diff --git a/apps/desktop/package.json b/apps/desktop/package.json
index 55bd6f4f56..37ff6800eb 100644
--- a/apps/desktop/package.json
+++ b/apps/desktop/package.json
@@ -102,6 +102,7 @@
         "mkdirp": "^3.0.0",
         "pacote": "^22.0.0",
         "rimraf": "^6.0.0",
+        "shared-types": "workspace:*",
         "tar": "^7.5.8",
         "typescript": "catalog:",
         "vitest": "catalog:"
diff --git a/apps/desktop/src/build-config.ts b/apps/desktop/src/build-config.ts
index b4d52865a3..5533e0b774 100644
--- a/apps/desktop/src/build-config.ts
+++ b/apps/desktop/src/build-config.ts
@@ -7,8 +7,9 @@ Please see LICENSE files in the repository root for full details.
 
 import path, { dirname } from "node:path";
 import { fileURLToPath } from "node:url";
+import { type JsonObject } from "shared-types";
 
-import { type JsonObject, loadJsonFile } from "./utils.js";
+import { loadJsonFile } from "./utils.js";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
diff --git a/apps/desktop/src/config.ts b/apps/desktop/src/config.ts
index 5f25066b63..09d3446300 100644
--- a/apps/desktop/src/config.ts
+++ b/apps/desktop/src/config.ts
@@ -7,27 +7,12 @@ Please see LICENSE files in the repository root for full details.
 
 import { app, dialog } from "electron";
 import path from "node:path";
+import { type ResolveDefaults, type DesktopConfigJson, type JsonDocument } from "shared-types";
 
 import { getAsarPath } from "./asar.js";
-import { type Json, loadJsonFile } from "./utils.js";
+import { loadJsonFile } from "./utils.js";
 
-export interface ConfigOptions {
-    brand: string;
-    help_url: string;
-    web_base_url: string;
-    modules?: string[];
-    sentry?: {
-        dsn?: string;
-        environment?: string;
-    };
-    update_base_url?: string;
-
-    // homeserver props
-    default_is_url?: string;
-    default_hs_url?: string;
-    default_server_name?: string;
-    default_server_config?: object;
-}
+export type ConfigOptions = ResolveDefaults<DesktopConfigJson, typeof DEFAULTS>;
 
 const ConfigFilename = "config.json";
 
@@ -35,7 +20,7 @@ let config: ConfigOptions;
 
 const homeserverProps = ["default_is_url", "default_hs_url", "default_server_name", "default_server_config"] as const;
 
-function loadLocalConfigFile(location: string | undefined): Json {
+function loadLocalConfigFile(location: string | undefined): JsonDocument {
     if (location) {
         console.log("Loading local config: " + location);
         return loadJsonFile(location);
@@ -50,9 +35,9 @@ const DEFAULTS = {
     brand: "Element",
     help_url: "https://element.io/help",
     web_base_url: "https://app.element.io/",
-} satisfies ConfigOptions;
+} satisfies DesktopConfigJson;
 
-function applyDefaults(conf: ConfigOptions): void {
+function applyDefaults(conf: DesktopConfigJson): asserts conf is ConfigOptions {
     for (const k in DEFAULTS) {
         const key = k as keyof typeof DEFAULTS;
         conf[key] ||= DEFAULTS[key];
@@ -71,7 +56,9 @@ export function loadConfig(localConfigPath: string | undefined): Promise<ConfigO
         try {
             console.log(`Loading app config: ${path.join(asarPath, ConfigFilename)}`);
             // XXX: we trust that we built the package with a sane config, but should use something like zod here in future
-            config = loadJsonFile(asarPath, ConfigFilename) as unknown as ConfigOptions;
+            const loadedConfig = loadJsonFile(asarPath, ConfigFilename) as unknown as DesktopConfigJson;
+            applyDefaults(loadedConfig);
+            config = loadedConfig;
         } catch {
             // it would be nice to check the error code here and bail if the config
             // is unparsable, but we get MODULE_NOT_FOUND in the case of a missing
@@ -80,8 +67,6 @@ export function loadConfig(localConfigPath: string | undefined): Promise<ConfigO
             config = { ...DEFAULTS };
         }
 
-        applyDefaults(config);
-
         try {
             // Load local config and use it to override values from the one baked with the build
             const localConfig = loadLocalConfigFile(localConfigPath);
diff --git a/apps/desktop/src/utils.ts b/apps/desktop/src/utils.ts
index 6adb91ffa8..eedabf5237 100644
--- a/apps/desktop/src/utils.ts
+++ b/apps/desktop/src/utils.ts
@@ -9,6 +9,7 @@ import crypto from "node:crypto";
 import fs from "node:fs";
 import path from "node:path";
 import afs from "node:fs/promises";
+import { type JsonDocument } from "shared-types";
 
 /**
  * Returns a random array of a specified size in unpadded base64
@@ -26,19 +27,12 @@ export async function randomArray(size: number): Promise<string> {
     });
 }
 
