diff --git a/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php b/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php
index 258138caa42be..a222fd1684dc5 100644
--- a/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php
+++ b/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php
@@ -11,6 +11,7 @@
 use OCP\IRequest;
 use OCP\IURLGenerator;
 use OCP\IUserSession;
+use OCP\Theming\IDefaults;
 use Sabre\DAV\Server;
 use Sabre\DAV\ServerPlugin;
 use Sabre\HTTP\RequestInterface;
@@ -22,23 +23,17 @@ class AppleProvisioningPlugin extends ServerPlugin {
 	 */
 	protected $server;
 
-	/**
-	 * @var \OC_Defaults
-	 */
-	protected $themingDefaults;
-
 	/**
 	 * AppleProvisioningPlugin constructor.
 	 */
 	public function __construct(
 		protected IUserSession $userSession,
 		protected IURLGenerator $urlGenerator,
-		\OC_Defaults $themingDefaults,
+		protected IDefaults $themingDefaults,
 		protected IRequest $request,
 		protected IL10N $l10n,
 		protected \Closure $uuidClosure,
 	) {
-		$this->themingDefaults = $themingDefaults;
 	}
 
 	/**
diff --git a/apps/files_sharing/tests/CapabilitiesTest.php b/apps/files_sharing/tests/CapabilitiesTest.php
index 644cde444bd32..cfad6d8ad503d 100644
--- a/apps/files_sharing/tests/CapabilitiesTest.php
+++ b/apps/files_sharing/tests/CapabilitiesTest.php
@@ -27,6 +27,7 @@
 use OCP\Security\IHasher;
 use OCP\Security\ISecureRandom;
 use OCP\Share\IProviderFactory;
+use OCP\Theming\IDefaults;
 use Psr\Log\LoggerInterface;
 
 /**
@@ -93,7 +94,7 @@ private function getResults(array $map, array $typedMap = [], bool $federationEn
 			$this->createMock(IRootFolder::class),
 			$this->createMock(IMailer::class),
 			$this->createMock(IURLGenerator::class),
-			$this->createMock(\OC_Defaults::class),
+			$this->createMock(IDefaults::class),
 			$this->createMock(IEventDispatcher::class),
 			$this->createMock(IUserSession::class),
 			$this->createMock(KnownUserService::class),
diff --git a/apps/theming/lib/ThemingDefaults.php b/apps/theming/lib/ThemingDefaults.php
index 71afae14a8ea7..aa74258a13c13 100644
--- a/apps/theming/lib/ThemingDefaults.php
+++ b/apps/theming/lib/ThemingDefaults.php
@@ -1,40 +1,39 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
+
 namespace OCA\Theming;
 
 use OCA\Theming\AppInfo\Application;
 use OCA\Theming\Service\BackgroundService;
 use OCP\App\AppPathNotFoundException;
 use OCP\App\IAppManager;
+use OCP\AppFramework\Services\IAppConfig;
 use OCP\Files\NotFoundException;
 use OCP\Files\SimpleFS\ISimpleFile;
-use OCP\IAppConfig;
 use OCP\ICacheFactory;
 use OCP\IConfig;
 use OCP\IL10N;
 use OCP\INavigationManager;
 use OCP\IURLGenerator;
 use OCP\IUserSession;
+use OCP\ServerVersion;
+use OCP\Theming\IDefaults;
 
-class ThemingDefaults extends \OC_Defaults {
-
-	private string $name;
-	private string $title;
-	private string $entity;
-	private string $productName;
-	private string $url;
-	private string $backgroundColor;
-	private string $primaryColor;
-	private string $docBaseUrl;
+class ThemingDefaults implements IDefaults {
+	private ?\OC_Theme $theme = null;
+	private ?string $defaultSlogan = null;
 
 	private string $iTunesAppId;
 	private string $iOSClientUrl;
 	private string $AndroidClientUrl;
 	private string $FDroidClientUrl;
+	private string $defaultDocVersion;
 
 	/**
 	 * ThemingDefaults constructor.
@@ -51,45 +50,69 @@ public function __construct(
 		private IAppManager $appManager,
 		private INavigationManager $navigationManager,
 		private BackgroundService $backgroundService,
+		ServerVersion $serverVersion,
 	) {
-		parent::__construct();
-
-		$this->name = parent::getName();
-		$this->title = parent::getTitle();
-		$this->entity = parent::getEntity();
-		$this->productName = parent::getProductName();
-		$this->url = parent::getBaseUrl();
-		$this->primaryColor = parent::getColorPrimary();
-		$this->backgroundColor = parent::getColorBackground();
-		$this->iTunesAppId = parent::getiTunesAppId();
-		$this->iOSClientUrl = parent::getiOSClientUrl();
-		$this->AndroidClientUrl = parent::getAndroidClientUrl();
-		$this->FDroidClientUrl = parent::getFDroidClientUrl();
-		$this->docBaseUrl = parent::getDocBaseUrl();
-	}
+		$themeName = $config->getSystemValueString('theme', '');
+		if ($themeName === '') {
+			if (is_dir(\OC::$SERVERROOT . '/themes/default')) {
+				$themeName = 'default';
+			}
+		}
+		$themePath = \OC::$SERVERROOT . '/themes/' . $themeName . '/defaults.php';
+		if (file_exists($themePath)) {
+			// prevent defaults.php from printing output
+			ob_start();
+			require_once $themePath;
+			ob_end_clean();
+			if (class_exists(\OC_Theme::class)) {
+				$this->theme = new \OC_Theme();
+			}
+		}
 
