078C1.797 10.83.88 9.576.43 8.898a1.62 1.62 0 0 1 0-1.798c.45-.677 1.367-1.931 2.637-3.022C4.33 2.992 6.019 2 8 2ZM1.679 7.932a.12.12 0 0 0 0 .136c.411.622 1.241 1.75 2.366 2.717C5.176 11.758 6.527 12.5 8 12.5c1.473 0 2.825-.742 3.955-1.715 1.124-.967 1.954-2.096 2.366-2.717a.12.12 0 0 0 0-.136c-.412-.621-1.242-1.75-2.366-2.717C10.824 4.242 9.473 3.5 8 3.5c-1.473 0-2.825.742-3.955 1.715-1.124.967-1.954 2.096-2.366 2.717ZM8 10a2 2 0 1 1-.001-3.999A2 2 0 0 1 8 10Z"
-                  />
-                </svg>
-              </button>
-              <span
-                aria-hidden="true"
-                class="prc-TooltipV2-Tooltip-tLeuB"
-                data-component="Tooltip"
-                data-direction="s"
-                id="_r_k_"
-                popover="auto"
-              >
-                Show token
-              </span>
-            </span>
-          </span>
-        </div>
-      </div>
-    </div>
-    <div
-      class="left-sidebar bg-gitify-footer"
-    >
-      <div
-        class="prc-Stack-Stack-UQ9k6"
-        data-align="stretch"
-        data-component="Stack"
-        data-direction="horizontal"
-        data-justify="space-between"
-        data-padding="condensed"
-        data-wrap="nowrap"
-      >
-        <button
-          aria-describedby="_r_m_"
-          class="prc-Button-ButtonBase-9n-Xk"
-          data-component="Button"
-          data-loading="false"
-          data-size="small"
-          data-testid="login-docs"
-          data-variant="default"
-          type="button"
-        >
-          <span
-            class="prc-Button-ButtonContent-Iohp5"
-            data-align="center"
-            data-component="buttonContent"
-          >
-            <span
-              class="prc-Button-Visual-YNt2F prc-Button-LeadingVisual-UySKu prc-Button-VisualWrap-E4cnq"
-              data-component="leadingVisual"
-            >
-              <svg
-                aria-hidden="true"
-                class="octicon octicon-book"
-                data-component="Octicon"
-                display="inline-block"
-                fill="currentColor"
-                focusable="false"
-                height="16"
-                overflow="visible"
-                style="vertical-align: text-bottom;"
-                viewBox="0 0 16 16"
-                width="16"
-              >
-                <path
-                  d="M0 1.75A.75.75 0 0 1 .75 1h4.253c1.227 0 2.317.59 3 1.501A3.743 3.743 0 0 1 11.006 1h4.245a.75.75 0 0 1 .75.75v10.5a.75.75 0 0 1-.75.75h-4.507a2.25 2.25 0 0 0-1.591.659l-.622.621a.75.75 0 0 1-1.06 0l-.622-.621A2.25 2.25 0 0 0 5.258 13H.75a.75.75 0 0 1-.75-.75Zm7.251 10.324.004-5.073-.002-2.253A2.25 2.25 0 0 0 5.003 2.5H1.5v9h3.757a3.75 3.75 0 0 1 1.994.574ZM8.755 4.75l-.004 7.322a3.752 3.752 0 0 1 1.992-.572H14.5v-9h-3.495a2.25 2.25 0 0 0-2.25 2.25Z"
-                />
-              </svg>
-            </span>
-            <span
-              class="prc-Button-Label-FWkx3"
-              data-component="text"
-            >
-              Docs
-            </span>
-          </span>
-        </button>
-        <span
-          aria-hidden="true"
-          class="prc-TooltipV2-Tooltip-tLeuB"
-          data-component="Tooltip"
-          data-direction="s"
-          id="_r_m_"
-          popover="auto"
-          role="tooltip"
-        >
-          GitHub documentation
-        </span>
-        <div
-          data-loading-wrapper="true"
-        >
-          <button
-            class="prc-Button-ButtonBase-9n-Xk"
-            data-component="Button"
-            data-loading="false"
-            data-size="medium"
-            data-testid="login-submit"
-            data-variant="primary"
-            type="button"
-          >
-            <span
-              class="prc-Button-ButtonContent-Iohp5"
-              data-align="center"
-              data-component="buttonContent"
-            >
-              <span
-                class="prc-Button-Visual-YNt2F prc-Button-LeadingVisual-UySKu prc-Button-VisualWrap-E4cnq"
-                data-component="leadingVisual"
-              >
-                <svg
-                  aria-hidden="true"
-                  class="octicon octicon-sign-in"
-                  data-component="Octicon"
-                  display="inline-block"
-                  fill="currentColor"
-                  focusable="false"
-                  height="16"
-                  overflow="visible"
-                  style="vertical-align: text-bottom;"
-                  viewBox="0 0 16 16"
-                  width="16"
-                >
-                  <path
-                    d="M2 2.75C2 1.784 2.784 1 3.75 1h2.5a.75.75 0 0 1 0 1.5h-2.5a.25.25 0 0 0-.25.25v10.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 0 1.5h-2.5A1.75 1.75 0 0 1 2 13.25Zm6.56 4.5h5.69a.75.75 0 0 1 0 1.5H8.56l1.97 1.97a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L6.22 8.53a.75.75 0 0 1 0-1.06l3.25-3.25a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734Z"
-                  />
-                </svg>
-              </span>
-              <span
-                class="prc-Button-Label-FWkx3"
-                data-component="text"
-              >
-                Login
-              </span>
-            </span>
-          </button>
-        </div>
-      </div>
-    </div>
-  </div>
-</div>
-`;
diff --git a/src/renderer/routes/routes.visual.test.tsx b/src/renderer/routes/routes.visual.test.tsx
index bb95e71b5..2c955687a 100644
--- a/src/renderer/routes/routes.visual.test.tsx
+++ b/src/renderer/routes/routes.visual.test.tsx
@@ -17,9 +17,9 @@ import { AccountScopesRoute } from './AccountScopes';
 import { BitbucketLoginWithPersonalAccessTokenRoute } from './bitbucket/LoginWithPersonalAccessToken';
 import { FiltersRoute } from './Filters';
 import { GiteaLoginWithPersonalAccessTokenRoute } from './gitea/LoginWithPersonalAccessToken';
+import { GitHubLoginWithCustomOAuthAppRoute } from './github/LoginWithCustomOAuthApp';
 import { GitHubLoginWithDeviceFlowRoute } from './github/LoginWithDeviceFlow';
 import { GitHubLoginWithCLIRoute } from './github/LoginWithGitHubCLI';
-import { GitHubLoginWithOAuthAppRoute } from './github/LoginWithOAuthApp';
 import { GitHubLoginWithPersonalAccessTokenRoute } from './github/LoginWithPersonalAccessToken';
 import { GitLabLoginWithPersonalAccessTokenRoute } from './gitlab/LoginWithPersonalAccessToken';
 import { LoginRoute } from './Login';
@@ -89,9 +89,9 @@ const ROUTES: RouteCase[] = [
     state: { initialEntries: ['/login/github/personal-access-token'] },
   },
   {
-    name: 'login-github-oauth-app',
-    element: <GitHubLoginWithOAuthAppRoute />,
-    state: { initialEntries: ['/login/github/oauth-app'] },
+    name: 'login-github-custom-oauth-app',
+    element: <GitHubLoginWithCustomOAuthAppRoute />,
+    state: { initialEntries: ['/login/github/custom-oauth-app'] },
   },
   {
     name: 'login-gitea-personal-access-token',
diff --git a/src/renderer/stores/types.ts b/src/renderer/stores/types.ts
index c7ca4575f..287391c18 100644
--- a/src/renderer/stores/types.ts
+++ b/src/renderer/stores/types.ts
@@ -1,6 +1,7 @@
 import type {
   Account,
   AccountUUID,
+  ClientID,
   FilterStateType,
   Forge,
   GitifyError,
@@ -40,6 +41,7 @@ export interface AccountsActions {
     hostname: Hostname,
     forge?: Forge,
     username?: string,
+    clientId?: ClientID,
   ) => Promise<void>;
 
   /**
diff --git a/src/renderer/stores/useAccountsStore.test.ts b/src/renderer/stores/useAccountsStore.test.ts
index 8a1b49df6..c900c51c9 100644
--- a/src/renderer/stores/useAccountsStore.test.ts
+++ b/src/renderer/stores/useAccountsStore.test.ts
@@ -1,6 +1,7 @@
 import { act, renderHook } from '@testing-library/react';
 
 import {
+  mockCustomOAuthAppAccount,
   mockGiteaAccount,
   mockGitHubCliAccount,
   mockGitHubCloudAccount,
@@ -8,7 +9,8 @@ import {
 } from '../__mocks__/account-mocks';
 import { mockRawUser } from '../utils/forges/github/__mocks__/response-mocks';
 
-import type { Account, Forge, Hostname, Link, Token } from '../types';
+import type { Account, ClientID, Forge, Hostname, Link, Token } from '../types';
+import type { AuthMethod } from '../utils/auth/types';
 import type { GetAuthenticatedUserResponse } from '../utils/forges/github/types';
 
 import { getRecommendedScopeNames } from '../utils/auth/scopes';
@@ -90,6 +92,25 @@ describe('renderer/stores/useAccountsStore.ts', () => {
         );
       },
     );
+
+    it('relabels a legacy GitHub App account as Gitify OAuth App without losing its token', () => {
+      const [account] = sanitizeAccounts([
+        { ...mockGitHubCloudAccount, method: 'GitHub App' as AuthMethod },
+      ]);
+
+      expect(account.method).toBe('Gitify OAuth App');
+      expect(account.token).toBe(mockGitHubCloudAccount.token);
+    });
+
+    it('relabels a legacy OAuth App account as Custom OAuth App and keeps its client ID', () => {
+      const [account] = sanitizeAccounts([
+        { ...mockCustomOAuthAppAccount, method: 'OAuth App' as AuthMethod },
+      ]);
+
+      expect(account.method).toBe('Custom OAuth App');
+      expect(account.token).toBe(mockCustomOAuthAppAccount.token);
+      expect(account.clientId).toBe('CUSTOM_CLIENT_ID_123');
+    });
   });
 
   it.each([
@@ -201,16 +222,24 @@ describe('renderer/stores/useAccountsStore.ts', () => {
         ]);
       });
 