-type JsonValue = null | string | number;
-type JsonArray = Array<JsonValue | JsonObject | JsonArray>;
-export interface JsonObject {
-    [key: string]: JsonObject | JsonArray | JsonValue;
-}
-export type Json = JsonArray | JsonObject;
-
 /**
  * Synchronously load a JSON file from the local filesystem.
  * Unlike `require`, will never execute any javascript in a loaded file.
  * @param paths - An array of path segments which will be joined using the system's path delimiter.
  */
-export function loadJsonFile<T extends Json>(...paths: string[]): T {
+export function loadJsonFile<T extends JsonDocument>(...paths: string[]): T {
     const joinedPaths = path.join(...paths);
 
     if (!fs.existsSync(joinedPaths)) {
diff --git a/apps/web/package.json b/apps/web/package.json
index 1b61489422..9b8b51e64a 100644
--- a/apps/web/package.json
+++ b/apps/web/package.json
@@ -217,6 +217,7 @@
         "postcss-simple-vars": "7.0.1",
         "process": "^0.11.10",
         "semver": "^7.5.2",
+        "shared-types": "workspace:*",
         "source-map-loader": "^5.0.0",
         "stylelint": "^17.0.0",
         "stylelint-config-standard": "^40.0.0",
diff --git a/apps/web/playwright/element-web-test.ts b/apps/web/playwright/element-web-test.ts
index b77a027241..c1b66e551c 100644
--- a/apps/web/playwright/element-web-test.ts
+++ b/apps/web/playwright/element-web-test.ts
@@ -20,7 +20,6 @@ import {
     type ToMatchScreenshotOptions,
 } from "@element-hq/element-web-playwright-common";
 
-import type { IConfigOptions } from "../src/IConfigOptions";
 import { type Credentials } from "./plugins/homeserver";
 import { ElementAppPage } from "./pages/ElementAppPage";
 import { Crypto } from "./pages/crypto";
@@ -32,11 +31,6 @@ import { type WorkerOptions, type Services, test as base } from "./services";
 // See https://playwright.dev/docs/service-workers-experimental#how-to-enable
 process.env["PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS"] = "1";
 
-declare module "@element-hq/element-web-playwright-common" {
-    // Improve the type for the config fixture based on the real type
-    export interface Config extends Omit<IConfigOptions, "default_server_config"> {}
-}
-
 export interface CredentialsWithDisplayName extends Credentials {
     displayName: string;
 }
diff --git a/apps/web/src/@types/common.ts b/apps/web/src/@types/common.ts
index bfb4f64c16..024e9cef86 100644
--- a/apps/web/src/@types/common.ts
+++ b/apps/web/src/@types/common.ts
@@ -10,55 +10,8 @@ import { type JSX, type JSXElementConstructor } from "react";
 
 export type { NonEmptyArray, XOR, Writeable } from "matrix-js-sdk/src/matrix";
 
+export type * from "shared-types/lib/utils";
+
 export type ComponentClass = keyof JSX.IntrinsicElements | JSXElementConstructor<any>;
 
 export type { Leaves } from "matrix-web-i18n";
-
-export type KeysStartingWith<Input extends object, Str extends string> = {
-    // eslint-disable-next-line @typescript-eslint/no-unused-vars
-    [P in keyof Input]: P extends `${Str}${infer _X}` ? P : never; // we don't use _X
-}[keyof Input];
-
-export type Defaultize<P, D> = P extends any
-    ? string extends keyof P
-        ? P
-        : Pick<P, Exclude<keyof P, keyof D>> &
-              Partial<Pick<P, Extract<keyof P, keyof D>>> &
-              Partial<Pick<D, Exclude<keyof D, keyof P>>>
-    : never;
-
-/* eslint-disable @typescript-eslint/no-unsafe-function-type */
-export type DeepReadonly<T> = T extends (infer R)[]
-    ? DeepReadonlyArray<R>
-    : T extends Function
-      ? T
-      : T extends object
-        ? DeepReadonlyObject<T>
-        : T;
-/* eslint-enable @typescript-eslint/no-unsafe-function-type */
-
-interface DeepReadonlyArray<T> extends ReadonlyArray<DeepReadonly<T>> {}
-
-type DeepReadonlyObject<T> = {
-    readonly [P in keyof T]: DeepReadonly<T[P]>;
-};
-
-export type AtLeastOne<T, U = { [K in keyof T]: Pick<T, K> }> = Partial<T> & U[keyof U];
-
-/**
- * Returns a union type of the keys of the input Object type whose values are assignable to the given Item type.
- * Based on https://stackoverflow.com/a/57862073
- */
-export type Assignable<Object, Item> = {
-    [Key in keyof Object]: Object[Key] extends Item ? Key : never;
-}[keyof Object];
-
-/**
- * Like `Partial` but for applied to all nested objects.
- * Based on https://dev.to/perennialautodidact/adventures-in-typescript-deeppartial-2f2a
- */
-export type DeepPartial<T> = T extends object
-    ? {
-          [P in keyof T]?: DeepPartial<T[P]>;
-      }
-    : T;
diff --git a/apps/web/src/IConfigOptions.ts b/apps/web/src/IConfigOptions.ts
index a3a6a32c91..16f28075ff 100644
--- a/apps/web/src/IConfigOptions.ts
+++ b/apps/web/src/IConfigOptions.ts
@@ -7,15 +7,10 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Com
 Please see LICENSE files in the repository root for full details.
 */
 
