diff --git a/Civi/Core/Themes.php b/Civi/Core/Themes.php
index 05469ba93710..340740ca27e8 100644
--- a/Civi/Core/Themes.php
+++ b/Civi/Core/Themes.php
@@ -265,4 +265,11 @@ public function cssId($cssExt, $cssFile) {
     return ($cssExt === 'civicrm') ? $cssFile : "$cssExt-$cssFile";
   }
 
+  /**
+   * Clear the cache
+   */
+  public function clearCache() {
+    $this->cache->clear();
+  }
+
 }
diff --git a/ext/riverlea/CRM/riverlea/BAO/RiverleaStream.php b/ext/riverlea/CRM/riverlea/BAO/RiverleaStream.php
new file mode 100644
index 000000000000..5d06d0bdccc7
--- /dev/null
+++ b/ext/riverlea/CRM/riverlea/BAO/RiverleaStream.php
@@ -0,0 +1,21 @@
+<?php
+
+use CRM_riverlea_ExtensionUtil as E;
+use Civi\Core\HookInterface;
+use Civi\Core\Event\PreEvent;
+use Civi\Core\Event\PostEvent;
+
+class CRM_riverlea_BAO_RiverleaStream extends CRM_riverlea_DAO_RiverleaStream implements HookInterface {
+
+  public static function self_hook_civicrm_pre(PreEvent $event): void {
+    // munge label for default name
+    if ($event->action === 'create' && !$event->params['name']) {
+      $event->params['name'] = \CRM_Utils_String::munge($event->params['label']);
+    }
+  }
+
+  public static function self_hook_civicrm_postCommit(PostEvent $event): void {
+    \Civi::service('themes')->clear();
+  }
+
+}
diff --git a/ext/riverlea/CRM/riverlea/DAO/RiverleaStream.php b/ext/riverlea/CRM/riverlea/DAO/RiverleaStream.php
new file mode 100644
index 000000000000..0fa0d57b18d5
--- /dev/null
+++ b/ext/riverlea/CRM/riverlea/DAO/RiverleaStream.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * DAOs provide an OOP-style facade for reading and writing database records.
+ *
+ * DAOs are a primary source for metadata in older versions of CiviCRM (<5.74)
+ * and are required for some subsystems (such as APIv3).
+ *
+ * This stub provides compatibility. It is not intended to be modified in a
+ * substantive way. Property annotations may be added, but are not required.
+ */
+class CRM_riverlea_DAO_RiverleaStream extends CRM_riverlea_DAO_Base {
+
+  /**
+   * Required by older versions of CiviCRM (<5.74).
+   * @var string
+   */
+  public static $_tableName = 'civicrm_riverlea_stream';
+
+}
diff --git a/ext/riverlea/CRM/riverlea/Upgrader.php b/ext/riverlea/CRM/riverlea/Upgrader.php
new file mode 100644
index 000000000000..283ce9c869b5
--- /dev/null
+++ b/ext/riverlea/CRM/riverlea/Upgrader.php
@@ -0,0 +1,14 @@
+<?php
+use CRM_riverlea_ExtensionUtil as E;
+
+/**
+ * Collection of upgrade steps.
+ */
+class CRM_riverlea_Upgrader extends \CRM_Extension_Upgrader_Base {
+
+  public function upgrade_1000(): bool {
+    E::schema()->createEntityTable('schema/upgrader/1000-RiverleaStream.entityType.php');
+    return TRUE;
+  }
+
+}
diff --git a/ext/riverlea/Civi/Api4/Action/RiverleaStream/GetWithFileContent.php b/ext/riverlea/Civi/Api4/Action/RiverleaStream/GetWithFileContent.php
new file mode 100644
index 000000000000..bebb08b9b67d
--- /dev/null
+++ b/ext/riverlea/Civi/Api4/Action/RiverleaStream/GetWithFileContent.php
@@ -0,0 +1,71 @@
+<?php
+
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+namespace Civi\Api4\Action\RiverleaStream;
+
+/**
+ * @inheritDoc
+ *
+ * This provides an API for getting the contents of stream css_files - which
+ * is useful for the previewer
+ */
+class GetWithFileContent extends \Civi\Api4\Generic\BasicBatchAction {
+
+  /**
+   * @inheritdoc
+   */
+  protected function getSelect(): array {
+    return [
+      'name', 'label', 'description', 'is_reserved',
+      'extension', 'file_prefix',
+      'css_file', 'css_file_dark',
+      'vars', 'vars_dark',
+      'custom_css', 'custom_css_dark',
+    ];
+  }
+
+  /**
+   * @inheritdoc
+   */
+  protected function doTask($stream): array {
+    $stream['css_file_content'] = self::getFileContent($stream['css_file'], $stream['extension'], $stream['file_prefix'] ?? NULL);
+    $stream['css_file_dark_content'] = self::getFileContent($stream['css_file_dark'], $stream['extension'], $stream['file_prefix'] ?? NULL);
+    return $stream;
+  }
+
+  /**
+   * @return string
+   */
+  public static function getFileContent(?string $path, ?string $extension, ?string $filePrefix): string {
+    if (!$path || !$extension) {
+      return '';
+    }
+    if ($filePrefix) {
+      $path = $filePrefix . '/' . $path;
+    }
+
+    // fix extra slashes
+    $path = str_replace('//', '/', $path);
+    // guard against path traversal
+    $path = str_replace('..', '', $path);
+
+    // get the full path based on the stream extension
+    $finalPath = \Civi::resources()->getPath($extension, $path);
+
+    if (is_file($finalPath)) {
+      // File exists and is a file? Return it!
+      return file_get_contents($finalPath) ?? '';
+    }
+    return '';
+  }
+
+}
diff --git a/ext/riverlea/Civi/Api4/Action/RiverleaStream/Render.php b/ext/riverlea/Civi/Api4/Action/RiverleaStream/Render.php
new file mode 100644
index 000000000000..cbbdd3eed518
--- /dev/null
+++ b/ext/riverlea/Civi/Api4/Action/RiverleaStream/Render.php
@@ -0,0 +1,162 @@
+<?php
+
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+namespace Civi\Api4\Action\RiverleaStream;
+
+/**
+ * @inheritDoc
+ */
+class Render extends \Civi\Api4\Generic\BasicBatchAction {
+
+  /**
+   * @var bool
+   *
+   */
+  protected bool $isFrontend = FALSE;
+
+  /**
+   * @var string
+   *
+   * How to handle dark mode when rendering
+   *
+   * By default this will be set based on isFrontend and the stream/global
+   * dark mode settings
+   *
+   * However it can set explicitly to 'dark', 'light', 'inherit' when previewing
+   */
+  protected string $darkMode = '';
+
+  /**
+   * @inheritdoc
+   */
+  protected function getSelect(): array {
+    return [
+      'name', 'label',
+      'extension', 'file_prefix',
+      'css_file', 'css_file_dark',
+      'vars', 'vars_dark',
+      'custom_css', 'custom_css_dark',
+      'dark_frontend', 'dark_backend',
+    ];
+  }
+
+  /**
+   * @inheritdoc
+   *
+   * Compile the dynamic css for a stream
+   */
+  protected function doTask($stream): array {
+    $content = [];
+
+    // if dark mode is not set explicitly, we derive it
+    // based on frontend/backend settings, stream level settings, global dark mode settings
+    if (!$this->darkMode) {
+      $this->darkMode = $this->getDarkModeDefault($stream);
+    }
+
+    $content[] = self::concatStreamCss($stream);
+
+    switch ($this->darkMode ?? NULL) {
+      case 'light':
+        // tell OS we want light for system elements
+        $content[] = ":root { color-scheme: light; }";
+        break;
+
+      case 'dark':
+        // tell OS we want dark for system elements
+        $content[] = ":root { color-scheme: dark; }";
+        // add stream dark unconditionally
+        $content[] = self::concatStreamCss($stream, TRUE);
+        break;
+
+      case 'inherit':
+      default:
+        // tell OS we are happy with light or dark for system elements
+        $content[] = ":root { color-scheme: light dark; }";
+        // add stream dark vars wrapped inside a media query
+        $content[] = '@media (prefers-color-scheme: dark) {';
+        $content[] = self::concatStreamCss($stream, TRUE);
+        $content[] = '}';
+        break;
+    }
+
+    return [
+      'content' => implode("\n", $content),
+    ];
+  }
+
+  private function getDarkModeDefault(array $stream) {
+    if ($this->isFrontend) {
+      return $stream['dark_frontend'] ?? \Civi::settings()->get('riverlea_dark_mode_frontend');
+    }
+    else {
+      return $stream['dark_backend'] ?? \Civi::settings()->get('riverlea_dark_mode_backend');
+    }
+  }
+
+  /**
+   * This replaces stream meta with its dark version, ready to pass
+   * to concatStreamCss / getStreamCssFromFile
+   */
+  private static function getDarkStream(array $stream): array {
+    $stream['label'] = $stream['label'] . " Dark Styles";
+    $stream['vars'] = $stream['vars_dark'];
+    $stream['css_file'] = $stream['css_file_dark'];
+    $stream['custom_css'] = $stream['custom_css_dark'];
+
+    return $stream;
+  }
+
+  /**
+   * @param array $stream the stream meta
+   * @param bool $darkMode whether to use the regular stream meta, or dark version
+   *
+   * @return string
+   */
+  private static function concatStreamCss(array $stream, bool $darkMode = FALSE): string {
+    if ($darkMode) {
+      $stream = self::getDarkStream($stream);
+    }
+
+    $content = [];
+
+    if ($stream['css_file']) {
+      $content[] = "/* {$stream['label']} file: {$stream['css_file']} */";
+      $content[] = self::getStreamCssFromFile($stream);
+    }
+
+    if ($stream['vars']) {
+      $content[] = "/* {$stream['label']} vars */";
+
+      $content[] = ":root {";
+      foreach ($stream['vars'] as $var => $value) {
+        $content[] = "{$var}: {$value};";
+      }
+      $content[] = "}";
+    }
+
+    if ($stream['custom_css']) {
+      $content[] = "/* {$stream['label']} custom css */";
+      $content[] = $stream['custom_css'];
+    }
+
+    return implode("\n", $content);
+  }
+
+  /**
+   * @return string
+   */
+  private static function getStreamCssFromFile(array $stream): string {
+    return GetWithFileContent::getFileContent($stream['css_file'], $stream['extension'], $stream['file_prefix']);
+  }
+
+}
diff --git a/ext/riverlea/Civi/Api4/RiverleaStream.php b/ext/riverlea/Civi/Api4/RiverleaStream.php
new file mode 100644
index 000000000000..9cf285612fe9
--- /dev/null
+++ b/ext/riverlea/Civi/Api4/RiverleaStream.php
@@ -0,0 +1,15 @@
+<?php
+namespace Civi\Api4;
+
+/**
+ * RiverleaStream entity.
+ *
+ * Provided by the RiverLea CiviCRM Theme Framework extension.
+ *
+ * @package Civi\Api4
+ */
+class RiverleaStream extends Generic\DAOEntity {
+
+  use Generic\Traits\ManagedEntity;
+
+}
diff --git a/ext/riverlea/Civi/Riverlea/DynamicCss.php b/ext/riverlea/Civi/Riverlea/DynamicCss.php
index 36ad9e12d525..6341ff58d8f2 100644
--- a/ext/riverlea/Civi/Riverlea/DynamicCss.php
+++ b/ext/riverlea/Civi/Riverlea/DynamicCss.php
@@ -5,7 +5,7 @@
 use CRM_riverlea_ExtensionUtil as E;
 