-      test('should add oauth app account', async () => {
+      test('should add a custom OAuth app account with its client ID', async () => {
         await useAccountsStore
           .getState()
-          .createAccount('OAuth App', '123-456' as Token, 'github.com' as Hostname);
+          .createAccount(
+            'Custom OAuth App',
+            '123-456' as Token,
+            'github.com' as Hostname,
+            'github',
+            undefined,
+            'CUSTOM_CLIENT_ID_123' as ClientID,
+          );
 
         expect(useAccountsStore.getState().accounts).toEqual([
           {
             forge: 'github',
             hostname: 'github.com' as Hostname,
-            method: 'OAuth App',
+            method: 'Custom OAuth App',
+            clientId: 'CUSTOM_CLIENT_ID_123' as ClientID,
             platform: 'GitHub Cloud',
             scopes: getRecommendedScopeNames(),
             token: 'encrypted' as Token,
@@ -306,16 +335,24 @@ describe('renderer/stores/useAccountsStore.ts', () => {
         ]);
       });
 
-      test('should add oauth app account', async () => {
+      test('should add a custom OAuth app account', async () => {
         await useAccountsStore
           .getState()
-          .createAccount('OAuth App', '123-456' as Token, 'github.gitify.io' as Hostname);
+          .createAccount(
+            'Custom OAuth App',
+            '123-456' as Token,
+            'github.gitify.io' as Hostname,
+            'github',
+            undefined,
+            'CUSTOM_CLIENT_ID_123' as ClientID,
+          );
 
         expect(useAccountsStore.getState().accounts).toEqual([
           {
             forge: 'github',
             hostname: 'github.gitify.io' as Hostname,
-            method: 'OAuth App',
+            method: 'Custom OAuth App',
+            clientId: 'CUSTOM_CLIENT_ID_123' as ClientID,
             platform: 'GitHub Enterprise Server',
             scopes: getRecommendedScopeNames(),
             token: 'encrypted' as Token,
diff --git a/src/renderer/stores/useAccountsStore.ts b/src/renderer/stores/useAccountsStore.ts
index a689d30a8..e98426ee8 100644
--- a/src/renderer/stores/useAccountsStore.ts
+++ b/src/renderer/stores/useAccountsStore.ts
@@ -3,7 +3,7 @@ import { persist } from 'zustand/middleware';
 
 import { Constants } from '../constants';
 
-import type { Account, Forge, Hostname, Token } from '../types';
+import type { Account, ClientID, Forge, Hostname, Token } from '../types';
 import type { AuthMethod } from '../utils/auth/types';
 import type { AccountsState, AccountsStore } from './types';
 
@@ -13,11 +13,30 @@ import { getAccountAdapter, getAdapter, isKnownForge } from '../utils/forges/reg
 import { decryptValue, encryptValue } from '../utils/system/comms';
 import { DEFAULT_ACCOUNTS_STATE } from './defaults';
 
+/**
+ * Map a persisted auth-method label onto the current vocabulary.
+ *
+ * Accounts stored before the custom OAuth app flow moved to the device flow
+ * carry the retired `GitHub App` / `OAuth App` labels; relabel them so their
+ * existing tokens keep working without forcing a re-login.
+ */
+function migrateLegacyAuthMethod(method: string): AuthMethod {
+  switch (method) {
+    case 'GitHub App':
+      return 'Gitify OAuth App';
+    case 'OAuth App':
+      return 'Custom OAuth App';
+    default:
+      return method as AuthMethod;
+  }
+}
+
 /**
  * Sanitise persisted accounts state. Persisted JSON is untrusted (XSS, malicious
  * extension, file-system tampering), so we project only the known fields,
- * coerce `forge` to a registered value, and drop accounts with a
- * structurally invalid hostname before the renderer ever touches them.
+ * coerce `forge` to a registered value, migrate retired auth-method labels, and
+ * drop accounts with a structurally invalid hostname before the renderer ever
+ * touches them.
  */
 export function sanitizeAccounts(accounts: Account[]): Account[] {
   return accounts.flatMap((a) => {
@@ -27,11 +46,12 @@ export function sanitizeAccounts(accounts: Account[]): Account[] {
     }
     const sanitised: Account = {
       forge,
-      method: a.method,
+      method: migrateLegacyAuthMethod(a.method as string),
       platform: a.platform,
       version: a.version,
       hostname: a.hostname,
       token: a.token,
+      clientId: a.clientId,
       username: a.username,
       user: a.user,
       scopes: a.scopes,
@@ -57,6 +77,7 @@ const useAccountsStore = create<AccountsStore>()(
         hostname: Hostname,
         forge: Forge = 'github',
         username?: string,
+        clientId?: ClientID,
       ) => {
         const encryptedToken = (await encryptValue(token)) as Token;
 
@@ -66,6 +87,7 @@ const useAccountsStore = create<AccountsStore>()(
           method: method,
           platform: getAdapter(forge).getPlatform(hostname),
           token: encryptedToken,
+          clientId,
           username,
           user: null, // Will be updated during the refresh call below
         };
diff --git a/src/renderer/types.ts b/src/renderer/types.ts
index 74298639c..6b5ba4be0 100644
--- a/src/renderer/types.ts
+++ b/src/renderer/types.ts
@@ -27,14 +27,10 @@ type Brand<B> = { [__brand]: B };
 
 export type Branded<T, B> = T & Brand<B>;
 
-export type AuthCode = Branded<string, 'AuthCode'>;
-
 export type Token = Branded<string, 'Token'>;
 
 export type ClientID = Branded<string, 'ClientID'>;
 
-export type ClientSecret = Branded<string, 'ClientSecret'>;
-
 export type Hostname = Branded<string, 'Hostname'>;
 
 export type Link = Branded<string, 'WebUrl'>;
@@ -73,6 +69,11 @@ export interface Account {
   version?: string;
   hostname: Hostname;
   token: Token;
+  /**
+   * OAuth app client ID for an account authorized through a user-supplied
+   * custom OAuth app; absent for Gitify's own preconfigured app.
+   */
+  clientId?: ClientID;
   /** Atlassian account email — required for Bitbucket Basic Auth (email:token). */
   username?: string;
   user: GitifyUser | null;
diff --git a/src/renderer/utils/auth/loginValidation.test.ts b/src/renderer/utils/auth/loginValidation.test.ts
index 6e4e136cc..0e34e1454 100644
--- a/src/renderer/utils/auth/loginValidation.test.ts
+++ b/src/renderer/utils/auth/loginValidation.test.ts
@@ -1,10 +1,10 @@
-import type { ClientID, ClientSecret, Forge, Hostname, Token } from '../../types';
+import type { ClientID, Forge, Hostname, Token } from '../../types';
 
 import {
-  type OAuthAppFormData,
+  type CustomOAuthAppFormData,
   type PersonalAccessTokenFormData,
   summarizeLoginError,
-  validateOAuthAppForm,
+  validateCustomOAuthAppForm,
   validatePersonalAccessTokenForm,
 } from './loginValidation';
 
@@ -153,29 +153,34 @@ describe('renderer/utils/auth/loginValidation.ts', () => {
     });
   });
 
-  describe('validateOAuthAppForm', () => {
-    it('reports missing hostname, client ID, and client secret', () => {
-      const values: OAuthAppFormData = {
+  describe('validateCustomOAuthAppForm', () => {
+    it('reports missing hostname and client ID', () => {
+      const values: CustomOAuthAppFormData = {
         hostname: null as unknown as Hostname,
         clientId: null as unknown as ClientID,
-        clientSecret: null as unknown as ClientSecret,
       };
 
-      expect(validateOAuthAppForm(values).hostname).toBe('Hostname is required');
-      expect(validateOAuthAppForm(values).clientId).toBe('Client ID is required');
-      expect(validateOAuthAppForm(values).clientSecret).toBe('Client Secret is required');
+      expect(validateCustomOAuthAppForm(values).hostname).toBe('Hostname is required');
+      expect(validateCustomOAuthAppForm(values).clientId).toBe('Client ID is required');
     });
 
-    it('reports invalid hostname, client ID, and client secret formats', () => {
-      const values: OAuthAppFormData = {
+    it('reports invalid hostname and client ID formats', () => {
+      const values: CustomOAuthAppFormData = {
         hostname: 'hello' as Hostname,
         clientId: '!@£INVALID-.1' as ClientID,
-        clientSecret: '!@£INVALID-.1' as ClientSecret,
       };
 
-      expect(validateOAuthAppForm(values).hostname).toBe('Hostname format is invalid');
-      expect(validateOAuthAppForm(values).clientId).toBe('Client ID format is invalid');
-      expect(validateOAuthAppForm(values).clientSecret).toBe('Client Secret format is invalid');
+      expect(validateCustomOAuthAppForm(values).hostname).toBe('Hostname format is invalid');
+      expect(validateCustomOAuthAppForm(values).clientId).toBe('Client ID format is invalid');
+    });
+
+    it('passes with a valid hostname and client ID and no client secret', () => {
+      const values: CustomOAuthAppFormData = {
+        hostname: 'github.com' as Hostname,
+        clientId: '1234567890_ASDFGHJKL' as ClientID,
+      };
+
+      expect(validateCustomOAuthAppForm(values)).toEqual({});
     });
   });
 
diff --git a/src/renderer/utils/auth/loginValidation.ts b/src/renderer/utils/auth/loginValidation.ts
index e076f9fde..44289c800 100644
--- a/src/renderer/utils/auth/loginValidation.ts
+++ b/src/renderer/utils/auth/loginValidation.ts
@@ -1,5 +1,4 @@
-import type { Forge, Hostname, Token } from '../../types';
-import type { LoginOAuthWebOptions } from './types';
+import type { ClientID, Forge, Hostname, Token } from '../../types';
 
 import { getAdapter } from '../forges/registry';
 import { isValidHostname } from './utils';
@@ -20,14 +19,16 @@ export interface PersonalAccessTokenFormErrors {
   invalidCredentialsDetail?: string;
 }
 
-/** OAuth app login form values — mirrors LoginOAuthWebOptions so it passes straight through. */
-export type OAuthAppFormData = LoginOAuthWebOptions;
+/** Custom OAuth app login form values. */
+export interface CustomOAuthAppFormData {
+  hostname: Hostname;
+  clientId: ClientID;
+}
 
-/** OAuth app login form errors. */
-export interface OAuthAppFormErrors {
+/** Custom OAuth app login form errors. */
+export interface CustomOAuthAppFormErrors {
   hostname?: string;
   clientId?: string;
-  clientSecret?: string;
   invalidCredentialsForHost?: string;
 }
 