-import { type IClientWellKnown } from "matrix-js-sdk/src/matrix";
+import { type ResolveDefaults, type WebConfigJson } from "shared-types";
 
 import { type ValidatedServerConfig } from "./utils/ValidatedServerConfig";
-
-// Convention decision: All config options are lower_snake_case
-// We use an isolated file for the interface so we can mess around with the eslint options.
-
-/* eslint-disable camelcase */
-/* eslint @typescript-eslint/naming-convention: ["error", { "selector": "property", "format": ["snake_case"] } ] */
+import { type DEFAULTS } from "./SdkConfig.ts";
 
 /**
  * Bug reports are enabled but must only be locally
@@ -23,202 +18,14 @@ import { type ValidatedServerConfig } from "./utils/ValidatedServerConfig";
  */
 export const BugReportEndpointURLLocal = "local";
 
-// see element-web config.md for non-developer docs
-export interface IConfigOptions {
-    // dev note: while true that this is arbitrary JSON, it's valuable to enforce that all
-    // config options are documented for "find all usages" sort of searching.
-    // [key: string]: any;
-
-    // Properties of this interface are roughly grouped by their subject matter, such as
-    // "instance customisation", "login stuff", "branding", etc. Use blank lines to denote
-    // a logical separation of properties, but keep similar ones near each other.
-
-    // Exactly one of the following must be supplied
-    default_server_config?: IClientWellKnown; // copy/paste of client well-known
-    default_server_name?: string; // domain to do well-known lookup on
-    default_hs_url?: string; // http url
-
-    default_is_url?: string; // used in combination with default_hs_url, but for the identity server
-
-    // This is intended to be overridden by app startup and not specified by the user
-    // This is also why it's allowed to have an interface that isn't snake_case
+export interface ConfigOptions extends WebConfigJson {
+    /**
+     * This is not a real config field, we're just abusing the config structure to pass around a validated server config
+     */
     validated_server_config?: ValidatedServerConfig;
-
-    fallback_hs_url?: string;
-
-    disable_custom_urls?: boolean;
-    disable_guests?: boolean;
-    disable_login_language_selector?: boolean;
-    disable_3pid_login?: boolean;
-
-    brand: string;
-    branding: {
-        welcome_background_url: string | string[]; // chosen at random if array
-        logo_link_url: string;
-        auth_header_logo_url?: string;
-        auth_footer_links?: { text: string; url: string }[];
-    };
-
-    force_verification?: boolean; // if true, users must verify new logins
-
-    map_style_url?: string; // for location-shared maps
-
-    embedded_pages?: {
-        welcome_url?: string;
-        home_url?: string;
-        login_for_welcome?: boolean;
-    };
-
-    permalink_prefix?: string;
-
-    update_base_url?: string;
-    desktop_builds: {
-        available: boolean;
-        logo: string; // url
-        url: string; // download url
-        url_macos?: string;
-        url_win64?: string;
-        url_win64arm?: string;
-        url_linux?: string;
-    };
-    mobile_builds: {
-        ios: string | null; // download url
-        android: string | null; // download url
-        fdroid: string | null; // download url
-    };
-
-    mobile_guide_toast?: boolean;
-    mobile_guide_app_variant?: "element" | "element-classic" | "element-pro";
-
-    default_theme?: "light" | "dark" | string; // custom themes are strings
-    default_country_code?: string; // ISO 3166 alpha2 country code
-    default_federate?: boolean;
-    default_device_display_name?: string; // for device naming on login+registration
-
-    setting_defaults?: Record<string, any>; // <SettingName, Value>
-
-    integrations_ui_url?: string;
-    integrations_rest_url?: string;
-    integrations_widgets_urls?: string[];
-    default_widget_container_height?: number; // height in pixels
-
-    show_labs_settings: boolean;
-    features?: Record<string, boolean>; // <FeatureName, EnabledBool>
-
-    /**
-     * Bug report endpoint URL. "local" means the logs should not be uploaded.
-     */
-    bug_report_endpoint_url?: typeof BugReportEndpointURLLocal | string; // omission disables bug reporting
-    sentry?: {
-        dsn: string;
-        environment?: string; // "production", etc
-    };
-
-    widget_build_url?: string; // url called to replace jitsi/call widget creation
-    widget_build_url_ignore_dm?: boolean;
-    audio_stream_url?: string;
-    jitsi?: {
-        preferred_domain: string;
-    };
-    jitsi_widget?: {
-        skip_built_in_welcome_screen?: boolean;
-    };
-    voip?: {
-        obey_asserted_identity?: boolean; // MSC3086
-    };
-    element_call: {
-        guest_spa_url?: string;
-        use_exclusively?: boolean;
-        brand?: string;
-    };
-
-    logout_redirect_url?: string;
-
-    sso_redirect_options?: ISsoRedirectOptions;
-
-    custom_translations_url?: string;
-
-    report_event?: {
-        admin_message_md: string; // message for how to contact the server owner when reporting an event
-    };
-
-    room_directory?: {
-        servers: string[];
-    };
-
-    posthog?: {
-        project_api_key: string;
-        api_host: string; // hostname
-    };
-    analytics_owner?: string; // defaults to `brand`
-    privacy_policy_url?: string; // location for cookie policy
-
-    enable_presence_by_hs_url?: Record<string, boolean>; // <HomeserverName, Enabled>
-
-    terms_and_conditions_links?: { url: string; text: string }[];
-    help_url: string;
-    help_encryption_url: string;
-    help_key_storage_url: string;
-
-    latex_maths_delims?: {
-        inline?: {
-            left?: string;
-            right?: string;
-            pattern?: {
-                tex?: string;
-                latex?: string;
-            };
-        };
-        display?: {
-            left?: string;
-            right?: string;
-            pattern?: {
-                tex?: string;
-                latex?: string;
-            };
-        };
-    };
-
-    sync_timeline_limit?: number;
-    dangerously_allow_unsafe_and_insecure_passwords?: boolean; // developer option
-
-    user_notice?: {
-        title: string;
-        description: string;
-        show_once?: boolean;
-    };
-
-    feedback: {
-        existing_issues_url: string;
-        new_issue_url: string;
-    };
-
-    /**
-     * Configuration for OIDC issuers where a static client_id has been issued for the app.
-     * Otherwise dynamic client registration is attempted.
-     * The issuer URL must have a trailing `/`.
-     * OPTIONAL
-     */
-    oidc_static_clients?: {
-        [issuer: string]: { client_id: string };
-    };
-
-    /**
-     * Configuration for OIDC dynamic registration where a static OIDC client is not configured.
-     */
-    oidc_metadata?: {
-        client_uri?: string;
-        logo_uri?: string;
-        tos_uri?: string;
-        policy_uri?: string;
-        contacts?: string[];
-    };
-
-    modules?: string[];
 }
 