 /**
- * This class generates a `river.css` file for Riverlea themes containing
+ * This class generates a `river.css` file for Riverlea streams containing
  * dynamically generated css content
  *
  * At the moment this is used to serve the right vars for a given dark mode setting
@@ -26,14 +26,38 @@ public static function getSubscribedEvents() {
     ];
   }
 
-  public static function getCssParams(): array {
-    $darkModeSetting = \CRM_Utils_System::isFrontendPage() ?
-      \Civi::settings()->get('riverlea_dark_mode_frontend') :
-      \Civi::settings()->get('riverlea_dark_mode_backend');
+  public function getAvailableStreamMeta(): array {
+    $streams = \Civi::$statics['riverlea_streams'] ?? NULL;
+
+    if (is_null($streams)) {
+      try {
+        $streams = (array) \Civi\Api4\RiverleaStream::get(FALSE)
+          ->addSelect('name', 'label', 'extension', 'file_prefix', 'parent_id', 'id', 'modified_date')
+          ->execute()
+          ->indexBy('name');
+
+        \Civi::$statics['riverlea_streams'] = $streams;
+      }
+      catch (\CRM_Core_Exception $e) {
+        \Civi::log()->warning('Error loading Riverlea stream meta');
+        return [];
+      }
+    }
+
+    return $streams;
+  }
+
+  public function getCssParams(): array {
+    $stream = \Civi::service('themes')->getActiveThemeKey();
+
+    // we add the stream modified date to asset params as a cache buster
+    $streamMeta = self::getAvailableStreamMeta()[$stream] ?? [];
+    $streamModified = $streamMeta['modified_date'] ?? NULL;
 
     return [
-      'stream' => \Civi::service('themes')->getActiveThemeKey(),
-      'dark' => $darkModeSetting,
+      'stream' => $stream,
+      'modified' => $streamModified,
+      'is_frontend' => \CRM_Utils_System::isFrontendPage(),
     ];
   }
 