-	public function getName() {
-		return strip_tags($this->config->getAppValue('theming', 'name', $this->name));
+		$this->iTunesAppId = $this->getFromLegacyTheme(
+			'getiTunesAppId',
+			$config->getSystemValueString('customclient_ios_appid', '1125420102')
+		);
+		$this->iOSClientUrl = $this->getFromLegacyTheme(
+			'getiOSClientUrl',
+			$config->getSystemValueString('customclient_ios', 'https://geo.itunes.apple.com/us/app/nextcloud/id1125420102?mt=8')
+		);
+		$this->AndroidClientUrl = $this->getFromLegacyTheme(
+			'getAndroidClientUrl',
+			$config->getSystemValueString('customclient_android', 'https://play.google.com/store/apps/details?id=com.nextcloud.client')
+		);
+		$this->FDroidClientUrl = $this->getFromLegacyTheme(
+			'getFDroidClientUrl',
+			$config->getSystemValueString('customclient_fdroid', 'https://f-droid.org/packages/com.nextcloud.client/')
+		);
+		$this->defaultDocVersion = (string)$serverVersion->getMajorVersion(); // used to generate doc links
+	}
+
+	private function getFromLegacyTheme(string $method, string $default): string {
+		if (isset($this->theme) && method_exists($this->theme, $method)) {
+			return $this->theme->$method();
+		}
+		return $default;
 	}
 
-	public function getHTMLName() {
-		return $this->config->getAppValue('theming', 'name', $this->name);
+	public function getName(): string {
+		return strip_tags($this->appConfig->getAppValueString('name', $this->getFromLegacyTheme('getName', 'Nextcloud')));
 	}
 
-	public function getTitle() {
-		return strip_tags($this->config->getAppValue('theming', 'name', $this->title));
+	public function getTitle(): string {
+		return strip_tags($this->appConfig->getAppValueString('name', $this->getFromLegacyTheme('getTitle', 'Nextcloud')));
 	}
 
-	public function getEntity() {
-		return strip_tags($this->config->getAppValue('theming', 'name', $this->entity));
+	public function getEntity(): string {
+		return strip_tags($this->appConfig->getAppValueString('name', $this->getFromLegacyTheme('getEntity', 'Nextcloud')));
 	}
 
-	public function getProductName() {
-		return strip_tags($this->config->getAppValue('theming', 'productName', $this->productName));
+	public function getProductName(): string {
+		return strip_tags($this->appConfig->getAppValueString('productName', $this->getFromLegacyTheme('getProductName', 'Nextcloud')));
 	}
 
-	public function getBaseUrl() {
-		return $this->config->getAppValue('theming', 'url', $this->url);
+	public function getBaseUrl(): string {
+		return $this->appConfig->getAppValueString('url', $this->getFromLegacyTheme('getBaseUrl', 'https://nextcloud.com'));
 	}
 
 	/**
@@ -97,23 +120,33 @@ public function getBaseUrl() {
 	 * @psalm-suppress InvalidReturnStatement
 	 * @psalm-suppress InvalidReturnType
 	 */
-	public function getSlogan(?string $lang = null) {
-		return \OCP\Util::sanitizeHTML($this->config->getAppValue('theming', 'slogan', parent::getSlogan($lang)));
+	public function getSlogan(?string $lang = null): string {
+		if ($this->appConfig->hasAppKey('slogan')) {
+			return \OCP\Util::sanitizeHTML($this->appConfig->getAppValueString('slogan'));
+		}
+		if (isset($this->theme) && method_exists($this->theme, 'getSlogan')) {
+			return $this->theme->getSlogan($lang);
+		}
+		if ($this->defaultSlogan === null) {
+			$l10n = \OCP\Util::getL10N('lib', $lang);
+			$this->defaultSlogan = $l10n->t('a safe home for all your data');
+		}
+		return $this->defaultSlogan;
 	}
 
-	public function getImprintUrl() {
-		return (string)$this->config->getAppValue('theming', 'imprintUrl', '');
+	public function getImprintUrl(): string {
+		return $this->appConfig->getAppValueString('imprintUrl', '');
 	}
 
-	public function getPrivacyUrl() {
-		return (string)$this->config->getAppValue('theming', 'privacyUrl', '');
+	public function getPrivacyUrl(): string {
+		return $this->appConfig->getAppValueString('privacyUrl', '');
 	}
 
-	public function getDocBaseUrl() {
-		return (string)$this->config->getAppValue('theming', 'docBaseUrl', $this->docBaseUrl);
+	public function getDocBaseUrl(): string {
+		return $this->appConfig->getAppValueString('docBaseUrl', $this->getFromLegacyTheme('getDocBaseUrl', 'https://docs.nextcloud.com'));
 	}
 
-	public function getShortFooter() {
+	public function getShortFooter(): string {
 		$slogan = $this->getSlogan();
 		$baseUrl = $this->getBaseUrl();
 		$entity = $this->getEntity();
@@ -132,11 +165,11 @@ public function getShortFooter() {
 		$links = [
 			[
 				'text' => $this->l->t('Legal notice'),
-				'url' => (string)$this->getImprintUrl()
+				'url' => $this->getImprintUrl()
 			],
 			[
 				'text' => $this->l->t('Privacy policy'),
-				'url' => (string)$this->getPrivacyUrl()
+				'url' => $this->getPrivacyUrl()
 			],
 		];
 
@@ -167,6 +200,13 @@ public function getShortFooter() {
 		return $footer;
 	}
 
+	/**
+	 * Returns long version of the footer
+	 */
+	public function getLongFooter(): string {
+		return $this->getFromLegacyTheme('getLongFooter', $this->getShortFooter());
+	}
+
 	/**
 	 * Color that is used for highlighting elements like important buttons
 	 * If user theming is enabled then the user defined value is returned
@@ -224,42 +264,40 @@ public function getColorBackground(): string {
 	 */
 	public function getDefaultColorPrimary(): string {
 		// try admin color
-		$defaultColor = $this->appConfig->getValueString(Application::APP_ID, 'primary_color', '');
+		$defaultColor = $this->appConfig->getAppValueString('primary_color', '');
 		if (preg_match('/^\#([0-9a-f]{3}|[0-9a-f]{6})$/i', $defaultColor)) {
 			return $defaultColor;
 		}
 
-		// fall back to default primary color
-		return $this->primaryColor;
+		return $this->getFromLegacyTheme('getColorPrimary', $this->getFromLegacyTheme('getMailHeaderColor', '#00679e'));
 	}
 
