Introduce a Module API to get application settings. (#34278)

* Add a module API to get application settings.

* fix test

packages/module-api/src/api/index.ts

@@ -24,6 +24,7 @@ import { type WidgetLifecycleApi } from "./widget-lifecycle.ts";
 import { type WidgetApi } from "./widget.ts";
 import { type CustomisationsApi } from "./customisations.ts";
 import { type ComposerApi } from "./composer.ts";
+import { type SettingsApi } from "./settings.ts";
 
 /**
  * Module interface for modules to implement.
@@ -166,6 +167,12 @@ export interface Api
      */
     readonly composer: ComposerApi;
 
+    /**
+     * Allows modules to read application settings.
+     * @alpha Subject to change.
+     */
+    readonly settings: SettingsApi;
+
     /**
      * Create a ReactDOM root for rendering React components.
      * Exposed to allow modules to avoid needing to bundle their own ReactDOM.

packages/module-api/src/api/settings.ts

@@ -0,0 +1,22 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+/**
+ * API for reading application settings.
+ * @alpha Subject to change.
+ */
+export interface SettingsApi {
+    /**
+     * Gets the value of a setting, computed across all applicable levels
+     * (device, room, account, config, default, etc.).
+     * @param settingName - The name of the setting to read.
+     * @param roomId - Room ID to read a room-scoped value for, or null/undefined for a
+     * non-room-scoped value.
+     * @param excludeDefault - If true, do not fall back to the setting's default value.
+     */
+    getValue<T = any>(settingName: string, roomId?: string | null, excludeDefault?: boolean): T | undefined;
+}