@@ -74,11 +75,11 @@ export const validatePersonalAccessTokenForm = (
   return errors;
 };
 
-export const validateOAuthAppForm = (
-  values: OAuthAppFormData,
+export const validateCustomOAuthAppForm = (
+  values: CustomOAuthAppFormData,
   forge: Forge = 'github',
-): OAuthAppFormErrors => {
-  const errors: OAuthAppFormErrors = {};
+): CustomOAuthAppFormErrors => {
+  const errors: CustomOAuthAppFormErrors = {};
   const adapter = getAdapter(forge);
 
   if (!values.hostname) {
@@ -89,15 +90,9 @@ export const validateOAuthAppForm = (
 
   if (!values.clientId) {
     errors.clientId = 'Client ID is required';
-  } else if (!adapter.oauthWebApp?.validateClientId(values.clientId)) {
+  } else if (!adapter.customOAuthApp?.validateClientId(values.clientId)) {
     errors.clientId = 'Client ID format is invalid';
   }
 
-  if (!values.clientSecret) {
-    errors.clientSecret = 'Client Secret is required';
-  } else if (!adapter.validateToken(values.clientSecret as unknown as Token)) {
-    errors.clientSecret = 'Client Secret format is invalid';
-  }
-
   return errors;
 };
diff --git a/src/renderer/utils/auth/state.test.ts b/src/renderer/utils/auth/state.test.ts
deleted file mode 100644
index 191a792b1..000000000
--- a/src/renderer/utils/auth/state.test.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-import { generateOAuthState } from './state';
-
-const UUID_V4 = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
-
-describe('renderer/utils/auth/state.ts', () => {
-  describe('generateOAuthState', () => {
-    it('should return a v4 UUID', () => {
-      expect(generateOAuthState()).toMatch(UUID_V4);
-    });
-
-    it('should return different values across calls', () => {
-      expect(generateOAuthState()).not.toBe(generateOAuthState());
-    });
-
-    it('should use crypto.randomUUID', () => {
-      const spy = vi.spyOn(globalThis.crypto, 'randomUUID');
-      generateOAuthState();
-      expect(spy).toHaveBeenCalledOnce();
-      spy.mockRestore();
-    });
-  });
-});
diff --git a/src/renderer/utils/auth/state.ts b/src/renderer/utils/auth/state.ts
deleted file mode 100644
index 3b88de7c3..000000000
--- a/src/renderer/utils/auth/state.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-/**
- * Generate a cryptographically random OAuth 2.0 `state` value.
- *
- * `crypto.randomUUID()` is backed by the platform CSPRNG and yields 122 random
- * bits — ample for a per-attempt, single-use value that an attacker cannot
- * guess in order to bind the client to a different account. Using the platform
- * primitive avoids hand-rolled random-value encoding entirely.
- *
- * @returns A random UUID to send as the OAuth `state` parameter.
- */
-export function generateOAuthState(): string {
-  return crypto.randomUUID();
-}
diff --git a/src/renderer/utils/auth/types.ts b/src/renderer/utils/auth/types.ts
index 60654acc2..d64e6fd1d 100644
--- a/src/renderer/utils/auth/types.ts
+++ b/src/renderer/utils/auth/types.ts
@@ -1,6 +1,10 @@
-import type { AuthCode, ClientID, ClientSecret, Forge, Hostname, Token } from '../../types';
+import type { ClientID, Forge, Hostname, Token } from '../../types';
 
-export type AuthMethod = 'GitHub App' | 'GitHub CLI' | 'Personal Access Token' | 'OAuth App';
+export type AuthMethod =
+  | 'Gitify OAuth App'
+  | 'Custom OAuth App'
+  | 'GitHub CLI'
+  | 'Personal Access Token';
 
 export type PlatformType =
   | 'Bitbucket Cloud'
@@ -11,12 +15,6 @@ export type PlatformType =
   | 'GitLab Self-Managed'
   | 'Gitea';
 
-export interface LoginOAuthWebOptions {
-  hostname: Hostname;
-  clientId: ClientID;
-  clientSecret: ClientSecret;
-}
-
 export interface DeviceFlowSession {
   hostname: Hostname;
   clientId: ClientID;
@@ -35,9 +33,3 @@ export interface LoginPersonalAccessTokenOptions {
   /** Defaults to GitHub when omitted. */
   forge?: Forge;
 }
-
-export interface AuthResponse {
-  authMethod: AuthMethod;
-  authCode: AuthCode;
-  authOptions: LoginOAuthWebOptions;
-}
diff --git a/src/renderer/utils/forges/bitbucket/adapter.test.ts b/src/renderer/utils/forges/bitbucket/adapter.test.ts
index 01a78619e..f5936d2d6 100644
--- a/src/renderer/utils/forges/bitbucket/adapter.test.ts
+++ b/src/renderer/utils/forges/bitbucket/adapter.test.ts
@@ -118,7 +118,7 @@ describe('renderer/utils/forges/bitbucket/adapter.ts', () => {
 
     it('returns KeyIcon for every auth method', () => {
       expect(bitbucketAdapter.getAuthMethodIcon('Personal Access Token')).toBe(KeyIcon);
-      expect(bitbucketAdapter.getAuthMethodIcon('OAuth App')).toBe(KeyIcon);
+      expect(bitbucketAdapter.getAuthMethodIcon('Custom OAuth App')).toBe(KeyIcon);
     });
   });
 
diff --git a/src/renderer/utils/forges/gitea/adapter.test.ts b/src/renderer/utils/forges/gitea/adapter.test.ts
index aa5c502f2..bc22f9c11 100644
--- a/src/renderer/utils/forges/gitea/adapter.test.ts
+++ b/src/renderer/utils/forges/gitea/adapter.test.ts
@@ -74,8 +74,8 @@ describe('renderer/utils/forges/gitea/adapter.ts', () => {
 
     it('returns the key icon for every auth method (PAT-only forge today)', () => {
       expect(giteaAdapter.getAuthMethodIcon('Personal Access Token')).toBe(KeyIcon);
-      expect(giteaAdapter.getAuthMethodIcon('GitHub App')).toBe(KeyIcon);
-      expect(giteaAdapter.getAuthMethodIcon('OAuth App')).toBe(KeyIcon);
+      expect(giteaAdapter.getAuthMethodIcon('Gitify OAuth App')).toBe(KeyIcon);
+      expect(giteaAdapter.getAuthMethodIcon('Custom OAuth App')).toBe(KeyIcon);
     });
   });
 
diff --git a/src/renderer/utils/forges/github/adapter.test.ts b/src/renderer/utils/forges/github/adapter.test.ts
index b1d588add..a9800ed9b 100644
--- a/src/renderer/utils/forges/github/adapter.test.ts
+++ b/src/renderer/utils/forges/github/adapter.test.ts
@@ -1,15 +1,33 @@
-import { AgentIcon, AppsIcon, CopilotIcon, KeyIcon, PersonIcon } from '@primer/octicons-react';
+vi.mock('@octokit/oauth-methods', async () => {
+  const actual =
+    await vi.importActual<typeof import('@octokit/oauth-methods')>('@octokit/oauth-methods');
+  return {
+    ...actual,
+    createDeviceCode: vi.fn(),
+    exchangeDeviceCode: vi.fn(),
+  };
+});
+
+import { AgentIcon, CopilotIcon, KeyIcon, PersonIcon } from '@primer/octicons-react';
+
+import { createDeviceCode } from '@octokit/oauth-methods';
+
+import type { MockedFunction } from 'vite-plus/test';
 
 import { mockGitHubCliAccount, mockGitHubCloudAccount } from '../../../__mocks__/account-mocks';
 import { mockPartialGitifyNotification } from '../../../__mocks__/notifications-mocks';
 
-import type { GitifyNotificationUser, Hostname, Link, Token } from '../../../types';
+import type { ClientID, GitifyNotificationUser, Hostname, Link, Token } from '../../../types';
 
 import { githubAdapter } from './adapter';
 import * as client from './client';
 import * as octokit from './octokit';
 
 describe('renderer/utils/forges/github/adapter.ts', () => {
+  const createDeviceCodeMock = createDeviceCode as unknown as MockedFunction<
+    typeof createDeviceCode
+  >;
+
   describe('static fields', () => {
     it('identifies as github', () => {
       expect(githubAdapter.id).toBe('github');
@@ -18,7 +36,12 @@ describe('renderer/utils/forges/github/adapter.ts', () => {
 
     it('exposes the device-flow / PAT / CLI / OAuth login methods', () => {
       const ids = githubAdapter.loginMethods.map((m) => m.testId);
-      expect(ids).toEqual(['login-github', 'login-pat', 'login-github-cli', 'login-oauth-app']);
+      expect(ids).toEqual([
+        'login-github',
+        'login-pat',
+        'login-github-cli',
+        'login-custom-oauth-app',
+      ]);
     });
 
     it('defaults the PAT hostname to github.com', () => {
@@ -54,20 +77,45 @@ describe('renderer/utils/forges/github/adapter.ts', () => {
     });
 
     it('maps each auth method to its icon', () => {
-      expect(githubAdapter.getAuthMethodIcon('GitHub App')).toBe(AppsIcon);
-      expect(githubAdapter.getAuthMethodIcon('OAuth App')).toBe(PersonIcon);
+      expect(githubAdapter.getAuthMethodIcon('Gitify OAuth App')).toBe(PersonIcon);
+      expect(githubAdapter.getAuthMethodIcon('Custom OAuth App')).toBe(PersonIcon);
       expect(githubAdapter.getAuthMethodIcon('Personal Access Token')).toBe(KeyIcon);
     });
 