 	/**
 	 * Default background color only taking admin setting into account
 	 */
 	public function getDefaultColorBackground(): string {
-		$defaultColor = $this->appConfig->getValueString(Application::APP_ID, 'background_color');
+		$defaultColor = $this->appConfig->getAppValueString('background_color');
 		if (preg_match('/^\#([0-9a-f]{3}|[0-9a-f]{6})$/i', $defaultColor)) {
 			return $defaultColor;
 		}
 
-		return $this->backgroundColor;
+		return $this->getFromLegacyTheme('getColorBackground', '#00679e');
 	}
 
 	/**
 	 * Themed logo url
 	 *
 	 * @param bool $useSvg Whether to point to the SVG image or a fallback
-	 * @return string
 	 */
-	public function getLogo($useSvg = true): string {
-		$logo = $this->config->getAppValue('theming', 'logoMime', '');
+	public function getLogo(bool $useSvg = true): string {
+		$logo = $this->appConfig->getAppValueString('logoMime', '');
 
 		// short cut to avoid setting up the filesystem just to check if the logo is there
 		//
 		// explanation: if an SVG is requested and the app config value for logoMime is set then the logo is there.
 		// otherwise we need to check it and maybe also generate a PNG from the SVG (that's done in getImage() which
 		// needs to be called then)
-		if ($useSvg === true && $logo !== false) {
+		if ($useSvg === true && $logo !== '') {
 			$logoExists = true;
 		} else {
 			try {
@@ -270,9 +308,9 @@ public function getLogo($useSvg = true): string {
 			}
 		}
 
-		$cacheBusterCounter = $this->config->getAppValue('theming', 'cachebuster', '0');
+		$cacheBusterCounter = $this->appConfig->getAppValueString('cachebuster', '0');
 
-		if (!$logo || !$logoExists) {
+		if ($logo !== '' || !$logoExists) {
 			if ($useSvg) {
 				$logo = $this->urlGenerator->imagePath('core', 'logo/logo.svg');
 			} else {
@@ -288,82 +326,32 @@ public function getLogo($useSvg = true): string {
 	 * Themed background image url
 	 *
 	 * @param bool $darkVariant if the dark variant (if available) of the background should be used
-	 * @return string
 	 */
 	public function getBackground(bool $darkVariant = false): string {
 		return $this->imageManager->getImageUrl('background' . ($darkVariant ? 'Dark' : ''));
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getiTunesAppId() {
-		return $this->config->getAppValue('theming', 'iTunesAppId', $this->iTunesAppId);
+	public function getiTunesAppId(): string {
+		return $this->appConfig->getAppValueString('iTunesAppId', $this->iTunesAppId);
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getiOSClientUrl() {
-		return $this->config->getAppValue('theming', 'iOSClientUrl', $this->iOSClientUrl);
+	public function getiOSClientUrl(): string {
+		return $this->appConfig->getAppValueString('iOSClientUrl', $this->iOSClientUrl);
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getAndroidClientUrl() {
-		return $this->config->getAppValue('theming', 'AndroidClientUrl', $this->AndroidClientUrl);
+	public function getAndroidClientUrl(): string {
+		return $this->appConfig->getAppValueString('AndroidClientUrl', $this->AndroidClientUrl);
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getFDroidClientUrl() {
-		return $this->config->getAppValue('theming', 'FDroidClientUrl', $this->FDroidClientUrl);
+	public function getFDroidClientUrl(): string {
+		return $this->appConfig->getAppValueString('FDroidClientUrl', $this->FDroidClientUrl);
 	}
 
 	/**
-	 * @return array scss variables to overwrite
-	 * @deprecated since Nextcloud 22 - https://github.com/nextcloud/server/issues/9940
+	 * Returns the URL where the sync clients are listed
 	 */
-	public function getScssVariables() {
-		$cacheBuster = $this->config->getAppValue('theming', 'cachebuster', '0');
-		$cache = $this->cacheFactory->createDistributed('theming-' . $cacheBuster . '-' . $this->urlGenerator->getBaseUrl());
-		if ($value = $cache->get('getScssVariables')) {
-			return $value;
-		}
-
-		$variables = [
-			'theming-cachebuster' => "'" . $cacheBuster . "'",
-			'theming-logo-mime' => "'" . $this->config->getAppValue('theming', 'logoMime') . "'",
-			'theming-background-mime' => "'" . $this->config->getAppValue('theming', 'backgroundMime') . "'",
-			'theming-logoheader-mime' => "'" . $this->config->getAppValue('theming', 'logoheaderMime') . "'",
-			'theming-favicon-mime' => "'" . $this->config->getAppValue('theming', 'faviconMime') . "'"
-		];
-
-		$variables['image-logo'] = "url('" . $this->imageManager->getImageUrl('logo') . "')";
-		$variables['image-logoheader'] = "url('" . $this->imageManager->getImageUrl('logoheader') . "')";
-		$variables['image-favicon'] = "url('" . $this->imageManager->getImageUrl('favicon') . "')";
-		$variables['image-login-background'] = "url('" . $this->imageManager->getImageUrl('background') . "')";
-		$variables['image-login-plain'] = 'false';
-
-		if ($this->appConfig->getValueString(Application::APP_ID, 'primary_color', '') !== '') {
-			$variables['color-primary'] = $this->getColorPrimary();
-			$variables['color-primary-text'] = $this->getTextColorPrimary();
-			$variables['color-primary-element'] = $this->util->elementColor($this->getColorPrimary());
-		}
-
-		if ($this->config->getAppValue('theming', 'backgroundMime', '') === 'backgroundColor') {
-			$variables['image-login-plain'] = 'true';
-		}
-
-		$variables['has-legal-links'] = 'false';
-		if ($this->getImprintUrl() !== '' || $this->getPrivacyUrl() !== '') {
-			$variables['has-legal-links'] = 'true';
-		}
-
-		$cache->set('getScssVariables', $variables);
-		return $variables;
+	public function getSyncClientUrl(): string {
+		return $this->getFromLegacyTheme('getSyncClientUrl', $this->config->getSystemValueString('customclient_desktop', 'https://nextcloud.com/install/#install-clients'));
 	}
 