-export interface ISsoRedirectOptions {
-    immediate?: boolean;
-    on_welcome_page?: boolean;
-    on_login_page?: boolean;
-}
+/**
+ * Type representing the effective config.json structure after DEFAULTS has been merged in
+ */
+export type IConfigOptions = ResolveDefaults<ConfigOptions, typeof DEFAULTS>;
diff --git a/apps/web/src/PosthogAnalytics.ts b/apps/web/src/PosthogAnalytics.ts
index 814d840f19..54e14ce028 100644
--- a/apps/web/src/PosthogAnalytics.ts
+++ b/apps/web/src/PosthogAnalytics.ts
@@ -139,10 +139,10 @@ export class PosthogAnalytics {
     }
 
     public constructor(private readonly posthog: PostHog) {
-        const posthogConfig = SdkConfig.getObject("posthog");
-        if (posthogConfig) {
-            this.posthog.init(posthogConfig.get("project_api_key"), {
-                api_host: posthogConfig.get("api_host"),
+        const posthogConfig = SdkConfig.get("posthog");
+        if (posthogConfig?.project_api_key && posthogConfig?.api_host) {
+            this.posthog.init(posthogConfig.project_api_key, {
+                api_host: posthogConfig.api_host,
                 autocapture: false,
                 mask_all_text: true,
                 mask_all_element_attributes: true,
diff --git a/apps/web/src/SdkConfig.ts b/apps/web/src/SdkConfig.ts
index 84b87e040c..76e4d47b39 100644
--- a/apps/web/src/SdkConfig.ts
+++ b/apps/web/src/SdkConfig.ts
@@ -8,15 +8,15 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import { mergeWith } from "lodash";
+import { type DeepReadonly } from "shared-types";
 
 import { SnakedObject } from "./utils/SnakedObject";
-import { type IConfigOptions } from "./IConfigOptions";
+import { type IConfigOptions, type ConfigOptions } from "./IConfigOptions";
 import { isObject, objectClone } from "./utils/objects";
-import { type DeepPartial, type DeepReadonly, type Defaultize } from "./@types/common";
 import ElementDesktopLogoSvg from "../res/img/element-desktop-logo.svg";
 
 // see element-web config.md for docs, or the IConfigOptions interface for dev docs
-export const DEFAULTS: DeepReadonly<IConfigOptions> = {
+export const DEFAULTS = {
     brand: "Element",
     branding: {
         logo_link_url: "https://element.io",
@@ -69,13 +69,13 @@ export const DEFAULTS: DeepReadonly<IConfigOptions> = {
         android: "https://play.google.com/store/apps/details?id=im.vector.app",
         fdroid: "https://f-droid.org/repository/browse/?fdid=im.vector.app",
     },
-};
+} satisfies ConfigOptions;
 
-export type ConfigOptions = Defaultize<IConfigOptions, typeof DEFAULTS>;
+export type { ConfigOptions };
 
 function mergeConfig(
     config: DeepReadonly<IConfigOptions>,
-    changes: DeepReadonly<DeepPartial<IConfigOptions>>,
+    changes: DeepReadonly<ConfigOptions>,
 ): DeepReadonly<IConfigOptions> {
     // return { ...config, ...changes };
     return mergeWith(objectClone(config), changes, (objValue, srcValue) => {
@@ -141,7 +141,7 @@ export default class SdkConfig {
         SdkConfig.setInstance(mergeConfig(DEFAULTS, {})); // safe to cast - defaults will be applied
     }
 