-    it('wires the device-flow and OAuth-app methods so the context can dispatch via the adapter', () => {
-      expect(githubAdapter.deviceFlow?.authMethod).toBe('GitHub App');
+    it('forwards a custom client ID through the device-flow start', async () => {
+      createDeviceCodeMock.mockResolvedValueOnce({
+        data: {
+          device_code: 'device-code',
+          user_code: 'user-code',
+          verification_uri: 'https://github.example.com/login/device',
+          expires_in: 600,
+          interval: 5,
+        },
+      } as unknown as Awaited<ReturnType<typeof createDeviceCode>>);
+
+      const session = await githubAdapter.deviceFlow!.start(
+        'github.example.com' as Hostname,
+        undefined,
+        'CUSTOM_CLIENT_ID_123' as ClientID,
+      );
+
+      expect(createDeviceCodeMock).toHaveBeenCalledWith({
+        clientType: 'oauth-app',
+        clientId: 'CUSTOM_CLIENT_ID_123',
+        scopes: expect.anything(),
+        request: expect.any(Function),
+      });
+      expect(session.clientId).toBe('CUSTOM_CLIENT_ID_123');
+    });
+
+    it('wires the device-flow and custom-OAuth-app methods so the context can dispatch via the adapter', () => {
+      expect(githubAdapter.deviceFlow?.authMethod).toBe('Gitify OAuth App');
       expect(githubAdapter.deviceFlow?.start).toBeDefined();
       expect(githubAdapter.deviceFlow?.poll).toBeDefined();
       expect(githubAdapter.deviceFlow?.getRevokeAccessUrl).toBeDefined();
-      expect(githubAdapter.oauthWebApp?.performWebOAuth).toBeDefined();
-      expect(githubAdapter.oauthWebApp?.exchangeAuthCodeForToken).toBeDefined();
-      expect(githubAdapter.oauthWebApp?.validateClientId).toBeDefined();
-      expect(githubAdapter.oauthWebApp?.getNewOAuthAppUrl).toBeDefined();
+      expect(githubAdapter.customOAuthApp?.authMethod).toBe('Custom OAuth App');
+      expect(githubAdapter.customOAuthApp?.validateClientId).toBeDefined();
+      expect(githubAdapter.customOAuthApp?.getNewOAuthAppUrl).toBeDefined();
     });
   });
 
diff --git a/src/renderer/utils/forges/github/adapter.ts b/src/renderer/utils/forges/github/adapter.ts
index 973a2acaf..05b01973e 100644
--- a/src/renderer/utils/forges/github/adapter.ts
+++ b/src/renderer/utils/forges/github/adapter.ts
@@ -1,10 +1,4 @@
-import {
-  AppsIcon,
-  KeyIcon,
-  MarkGithubIcon,
-  PersonIcon,
-  TerminalIcon,
-} from '@primer/octicons-react';
+import { KeyIcon, MarkGithubIcon, PersonIcon, TerminalIcon } from '@primer/octicons-react';
 
 import { Constants, OAUTH_SCOPE } from '../../../constants';
 
@@ -15,6 +9,7 @@ import type { ForgeAdapter, NotificationDisplayHelpers, RefreshAccountData } fro
 import { isValidHostname } from '../../auth/utils';
 import {
   extractHostVersion,
+  getAuthorizedOAuthAppURL,
   getDeveloperSettingsURL,
   getNewOAuthAppURL,
   getNewTokenURL,
@@ -31,12 +26,7 @@ import {
   markNotificationThreadAsRead,
 } from './client';
 import { enrichGitHubNotifications } from './enrich';
-import {
-  exchangeAuthCodeForAccessToken,
-  performGitHubWebOAuth,
-  pollGitHubDeviceFlow,
-  startGitHubDeviceFlow,
-} from './flows';
+import { pollGitHubDeviceFlow, startGitHubDeviceFlow } from './flows';
 import { createNotificationHandler } from './handlers';
 import { clearOctokitClientCacheForAccount, createOctokitClient } from './octokit';
 import { getGitHubPlatform } from './platform';
@@ -116,7 +106,7 @@ export const githubAdapter: ForgeAdapter = {
       label: 'GitHub',
       variant: 'primary',
       route: '/login/github/device-flow',
-      authMethod: 'GitHub App',
+      authMethod: 'Gitify OAuth App',
     },
     {
       testId: 'login-pat',
@@ -133,25 +123,23 @@ export const githubAdapter: ForgeAdapter = {
       authMethod: 'GitHub CLI',
     },
     {
-      testId: 'login-oauth-app',
+      testId: 'login-custom-oauth-app',
       icon: PersonIcon,
-      label: 'OAuth App',
-      route: '/login/github/oauth-app',
-      authMethod: 'OAuth App',
+      label: 'Custom OAuth App',
+      route: '/login/github/custom-oauth-app',
+      authMethod: 'Custom OAuth App',
     },
   ],
 
   deviceFlow: {
-    authMethod: 'GitHub App',
+    authMethod: 'Gitify OAuth App',
     start: startGitHubDeviceFlow,
     poll: pollGitHubDeviceFlow,
-    getRevokeAccessUrl: (hostname) =>
-      getDeveloperSettingsURL({ hostname, method: 'GitHub App' } as Account),
+    getRevokeAccessUrl: getAuthorizedOAuthAppURL,
   },
 
-  oauthWebApp: {
-    performWebOAuth: performGitHubWebOAuth,
-    exchangeAuthCodeForToken: exchangeAuthCodeForAccessToken,
+  customOAuthApp: {
+    authMethod: 'Custom OAuth App',
     validateClientId: isValidClientId,
     getNewOAuthAppUrl: getNewOAuthAppURL,
   },
@@ -231,12 +219,11 @@ function accountHasScopes(
 
 function githubAuthMethodIcon(method: AuthMethod) {
   switch (method) {
-    case 'GitHub App':
-      return AppsIcon;
+    case 'Gitify OAuth App':
+    case 'Custom OAuth App':
+      return PersonIcon;
     case 'GitHub CLI':
       return TerminalIcon;
-    case 'OAuth App':
-      return PersonIcon;
     default:
       return KeyIcon;
   }
diff --git a/src/renderer/utils/forges/github/auth.test.ts b/src/renderer/utils/forges/github/auth.test.ts
index 618bc917f..fb922a6e9 100644
--- a/src/renderer/utils/forges/github/auth.test.ts
+++ b/src/renderer/utils/forges/github/auth.test.ts
@@ -5,6 +5,7 @@ import type { AuthMethod } from '../../auth/types';
 
 import {
   extractHostVersion,
+  getAuthorizedOAuthAppURL,
   getDeveloperSettingsURL,
   getGitHubAuthBaseUrl,
   getNewOAuthAppURL,
@@ -60,23 +61,50 @@ describe('renderer/utils/forges/github/auth.ts', () => {
     });
   });
 
+  describe('getAuthorizedOAuthAppURL', () => {
+    it("builds the connections URL for a custom app's own client ID", () => {
+      expect(
+        getAuthorizedOAuthAppURL(
+          'github.example.com' as Hostname,
+          'CUSTOM_CLIENT_ID_123' as ClientID,
+        ),
+      ).toBe('https://github.example.com/settings/connections/applications/CUSTOM_CLIENT_ID_123');
+    });
+
+    it("falls back to Gitify's preconfigured client ID when none is supplied", () => {
+      expect(getAuthorizedOAuthAppURL('github.com' as Hostname)).toBe(
+        'https://github.com/settings/connections/applications/FAKE_CLIENT_ID_123',
+      );
+    });
+  });
+
   describe('getDeveloperSettingsURL', () => {
-    it('returns the GitHub App connections URL', () => {
+    it('returns the connections URL for Gitify OAuth App accounts', () => {
       expect(
         getDeveloperSettingsURL({
           hostname: 'github.com' as Hostname,
-          method: 'GitHub App',
+          method: 'Gitify OAuth App',
         } as Account),
       ).toBe('https://github.com/settings/connections/applications/FAKE_CLIENT_ID_123');
     });
 
-    it('returns the OAuth App developer URL', () => {
+    it("returns the connections URL for a custom app's own client ID", () => {
       expect(
         getDeveloperSettingsURL({
           hostname: 'github.com' as Hostname,
-          method: 'OAuth App',
+          method: 'Custom OAuth App',
+          clientId: 'CUSTOM_CLIENT_ID_123' as ClientID,
         } as Account),
-      ).toBe('https://github.com/settings/developers');
+      ).toBe('https://github.com/settings/connections/applications/CUSTOM_CLIENT_ID_123');
+    });
+
+    it('falls back to the preconfigured app when a custom account stores no client ID', () => {
+      expect(
+        getDeveloperSettingsURL({
+          hostname: 'github.com' as Hostname,
+          method: 'Custom OAuth App',
+        } as Account),
+      ).toBe('https://github.com/settings/connections/applications/FAKE_CLIENT_ID_123');
     });
 
     it('returns the PAT settings URL', () => {
@@ -132,6 +160,10 @@ describe('renderer/utils/forges/github/auth.ts', () => {
         ),
       ).toBeTruthy();
     });
+
+    it('does not pre-fill a callback URL for a device-flow custom app', () => {
+      expect(getNewOAuthAppURL('github.com' as Hostname)).not.toContain('callback_url');
+    });
   });
 
   describe('isValidClientId', () => {
diff --git a/src/renderer/utils/forges/github/auth.ts b/src/renderer/utils/forges/github/auth.ts
index 99915c750..f10568654 100644
--- a/src/renderer/utils/forges/github/auth.ts
+++ b/src/renderer/utils/forges/github/auth.ts
@@ -59,38 +59,45 @@ export function getGitHubAuthBaseUrl(hostname: Hostname): URL {
   return url;
 }
 
+/**
+ * Build the URL where a user reviews and revokes an authorized OAuth app's access.
+ *
+ * Omit `clientId` for Gitify's preconfigured app; pass one for a user-supplied app.
+ *
+ * @param hostname - The GitHub hostname the app is authorized on.
+ * @param clientId - The OAuth app's client ID, when the account supplied one.
+ * @returns The authorized-applications URL for that client ID.
+ */
+export function getAuthorizedOAuthAppURL(hostname: Hostname, clientId?: ClientID): Link {
+  const url = new URL(`https://${hostname}`);
+  url.pathname = `/settings/connections/applications/${
+    clientId ?? Constants.OAUTH_DEVICE_FLOW_CLIENT_ID
+  }`;
+  return url.toString() as Link;
+}
+
 /**
  * Return the GitHub developer settings URL appropriate for the account's auth method.
  *
- * - GitHub App → application connections page
+ * - Gitify OAuth App / Custom OAuth App → the OAuth app's authorized-applications page
  * - GitHub CLI → authorized applications page
- * - OAuth App → developer settings page
  * - Personal Access Token → tokens settings page
  *
  * @param account - The account whose settings URL to build.
  * @returns The URL to the relevant GitHub developer settings page.
  */
 export function getDeveloperSettingsURL(account: Account): Link {
-  const settingsURL = new URL(`https://${account.hostname}`);
-
   switch (account.method) {
-    case 'GitHub App':
-      settingsURL.pathname = `/settings/connections/applications/${Constants.OAUTH_DEVICE_FLOW_CLIENT_ID}`;
-      break;
+    case 'Gitify OAuth App':
+    case 'Custom OAuth App':
+      return getAuthorizedOAuthAppURL(account.hostname, account.clientId);
     case 'GitHub CLI':
-      settingsURL.pathname = '/settings/applications';
-      break;
-    case 'OAuth App':
-      settingsURL.pathname = '/settings/developers';
-      break;
+      return `https://${account.hostname}/settings/applications` as Link;
     case 'Personal Access Token':
-      settingsURL.pathname = '/settings/tokens';
-      break;
+      return `https://${account.hostname}/settings/tokens` as Link;
     default:
-      settingsURL.pathname = '/settings';
-      break;
+      return `https://${account.hostname}/settings` as Link;
   }
-  return settingsURL.toString() as Link;
 }
 