@@ -45,75 +69,19 @@ public static function getCssParams(): array {
    * @see CRM_Utils_hook::buildAsset()
    * @see \Civi\Core\AssetBuilder
    */
-  public static function buildAssetCss($e) {
+  public function buildAssetCss($e) {
     if ($e->asset !== static::CSS_FILE) {
       return;
     }
     $e->mimeType = 'text/css';
 
-    $params = $e->params;
-
-    $stream = $params['stream'] ?? 'empty';
-
-    $content = [];
-
-    // add base vars for the stream
-    $content[] = self::getCSSFromFile('_variables.css', $stream);
-
-    switch ($params['dark'] ?? NULL) {
-      case 'light':
-        // tell OS we want light for system elements
-        $content[] = ":root { color-scheme: light; }";
-        break;
-
-      case 'dark':
-        // tell OS we want dark for system elements
-        $content[] = ":root { color-scheme: dark; }";
-        // add stream dark vars unconditionally
-        $content[] = self::getCSSFromFile('_dark.css', $stream);
-        break;
-
-      case 'inherit':
-      default:
-        // tell OS we are happy with light or dark for system elements
-        $content[] = ":root { color-scheme: light dark; }";
-        // add stream dark vars wrapped inside a media query
-        $content[] = '@media (prefers-color-scheme: dark) {';
-        $content[] = self::getCSSFromFile('_dark.css', $stream);
-        $content[] = '}';
-        break;
-    }
-
-    $e->content = implode("\n", $content);
-  }
+    $render = \Civi\Api4\RiverleaStream::render(FALSE)
+      ->addWhere('name', '=', $e->params['stream'])
+      ->setIsFrontend($e->params['is_frontend'])
+      ->execute()
+      ->first();
 
-  /**
-   * Check file exists and return contents or empty string
-   *
-   * @param string $cssFileName The name of the css file (eg. _variables.css)
-   * @param string $stream The name of the riverlea stream (eg. walbrook)
-   *
-   * @return string
-   */
-  private static function getCSSFromFile(string $cssFileName, string $stream): string {
-    $res = \Civi::resources();
-    $theme = \Civi::service('themes')->get($stream);
-    $file = '';
-    // For riverlea themes CSS should be located in stream/streamname/css - prefix="stream/streamname/"
-    if (isset($theme['prefix'])) {
-      $file .= $theme['prefix'];
-    }
-    // Append css dir and filename so we end up with stream/streamname/css/filename.css
-    $file .= 'css/' . $cssFileName;
-    $file = $res->filterMinify($theme['ext'], $file);
-
-    // Now get the full path for the css file
-    $filePath = $res->getPath($theme['ext'], $file);
-    if (is_file($filePath)) {
-      // File exists and is a file? Return it!
-      return file_get_contents($filePath) ?? '';
-    }
-    return '';
+    $e->content = $render['content'] ?? '';
   }
 
 }
diff --git a/ext/riverlea/README.md b/ext/riverlea/README.md
index d109bf61eabb..0756f07b95b3 100755
--- a/ext/riverlea/README.md
+++ b/ext/riverlea/README.md
@@ -1,15 +1,16 @@
 # RiverLea Theme Framework
 
-This Framework separates CiviCRM's visual/UI CSS from structural CSS, using CSS variables. Installing it provides you with four subthemes or 'Streams' which are entirely created with CSS variables (other than Thames, which uses a little bit of CSS as well):
+This Framework separates CiviCRM's visual/UI CSS from structural CSS, using CSS variables. Installing it provides you with four new Riverlea Themes or "Streams" which are almost entirely created with CSS variables:
  - Minetta, named after the river that runs under Greenwich, NYC. It is based on Civi's default 'Greenwich' theme.
  - Walbrook, named after the river that runs under Shoreditch, London. It is based on Shoreditch/TheIsland theme.
  - Hackney, named after the river that runs under Finsbury Park, based on Finsbury Park theme.
  - Thames, named after the river that runs close to Artful Robot HQ, based on their Aah theme.
- You can chose between these subthemes via Display Settings, where you can also set dark-mode preferences.
 
- The extension is licensed under [AGPL-3.0](LICENSE.txt).
+When you enable CiviCRM, you will see these themes in your usual CiviCRM theme options on the Display Settings page.
 
- ## Use in Front-End CiviCRM
+The extension is licensed under [AGPL-3.0](LICENSE.txt).
+
+## Use in Front-End CiviCRM
 
 **USE WITH CAUTION AND TESTING** While RiverLea has been widely tested in the backend of CiviCRM, be very careful to use in front-end. Given the wide number of themes and scenarios for front-end pages, for existing sites we recommend only applying it to an existing web front-end after comprehensive testing on a dev site.
 
@@ -42,40 +43,23 @@ Please ignore previous numbering patterns.
 
 ## Installation
 
-### With (CLI, Zip)
-
-Sysadmins and developers may download the `.zip` file for this extension and
-install it with the command-line tool [cv](https://github.com/civicrm/cv).
-
-```bash
-cd <extension-dir>
-wget https://lab.civicrm.org/extensions/riverlea/-/archive/main/riverlea-main.zip
-unzip riverlea-main.zip
-```
-
-### With (CLI, Git)
-
-Sysadmins and developers may clone the [Git](https://en.wikipedia.org/wiki/Git) repo for this extension and
-install it with the command-line tool [cv](https://github.com/civicrm/cv).
-
-```bash
-git clone https://lab.civicrm.org/extensions/riverlea.git
-cv en riverlea
-```
+This extension is bundled with CiviCRM core from version 5.82 onwards. You can install it from the Manage Extensions page.
 
 ### After installation
 
-After installing the extension, go to Nav menu > Administer > Customize Data and Screens > Display Preferences, and select which subtheme/stream you want.
+After installing the extension, go to Nav menu > Administer > Customize Data and Screens > Display Preferences, and select the stream you want.
+
+You can also set your Dark Mode preference on this screen: either always use Light Mode, always use Dark Mode, or let the user's browser/OS decide.
 