-    public static add(cfg: DeepPartial<ConfigOptions>): void {
+    public static add(cfg: DeepReadonly<ConfigOptions>): void {
         SdkConfig.put(mergeConfig(SdkConfig.get(), cfg));
     }
 }
diff --git a/apps/web/src/models/Call.ts b/apps/web/src/models/Call.ts
index 6cf95a0681..617bacfb2a 100644
--- a/apps/web/src/models/Call.ts
+++ b/apps/web/src/models/Call.ts
@@ -707,7 +707,11 @@ export class ElementCall extends Call {
      */
     private static appendAnalyticsParams(params: URLSearchParams, client: MatrixClient): void {
         const posthogConfig = SdkConfig.get("posthog");
-        if (!posthogConfig || PosthogAnalytics.instance.getAnonymity() === Anonymity.Disabled) {
+        if (
+            !posthogConfig?.project_api_key ||
+            !posthogConfig?.api_host ||
+            PosthogAnalytics.instance.getAnonymity() === Anonymity.Disabled
+        ) {
             return;
         }
 
@@ -725,7 +729,7 @@ export class ElementCall extends Call {
         // We gate passing sentry behind analytics consent as EC shares data automatically without user-consent,
         // unlike EW where data is shared upon an intentional user action (rageshake).
         const sentryConfig = SdkConfig.get("sentry");
-        if (sentryConfig) {
+        if (sentryConfig?.dsn) {
             params.append("sentryDsn", sentryConfig.dsn);
             params.append("sentryEnvironment", sentryConfig.environment ?? "");
         }
diff --git a/apps/web/src/settings/Settings.tsx b/apps/web/src/settings/Settings.tsx
index bd29b7484b..f379bead93 100644
--- a/apps/web/src/settings/Settings.tsx
+++ b/apps/web/src/settings/Settings.tsx
@@ -10,6 +10,7 @@ Please see LICENSE files in the repository root for full details.
 
 import React, { type ReactNode } from "react";
 import { STABLE_MSC4133_EXTENDED_PROFILES, UNSTABLE_MSC4133_EXTENDED_PROFILES } from "matrix-js-sdk/src/matrix";
+import { type JsonDocument, type JsonValue } from "shared-types";
 // Import these directly from shared-components to avoid circular deps
 import { _t, _td } from "@element-hq/web-shared-components";
 
@@ -44,7 +45,6 @@ import FallbackIceServerController from "./controllers/FallbackIceServerControll
 import { type IRightPanelForRoomStored } from "../stores/right-panel/RightPanelStoreIPanelState.ts";
 import { type ILayoutSettings } from "../stores/widgets/WidgetLayoutStore.ts";
 import { type ReleaseAnnouncementData } from "../stores/ReleaseAnnouncementStore.ts";
-import { type Json, type JsonValue } from "../@types/json.ts";
 import { type RecentEmojiData } from "../emojipicker/recent.ts";
 import { type Assignable } from "../@types/common.ts";
 import { SortingAlgorithm } from "../stores/room-list-v3/skip-list/sorters/index.ts";
@@ -121,7 +121,7 @@ export const labGroupNames: Record<LabGroup, TranslationKey> = {
     [LabGroup.Ui]: _td("labs|group_ui"),
 };
 
-export type SettingValueType = Json | JsonValue | Record<string, unknown> | Record<string, unknown>[];
+export type SettingValueType = JsonDocument | JsonValue | Record<string, unknown> | Record<string, unknown>[];
 
 export interface IBaseSetting<T extends SettingValueType = SettingValueType> {
     isFeature?: false | undefined;
diff --git a/packages/module-api/api-extractor.json b/packages/module-api/api-extractor.json
index e945efc023..dd2aafef65 100644
--- a/packages/module-api/api-extractor.json
+++ b/packages/module-api/api-extractor.json
@@ -67,7 +67,7 @@
      *
      *   "bundledPackages": [ "@my-company/*" ],
      */
-    "bundledPackages": [],
+    "bundledPackages": ["shared-types"],
 
     /**
      * Specifies what type of newlines API Extractor should use when writing output files.  By default, the output files
diff --git a/packages/module-api/element-web-module-api.api.md b/packages/module-api/element-web-module-api.api.md
index c23218f60e..2318c1028a 100644
--- a/packages/module-api/element-web-module-api.api.md
+++ b/packages/module-api/element-web-module-api.api.md
@@ -125,8 +125,10 @@ export type ComposerApiTarget = {
     view: "thread";
 };
 
+// Warning: (ae-forgotten-export) The symbol "WebConfigJson" needs to be exported by the entry point index.d.ts
+//
 // @public
-export interface Config {
+export interface Config extends WebConfigJson {
     // (undocumented)
     brand: string;
 }
diff --git a/packages/module-api/package.json b/packages/module-api/package.json
index 1b6cea2a2f..ceaf85978f 100644
--- a/packages/module-api/package.json
+++ b/packages/module-api/package.json
@@ -46,6 +46,7 @@
         "matrix-widget-api": "^1.17.0",
         "rollup-plugin-external-globals": "^0.13.0",
         "semver": "^7.6.3",
+        "shared-types": "workspace:*",
         "typescript": "catalog:",
         "unplugin-dts": "catalog:",
         "vite": "catalog:",
diff --git a/packages/module-api/project.json b/packages/module-api/project.json
index 2b7e0be792..e7979345be 100644
--- a/packages/module-api/project.json
+++ b/packages/module-api/project.json
@@ -5,14 +5,10 @@
     "targets": {
         "build": {
             "cache": true,
-            "executor": "nx:run-commands",
             "inputs": ["src"],
             "outputs": ["{projectRoot}/lib"],
-            "options": {
-                "commands": ["vite build", "api-extractor run"],
-                "parallel": false,
-                "cwd": "packages/module-api"
-            }
+            "command": "vite build",
+            "options": { "cwd": "packages/module-api" }
         },
         "start": {
             "command": "vite build --watch",
diff --git a/packages/module-api/src/api/config.ts b/packages/module-api/src/api/config.ts
index 5f708b4983..84e3e4cdb1 100644
--- a/packages/module-api/src/api/config.ts
+++ b/packages/module-api/src/api/config.ts
@@ -5,16 +5,16 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE files in the repository root for full details.
 */
 