 /**
@@ -115,8 +122,10 @@ export function getNewTokenURL(hostname: Hostname): Link {
 /**
  * Build a pre-filled URL for registering a new OAuth App.
  *
- * Pre-populates the app name (with creation date), homepage URL, and
- * the `gitify://oauth` callback URL.
+ * Pre-populates the app name (with creation date) and homepage URL. No callback
+ * URL is set: the custom OAuth app authorizes through the device flow, which
+ * needs no browser redirect. The user must still enable the device flow in the
+ * app's settings after registering it.
  *
  * @param hostname - The GitHub hostname to register the app on.
  * @returns The URL with pre-filled query parameters.
@@ -129,7 +138,6 @@ export function getNewOAuthAppURL(hostname: Hostname): Link {
     `${APPLICATION.NAME} (Created on ${date})`,
   );
   newOAuthAppURL.searchParams.append('oauth_application[url]', 'https://gitify.io');
-  newOAuthAppURL.searchParams.append('oauth_application[callback_url]', 'gitify://oauth');
 
   return newOAuthAppURL.toString() as Link;
 }
diff --git a/src/renderer/utils/forges/github/flows.test.ts b/src/renderer/utils/forges/github/flows.test.ts
index e9adc14fb..b3852cf22 100644
--- a/src/renderer/utils/forges/github/flows.test.ts
+++ b/src/renderer/utils/forges/github/flows.test.ts
@@ -6,23 +6,21 @@ vi.mock('@octokit/oauth-methods', async () => {
     ...actual,
     createDeviceCode: vi.fn(),
     exchangeDeviceCode: vi.fn(),
-    exchangeWebFlowCode: vi.fn(),
   };
 });
 
-import { createDeviceCode, exchangeDeviceCode, exchangeWebFlowCode } from '@octokit/oauth-methods';
+import { createDeviceCode, exchangeDeviceCode } from '@octokit/oauth-methods';
 import { RequestError } from '@octokit/request-error';
 
 import type { MockedFunction } from 'vite-plus/test';
 
 import { Constants } from '../../../constants';
 
-import type { AuthCode, ClientID, ClientSecret, Hostname } from '../../../types';
-import type { DeviceFlowSession, LoginOAuthWebOptions } from '../../auth/types';
+import type { ClientID, Hostname } from '../../../types';
+import type { DeviceFlowSession } from '../../auth/types';
 
 import { getRecommendedScopeNames } from '../../auth/scopes';
 import * as logger from '../../core/logger';
-import * as comms from '../../system/comms';
 import * as flows from './flows';
 
 const createDeviceCodeMock = createDeviceCode as unknown as MockedFunction<typeof createDeviceCode>;
@@ -31,327 +29,189 @@ const exchangeDeviceCodeMock = exchangeDeviceCode as unknown as MockedFunction<
   typeof exchangeDeviceCode
 >;
 
-const exchangeWebFlowCodeMock = exchangeWebFlowCode as unknown as MockedFunction<
-  typeof exchangeWebFlowCode
->;
-
 describe('renderer/utils/forges/github/flows.ts', () => {
-  vi.spyOn(logger, 'rendererLogInfo').mockImplementation(vi.fn());
   const rendererLogErrorSpy = vi.spyOn(logger, 'rendererLogError').mockImplementation(vi.fn());
-  const rendererLogWarnSpy = vi.spyOn(logger, 'rendererLogWarn').mockImplementation(vi.fn());
-  const openExternalLinkSpy = vi.spyOn(comms, 'openExternalLink').mockImplementation(vi.fn());
 
   beforeEach(() => {
     // Mock OAUTH_DEVICE_FLOW_CLIENT_ID value
     Constants.OAUTH_DEVICE_FLOW_CLIENT_ID = 'FAKE_CLIENT_ID_123' as ClientID;
   });
 
-  describe('Gitify GitHub OAuth - Device Code Flow', () => {
-    describe('startGitHubDeviceFlow', () => {
-      it('should request a device code and return a session', async () => {
-        createDeviceCodeMock.mockResolvedValueOnce({
-          data: {
-            device_code: 'device-code-xyz',
-            user_code: 'user-code-xyz',
-            verification_uri: 'https://github.com/login/device',
-            expires_in: 600,
-            interval: 5,
-          },
-        } as unknown as Awaited<ReturnType<typeof createDeviceCode>>);
-
-        const session = await flows.startGitHubDeviceFlow();
-
-        expect(createDeviceCodeMock).toHaveBeenCalledWith({
-          clientType: 'oauth-app',
-          clientId: 'FAKE_CLIENT_ID_123',
-          scopes: getRecommendedScopeNames(),
-          request: expect.any(Function),
-        });
-
-        expect(session.deviceCode).toBe('device-code-xyz');
-        expect(session.userCode).toBe('user-code-xyz');
-        expect(session.verificationUri).toBe('https://github.com/login/device');
-        expect(session.intervalSeconds).toBe(5);
-        expect(session.expiresAt).toBeGreaterThan(Date.now());
-      });
-    });
-
-    describe('pollGitHubDeviceFlow', () => {
-      const baseSession = {
-        hostname: 'github.com',
-        clientId: 'FAKE_CLIENT_ID_123',
-        deviceCode: 'device-code',
-        userCode: 'user-code',
-        verificationUri: 'https://github.com/login/device',
-        intervalSeconds: 5,
-        expiresAt: Date.now() + 10000,
-      } as const;
-
-      it('returns token on successful exchange', async () => {
-        exchangeDeviceCodeMock.mockResolvedValueOnce({
-          authentication: { token: 'device-token-xyz' },
-        } as unknown as Awaited<ReturnType<typeof exchangeDeviceCode>>);
-
-        const token = await flows.pollGitHubDeviceFlow(baseSession as DeviceFlowSession);
-
-        expect(exchangeDeviceCodeMock).toHaveBeenCalledWith({
-          clientType: 'oauth-app',
-          clientId: 'FAKE_CLIENT_ID_123',
-          code: 'device-code',
-          request: expect.any(Function),
-        });
-
-        expect(token).toBe('device-token-xyz');
-      });
-
-      it('returns null and does not change interval when authorization is pending', async () => {
-        const pendingErr = Object.create(RequestError.prototype);
-        pendingErr.response = { data: { error: 'authorization_pending' } };
-
-        exchangeDeviceCodeMock.mockRejectedValueOnce(pendingErr);
+  describe('startGitHubDeviceFlow', () => {
+    it('should request a device code and return a session', async () => {
+      createDeviceCodeMock.mockResolvedValueOnce({
+        data: {
+          device_code: 'device-code-xyz',
+          user_code: 'user-code-xyz',
+          verification_uri: 'https://github.com/login/device',
+          expires_in: 600,
+          interval: 5,
+        },
+      } as unknown as Awaited<ReturnType<typeof createDeviceCode>>);
 
-        const session = { ...baseSession } as DeviceFlowSession;
-        const token = await flows.pollGitHubDeviceFlow(session);
+      const session = await flows.startGitHubDeviceFlow();
 
-        expect(token).toBeNull();
-        expect(session.intervalSeconds).toBe(5);
+      expect(createDeviceCodeMock).toHaveBeenCalledWith({
+        clientType: 'oauth-app',
+        clientId: 'FAKE_CLIENT_ID_123',
+        scopes: getRecommendedScopeNames(),
+        request: expect.any(Function),
       });
 
-      it('returns null and increases interval by 5 when slow_down', async () => {
-        const slowDownErr = Object.create(RequestError.prototype);
-        slowDownErr.response = { data: { error: 'slow_down' } };
-
-        exchangeDeviceCodeMock.mockRejectedValueOnce(slowDownErr);
-
-        const session = { ...baseSession } as DeviceFlowSession;
-        const token = await flows.pollGitHubDeviceFlow(session);
-
-        expect(token).toBeNull();
-        expect(session.intervalSeconds).toBe(10);
-      });
+      expect(session.deviceCode).toBe('device-code-xyz');
+      expect(session.userCode).toBe('user-code-xyz');
+      expect(session.verificationUri).toBe('https://github.com/login/device');
+      expect(session.intervalSeconds).toBe(5);
+      expect(session.expiresAt).toBeGreaterThan(Date.now());
+    });
 
-      it('throws on other errors', async () => {
-        const otherErr = new Error('boom');
+    it('authorizes a supplied custom OAuth app client ID', async () => {
+      createDeviceCodeMock.mockResolvedValueOnce({
+        data: {
+          device_code: 'device-code-xyz',
+          user_code: 'user-code-xyz',
+          verification_uri: 'https://github.example.com/login/device',
+          expires_in: 600,
+          interval: 5,
+        },
+      } as unknown as Awaited<ReturnType<typeof createDeviceCode>>);
 
-        exchangeDeviceCodeMock.mockRejectedValueOnce(otherErr);
+      const session = await flows.startGitHubDeviceFlow(
+        'github.example.com' as Hostname,
+        getRecommendedScopeNames(),
+        'CUSTOM_CLIENT_ID_123' as ClientID,
+      );
 
-        await expect(
-          async () => await flows.pollGitHubDeviceFlow(baseSession as DeviceFlowSession),
-        ).rejects.toThrow('boom');
-        expect(rendererLogErrorSpy).toHaveBeenCalledTimes(1);
+      expect(createDeviceCodeMock).toHaveBeenCalledWith({
+        clientType: 'oauth-app',
+        clientId: 'CUSTOM_CLIENT_ID_123',
+        scopes: getRecommendedScopeNames(),
+        request: expect.any(Function),
       });
+      expect(session.clientId).toBe('CUSTOM_CLIENT_ID_123');
+      expect(session.hostname).toBe('github.example.com');
     });
   });
 