 ## Extension Structure
 
-### Core variables
-A list of all base variables used on all streams is at `core/css/_variables.css`.
+### Core directory - `core`
+
+The majority of the Riverlea extension is a layer of core CSS, which styles CiviCRM markup based on the value
+of a number of CSS variables.
 
-### Stream/subtheme directories
-Each ‘stream’ or subtheme directory must contain a further directory `css` with a `_variables.css`file and a `_dark.css` if darkmode is supported. Variables in this `_variables.css` file will overrule any variables in the core list above. The subtheme can also include fonts, images and other CSS files, which can be loaded from the `_variables.css` file as an import.
+The list of all CSS variables with their default values can be found at `core/css/_variables.css`.
 
-### Core directory
 Contains CSS files in:
 - In the **core/css** directory are theme files marked with an underscore:
   - core/css/_base.css – resets, basic type, colours, links, positioning
@@ -89,9 +73,24 @@ Contains CSS files in:
 - other files here without underscore (`admin.css`, `api4-explorer.css`, `contactSummary.css` etc) overrides civicrm's CSS core directory with files of the same name that are called by templates and only load in certain parts of Civi. E.g. `dashboard.css` loads on the CiviCRM main dashboard, and no-where else.
 - three directories: `org.civicrm.afform-ang` for Afform output, `org.civicrm.afform_admin-ang` for FormBuilder and `org.civicrm.search_kit-css` for SearchKit replace css files in core Civi extensions.
 
+### Stream directories - `streams/[stream_name]`
+Each stream in the extension has a subdirectory under `streams` which primarily contains CSS files for the stream: a `_variables.css`file and a `_dark.css` if darkmode is supported. Variables in this `_variables.css` file will overrule any variables in the core list above.
+
+A stream could also include fonts, images and other CSS files, which can be loaded from the `_variables.css` file as an import.
+
+Each stream also has a Managed Record file which is used to "install" the stream. These are found in the `managed` directory.
+
 ## Customising
 
-Adding a customiser is on the roadmap, with a working prototype, but until its issues are resolved customising can be done through one of the three following methods:
+Riverlea is designed to allow users to customise their UI by tweaking variables or creating new streams.
+
+At this stage, small changes are still being made to the variable structure, so any customisations you make may require revisiting in a future upgrade.
+
+The `core/css/_variables.css` file will give you idea of variables which can be altered.
+
+A [Customiser tool](https://github.com/civicrm/civicrm-core/pull/32344) is also being developed to create and edit Streams more easily through the UI.
+
+Use of the [ThemeTest extension](https://lab.civicrm.org/extensions/themetest) is recommended to more quickly identify which CSS variables match which UI element, and test multiple variations for each.
 
 ### 1. Add CSS variables to your parent theme
 
@@ -101,55 +100,51 @@ For instance, to give all contribution page buttons rounded corners, you could a
 --crm-btn-radius: 2rem;
 ```
 
-Exploring the _variables.css file will give you idea of how much can be overwritten.
-
-### 2. Create a subtheme 'stream'
+### 2. Add a custom CSS snippet in an extension
 
-1. Inside the `/streams/` directory is an example stream called `empty`. Duplicate this and rename it the name of your stream.
-2. In riverlea.php add a theme array to the function `riverlea_civicrm_themes(&$themes)`.
-3. Edit `/streams/[streamname]/css/_variables.css` with your custom css variables. You can link to other CSS files, fonts or images in this file - inside the stream.
-
-E.g. to add a stream called "Vimur", you would name the directory 'vimur', and add the following:
+You can override variables by listening to `hook_civicrm_alterBundle`:
 
 ```
- function riverlea_civicrm_themes(&$themes) {
-  $themes['vimur'] = array(
-    'ext' => 'riverlea',
-    'title' => 'Riverlea: Vimur',
-    'prefix' => 'streams/vimur/',
-  );
-  $themes['minetta'] = array(
-    'ext' => 'riverlea',
-    'title' => 'Riverlea: Minetta (~Greenwich)',
-    'prefix' => 'streams/minetta/',
-  );
-  …
- }
+function my_ext_civicrm_alterBundle(CRM_Core_Resources_Bundle $bundle) {
+  if ($bundle->name === 'coreResources') {
+    $riverleaOverrides = <<<CSS
+      :root {
+        --crm-c-primary: green;
+      }
+    CSS;
+    # weight should override river.css
+    $bundle->addStyle($riverleaOverrides, ['weight' => 200]);
+  }
+}
 ```
 
-Use of the [ThemeTest extension](https://lab.civicrm.org/extensions/themetest) is recommended to more quickly identify which CSS variables match which UI element, and test multiple variations for each.
+### 3. Create a new stream (preview)
 
-IMPORTANT NOTE: Every time you upgrade RiverLea you will need to add your Stream again. This is obviously less than ideal, so for produciton you may prefer option 3:
+New streams can be created using CiviCRM's Managed Entity system. (This is the same mechanism as can be used for packaging SearchKits, CustomFields, ContactTypes etc).
 
-### 3. Create a subtheme extension
+The Customiser will provide tools to automate some of this process.
 
-NB: this approach has had very limited testing
+0. If not adding to an existing extension, [follow the docs to create one](https://docs.civicrm.org/dev/en/latest/extensions/civix/#generate-module).
 
-1. Create a theme extension using Civix, following the [instructions in the CiviCRM Developer Guide](https://docs.civicrm.org/dev/en/latest/framework/theme/).
-2. Create a subtheme of RiverLea using the instructions in **2. Create a subtheme 'stream'** above.
-3. Copy the subtheme into the root of your new theme extenion.
-4. Edit its main php file, enable both extensions and select your stream.
-E.g. for a stream called 'styx', with a theme extension called 'ocean', then in ocean.php you would write:
+1. Enable the `mgd-php` mixin in your extensions `info.xml`
 
 ```
-function ocean_civicrm_themes(&$themes) {
-  $themes['styx'] = array(
-    'ext' => 'ocean',
-    'title' => 'River Styx',
-    'prefix' => 'styx/',
-    'search_order' => array('_riverlea_core_', 'styx',  '_fallback_'),
-  );
-}
+  <mixins>
+    <mixin>menu-xml@1.0.0</mixin>
+    <mixin>mgd-php@1.0.0</mixin>
+    ...
+  </mixins>
+```
+
+2. Copy the template `*.mgd.php` from the `docs` folder of this extension into your extension's `managed` folder (create the managed folder if it doesn't exist). Remove the `.template` part so the file extension is `*.mgd.php`.
+
+3. Update the `use CRM_riverlea_ExtensionUtil` line for the equivalent from your extension.
+
+4. You can add variable declarations directly to the `vars` and `vars_dark` keys in the `*.mgd.php` file.
+
+5. Or you can create `stream/main.css` and `stream/dark.css` files in your extension, and add your CSS to them. It's best to use variable declarations as much as possible to maintain compatibility with future versions
+of CiviCRM.
+
 