 	/**
@@ -372,15 +360,15 @@ public function getScssVariables() {
 	 *
 	 * @param string $app name of the app
 	 * @param string $image filename of the image
-	 * @return bool|string false if image should not replaced, otherwise the location of the image
+	 * @return string|false false if image should not replaced, otherwise the location of the image
 	 */
-	public function replaceImagePath($app, $image) {
+	public function replaceImagePath(string $app, string $image): string|false {
 		if ($app === '' || $app === 'files_sharing') {
 			$app = 'core';
 		}
-		$cacheBusterValue = $this->config->getAppValue('theming', 'cachebuster', '0');
+		$cacheBusterValue = $this->appConfig->getAppValueString('cachebuster', '0');
 
-		$route = false;
+		$route = '';
 		if ($image === 'favicon.ico' && ($this->imageManager->shouldReplaceIcons() || $this->getCustomFavicon() !== null)) {
 			$route = $this->urlGenerator->linkToRoute('theming.Icon.getFavicon', ['app' => $app]);
 		}
@@ -401,7 +389,7 @@ public function replaceImagePath($app, $image) {
 			$route = $this->urlGenerator->linkToRoute('theming.Icon.getThemedIcon', ['app' => $app, 'image' => $image]);
 		}
 
-		if ($route) {
+		if ($route !== '') {
 			return $route . '?v=' . $this->util->getCacheBuster();
 		}
 
@@ -420,20 +408,17 @@ protected function getCustomFavicon(): ?ISimpleFile {
 	 * Increases the cache buster key
 	 */
 	public function increaseCacheBuster(): void {
-		$cacheBusterKey = (int)$this->config->getAppValue('theming', 'cachebuster', '0');
-		$this->config->setAppValue('theming', 'cachebuster', (string)($cacheBusterKey + 1));
+		$cacheBusterKey = (int)$this->appConfig->getAppValueString('cachebuster', '0');
+		$this->appConfig->setAppValueString('cachebuster', (string)($cacheBusterKey + 1));
 		$this->cacheFactory->createDistributed('theming-')->clear();
 		$this->cacheFactory->createDistributed('imagePath')->clear();
 	}
 
 	/**
 	 * Update setting in the database
-	 *
-	 * @param string $setting
-	 * @param string $value
 	 */
-	public function set($setting, $value): void {
-		$this->appConfig->setValueString('theming', $setting, $value);
+	public function set(string $setting, string $value): void {
+		$this->appConfig->setAppValueString($setting, $value);
 		$this->increaseCacheBuster();
 	}
 
@@ -443,9 +428,9 @@ public function set($setting, $value): void {
 	public function undoAll(): void {
 		// Remember the current cachebuster value, as we do not want to reset this value
 		// Otherwise this can lead to caching issues as the value might be known to a browser already
-		$cacheBusterKey = $this->config->getAppValue('theming', 'cachebuster', '0');
-		$this->config->deleteAppValues('theming');
-		$this->config->setAppValue('theming', 'cachebuster', $cacheBusterKey);
+		$cacheBusterKey = $this->appConfig->getAppValueString('cachebuster', '0');
+		$this->appConfig->deleteAppValues();
+		$this->appConfig->setAppValueString('cachebuster', $cacheBusterKey);
 		$this->increaseCacheBuster();
 	}
 
@@ -455,8 +440,8 @@ public function undoAll(): void {
 	 * @param string $setting setting which should be reverted
 	 * @return string default value
 	 */
-	public function undo($setting): string {
-		$this->config->deleteAppValue('theming', $setting);
+	public function undo(string $setting): string {
+		$this->appConfig->deleteAppValue($setting);
 		$this->increaseCacheBuster();
 
 		$returnValue = '';
@@ -485,7 +470,7 @@ public function undo($setting): string {
 			case 'background':
 			case 'favicon':
 				$this->imageManager->delete($setting);
-				$this->config->deleteAppValue('theming', $setting . 'Mime');
+				$this->appConfig->deleteAppValue($setting . 'Mime');
 				break;
 		}
 
@@ -494,28 +479,22 @@ public function undo($setting): string {
 
 	/**
 	 * Color of text in the header menu
-	 *
-	 * @return string
 	 */
-	public function getTextColorBackground() {
+	public function getTextColorBackground(): string {
 		return $this->util->invertTextColor($this->getColorBackground()) ? '#000000' : '#ffffff';
 	}
 
 	/**
 	 * Color of text on primary buttons and other elements
-	 *
-	 * @return string
 	 */
-	public function getTextColorPrimary() {
+	public function getTextColorPrimary(): string {
 		return $this->util->invertTextColor($this->getColorPrimary()) ? '#000000' : '#ffffff';
 	}
 
 	/**
 	 * Color of text in the header and primary buttons
-	 *
-	 * @return string
 	 */
-	public function getDefaultTextColorPrimary() {
+	public function getDefaultTextColorPrimary(): string {
 		return $this->util->invertTextColor($this->getDefaultColorPrimary()) ? '#000000' : '#ffffff';
 	}
 
@@ -523,6 +502,16 @@ public function getDefaultTextColorPrimary() {
 	 * Has the admin disabled user customization
 	 */
 	public function isUserThemingDisabled(): bool {
-		return $this->appConfig->getValueBool(Application::APP_ID, 'disable-user-theming');
+		return $this->appConfig->getAppValueBool('disable-user-theming');
+	}
+
+	/**
+	 * @return string URL to doc with key
+	 */
+	public function buildDocLinkToKey(string $key): string {
+		if (isset($this->theme) && method_exists($this->theme, 'buildDocLinkToKey')) {
+			return $this->theme->buildDocLinkToKey($key);
+		}
+		return $this->getDocBaseUrl() . '/server/' . $this->defaultDocVersion . '/go.php?to=' . $key;
 	}
 }
diff --git a/apps/theming/tests/ServicesTest.php b/apps/theming/tests/ServicesTest.php
index 3971c9b66986a..c7952be5894f2 100644
--- a/apps/theming/tests/ServicesTest.php
+++ b/apps/theming/tests/ServicesTest.php
@@ -46,7 +46,6 @@ public static function queryData(): array {
 			[Capabilities::class],
 			[Capabilities::class, ICapability::class],
 			[ThemingDefaults::class],
-			[ThemingDefaults::class, \OC_Defaults::class],
 			[Util::class],
 