-  describe('performGitHubWebOAuth', () => {
-    const webAuthOptions: LoginOAuthWebOptions = {
-      hostname: 'github.com' as Hostname,
-      clientId: 'FAKE_CLIENT_ID_123' as ClientID,
-      clientSecret: 'FAKE_CLIENT_SECRET_123' as ClientSecret,
-    };
-
-    it('should call performGitHubWebOAuth using custom oauth app - success oauth flow', async () => {
-      let deliverCallback: (callbackUrl: string) => void = () => {};
-      window.gitify.onAuthCallback = vi.fn().mockImplementation((callback) => {
-        deliverCallback = callback;
-      });
-
-      const resultPromise = flows.performGitHubWebOAuth({
-        clientId: 'BYO_CLIENT_ID' as ClientID,
-        clientSecret: 'BYO_CLIENT_SECRET' as ClientSecret,
-        hostname: 'my.git.com' as Hostname,
+  describe('pollGitHubDeviceFlow', () => {
+    const baseSession = {
+      hostname: 'github.com',
+      clientId: 'FAKE_CLIENT_ID_123',
+      deviceCode: 'device-code',
+      userCode: 'user-code',
+      verificationUri: 'https://github.com/login/device',
+      intervalSeconds: 5,
+      expiresAt: Date.now() + 10000,
+    } as const;
+
+    it('returns token on successful exchange', async () => {
+      exchangeDeviceCodeMock.mockResolvedValueOnce({
+        authentication: { token: 'device-token-xyz' },
+      } as unknown as Awaited<ReturnType<typeof exchangeDeviceCode>>);
+
+      const token = await flows.pollGitHubDeviceFlow(baseSession as DeviceFlowSession);
+
+      expect(exchangeDeviceCodeMock).toHaveBeenCalledWith({
+        clientType: 'oauth-app',
+        clientId: 'FAKE_CLIENT_ID_123',
+        code: 'device-code',
+        request: expect.any(Function),
       });
 
-      expect(openExternalLinkSpy).toHaveBeenCalledTimes(1);
-      expect(openExternalLinkSpy).toHaveBeenCalledWith(
-        expect.stringContaining(
-          'https://my.git.com/login/oauth/authorize?allow_signup=false&client_id=BYO_CLIENT_ID&scope=notifications%2Cread%3Auser%2Crepo',
-        ),
-      );
-
-      // The authorization URL must carry a per-attempt state, and the login
-      // only completes when the callback echoes that same value back.
-      const authorizeUrl = new URL(openExternalLinkSpy.mock.calls[0][0] as string);
-      const state = authorizeUrl.searchParams.get('state');
-      expect(state).toBeTruthy();
-
-      deliverCallback(`gitify://oauth?code=123-456&state=${state}`);
-
-      const res = await resultPromise;
-
-      expect(window.gitify.onAuthCallback).toHaveBeenCalledTimes(1);
-      expect(window.gitify.onAuthCallback).toHaveBeenCalledWith(expect.any(Function));
-
-      expect(res.authMethod).toBe('OAuth App');
-      expect(res.authCode).toBe('123-456');
+      expect(token).toBe('device-token-xyz');
     });
 
-    it('does not resolve when the callback state does not match the generated state', async () => {
-      let deliverCallback: (callbackUrl: string) => void = () => {};
-      window.gitify.onAuthCallback = vi.fn().mockImplementation((callback) => {
-        deliverCallback = callback;
-      });
-
-      let resolved = false;
-      const resultPromise = flows.performGitHubWebOAuth(webAuthOptions).then((res) => {
-        resolved = true;
-        return res;
+    it("uses the session's own client ID when polling a custom app", async () => {
+      exchangeDeviceCodeMock.mockResolvedValueOnce({
+        authentication: { token: 'custom-token' },
+      } as unknown as Awaited<ReturnType<typeof exchangeDeviceCode>>);
+
+      const token = await flows.pollGitHubDeviceFlow({
+        ...baseSession,
+        clientId: 'CUSTOM_CLIENT_ID_123',
+      } as DeviceFlowSession);
+
+      expect(exchangeDeviceCodeMock).toHaveBeenCalledWith({
+        clientType: 'oauth-app',
+        clientId: 'CUSTOM_CLIENT_ID_123',
+        code: 'device-code',
+        request: expect.any(Function),
       });
+      expect(token).toBe('custom-token');
+    });
 
-      const authorizeUrl = new URL(openExternalLinkSpy.mock.calls[0][0] as string);
-      const state = authorizeUrl.searchParams.get('state');
+    it('returns null and does not change interval when authorization is pending', async () => {
+      const pendingErr = Object.create(RequestError.prototype);
+      pendingErr.response = { data: { error: 'authorization_pending' } };
 
-      deliverCallback('gitify://oauth?code=attacker-code&state=not-the-real-state');
-      deliverCallback('gitify://oauth?code=attacker-code-no-state');
+      exchangeDeviceCodeMock.mockRejectedValueOnce(pendingErr);
 
-      // Give any pending microtasks a chance to run, then confirm neither
-      // injected callback settled the login.
-      await Promise.resolve();
-      await Promise.resolve();
-      expect(resolved).toBe(false);
-      expect(rendererLogWarnSpy).toHaveBeenCalledTimes(2);
+      const session = { ...baseSession } as DeviceFlowSession;
+      const token = await flows.pollGitHubDeviceFlow(session);
 
-      // The still-pending attempt completes once the matching state arrives.
-      deliverCallback(`gitify://oauth?code=the-real-code&state=${state}`);
-      const res = await resultPromise;
-      expect(res.authCode).toBe('the-real-code');
+      expect(token).toBeNull();
+      expect(session.intervalSeconds).toBe(5);
     });
 
-    it('ignores an unparseable callback URL instead of tearing down the pending login', async () => {
-      let deliverCallback: (callbackUrl: string) => void = () => {};
-      window.gitify.onAuthCallback = vi.fn().mockImplementation((callback) => {
-        deliverCallback = callback;
-      });
-
-      let settled = false;
-      const resultPromise = flows.performGitHubWebOAuth(webAuthOptions).then(
-        (res) => {
-          settled = true;
-          return res;
-        },
-        (err: unknown) => {
-          settled = true;
-          throw err;
-        },
-      );
-
-      // `gitify://[` passes the protocol handler's `gitify://` prefix check but
-      // is not a parseable URL, so it must be ignored rather than rejecting the
-      // login before the state is ever compared.
-      deliverCallback('gitify://[');
+    it('returns null and increases interval by 5 when slow_down', async () => {
+      const slowDownErr = Object.create(RequestError.prototype);
+      slowDownErr.response = { data: { error: 'slow_down' } };
 
-      await Promise.resolve();
-      await Promise.resolve();
-      expect(settled).toBe(false);
-      expect(rendererLogWarnSpy).toHaveBeenCalledTimes(1);
+      exchangeDeviceCodeMock.mockRejectedValueOnce(slowDownErr);
 
-      // Settle the still-pending attempt so no listener is left dangling.
-      const authorizeUrl = new URL(openExternalLinkSpy.mock.calls[0][0] as string);
-      const state = authorizeUrl.searchParams.get('state');
-      deliverCallback(`gitify://oauth?code=real-code&state=${state}`);
+      const session = { ...baseSession } as DeviceFlowSession;
+      const token = await flows.pollGitHubDeviceFlow(session);
 
-      await expect(resultPromise).resolves.toMatchObject({ authCode: 'real-code' });
+      expect(token).toBeNull();
+      expect(session.intervalSeconds).toBe(10);
     });
 
-    it('should call performGitHubWebOAuth - failure', async () => {
-      let deliverCallback: (callbackUrl: string) => void = () => {};
-      window.gitify.onAuthCallback = vi.fn().mockImplementation((callback) => {
-        deliverCallback = callback;
-      });
+    it('throws on other errors', async () => {
+      const otherErr = new Error('boom');
 
-      const resultPromise = flows.performGitHubWebOAuth(webAuthOptions);
+      exchangeDeviceCodeMock.mockRejectedValueOnce(otherErr);
 
-      const authorizeUrl = new URL(openExternalLinkSpy.mock.calls[0][0] as string);
-      const state = authorizeUrl.searchParams.get('state');
+      await expect(
+        async () => await flows.pollGitHubDeviceFlow(baseSession as DeviceFlowSession),
+      ).rejects.toThrow('boom');
+      expect(rendererLogErrorSpy).toHaveBeenCalledTimes(1);
+    });
+  });
 
-      deliverCallback(
-        `gitify://oauth?state=${state}&error=invalid_request&error_description=The+redirect_uri+is+missing+or+invalid.&error_uri=https://docs.github.com/en/developers/apps/troubleshooting-oauth-errors`,
-      );
+  describe('describeDeviceFlowStartError', () => {
+    it('explains how to enable device flow for a custom app', () => {
+      const err = Object.create(RequestError.prototype);
+      err.response = { data: { error: 'device_flow_disabled' } };
 
-      await expect(resultPromise).rejects.toEqual(
-        new Error(
-          "Oops! Something went wrong and we couldn't log you in using GitHub. Please try again. Reason: The redirect_uri is missing or invalid. Docs: https://docs.github.com/en/developers/apps/troubleshooting-oauth-errors",
-        ),
+      const message = flows.describeDeviceFlowStartError(
+        err,
+        'github.example.com' as Hostname,
+        'CUSTOM_CLIENT_ID_123' as ClientID,
       );
 
-      expect(openExternalLinkSpy).toHaveBeenCalledTimes(1);
-      expect(openExternalLinkSpy).toHaveBeenCalledWith(
-        expect.stringContaining(
-          'https://github.com/login/oauth/authorize?allow_signup=false&client_id=FAKE_CLIENT_ID_123&scope=notifications%2Cread%3Auser%2Crepo',
-        ),
+      expect(message).toContain('Device flow is not enabled');
+      expect(message).toContain(
+        'https://github.example.com/settings/applications/CUSTOM_CLIENT_ID_123',
       );
-
-      expect(window.gitify.onAuthCallback).toHaveBeenCalledTimes(1);
-      expect(window.gitify.onAuthCallback).toHaveBeenCalledWith(expect.any(Function));
     });
 
-    it('ignores a callback error whose state does not match the attempt', async () => {
-      let deliverCallback: (callbackUrl: string) => void = () => {};
-      window.gitify.onAuthCallback = vi.fn().mockImplementation((callback) => {
-        deliverCallback = callback;
-      });
-
-      let settled = false;
-      const resultPromise = flows.performGitHubWebOAuth(webAuthOptions).then(
-        (res) => {
-          settled = true;
-          return res;
-        },
-        (err: unknown) => {
-          settled = true;
-          throw err;
-        },
-      );
-
-      deliverCallback('gitify://oauth?error=access_denied');
-      deliverCallback('gitify://oauth?error=access_denied&state=not-the-real-state');
-
-      await Promise.resolve();
-      await Promise.resolve();
-      expect(settled).toBe(false);
-      expect(rendererLogWarnSpy).toHaveBeenCalledTimes(2);
+    it('names an unrecognized client ID as invalid for the host', () => {
+      const err = Object.create(RequestError.prototype);
+      err.response = { data: { error: 'incorrect_client_credentials' } };
 