 ## Troubleshooting
 - Unless you really need it (e.g. applying an urgent fix, or running a test), delete the custom/ext version of RiverLea, once you are on CiviCRM 5.80 or later.
diff --git a/ext/riverlea/docs/RiverleaStream_MyStream.mgd.php.template b/ext/riverlea/docs/RiverleaStream_MyStream.mgd.php.template
new file mode 100644
index 000000000000..d58db63425d2
--- /dev/null
+++ b/ext/riverlea/docs/RiverleaStream_MyStream.mgd.php.template
@@ -0,0 +1,45 @@
+<?php
+
+// Replace this with your extensions extensionUtil class (if unsure look in your extension's root my_extension.php file)
+// use CRM_riverlea_ExtensionUtil as E;
+
+// return [
+//   [
+//     'name' => 'RiverleaStream_MyStream',
+//     'entity' => 'RiverleaStream',
+//     'update' => 'always',
+//     'cleanup' => 'always',
+//     'params' => [
+//       'version' => 4,
+//       'values' => [
+//
+//          # Describe your stream:
+//
+//         'name' => 'my_unique_stream_name',
+//         'label' => E::ts('My Stream'),
+//         'description' => 'Describe your stream...',
+//
+//          # Set stream variables directly here:
+//
+//         'vars' => [
+//            '--crm-c-primary' => 'purple',
+//          ],
+//         'vars_dark' => [
+//            # Extra variables for dark mode
+//            '--crm-c-primary' => 'blue',
+//          ],
+//
+//          # If you want to add static css files to your stream, then uncomment
+//          # the following four lines, and create your files at
+//          #  - 'your_extension/stream/main.css'
+//          #  - 'your_extension/stream/dark.css'
+//
+//         'extension' => 'my_extension_name', # or E::SHORT_NAME if you update the extensionutils above
+//         'file_prefix' => 'stream/',
+//         'css_file' => 'main.css',
+//         'css_file_dark' => 'dark.css',
+//       ],
+//       'match' => ['name'],
+//     ],
+//   ],
+// ];
diff --git a/ext/riverlea/info.xml b/ext/riverlea/info.xml
index f05fb3112769..8ad7ab5dd3d6 100755
--- a/ext/riverlea/info.xml
+++ b/ext/riverlea/info.xml
@@ -20,6 +20,7 @@
   <comments>A cross-CMS CiviCRM theme framework.</comments>
   <classloader>
     <psr4 prefix="Civi\" path="Civi"/>
+    <psr0 prefix="CRM_" path="."/>
   </classloader>
   <civix>
     <namespace>CRM/Riverlea</namespace>
@@ -31,5 +32,7 @@
     <mixin>setting-admin@1.0.1</mixin>
     <mixin>mgd-php@1.0.0</mixin>
     <mixin>scan-classes@1.0.0</mixin>
+    <mixin>entity-types-php@2.0.0</mixin>
   </mixins>
+  <upgrader>CiviMix\Schema\Riverlea\AutomaticUpgrader</upgrader>
 </extension>
diff --git a/ext/riverlea/managed/RiverleaStream_HackneyBrook.mgd.php b/ext/riverlea/managed/RiverleaStream_HackneyBrook.mgd.php
new file mode 100644
index 000000000000..ebfb99f2eb53
--- /dev/null
+++ b/ext/riverlea/managed/RiverleaStream_HackneyBrook.mgd.php
@@ -0,0 +1,28 @@
+<?php
+
+use CRM_riverlea_ExtensionUtil as E;
+
+return [
+  [
+    'name' => 'RiverleaStream_HackneyBrook',
+    'entity' => 'RiverleaStream',
+    'update' => 'always',
+    'cleanup' => 'always',
+    'params' => [
+      'version' => 4,
+      'values' => [
+        'name' => 'hackneybrook',
+        'label' => E::ts('Hackney Brook'),
+        'description' => 'named after the Hackney Brook, a tributary of the River Lea that ran through Finsbury Park',
+        'is_reserved' => TRUE,
+        'extension' => E::SHORT_NAME,
+        'file_prefix' => 'streams/hackneybrook/css/',
+        'css_file' => '_variables.css',
+        'css_file_dark' => '_dark.css',
+        'vars' => [],
+        'vars_dark' => [],
+      ],
+      'match' => ['name'],
+    ],
+  ],
+];
diff --git a/ext/riverlea/managed/RiverleaStream_Minetta.mgd.php b/ext/riverlea/managed/RiverleaStream_Minetta.mgd.php
new file mode 100644
index 000000000000..f898a559dde1
--- /dev/null
+++ b/ext/riverlea/managed/RiverleaStream_Minetta.mgd.php
@@ -0,0 +1,29 @@
+<?php
+
+use CRM_riverlea_ExtensionUtil as E;
+
+return [
+  [
+    'name' => 'RiverleaStream_Minetta',
+    'entity' => 'RiverleaStream',
+    'update' => 'always',
+    'cleanup' => 'always',
+    'params' => [
+      'version' => 4,
+      'values' => [
+        'name' => 'minetta',
+        'description' => 'Generic CiviCRM UI, somewhat familiar to users of CiviCRM since 2014. Named after Minetta Creek, which runs under Greenwich, New York',
+        'label' => E::ts('Minetta'),
+        'is_reserved' => TRUE,
+        'extension' => E::SHORT_NAME,
+        'file_prefix' => 'streams/minetta/css/',
+        'css_file' => '_variables.css',
+        'css_file_dark' => '_dark.css',
+        'vars' => [
+          '--crm-version' => "'Minetta, v' var(--crm-release)",
+        ],
+      ],
+      'match' => ['name'],
+    ],
+  ],
+];
diff --git a/ext/riverlea/managed/RiverleaStream_Thames.mgd.php b/ext/riverlea/managed/RiverleaStream_Thames.mgd.php
new file mode 100644
index 000000000000..403a6b2d41bc
--- /dev/null
+++ b/ext/riverlea/managed/RiverleaStream_Thames.mgd.php
@@ -0,0 +1,27 @@
+<?php
+
+use CRM_riverlea_ExtensionUtil as E;
+
+return [
+  [
+    'name' => 'RiverleaStream_Thames',
+    'entity' => 'RiverleaStream',
+    'update' => 'always',
+    'cleanup' => 'always',
+    'params' => [
+      'version' => 4,
+      'values' => [
+        'name' => 'thames',
+        'description' => 'Aaaaah',
+        'label' => E::ts('Thames'),
+        'is_reserved' => TRUE,
+        'extension' => E::SHORT_NAME,
+        'file_prefix' => 'streams/thames/css/',
+        'css_file' => '_variables.css',
+        'css_file_dark' => '_dark.css',
+        'vars' => [],
+      ],
+      'match' => ['name'],
+    ],
+  ],
+];
diff --git a/ext/riverlea/managed/RiverleaStream_Walbrook.mgd.php b/ext/riverlea/managed/RiverleaStream_Walbrook.mgd.php
new file mode 100644
index 000000000000..67027d3b8c13
--- /dev/null
+++ b/ext/riverlea/managed/RiverleaStream_Walbrook.mgd.php
@@ -0,0 +1,27 @@
+<?php
+
+use CRM_riverlea_ExtensionUtil as E;
+
+return [
+  [
+    'name' => 'RiverleaStream_Walbrook',
+    'entity' => 'RiverleaStream',
+    'update' => 'always',
+    'cleanup' => 'always',
+    'params' => [
+      'version' => 4,
+      'values' => [
+        'name' => 'walbrook',
+        'description' => 'Based on Shoreditch theme. Named after after River Walbrook, which runs under Shoreditch, London',
+        'label' => E::ts('Walbrook'),
+        'is_reserved' => TRUE,
+        'extension' => E::SHORT_NAME,
+        'file_prefix' => 'streams/walbrook/css/',
+        'css_file' => '_variables.css',
+        'css_file_dark' => '_dark.css',
+        'vars' => [],
+      ],
+      'match' => ['name'],
+    ],
+  ],
+];
diff --git a/ext/riverlea/riverlea.civix.php b/ext/riverlea/riverlea.civix.php
index 01dd89c91247..8fe8da11c003 100755
--- a/ext/riverlea/riverlea.civix.php
+++ b/ext/riverlea/riverlea.civix.php
@@ -75,10 +75,45 @@ public static function findClass($suffix) {
     return self::CLASS_PREFIX . '_' . str_replace('\\', '_', $suffix);
   }
 