 			// Controller
diff --git a/apps/theming/tests/ThemingDefaultsTest.php b/apps/theming/tests/ThemingDefaultsTest.php
index 917ab960318a0..7f53ece431f04 100644
--- a/apps/theming/tests/ThemingDefaultsTest.php
+++ b/apps/theming/tests/ThemingDefaultsTest.php
@@ -650,71 +650,6 @@ public function testGetLogoCustom(): void {
 		$this->assertEquals('custom-logo' . '?v=0', $this->template->getLogo());
 	}
 
-	public function testGetScssVariablesCached(): void {
-		$this->config->expects($this->any())->method('getAppValue')->with('theming', 'cachebuster', '0')->willReturn('1');
-		$this->cacheFactory->expects($this->once())
-			->method('createDistributed')
-			->with('theming-1-')
-			->willReturn($this->cache);
-		$this->cache->expects($this->once())->method('get')->with('getScssVariables')->willReturn(['foo' => 'bar']);
-		$this->assertEquals(['foo' => 'bar'], $this->template->getScssVariables());
-	}
-
-	public function testGetScssVariables(): void {
-		$this->config
-			->expects($this->any())
-			->method('getAppValue')
-			->willReturnMap([
-				['theming', 'cachebuster', '0', '0'],
-				['theming', 'logoMime', '', 'jpeg'],
-				['theming', 'backgroundMime', '', 'jpeg'],
-				['theming', 'logoheaderMime', '', 'jpeg'],
-				['theming', 'faviconMime', '', 'jpeg'],
-			]);
-
-		$this->appConfig
-			->expects(self::atLeastOnce())
-			->method('getValueString')
-			->willReturnMap([
-				['theming', 'primary_color', '', false, $this->defaults->getColorPrimary()],
-				['theming', 'primary_color', $this->defaults->getColorPrimary(), false, $this->defaults->getColorPrimary()],
-			]);
-
-		$this->util->expects($this->any())->method('invertTextColor')->with($this->defaults->getColorPrimary())->willReturn(false);
-		$this->util->expects($this->any())->method('elementColor')->with($this->defaults->getColorPrimary())->willReturn('#aaaaaa');
-		$this->cacheFactory->expects($this->once())
-			->method('createDistributed')
-			->with('theming-0-')
-			->willReturn($this->cache);
-		$this->cache->expects($this->once())->method('get')->with('getScssVariables')->willReturn(null);
-		$this->imageManager->expects($this->exactly(4))
-			->method('getImageUrl')
-			->willReturnMap([
-				['logo', 'custom-logo?v=0'],
-				['logoheader', 'custom-logoheader?v=0'],
-				['favicon', 'custom-favicon?v=0'],
-				['background', 'custom-background?v=0'],
-			]);
-
-		$expected = [
-			'theming-cachebuster' => '\'0\'',
-			'theming-logo-mime' => '\'jpeg\'',
-			'theming-background-mime' => '\'jpeg\'',
-			'image-logo' => "url('custom-logo?v=0')",
-			'image-login-background' => "url('custom-background?v=0')",
-			'color-primary' => $this->defaults->getColorPrimary(),
-			'color-primary-text' => '#ffffff',
-			'image-login-plain' => 'false',
-			'color-primary-element' => '#aaaaaa',
-			'theming-logoheader-mime' => '\'jpeg\'',
-			'theming-favicon-mime' => '\'jpeg\'',
-			'image-logoheader' => "url('custom-logoheader?v=0')",
-			'image-favicon' => "url('custom-favicon?v=0')",
-			'has-legal-links' => 'false'
-		];
-		$this->assertEquals($expected, $this->template->getScssVariables());
-	}
-
 	public function testGetDefaultAndroidURL(): void {
 		$this->config
 			->expects($this->once())
diff --git a/core/Command/Base.php b/core/Command/Base.php
index 138f3ca613bf7..7ea1ab04197fb 100644
--- a/core/Command/Base.php
+++ b/core/Command/Base.php
@@ -8,8 +8,8 @@
 namespace OC\Core\Command;
 
 use OC\Core\Command\User\ListCommand;
-use OCP\Defaults;
 use OCP\Server;
+use OCP\Theming\IDefaults;
 use Stecman\Component\Symfony\Console\BashCompletion\Completion\CompletionAwareInterface;
 use Stecman\Component\Symfony\Console\BashCompletion\CompletionContext;
 use Symfony\Component\Console\Command\Command;
@@ -29,7 +29,7 @@ class Base extends Command implements CompletionAwareInterface {
 
 	protected function configure() {
 		// Some of our commands do not extend this class; and some of those that do do not call parent::configure()
-		$defaultHelp = 'More extensive and thorough documentation may be found at ' . Server::get(Defaults::class)->getDocBaseUrl() . PHP_EOL;
+		$defaultHelp = '';//'More extensive and thorough documentation may be found at ' . Server::get(IDefaults::class)->getDocBaseUrl() . PHP_EOL;
 		$this
 			->setHelp($defaultHelp)
 			->addOption(
diff --git a/core/Command/Status.php b/core/Command/Status.php
index a00d4a94658fd..099b8c8fb90be 100644
--- a/core/Command/Status.php
+++ b/core/Command/Status.php
@@ -7,7 +7,6 @@
  */
 namespace OC\Core\Command;
 