-      // Settle the still-pending attempt so no listener is left dangling.
-      const authorizeUrl = new URL(openExternalLinkSpy.mock.calls[0][0] as string);
-      const state = authorizeUrl.searchParams.get('state');
-      deliverCallback(`gitify://oauth?code=real-code&state=${state}`);
-
-      await expect(resultPromise).resolves.toMatchObject({ authCode: 'real-code' });
+      expect(
+        flows.describeDeviceFlowStartError(
+          err,
+          'github.example.com' as Hostname,
+          'CUSTOM_CLIENT_ID_123' as ClientID,
+        ),
+      ).toBe('The client ID is not valid for github.example.com. Check it and try again.');
     });
 
-    describe('exchangeAuthCodeForAccessToken', () => {
-      const authCode = '123-456' as AuthCode;
-
-      it('should exchange auth code for access token', async () => {
-        exchangeWebFlowCodeMock.mockResolvedValueOnce({
-          authentication: {
-            token: 'this-is-a-token',
-          },
-        } as unknown as Awaited<ReturnType<typeof exchangeWebFlowCode>>);
-
-        const res = await flows.exchangeAuthCodeForAccessToken(authCode, {
-          ...webAuthOptions,
-        });
-
-        expect(exchangeWebFlowCodeMock).toHaveBeenCalledWith({
-          clientType: 'oauth-app',
-          clientId: 'FAKE_CLIENT_ID_123',
-          clientSecret: 'FAKE_CLIENT_SECRET_123',
-          code: '123-456',
-          request: expect.any(Function),
-        });
-        expect(res).toBe('this-is-a-token');
-      });
-
-      it('should throw when client secret is missing', async () => {
-        await expect(
-          async () =>
-            await flows.exchangeAuthCodeForAccessToken(authCode, {
-              ...webAuthOptions,
-              clientSecret: undefined as unknown as ClientSecret,
-            }),
-        ).rejects.toThrow('clientSecret is required to exchange an auth code');
-      });
+    it('returns undefined for a non-RequestError', () => {
+      expect(
+        flows.describeDeviceFlowStartError(new Error('boom'), 'github.com' as Hostname),
+      ).toBeUndefined();
     });
   });
 });
diff --git a/src/renderer/utils/forges/github/flows.ts b/src/renderer/utils/forges/github/flows.ts
index 6b7fe1d22..1b49ebf17 100644
--- a/src/renderer/utils/forges/github/flows.ts
+++ b/src/renderer/utils/forges/github/flows.ts
@@ -1,21 +1,14 @@
-import {
-  createDeviceCode,
-  exchangeDeviceCode,
-  exchangeWebFlowCode,
-  getWebFlowAuthorizationUrl,
-} from '@octokit/oauth-methods';
+import { createDeviceCode, exchangeDeviceCode } from '@octokit/oauth-methods';
 import { request } from '@octokit/request';
 import { RequestError } from '@octokit/request-error';
 
 import { Constants } from '../../../constants';
 
-import type { AuthCode, Hostname, Link, Token } from '../../../types';
-import type { AuthResponse, DeviceFlowSession, LoginOAuthWebOptions } from '../../auth/types';
+import type { ClientID, Hostname, Token } from '../../../types';
+import type { DeviceFlowSession } from '../../auth/types';
 
 import { getRecommendedScopeNames } from '../../auth/scopes';
-import { generateOAuthState } from '../../auth/state';
-import { rendererLogError, rendererLogInfo, rendererLogWarn, toError } from '../../core/logger';
-import { openExternalLink } from '../../system/comms';
+import { rendererLogError, toError } from '../../core/logger';
 import { getGitHubAuthBaseUrl } from './auth';
 
 type DeviceFlowErrorResponse = {
@@ -24,115 +17,6 @@ type DeviceFlowErrorResponse = {
   error_uri: string;
 };
 
-/**
- * Initiate a GitHub OAuth Web Flow (OAuth App) authentication.
- *
- * Opens the GitHub authorization URL in the user's browser, then waits for the
- * app's custom `gitify://oauth` callback to receive the authorization code.
- *
- * The login is bound to a per-attempt random `state` that is sent with the
- * authorization request and must be echoed by the callback. A callback
- * carrying a missing or mismatched `state` is logged and ignored, so a
- * `gitify://oauth` link delivered from outside this attempt cannot bind the
- * client to a different GitHub account or tear down the pending login.
- *
- * @param authOptions - The OAuth App client configuration and target hostname.
- * @returns Resolves with the authorization code and options on success.
- */
-export function performGitHubWebOAuth(authOptions: LoginOAuthWebOptions): Promise<AuthResponse> {
-  return new Promise((resolve, reject) => {
-    // A per-attempt, unguessable value this app itself tracks and checks on
-    // callback, so a `gitify://oauth` callback carrying an authorization code
-    // this specific login attempt never requested (e.g. one an attacker
-    // obtained for their own GitHub account) is rejected instead of silently
-    // accepted and exchanged for a token.
-    //
-    // Read the state back from the library's result rather than trusting the
-    // value echoed to us, so the string compared on callback is exactly the one
-    // the library embedded in the authorization URL.
-    const { url, state: expectedState } = getWebFlowAuthorizationUrl({
-      clientType: 'oauth-app',
-      clientId: authOptions.clientId,
-      scopes: getRecommendedScopeNames(),
-      allowSignup: false,
-      state: generateOAuthState(),
-      request: request.defaults({
-        baseUrl: `https://${authOptions.hostname}`,
-      }),
-    });
-
-    openExternalLink(url as Link);
-
-    // Assigned once the listener is registered below; optional-chained in
-    // `handleCallback` so a synchronously-firing callback cannot hit the
-    // temporal dead zone.
-    let unsubscribeAuthCallback: (() => void) | undefined;
-
-    const handleCallback = (callbackUrl: string) => {
-      let url: URL;
-      try {
-        url = new URL(callbackUrl);
-      } catch {
-        // An unparseable callback cannot carry the state this attempt
-        // generated, so treat it like any other unmatched callback: log and
-        // ignore rather than tearing down the pending login. Otherwise a
-        // forged `gitify://` URL (e.g. `gitify://[`) would abort a legitimate
-        // login even though the state check never runs.
-        rendererLogWarn(
-          'renderer:auth-callback',
-          'Ignored an unparseable authentication callback URL',
-        );
-        return;
-      }
-
-      const type = url.hostname;
-      const code = url.searchParams.get('code');
-      const state = url.searchParams.get('state');
-      const error = url.searchParams.get('error');
-      const errorDescription = url.searchParams.get('error_description');
-      const errorUri = url.searchParams.get('error_uri');
-
-      // A callback belongs to this login attempt only when it echoes the state
-      // this attempt generated. Anything else (missing or mismatched state) is
-      // logged and ignored, leaving the pending login intact so an injected
-      // callback can neither bind another account nor tear down the attempt.
-      if (state !== expectedState) {
-        rendererLogWarn(
-          'renderer:auth-callback',
-          'Ignored an authentication callback with a missing or mismatched state parameter',
-        );
-        return;
-      }
-
-      if (code && type === 'oauth') {
-        unsubscribeAuthCallback?.();
-        resolve({
-          authMethod: 'OAuth App',
-          authCode: code as AuthCode,
-          authOptions: authOptions,
-        });
-      } else if (error) {
-        unsubscribeAuthCallback?.();
-        reject(
-          new Error(
-            `Oops! Something went wrong and we couldn't log you in using GitHub. Please try again. Reason: ${errorDescription} Docs: ${errorUri}`,
-          ),
-        );
-      }
-    };
-
-    // Unsubscribed inside `handleCallback` once the flow settles so repeated
-    // login attempts do not accumulate stale ipcRenderer listeners.
-    unsubscribeAuthCallback = window.gitify.onAuthCallback((callbackUrl: string) => {
-      rendererLogInfo(
-        'renderer:auth-callback',
-        `received authentication callback URL ${callbackUrl}`,
-      );
-      handleCallback(callbackUrl);
-    });
-  });
-}
-
 /**
  * Start a GitHub Device Flow authorization session.
  *
@@ -141,15 +25,18 @@ export function performGitHubWebOAuth(authOptions: LoginOAuthWebOptions): Promis
  *
  * @param hostname - The GitHub hostname to authenticate against. Defaults to github.com.
  * @param scopes - Array of scope names to request. Defaults to recommended (full) scopes.
+ * @param clientId - The OAuth app client ID to authorize with. Defaults to Gitify's
+ *                   own preconfigured app; a user-supplied custom app passes its own.
  * @returns The device flow session data.
  */
 export async function startGitHubDeviceFlow(
   hostname: Hostname = Constants.GITHUB_HOSTNAME,
   scopes: string[] = getRecommendedScopeNames(),
+  clientId: ClientID = Constants.OAUTH_DEVICE_FLOW_CLIENT_ID,
 ): Promise<DeviceFlowSession> {
   const deviceCode = await createDeviceCode({
     clientType: 'oauth-app' as const,
-    clientId: Constants.OAUTH_DEVICE_FLOW_CLIENT_ID,
+    clientId: clientId,
     scopes: scopes,
     request: request.defaults({
       baseUrl: getGitHubAuthBaseUrl(hostname).toString(),
@@ -158,7 +45,7 @@ export async function startGitHubDeviceFlow(
 
   return {
     hostname: hostname,
-    clientId: Constants.OAUTH_DEVICE_FLOW_CLIENT_ID,
+    clientId: clientId,
     deviceCode: deviceCode.data.device_code,
     userCode: deviceCode.data.user_code,
     verificationUri: deviceCode.data.verification_uri,
@@ -167,6 +54,42 @@ export async function startGitHubDeviceFlow(
   } as DeviceFlowSession;
 }
 