+  /**
+   * @return \CiviMix\Schema\SchemaHelperInterface
+   */
+  public static function schema() {
+    if (!isset($GLOBALS['CiviMixSchema'])) {
+      pathload()->loadPackage('civimix-schema@5', TRUE);
+    }
+    return $GLOBALS['CiviMixSchema']->getHelper(static::LONG_NAME);
+  }
+
 }
 
 use CRM_riverlea_ExtensionUtil as E;
 
+spl_autoload_register('_riverlea_civix_class_loader', TRUE, TRUE);
+
+function _riverlea_civix_class_loader($class) {
+  if ($class === 'CRM_riverlea_DAO_Base') {
+    if (version_compare(CRM_Utils_System::version(), '5.74.beta', '>=')) {
+      class_alias('CRM_Core_DAO_Base', 'CRM_riverlea_DAO_Base');
+      // ^^ Materialize concrete names -- encourage IDE's to pick up on this association.
+    }
+    else {
+      $realClass = 'CiviMix\\Schema\\Riverlea\\DAO';
+      class_alias($realClass, $class);
+      // ^^ Abstract names -- discourage IDE's from picking up on this association.
+    }
+    return;
+  }
+
+  // This allows us to tap-in to the installation process (without incurring real file-reads on typical requests).
+  if (strpos($class, 'CiviMix\\Schema\\Riverlea\\') === 0) {
+    // civimix-schema@5 is designed for backported use in download/activation workflows,
+    // where new revisions may become dynamically available.
+    pathload()->loadPackage('civimix-schema@5', TRUE);
+    CiviMix\Schema\loadClass($class);
+  }
+}
+
 /**
  * (Delegated) Implements hook_civicrm_config().
  *
diff --git a/ext/riverlea/riverlea.php b/ext/riverlea/riverlea.php
index 555aa4a7a9df..2ce580b33993 100755
--- a/ext/riverlea/riverlea.php
+++ b/ext/riverlea/riverlea.php
@@ -4,39 +4,55 @@
 use CRM_riverlea_ExtensionUtil as E;
 
 /**
- * Supports multiple theme variations/streams.
+ * Supply available streams to the theme hook
+ *
+ * Note: if this looks labour intensive, don't worry - the output
+ * is cached in \Civi\Core\Themes
  */
 function riverlea_civicrm_themes(&$themes) {
-  $themes['minetta'] = array(
-    'ext' => 'riverlea',
-    'title' => 'Minetta (RiverLea ~Greenwich)',
-    'prefix' => 'streams/minetta/',
-    'search_order' => array('minetta', '_riverlea_core_', '_fallback_'),
-  );
-  $themes['walbrook'] = array(
-    'ext' => 'riverlea',
-    'title' => 'Walbrook (RiverLea ~Shoreditch/Island)',
-    'prefix' => 'streams/walbrook/',
-    'search_order' => array('walbrook', '_riverlea_core_', '_fallback_'),
-  );
-  $themes['hackneybrook'] = array(
-    'ext' => 'riverlea',
-    'title' => 'Hackney Brook (RiverLea ~Finsbury Park)',
-    'prefix' => 'streams/hackneybrook/',
-    'search_order' => array('hackneybrook', '_riverlea_core_', '_fallback_'),
-  );
-  $themes['thames'] = array(
-    'ext' => 'riverlea',
-    'title' => 'Thames (RiverLea ~Aah)',
-    'prefix' => 'streams/thames/',
-    'search_order' => array('thames', '_riverlea_core_', '_fallback_'),
-  );
-  $themes['_riverlea_core_'] = array(
+  // always add (hidden) Riverlea base theme
+  $themes['_riverlea_core_'] = [
     'ext' => 'riverlea',
     'title' => 'Riverlea: base theme',
     'prefix' => 'core/',
-    'search_order' => array('_riverlea_core_', '_fallback_'),
-  );
+    'search_order' => ['_riverlea_core_', '_fallback_'],
+  ];
+
+  try {
+    $streams = \Civi::service('riverlea.dynamic_css')->getAvailableStreamMeta();
+  }
+  catch (\CRM_Core_Exception $e) {
+    // dont crash the whole hook if Riverlea is broken
+    \CRM_Core_Session::setStatus('Error occured making Riverlea streams available to the theme engine: ' . $e->getMessage());
+    return;
+  }
+
+  $streamsById = array_column($streams, NULL, 'id');
+
+  foreach ($streams as $name => $stream) {
+    $themeMeta = [
+      'title' => $stream['label'],
+      'search_order' => [],
+    ];
+
+    $extension = $stream['extension'];
+
+    // we only add the stream itself to the search order if
+    // it has an extension (which indicates it may have its own
+    // file overrides)
+    if ($extension) {
+      $themeMeta['search_order'][] = $name;
+
+      // used to resolve files from this stream
+      $themeMeta['ext'] = $extension;
+      $themeMeta['prefix'] = $stream['file_prefix'] ?? '';
+    }
+
+    $themeMeta['search_order'][] = '_riverlea_core_';
+    $themeMeta['search_order'][] = '_fallback_';
+
+    $themes[$name] = $themeMeta;
+  }
 }
 