+import { type WebConfigJson } from "shared-types";
+
 /**
  * The configuration for the application.
  * Should be extended via declaration merging.
  * @public
  */
-export interface Config {
+export interface Config extends WebConfigJson {
     // The branding name of the application
     brand: string;
-    // Other config options are available but not specified in the types as that would make it difficult to change for element-web
-    // they are accessible at runtime all the same, see list at https://github.com/element-hq/element-web/blob/develop/docs/config.md
 }
 
 /**
diff --git a/packages/module-api/vite.config.ts b/packages/module-api/vite.config.ts
index 305a482983..5e01e921b3 100644
--- a/packages/module-api/vite.config.ts
+++ b/packages/module-api/vite.config.ts
@@ -27,7 +27,11 @@ export default defineConfig({
         sourcemap: true,
     },
     plugins: [
-        dts(),
+        dts({
+            bundleTypes: {
+                configPath: "./api-extractor.json",
+            },
+        }),
         externalGlobals({
             // Reuse React from the host app
             react: "window.React",
diff --git a/packages/playwright-common/src/index.ts b/packages/playwright-common/src/index.ts
index abbee03316..8fbf36e212 100644
--- a/packages/playwright-common/src/index.ts
+++ b/packages/playwright-common/src/index.ts
@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE files in the repository root for full details.
 */
 
-import { type Config as BaseConfig } from "@element-hq/element-web-module-api";
+import { type Config } from "@element-hq/element-web-module-api";
 
 import { test as base } from "./fixtures/index.js";
 import { routeConfigJson } from "./utils/config_json.js";
@@ -22,27 +22,11 @@ export { populateLocalStorageWithCredentials } from "./fixtures/user.js";
 // See https://playwright.dev/docs/service-workers-experimental#how-to-enable
 process.env["PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS"] = "1";
 
-// We extend the Module API Config interface so that all modules
-// which use declaration merging will have their config types correctly applied.
-export interface Config extends BaseConfig {
-    default_server_config: {
-        "m.homeserver"?: {
-            base_url: string;
-            server_name?: string;
-        };
-        "m.identity_server"?: {
-            base_url: string;
-            server_name?: string;
-        };
-    };
-    enable_presence_by_hs_url?: Record<string, boolean>;
-    setting_defaults: Record<string, unknown>;
-    map_style_url?: string;
-    features: Record<string, boolean>;
-    modules?: string[];
-}
+export type { Config };
 
 // This is deliberately quite a minimal config.json, so that we can test that the default settings actually work.
+// We use the Module API Config interface so that all modules
+// which use declaration merging will have their config types correctly applied.
 export const CONFIG_JSON: Partial<Config> = {
     default_server_config: {},
 