+/**
+ * Describe a device-flow start failure in actionable terms.
+ *
+ * A device flow can only start when the app has device flow enabled and the
+ * client ID is known to the host. Both are common setup mistakes for a
+ * user-supplied custom app, so they are surfaced with a named cause and fix
+ * instead of a raw transport error.
+ *
+ * @param err - The error thrown while starting the device flow.
+ * @param hostname - The host the session was started against.
+ * @param clientId - The client ID supplied for a custom app, when any.
+ * @returns A user-facing message, or `undefined` for an unrecognised failure.
+ */
+export function describeDeviceFlowStartError(
+  err: unknown,
+  hostname: Hostname,
+  clientId?: ClientID,
+): string | undefined {
+  if (!(err instanceof RequestError)) {
+    return undefined;
+  }
+
+  const errorCode = (err.response?.data as Partial<DeviceFlowErrorResponse> | undefined)?.error;
+
+  switch (errorCode) {
+    case 'device_flow_disabled':
+      return clientId
+        ? `Device flow is not enabled for this OAuth app. Enable it in that app's settings at https://${hostname}/settings/applications/${clientId}, then try again.`
+        : `Device flow is not enabled for this OAuth app. Enable it in the app's settings on ${hostname}, then try again.`;
+    case 'incorrect_client_credentials':
+      return `The client ID is not valid for ${hostname}. Check it and try again.`;
+    default:
+      return undefined;
+  }
+}
+
 /**
  * Poll GitHub to exchange a device code for an access token.
  *
@@ -209,35 +132,3 @@ export async function pollGitHubDeviceFlow(session: DeviceFlowSession): Promise<
     throw err;
   }
 }
-
-/**
- * Exchange an OAuth authorization code for an access token.
- *
- * `authOptions.clientSecret` is required; this step must be performed
- * server-side or in a trusted context to keep the secret confidential.
- *
- * @param authCode - The authorization code received from the OAuth callback.
- * @param authOptions - The OAuth App options, including the client secret.
- * @returns The access token.
- * @throws If `clientSecret` is absent.
- */
-export async function exchangeAuthCodeForAccessToken(
-  authCode: AuthCode,
-  authOptions: LoginOAuthWebOptions,
-): Promise<Token> {
-  if (!authOptions.clientSecret) {
-    throw new Error('clientSecret is required to exchange an auth code');
-  }
-
-  const { authentication } = await exchangeWebFlowCode({
-    clientType: 'oauth-app',
-    clientId: authOptions.clientId,
-    clientSecret: authOptions.clientSecret,
-    code: authCode,
-    request: request.defaults({
-      baseUrl: getGitHubAuthBaseUrl(authOptions.hostname).toString().replace(/\/$/, ''),
-    }),
-  });
-
-  return authentication.token as Token;
-}
diff --git a/src/renderer/utils/forges/github/octokit.test.ts b/src/renderer/utils/forges/github/octokit.test.ts
index 588c468f4..da1a96693 100644
--- a/src/renderer/utils/forges/github/octokit.test.ts
+++ b/src/renderer/utils/forges/github/octokit.test.ts
@@ -1,5 +1,5 @@
 import {
-  mockGitHubAppAccount,
+  mockGitifyOAuthAppAccount,
   mockGitHubCliAccount,
   mockGitHubCloudAccount,
   mockGitHubEnterpriseServerAccount,
@@ -113,7 +113,7 @@ describe('renderer/utils/forges/github/octokit.ts', () => {
       const getGitHubAPIBaseUrlSpy = vi.spyOn(utils, 'getGitHubAPIBaseUrl');
       getGitHubAPIBaseUrlSpy.mockReturnValue(new URL('https://api.github.com/'));
 
-      const octokit1 = await createOctokitClient(mockGitHubAppAccount, 'rest');
+      const octokit1 = await createOctokitClient(mockGitifyOAuthAppAccount, 'rest');
 
       const octokit2 = await createOctokitClient(mockGitHubCloudAccount, 'rest');
 
diff --git a/src/renderer/utils/forges/gitlab/adapter.test.ts b/src/renderer/utils/forges/gitlab/adapter.test.ts
index 1f2ddeddd..275faca28 100644
--- a/src/renderer/utils/forges/gitlab/adapter.test.ts
+++ b/src/renderer/utils/forges/gitlab/adapter.test.ts
@@ -83,7 +83,7 @@ describe('renderer/utils/forges/gitlab/adapter.ts', () => {
 
     it('returns the key icon for every auth method (PAT-only forge today)', () => {
       expect(gitlabAdapter.getAuthMethodIcon('Personal Access Token')).toBe(KeyIcon);
-      expect(gitlabAdapter.getAuthMethodIcon('OAuth App')).toBe(KeyIcon);
+      expect(gitlabAdapter.getAuthMethodIcon('Custom OAuth App')).toBe(KeyIcon);
     });
 
     it('omits the oauthScopes bundle', () => {
diff --git a/src/renderer/utils/forges/types.ts b/src/renderer/utils/forges/types.ts
index 745d472d6..b5da9fe08 100644
--- a/src/renderer/utils/forges/types.ts
+++ b/src/renderer/utils/forges/types.ts
@@ -4,7 +4,7 @@ import type { OcticonProps } from '@primer/octicons-react';
 
 import type {
   Account,
-  AuthCode,
+  ClientID,
   Forge,
   Hostname,
   IconColor,
@@ -14,13 +14,7 @@ import type {
   Token,
   UserType,
 } from '../../types';
-import type {
-  AuthMethod,
-  AuthResponse,
-  DeviceFlowSession,
-  LoginOAuthWebOptions,
-  PlatformType,
-} from '../auth/types';
+import type { AuthMethod, DeviceFlowSession, PlatformType } from '../auth/types';
 
 /**
  * Capability flags exposed by a forge adapter.
@@ -168,9 +162,9 @@ export interface ForgeAdapter {
 
   // --- Auth flows ---
   // Optional because not every forge supports every flow. Gitea today is
-  // PAT-only and omits both bundles. The orchestrator gates UI on the
+  // PAT-only and omits every bundle. The orchestrator gates UI on the
   // presence of these bundles (and on `loginMethods` entries pointing at
-  // the forge's device-flow or OAuth-app routes).
+  // the forge's device-flow or custom-OAuth-app routes).
 
   /**
    * OAuth device-flow capability. Forges without device-flow support (e.g.
@@ -180,10 +174,11 @@ export interface ForgeAdapter {
   deviceFlow?: DeviceFlowSupport;
 
   /**
-   * Custom-OAuth-app web flow. Forges without OAuth-app support (e.g. Gitea)
-   * omit this bundle entirely — callers gate the OAuth-app UI on its presence.
+   * Custom-OAuth-app capability. Forges where a user cannot authorize their
+   * own OAuth app (e.g. Gitea) omit this bundle entirely — callers gate the
+   * custom-app UI on its presence.
    */
-  oauthWebApp?: OAuthWebAppSupport;
+  customOAuthApp?: CustomOAuthAppSupport;
 
   /**
    * Reuse of a locally installed forge CLI's credential. Forges whose CLI
@@ -320,22 +315,6 @@ export interface ExternallyManagedScopes {
   command: string;
 }
 
-/**
- * Custom-OAuth-app web flow capability bundle. Present only on forges that
- * support browser-redirect OAuth with user-supplied client credentials
- * (GitHub today).
- */
-export interface OAuthWebAppSupport {
-  /** Start the OAuth web flow and return the auth code once the user consents. */
-  performWebOAuth(options: LoginOAuthWebOptions): Promise<AuthResponse>;
-  /** Exchange an OAuth web-flow authorization code for an access token. */
-  exchangeAuthCodeForToken(authCode: AuthCode, options: LoginOAuthWebOptions): Promise<Token>;
-  /** Whether the supplied OAuth client ID matches the forge's expected format. */
-  validateClientId(clientId: string): boolean;
-  /** URL the user visits to create a new OAuth app on the forge. */
-  getNewOAuthAppUrl(hostname: Hostname): Link;
-}
-
 /**
  * OAuth device-flow capability bundle. Present only on forges that support
  * browser-side device authorisation (GitHub today).
@@ -343,12 +322,30 @@ export interface OAuthWebAppSupport {
 export interface DeviceFlowSupport {
   /** `AuthMethod` recorded on the account when a successful login completes. */
   authMethod: AuthMethod;
-  /** Start a device-flow authorization session. */
-  start(hostname?: Hostname, scopes?: string[]): Promise<DeviceFlowSession>;
+  /**
+   * Start a device-flow authorization session.
+   *
+   * `clientId` authorizes the user's own OAuth app instead of Gitify's
+   * preconfigured one; when omitted the forge's built-in app is used.
+   */
+  start(hostname?: Hostname, scopes?: string[], clientId?: ClientID): Promise<DeviceFlowSession>;
   /** Poll for completion; resolves to a token when granted. */
   poll(session: DeviceFlowSession): Promise<Token | null>;
-  /** URL the user visits to revoke Gitify's access on this forge. */
-  getRevokeAccessUrl(hostname: Hostname): Link;
+  /** URL the user visits to revoke the authorized OAuth app's access on this forge. */
+  getRevokeAccessUrl(hostname: Hostname, clientId?: ClientID): Link;
+}
+
+/**
+ * Custom-OAuth-app capability bundle. Present only on forges where a user can
+ * authorize their own OAuth app (GitHub today).
+ */
+export interface CustomOAuthAppSupport {
+  /** `AuthMethod` recorded on accounts created from a user-supplied OAuth app. */
+  authMethod: AuthMethod;
+  /** Whether the supplied OAuth client ID matches the forge's expected format. */
+  validateClientId(clientId: string): boolean;
+  /** URL the user visits to register a new OAuth app on the forge. */
+  getNewOAuthAppUrl(hostname: Hostname): Link;
 }
 
 /**
diff --git a/src/shared/events.ts b/src/shared/events.ts
index 90e88c632..ddac48bd3 100644
--- a/src/shared/events.ts
+++ b/src/shared/events.ts
@@ -5,7 +5,6 @@ const P = 'gitify:' as const;
  * Each value is prefixed with `gitify:` to prevent collisions.
  */
 export const EVENTS = {
-  AUTH_CALLBACK: `${P}auth-callback`,
   QUIT: `${P}quit`,
   WINDOW_SHOW: `${P}window-show`,
   WINDOW_HIDE: `${P}window-hide`,
@@ -117,7 +116,6 @@ type AssertEventCoverage<T extends Record<EventType, Contract>> = T;
  * - For events with no payload, `request` is `undefined`.
  */
 export type EventContracts = AssertEventCoverage<{
-  [EVENTS.AUTH_CALLBACK]: { request: string; response: undefined };
   [EVENTS.QUIT]: { request: undefined; response: undefined };
   [EVENTS.WINDOW_SHOW]: { request: undefined; response: undefined };
   [EVENTS.WINDOW_HIDE]: { request: undefined; response: undefined };