 /**
@@ -77,7 +93,7 @@ function riverlea_civicrm_alterBundle(CRM_Core_Resources_Bundle $bundle) {
     // get DynamicCss asset
     $bundle->addStyleUrl(\Civi::service('asset_builder')->getUrl(
       \Civi\Riverlea\DynamicCss::CSS_FILE,
-      \Civi\Riverlea\DynamicCss::getCssParams()
+      \Civi::service('riverlea.dynamic_css')->getCssParams()
     ));
   }
 }
diff --git a/ext/riverlea/schema/RiverleaStream.entityType.php b/ext/riverlea/schema/RiverleaStream.entityType.php
new file mode 100644
index 000000000000..12b5c2fe2489
--- /dev/null
+++ b/ext/riverlea/schema/RiverleaStream.entityType.php
@@ -0,0 +1,137 @@
+<?php
+use CRM_riverlea_ExtensionUtil as E;
+
+return [
+  'name' => 'RiverleaStream',
+  'table' => 'civicrm_riverlea_stream',
+  'class' => 'CRM_riverlea_DAO_RiverleaStream',
+  'getInfo' => fn() => [
+    'title' => E::ts('RiverleaStream'),
+    'title_plural' => E::ts('RiverleaStreams'),
+    'description' => E::ts('Streams are configurable themes in the Riverlea Theme Framework'),
+    'log' => TRUE,
+  ],
+  'getIndices' => fn() => [
+    'index_stream_name' => [
+      'fields' => [
+        'name' => TRUE,
+      ],
+      'unique' => TRUE,
+      'add' => '6.1',
+    ],
+  ],
+  'getPaths' => fn() => [
+    // 'add' => 'civicrm/admin/riverlea/stream/create',
+    // 'update' => 'civicrm/admin/riverlea/stream/update#?RiverleaStream=[id]',
+    // 'delete' => 'civicrm/contact/view/delete?reset=1&delete=1&cid=[id]',
+  ],
+  'getFields' => fn() => [
+    'id' => [
+      'title' => E::ts('ID'),
+      'sql_type' => 'int unsigned',
+      'input_type' => 'Number',
+      'required' => TRUE,
+      'description' => E::ts('Unique RiverleaStream ID'),
+      'primary_key' => TRUE,
+      'auto_increment' => TRUE,
+    ],
+    'name' => [
+      'title' => ts('Machine-Name'),
+      'sql_type' => 'varchar(255)',
+      'input_type' => 'Text',
+      'description' => ts('Machine-name for this stream.'),
+    ],
+    'label' => [
+      'title' => ts('Label'),
+      'sql_type' => 'varchar(512)',
+      'input_type' => 'Text',
+      'required' => TRUE,
+      'description' => ts('User-facing name for this stream'),
+    ],
+    'description' => [
+      'title' => E::ts('Description'),
+      'sql_type' => 'text',
+      'input_type' => 'TextArea',
+      'description' => E::ts('Description of this stream'),
+      'default' => NULL,
+    ],
+    'is_reserved' => [
+      'title' => E::ts('Is Reserved?'),
+      'description' => E::ts('Reserved streams are not editable through the UI'),
+      'sql_type' => 'boolean',
+      'input_type' => 'CheckBox',
+      'required' => TRUE,
+      'default' => FALSE,
+    ],
+    'extension' => [
+      'title' => ts('Extension'),
+      'sql_type' => 'varchar(255)',
+      'input_type' => 'Select',
+      'description' => ts('Extension that provides this stream.'),
+      'default' => NULL,
+      // @todo why not work?
+      // 'entity_reference' => [
+      //   'entity' => 'Extension',
+      //   'key' => 'file',
+      //   'on_delete' => 'CASCADE',
+      // ],
+    ],
+    'file_prefix' => [
+      'title' => ts('Extension File Prefix'),
+      'sql_type' => 'varchar(255)',
+      'input_type' => 'Text',
+      'description' => ts('File prefix to stream files within extension'),
+      'default' => NULL,
+    ],
+    'css_file' => [
+      'title' => ts('CSS File'),
+      'description' => ts('A file containing stream css - path should be relative to the extension and file_prefix'),
+      'sql_type' => 'varchar(512)',
+      'input_type' => 'Text',
+      'default' => NULL,
+    ],
+    'css_file_dark' => [
+      'title' => ts('Dark-mode CSS File'),
+      'description' => ts('A file containing stream css for darkmode - path should be relative to the extension and file_prefix'),
+      'sql_type' => 'varchar(512)',
+      'input_type' => 'Text',
+      'default' => NULL,
+    ],
+    'vars' => [
+      'title' => E::ts('Variable Settings'),
+      'sql_type' => 'text',
+      'description' => E::ts('Variable declarations for this stream'),
+      'default' => NULL,
+      'serialize' => CRM_Core_DAO::SERIALIZE_JSON,
+    ],
+    'vars_dark' => [
+      'title' => E::ts('Dark-mode Variable Settings'),
+      'sql_type' => 'text',
+      'description' => E::ts('Variable declaration overrides for the dark mode of this stream'),
+      'default' => NULL,
+      'serialize' => CRM_Core_DAO::SERIALIZE_JSON,
+    ],
+    'custom_css' => [
+      'title' => E::ts('Custom CSS'),
+      'sql_type' => 'text',
+      'input_type' => 'TextArea',
+      'description' => E::ts('Custom css for this stream'),
+      'default' => NULL,
+    ],
+    'custom_css_dark' => [
+      'title' => E::ts('Dark-mode Custom CSS'),
+      'sql_type' => 'text',
+      'input_type' => 'TextArea',
+      'description' => E::ts('Custom css for the darkmode of this stream'),
+      'default' => NULL,
+    ],
+    'modified_date' => [
+      'title' => ts('Modified Date'),
+      'sql_type' => 'timestamp',
+      'input_type' => 'Select Date',
+      'readonly' => TRUE,
+      'description' => ts('When the stream was last modified - helps with cache busting.'),
+      'default' => 'CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP',
+    ],
+  ],
+];
diff --git a/ext/riverlea/schema/upgrader/1000-RiverleaStream.entityType.php b/ext/riverlea/schema/upgrader/1000-RiverleaStream.entityType.php