-use OCP\Defaults;
 use OCP\IConfig;
 use OCP\ServerVersion;
 use OCP\Util;
@@ -18,7 +17,7 @@
 class Status extends Base {
 	public function __construct(
 		private IConfig $config,
-		private Defaults $themingDefaults,
+		private string $productName,
 		private ServerVersion $serverVersion,
 	) {
 		parent::__construct('status');
@@ -47,7 +46,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 			'edition' => '',
 			'maintenance' => $maintenanceMode,
 			'needsDbUpgrade' => $needUpgrade,
-			'productname' => $this->themingDefaults->getProductName(),
+			'productname' => $this->productName,
 			'extendedSupport' => Util::hasExtendedSupport()
 		];
 
diff --git a/core/templates/layout.user.php b/core/templates/layout.user.php
index 47cced308bcbf..0ef6f27876a9c 100644
--- a/core/templates/layout.user.php
+++ b/core/templates/layout.user.php
@@ -6,7 +6,7 @@
  */
 
 /**
- * @var \OC_Defaults $theme
+ * @var \OCP\Theming\IDefaults $theme
  * @var array $_
  */
 
diff --git a/lib/base.php b/lib/base.php
index fb3794aa8ec17..f72ca26cd3a78 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -354,7 +354,7 @@ private static function printUpgradePage(\OC\SystemConfig $systemConfig): void {
 		$tmpl->assign('appsToUpgrade', $appManager->getAppsNeedingUpgrade($ocVersion));
 		$tmpl->assign('incompatibleAppsList', $incompatibleDisabledApps);
 		try {
-			$defaults = new \OC_Defaults();
+			$defaults = Server::get(\OCP\Theming\IDefaults::class);
 			$tmpl->assign('productName', $defaults->getName());
 		} catch (Throwable $error) {
 			$tmpl->assign('productName', 'Nextcloud');
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 4cbade8e68e3b..88e69ca230465 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -932,6 +932,7 @@
     'OCP\\TextToImage\\IProvider' => $baseDir . '/lib/public/TextToImage/IProvider.php',
     'OCP\\TextToImage\\IProviderWithUserId' => $baseDir . '/lib/public/TextToImage/IProviderWithUserId.php',
     'OCP\\TextToImage\\Task' => $baseDir . '/lib/public/TextToImage/Task.php',
+    'OCP\\Theming\\IDefaults' => $baseDir . '/lib/public/Theming/IDefaults.php',
     'OCP\\Translation\\CouldNotTranslateException' => $baseDir . '/lib/public/Translation/CouldNotTranslateException.php',
     'OCP\\Translation\\IDetectLanguageProvider' => $baseDir . '/lib/public/Translation/IDetectLanguageProvider.php',
     'OCP\\Translation\\ITranslationManager' => $baseDir . '/lib/public/Translation/ITranslationManager.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 79f4c88358f00..5788526fe54f9 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -973,6 +973,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OCP\\TextToImage\\IProvider' => __DIR__ . '/../../..' . '/lib/public/TextToImage/IProvider.php',
         'OCP\\TextToImage\\IProviderWithUserId' => __DIR__ . '/../../..' . '/lib/public/TextToImage/IProviderWithUserId.php',
         'OCP\\TextToImage\\Task' => __DIR__ . '/../../..' . '/lib/public/TextToImage/Task.php',
+        'OCP\\Theming\\IDefaults' => __DIR__ . '/../../..' . '/lib/public/Theming/IDefaults.php',
         'OCP\\Translation\\CouldNotTranslateException' => __DIR__ . '/../../..' . '/lib/public/Translation/CouldNotTranslateException.php',
         'OCP\\Translation\\IDetectLanguageProvider' => __DIR__ . '/../../..' . '/lib/public/Translation/IDetectLanguageProvider.php',
         'OCP\\Translation\\ITranslationManager' => __DIR__ . '/../../..' . '/lib/public/Translation/ITranslationManager.php',
diff --git a/lib/private/AppFramework/DependencyInjection/DIContainer.php b/lib/private/AppFramework/DependencyInjection/DIContainer.php
index 76261fe6b92c5..95406789d1c42 100644
--- a/lib/private/AppFramework/DependencyInjection/DIContainer.php
+++ b/lib/private/AppFramework/DependencyInjection/DIContainer.php
@@ -138,9 +138,7 @@ public function __construct(string $appName, array $urlParams = [], ?ServerConta
 			return $c->get(IServerContainer::class)->getWebRoot();
 		});
 
-		$this->registerService('OC_Defaults', function (ContainerInterface $c): object {
-			return $c->get(IServerContainer::class)->get('ThemingDefaults');
-		});
+		$this->registerDeprecatedAlias('OC_Defaults', \OCP\Theming\IDefaults::class);
 
 		/** @deprecated 32.0.0 */
 		$this->registerDeprecatedAlias('Protocol', Http::class);
diff --git a/lib/private/Console/Application.php b/lib/private/Console/Application.php
index 4cf1e0da8ca13..fa08872fb6440 100644
--- a/lib/private/Console/Application.php
+++ b/lib/private/Console/Application.php
@@ -14,7 +14,6 @@
 use OCP\App\AppPathNotFoundException;
 use OCP\App\IAppManager;
 use OCP\Console\ConsoleEvent;
-use OCP\Defaults;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\IConfig;
 use OCP\IRequest;
@@ -39,9 +38,9 @@ public function __construct(
 		private LoggerInterface $logger,
 		private MemoryInfo $memoryInfo,
 		private IAppManager $appManager,
-		private Defaults $defaults,
+		string $instanceName,
 	) {
-		$this->application = new SymfonyApplication($defaults->getName(), $serverVersion->getVersionString());
+		$this->application = new SymfonyApplication($instanceName, $serverVersion->getVersionString());
 	}
 
 	/**
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 2804acbbb7964..1de2a60ec7682 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -1001,8 +1001,24 @@ public function __construct($webRoot, \OC\Config $config) {
 			return $manager;
 		});
 