new file mode 100644
index 000000000000..12b5c2fe2489
--- /dev/null
+++ b/ext/riverlea/schema/upgrader/1000-RiverleaStream.entityType.php
@@ -0,0 +1,137 @@
+<?php
+use CRM_riverlea_ExtensionUtil as E;
+
+return [
+  'name' => 'RiverleaStream',
+  'table' => 'civicrm_riverlea_stream',
+  'class' => 'CRM_riverlea_DAO_RiverleaStream',
+  'getInfo' => fn() => [
+    'title' => E::ts('RiverleaStream'),
+    'title_plural' => E::ts('RiverleaStreams'),
+    'description' => E::ts('Streams are configurable themes in the Riverlea Theme Framework'),
+    'log' => TRUE,
+  ],
+  'getIndices' => fn() => [
+    'index_stream_name' => [
+      'fields' => [
+        'name' => TRUE,
+      ],
+      'unique' => TRUE,
+      'add' => '6.1',
+    ],
+  ],
+  'getPaths' => fn() => [
+    // 'add' => 'civicrm/admin/riverlea/stream/create',
+    // 'update' => 'civicrm/admin/riverlea/stream/update#?RiverleaStream=[id]',
+    // 'delete' => 'civicrm/contact/view/delete?reset=1&delete=1&cid=[id]',
+  ],
+  'getFields' => fn() => [
+    'id' => [
+      'title' => E::ts('ID'),
+      'sql_type' => 'int unsigned',
+      'input_type' => 'Number',
+      'required' => TRUE,
+      'description' => E::ts('Unique RiverleaStream ID'),
+      'primary_key' => TRUE,
+      'auto_increment' => TRUE,
+    ],
+    'name' => [
+      'title' => ts('Machine-Name'),
+      'sql_type' => 'varchar(255)',
+      'input_type' => 'Text',
+      'description' => ts('Machine-name for this stream.'),
+    ],
+    'label' => [
+      'title' => ts('Label'),
+      'sql_type' => 'varchar(512)',
+      'input_type' => 'Text',
+      'required' => TRUE,
+      'description' => ts('User-facing name for this stream'),
+    ],
+    'description' => [
+      'title' => E::ts('Description'),
+      'sql_type' => 'text',
+      'input_type' => 'TextArea',
+      'description' => E::ts('Description of this stream'),
+      'default' => NULL,
+    ],
+    'is_reserved' => [
+      'title' => E::ts('Is Reserved?'),
+      'description' => E::ts('Reserved streams are not editable through the UI'),
+      'sql_type' => 'boolean',
+      'input_type' => 'CheckBox',
+      'required' => TRUE,
+      'default' => FALSE,
+    ],
+    'extension' => [
+      'title' => ts('Extension'),
+      'sql_type' => 'varchar(255)',
+      'input_type' => 'Select',
+      'description' => ts('Extension that provides this stream.'),
+      'default' => NULL,
+      // @todo why not work?
+      // 'entity_reference' => [
+      //   'entity' => 'Extension',
+      //   'key' => 'file',
+      //   'on_delete' => 'CASCADE',
+      // ],
+    ],
+    'file_prefix' => [
+      'title' => ts('Extension File Prefix'),
+      'sql_type' => 'varchar(255)',
+      'input_type' => 'Text',
+      'description' => ts('File prefix to stream files within extension'),
+      'default' => NULL,
+    ],
+    'css_file' => [
+      'title' => ts('CSS File'),
+      'description' => ts('A file containing stream css - path should be relative to the extension and file_prefix'),
+      'sql_type' => 'varchar(512)',
+      'input_type' => 'Text',
+      'default' => NULL,
+    ],
+    'css_file_dark' => [
+      'title' => ts('Dark-mode CSS File'),
+      'description' => ts('A file containing stream css for darkmode - path should be relative to the extension and file_prefix'),
+      'sql_type' => 'varchar(512)',
+      'input_type' => 'Text',
+      'default' => NULL,
+    ],
+    'vars' => [
+      'title' => E::ts('Variable Settings'),
+      'sql_type' => 'text',
+      'description' => E::ts('Variable declarations for this stream'),
+      'default' => NULL,
+      'serialize' => CRM_Core_DAO::SERIALIZE_JSON,
+    ],
+    'vars_dark' => [
+      'title' => E::ts('Dark-mode Variable Settings'),
+      'sql_type' => 'text',
+      'description' => E::ts('Variable declaration overrides for the dark mode of this stream'),
+      'default' => NULL,
+      'serialize' => CRM_Core_DAO::SERIALIZE_JSON,
+    ],
+    'custom_css' => [
+      'title' => E::ts('Custom CSS'),
+      'sql_type' => 'text',
+      'input_type' => 'TextArea',
+      'description' => E::ts('Custom css for this stream'),
+      'default' => NULL,
+    ],
+    'custom_css_dark' => [
+      'title' => E::ts('Dark-mode Custom CSS'),
+      'sql_type' => 'text',
+      'input_type' => 'TextArea',
+      'description' => E::ts('Custom css for the darkmode of this stream'),
+      'default' => NULL,
+    ],
+    'modified_date' => [
+      'title' => ts('Modified Date'),
+      'sql_type' => 'timestamp',
+      'input_type' => 'Select Date',
+      'readonly' => TRUE,
+      'description' => ts('When the stream was last modified - helps with cache busting.'),
+      'default' => 'CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP',
+    ],
+  ],
+];
diff --git a/ext/riverlea/streams/minetta/css/_variables.css b/ext/riverlea/streams/minetta/css/_variables.css
index 64f8073ce95c..bceec0776c32 100644
--- a/ext/riverlea/streams/minetta/css/_variables.css
+++ b/ext/riverlea/streams/minetta/css/_variables.css
@@ -4,9 +4,6 @@
     Riverlea version: 1.3.8;
 */
 
-:root {
-  --crm-version: 'Minetta, v' var(--crm-release);
-}
 .contactCardRight:has(#crm-contact-thumbnail) .float-left {
   width: calc(100% - var(--crm-flex-gap) - var(--crm-dash-image-size));
 }