-		$this->registerAlias(\OC_Defaults::class, 'ThemingDefaults');
-		$this->registerService('ThemingDefaults', function (Server $c) {
+		$this->registerService('instanceName', function (ContainerInterface $c) {
+			try {
+				return $c->get(\OCP\Theming\IDefaults::class)->getName();
+			} catch (\Throwable $e) {
+				return 'Nextcloud';
+			}
+		});
+		$this->registerService('productName', function (ContainerInterface $c) {
+			try {
+				return $c->get(\OCP\Theming\IDefaults::class)->getProductName();
+			} catch (\Throwable $e) {
+				return 'Nextcloud';
+			}
+		});
+		$this->registerDeprecatedAlias(\OC_Defaults::class, \OCP\Theming\IDefaults::class);
+		$this->registerDeprecatedAlias('ThemingDefaults', \OCP\Theming\IDefaults::class);
+		$this->registerAlias(ThemingDefaults::class, \OCP\Theming\IDefaults::class);
+		$this->registerService(\OCP\Theming\IDefaults::class, function (Server $c) {
 			try {
 				$classExists = class_exists('OCA\Theming\ThemingDefaults');
 			} catch (\OCP\AutoloadNotAllowedException $e) {
@@ -1010,7 +1026,7 @@ public function __construct($webRoot, \OC\Config $config) {
 				$classExists = false;
 			}
 
-			if ($classExists && $c->get(\OCP\IConfig::class)->getSystemValueBool('installed', false) && $c->get(IAppManager::class)->isEnabledForAnyone('theming') && $c->get(TrustedDomainHelper::class)->isTrustedDomain($c->getRequest()->getInsecureServerHost())) {
+			if ($classExists && $c->get(\OCP\IConfig::class)->getSystemValueBool('installed', false) && $c->get(TrustedDomainHelper::class)->isTrustedDomain($c->getRequest()->getInsecureServerHost())) {
 				$backgroundService = new BackgroundService(
 					$c->get(IRootFolder::class),
 					$c->getAppDataDir('theming'),
@@ -1029,7 +1045,7 @@ public function __construct($webRoot, \OC\Config $config) {
 				);
 				return new ThemingDefaults(
 					$c->get(\OCP\IConfig::class),
-					$c->get(\OCP\IAppConfig::class),
+					$c->getAppContainerForService(\OCA\Theming\ThemingDefaults::class)->get(\OCP\AppFramework\Services\IAppConfig::class),
 					$c->getL10N('theming'),
 					$c->get(IUserSession::class),
 					$c->get(IURLGenerator::class),
@@ -1039,8 +1055,14 @@ public function __construct($webRoot, \OC\Config $config) {
 					$c->get(IAppManager::class),
 					$c->get(INavigationManager::class),
 					$backgroundService,
+					$c->get(ServerVersion::class),
 				);
 			}
+			var_dump(
+				$classExists,
+				$c->get(\OCP\IConfig::class)->getSystemValueBool('installed', false),
+				$c->get(TrustedDomainHelper::class)->isTrustedDomain($c->getRequest()->getInsecureServerHost()));
+			throw new \Exception('Does it break?');
 			return new \OC_Defaults();
 		});
 		$this->registerService(JSCombiner::class, function (Server $c) {
diff --git a/lib/private/Setup.php b/lib/private/Setup.php
index 15f0a4eb61700..f0a8beaa43f97 100644
--- a/lib/private/Setup.php
+++ b/lib/private/Setup.php
@@ -21,7 +21,6 @@
 use OC\User\BackgroundJobs\CleanupDeletedUsers;
 use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\BackgroundJob\IJobList;
-use OCP\Defaults;
 use OCP\Http\Client\IClientService;
 use OCP\IAppConfig;
 use OCP\IConfig;
@@ -46,7 +45,7 @@ public function __construct(
 		protected SystemConfig $config,
 		protected IniGetWrapper $iniWrapper,
 		IL10NFactory $l10nFactory,
-		protected Defaults $defaults,
+		protected string $productName,
 		protected LoggerInterface $logger,
 		protected ISecureRandom $random,
 		protected Installer $installer,
@@ -189,7 +188,7 @@ public function getSystemInfo(bool $allowAllDatabases = false): array {
 				'error' => $this->l10n->t(
 					'Mac OS X is not supported and %s will not work properly on this platform. '
 					. 'Use it at your own risk!',
-					[$this->defaults->getProductName()]
+					[$this->productName]
 				),
 				'hint' => $this->l10n->t('For the best results, please consider using a GNU/Linux server instead.'),
 			];
@@ -200,7 +199,7 @@ public function getSystemInfo(bool $allowAllDatabases = false): array {
 				'error' => $this->l10n->t(
 					'It seems that this %s instance is running on a 32-bit PHP environment and the open_basedir has been configured in php.ini. '
 					. 'This will lead to problems with files over 4 GB and is highly discouraged.',
-					[$this->defaults->getProductName()]
+					[$this->productName]
 				),
 				'hint' => $this->l10n->t('Please remove the open_basedir setting within your php.ini or switch to 64-bit PHP.'),
 			];
diff --git a/lib/private/Share20/Manager.php b/lib/private/Share20/Manager.php
index 4abc3a3f54cad..20c80a45bd9ee 100644
--- a/lib/private/Share20/Manager.php
+++ b/lib/private/Share20/Manager.php
@@ -56,6 +56,7 @@
 use OCP\Share\IShareProviderSupportsAccept;
 use OCP\Share\IShareProviderSupportsAllSharesInFolder;
 use OCP\Share\IShareProviderWithNotification;
+use OCP\Theming\IDefaults;
 use Psr\Log\LoggerInterface;
 
 /**
@@ -79,7 +80,7 @@ public function __construct(
 		private IRootFolder $rootFolder,
 		private IMailer $mailer,
 		private IURLGenerator $urlGenerator,
-		private \OC_Defaults $defaults,
+		private IDefaults $defaults,
 		private IEventDispatcher $dispatcher,
 		private IUserSession $userSession,
 		private KnownUserService $knownUserService,
diff --git a/lib/private/legacy/OC_Defaults.php b/lib/private/legacy/OC_Defaults.php
index 0d460ff966d9c..dc4cc3718a0c5 100644
--- a/lib/private/legacy/OC_Defaults.php
+++ b/lib/private/legacy/OC_Defaults.php
@@ -84,18 +84,6 @@ public function getBaseUrl() {
 		}
 	}
 
-	/**
-	 * Returns the URL where the sync clients are listed
-	 * @return string URL
-	 */
-	public function getSyncClientUrl() {
-		if ($this->themeExist('getSyncClientUrl')) {
-			return $this->theme->getSyncClientUrl();
-		} else {
-			return $this->defaultSyncClientUrl;
-		}
-	}
-
 	/**
 	 * Returns the URL to the App Store for the iOS Client
 	 * @return string URL
diff --git a/lib/public/Theming/IDefaults.php b/lib/public/Theming/IDefaults.php
new file mode 100644
index 0000000000000..49a8b8ab1aa59
--- /dev/null
+++ b/lib/public/Theming/IDefaults.php
@@ -0,0 +1,141 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Theming;
+
+use OCP\AppFramework\Attribute\Consumable;
+
+/**
+ * Public api to access default strings and urls for your templates
+ */
+#[Consumable('33.0.0')]
+interface IDefaults {
+	/**
+	 * Get base URL for the organisation behind your instance
+	 * @since 33.0.0
+	 */
+	public function getBaseUrl(): string;
+
+	/**
+	 * Link to the desktop sync client
+	 * @since 33.0.0
+	 */
+	public function getSyncClientUrl(): string;
+
+	/**
+	 * Link to the iOS client
+	 * @since 33.0.0
+	 */
+	public function getiOSClientUrl(): string;
+
+	/**
+	 * Link to the Android client
+	 * @since 33.0.0
+	 */
+	public function getAndroidClientUrl(): string;
+
+	/**
+	 * link to the Android client on F-Droid
+	 * @since 33.0.0
+	 */
+	public function getFDroidClientUrl(): string;
+
+	/**
+	 * base URL to the documentation of your ownCloud instance
+	 * @since 33.0.0
+	 */
+	public function getDocBaseUrl(): string;
+
+	/**
+	 * name of your Nextcloud instance (e.g. MyPrivateCloud)
+	 * @since 33.0.0
+	 */
+	public function getName(): string;
+
+	/**
+	 * Name of the software product (defaults to Nextcloud)
+	 *
+	 * @since 33.0.0
+	 */
+	public function getProductName(): string;
+
+	/**
+	 * Entity behind your instance
+	 * @since 33.0.0
+	 */
+	public function getEntity(): string;
+
+	/**
+	 * Slogan
+	 * @since 33.0.0
+	 */
+	public function getSlogan(?string $lang = null): string;
+
+	/**
+	 * Footer, short version
+	 * @since 33.0.0
+	 */
+	public function getShortFooter(): string;
+
+	/**
+	 * footer, long version
+	 * @since 33.0.0
+	 */
+	public function getLongFooter(): string;
+
+	/**
+	 * Returns the AppId for the App Store for the iOS Client
+	 * @since 33.0.0
+	 */
+	public function getiTunesAppId(): string;
+
+	/**
+	 * Themed logo url
+	 *
+	 * @param bool $useSvg Whether to point to the SVG image or a fallback
+	 * @since 33.0.0
+	 */
+	public function getLogo(bool $useSvg = true): string;
+
+	/**
+	 * Returns primary color
+	 * @since 33.0.0
+	 */
+	public function getColorPrimary(): string;
+
+	/**
+	 * Return the default color primary
+	 * @since 33.0.0
+	 */
+	public function getDefaultColorPrimary(): string;
+
+	/**
+	 * @return string URL to doc with key
+	 * @since 33.0.0
+	 */
+	public function buildDocLinkToKey(string $key): string;
+
+	/**
+	 * Returns the title
+	 * @since 33.0.0
+	 */
+	public function getTitle(): string;
+
+	/**
+	 * Returns primary color
+	 * @since 33.0.0
+	 */
+	public function getTextColorPrimary(): string;
+
+	/**
+	 * Returns primary color
+	 * @since 33.0.0
+	 */
+	public function getDefaultTextColorPrimary(): string;
+}
diff --git a/tests/lib/Share20/ManagerTest.php b/tests/lib/Share20/ManagerTest.php
index aa42b685ffab1..df322e337b989 100644
--- a/tests/lib/Share20/ManagerTest.php
+++ b/tests/lib/Share20/ManagerTest.php
@@ -58,6 +58,7 @@
 use OCP\Share\IShare;
 use OCP\Share\IShareProvider;
 use OCP\Share\IShareProviderSupportsAllSharesInFolder;
+use OCP\Theming\IDefaults;
 use OCP\Util;
 use PHPUnit\Framework\MockObject\MockBuilder;
 use PHPUnit\Framework\MockObject\MockObject;
@@ -109,7 +110,7 @@ class ManagerTest extends \Test\TestCase {
 	protected $mailer;
 	/** @var IURLGenerator|MockObject */
 	protected $urlGenerator;
-	/** @var \OC_Defaults|MockObject */
+	/** @var IDefaults|MockObject */
 	protected $defaults;
 	/** @var IUserSession|MockObject */
 	protected $userSession;
@@ -134,7 +135,7 @@ protected function setUp(): void {
 		$this->rootFolder = $this->createMock(IRootFolder::class);
 		$this->mailer = $this->createMock(IMailer::class);
 		$this->urlGenerator = $this->createMock(IURLGenerator::class);
-		$this->defaults = $this->createMock(\OC_Defaults::class);
+		$this->defaults = $this->createMock(IDefaults::class);
 		$this->dispatcher = $this->createMock(IEventDispatcher::class);
 		$this->userSession = $this->createMock(IUserSession::class);
 		$this->knownUserService = $this->createMock(KnownUserService::class);
diff --git a/themes/example/defaults.php b/themes/example/defaults.php
index 6bf93e62681f8..a7fb6d3e0c5cd 100644
--- a/themes/example/defaults.php
+++ b/themes/example/defaults.php
@@ -118,14 +118,4 @@ public function getColorPrimary(): string {
 	public function getColorBackground(): string {
 		return '#3d85c6';
 	}
-
-	/**
-	 * Returns variables to overload defaults from core/css/variables.scss
-	 * @return array
-	 */
-	public function getScssVariables(): array {
-		return [
-			'color-primary' => '#745bca'
-		];
-	}
 }