diff --git a/packages/shared-types/lib/config.json.d.ts b/packages/shared-types/lib/config.json.d.ts
new file mode 100644
index 0000000000..b9992ef5fb
--- /dev/null
+++ b/packages/shared-types/lib/config.json.d.ts
@@ -0,0 +1,217 @@
+/*
+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.
+*/
+
+import { DeepPartial } from "./utils";
+import { ClientWellKnown } from "./matrix";
+
+// Convention decision: All config options are lower_snake_case
+// see docs/config.md for non-developer docs
+
+/**
+ * Type describing the `config.json` format for Element Web
+ * All fields are optional here, consumers should validate that fields are present before assuming otherwise
+ */
+export interface WebConfigJson {
+    // dev note: while true that this is arbitrary JSON, it's valuable to enforce that all
+    // config options are documented for "find all usages" sort of searching.
+
+    // Properties of this interface are roughly grouped by their subject matter, such as
+    // "instance customisation", "login stuff", "branding", etc. Use blank lines to denote
+    // a logical separation of properties, but keep similar ones near each other.
+
+    // Exactly one of the following must be supplied
+    default_server_config?: DeepPartial<Pick<ClientWellKnown, "m.homeserver" | "m.identity_server">>;
+    default_server_name?: string; // domain to do well-known lookup on
+    default_hs_url?: string; // http url
+
+    default_is_url?: string; // used in combination with default_hs_url, but for the identity server
+
+    fallback_hs_url?: string;
+
+    disable_custom_urls?: boolean;
+    disable_guests?: boolean;
+    disable_login_language_selector?: boolean;
+    disable_3pid_login?: boolean;
+
+    brand?: string;
+    branding?: {
+        welcome_background_url?: string | string[]; // chosen at random if array
+        logo_link_url?: string;
+        auth_header_logo_url?: string;
+        auth_footer_links?: { text: string; url: string }[];
+    };
+
+    force_verification?: boolean; // if true, users must verify new logins
+
+    map_style_url?: string; // for location-shared maps
+
+    embedded_pages?: {
+        welcome_url?: string;
+        home_url?: string;
+        login_for_welcome?: boolean;
+    };
+
+    permalink_prefix?: string;
+
+    desktop_builds?: {
+        available?: boolean;
+        logo?: string; // url
+        url?: string; // download url
+        url_macos?: string;
+        url_win64?: string;
+        url_win64arm?: string;
+        url_linux?: string;
+    };
+    mobile_builds?: {
+        ios?: string; // download url
+        android?: string; // download url
+        fdroid?: string; // download url
+    };
+
+    mobile_guide_toast?: boolean;
+    mobile_guide_app_variant?: "element" | "element-classic" | "element-pro";
+
+    default_theme?: "light" | "dark" | string; // custom themes are strings
+    default_country_code?: string; // ISO 3166 alpha2 country code
+    default_federate?: boolean;
+    default_device_display_name?: string; // for device naming on login+registration
+
+    setting_defaults?: Record<string, any>; // <SettingName, Value>
+
+    integrations_ui_url?: string;
+    integrations_rest_url?: string;
+    integrations_widgets_urls?: string[];
+    default_widget_container_height?: number; // height in pixels
+
+    show_labs_settings?: boolean;
+    features?: Record<string, boolean>; // <FeatureName, EnabledBool>
+
+    /**
+     * Bug report endpoint URL. "local" means the logs should not be uploaded.
+     * Omission disables bug reporting
+     */
+    bug_report_endpoint_url?: string;
+    sentry?: {
+        dsn?: string;
+        environment?: string; // "production", etc
+    };
+
+    widget_build_url?: string; // url called to replace jitsi/call widget creation
+    widget_build_url_ignore_dm?: boolean;
+    audio_stream_url?: string;
+    jitsi?: {
+        preferred_domain?: string;
+    };
+    jitsi_widget?: {
+        skip_built_in_welcome_screen?: boolean;
+    };
+    voip?: {
+        obey_asserted_identity?: boolean; // MSC3086
+    };
+    element_call?: {
+        guest_spa_url?: string;
+        use_exclusively?: boolean;
+        brand?: string;
+    };
+
+    logout_redirect_url?: string;
+
+    sso_redirect_options?: {
+        immediate?: boolean;
+        on_welcome_page?: boolean;
+        on_login_page?: boolean;
+    };
+
+    custom_translations_url?: string;
+
+    report_event?: {
+        admin_message_md?: string; // message for how to contact the server owner when reporting an event
+    };
+
+    room_directory?: {
+        servers?: string[];
+    };
+
+    posthog?: {
+        project_api_key?: string;
+        api_host?: string; // hostname
+    };
+    analytics_owner?: string; // defaults to `brand`
+    privacy_policy_url?: string; // location for cookie policy
+
+    enable_presence_by_hs_url?: Record<string, boolean>; // <HomeserverName, Enabled>
+
+    terms_and_conditions_links?: { url: string; text: string }[];
+    help_url?: string;
+    help_encryption_url?: string;
+    help_key_storage_url?: string;
+
+    latex_maths_delims?: {
+        inline?: {
+            left?: string;
+            right?: string;
+            pattern?: {
+                tex?: string;
+                latex?: string;
+            };
+        };
+        display?: {
+            left?: string;
+            right?: string;
+            pattern?: {
+                tex?: string;
+                latex?: string;
+            };
+        };
+    };
+
+    sync_timeline_limit?: number;
+    dangerously_allow_unsafe_and_insecure_passwords?: boolean; // developer option
+
+    user_notice?: {
+        title?: string;
+        description?: string;
+        show_once?: boolean;
+    };
+
+    feedback?: {
+        existing_issues_url?: string;
+        new_issue_url?: string;
+    };
+
+    /**
+     * Configuration for OIDC issuers where a static client_id has been issued for the app.
+     * Otherwise dynamic client registration is attempted.
+     * The issuer URL must have a trailing `/`.
+     * OPTIONAL
+     */
+    oidc_static_clients?: {
+        [issuer: string]: { client_id: string };
+    };
+
+    /**
+     * Configuration for OIDC dynamic registration where a static OIDC client is not configured.
+     */
+    oidc_metadata?: {
+        client_uri?: string;
+        logo_uri?: string;
+        tos_uri?: string;
+        policy_uri?: string;
+        contacts?: string[];
+    };
+
+    modules?: string[];
+}
+
+/**
+ * Type describing the `config.json` format for Element Desktop, a superset of Element Web's config.
+ * All fields are optional here, consumers should validate that fields are present before assuming otherwise
+ */
+export interface DesktopConfigJson extends WebConfigJson {
+    web_base_url?: string;
+    update_base_url?: string;
+}
diff --git a/packages/shared-types/lib/index.d.ts b/packages/shared-types/lib/index.d.ts
new file mode 100644
index 0000000000..d07922b4ab
--- /dev/null
+++ b/packages/shared-types/lib/index.d.ts
@@ -0,0 +1,11 @@
+/*
+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.
+*/
+
+export type * from "./config.json.d.ts";
+export type * from "./utils.d.ts";
+export type * from "./matrix.d.ts";
+export type * from "./json.d.ts";
diff --git a/packages/shared-types/lib/index.js b/packages/shared-types/lib/index.js
new file mode 100644
index 0000000000..1be6a73d8c
--- /dev/null
+++ b/packages/shared-types/lib/index.js
@@ -0,0 +1 @@
+// Dummy file to make Node happy to import `shared-types` lib.
diff --git a/apps/web/src/@types/json.ts b/packages/shared-types/lib/json.d.ts
similarity index 57%
rename from apps/web/src/@types/json.ts
rename to packages/shared-types/lib/json.d.ts
index 33af49a19f..cf7255954a 100644
--- a/apps/web/src/@types/json.ts
+++ b/packages/shared-types/lib/json.d.ts
@@ -1,13 +1,20 @@
 /*
-Copyright 2024 New Vector Ltd.
+Copyright 2026 Element Creations Ltd.
 
 SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE files in the repository root for full details.
 */
 
+/** Type representing a valid JSON value */
 export type JsonValue = null | string | number | boolean;
+
+/** Type representing a valid JSON array */
 export type JsonArray = Array<JsonValue | JsonObject | JsonArray>;
+
+/** Type representing a valid JSON object */
 export interface JsonObject {
     [key: string]: JsonObject | JsonArray | JsonValue;
 }
-export type Json = JsonArray | JsonObject;
+
+/** Type representing a valid JSON document */
+export type JsonDocument = JsonArray | JsonObject;
diff --git a/packages/shared-types/lib/matrix.d.ts b/packages/shared-types/lib/matrix.d.ts
new file mode 100644
index 0000000000..609f62a0dd
--- /dev/null
+++ b/packages/shared-types/lib/matrix.d.ts
@@ -0,0 +1,43 @@
+/*
+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.
+*/
+
+import { JsonDocument } from "./json";
+
+/**
+ * As specified by https://spec.matrix.org/latest/client-server-api/#getwell-knownmatrixclient
+ */
+export type ClientWellKnown = {
+    /**
+     * Used by clients to discover homeserver information.
+     */
+    "m.homeserver": {
+        /**
+         * The base URL for the homeserver for client-server connections.
+         */
+        base_url: string;
+        /**
+         * This field is not part of the spec but supported by Element Web's config.json
+         * @deprecated - we should figure out whether we want to keep this or not.
+         */
+        server_name?: string;
+    };
+    /**
+     * Used by clients to discover identity server information.
+     */
+    "m.identity_server"?: {
+        /**
+         * The base URL for the identity server for client-server connections.
+         */
+        base_url: string;
+    };
+} & {
+    /**
+     * Other properties
+     * Application-dependent keys using Java package naming convention.
+     */
+    [key: string]: JsonDocument;
+};
diff --git a/packages/shared-types/lib/utils.d.ts b/packages/shared-types/lib/utils.d.ts
new file mode 100644
index 0000000000..e68cf0bfba
--- /dev/null
+++ b/packages/shared-types/lib/utils.d.ts
@@ -0,0 +1,83 @@
+/*
+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.
+*/
+
+/**
+ * Returns a union type of the keys of the Input type whose names start with the given string Str.
+ */
+export type KeysStartingWith<Input extends object, Str extends string> = {
+    [P in keyof Input]: P extends `${Str}${infer _X}` ? P : never; // we don't use _X
+}[keyof Input];
+
+/**
+ * Makes fields of T and its object children optional if they are defined in D.
+ * Useful for generating the input type for a given function if it applies an object of defaults.
+ */
+export type Defaultize<P, D> = P extends any
+    ? string extends keyof P
+        ? P
+        : Pick<P, Exclude<keyof P, keyof D>> &
+              Partial<Pick<P, Extract<keyof P, keyof D>>> &
+              Partial<Pick<D, Exclude<keyof D, keyof P>>>
+    : never;
+
+/**
+ * Makes fields of T and its object children non-optional if they are defined in D.
+ * Useful for generating a type which allows you to know which fields will be defined once you apply default values.
+ */
+export type ResolveDefaults<T, D> = {
+    [K in keyof T as K extends keyof D ? K : never]-?: SafeIndex<D, K> extends object
+        ? NonNullable<T[K]> extends any[]
+            ? NonNullable<T[K]>
+            : NonNullable<T[K]> extends object
+              ? ResolveDefaults<NonNullable<T[K]>, SafeIndex<D, K>>
+              : NonNullable<T[K]>
+        : NonNullable<T[K]>;
+} & {
+    [K in keyof T as K extends keyof D ? never : K]: T[K];
+} & {};
+
+type SafeIndex<D, K> = K extends keyof D ? D[K] : never;
+
+/**
+ * Applies the `readonly` modifier to all fields of T and its object children.
+ */
+export type DeepReadonly<T> = T extends (infer R)[]
+    ? DeepReadonlyArray<R>
+    : T extends Function
+      ? T
+      : T extends object
+        ? DeepReadonlyObject<T>
+        : T;
+
+interface DeepReadonlyArray<T> extends ReadonlyArray<DeepReadonly<T>> {}
+
+type DeepReadonlyObject<T> = {
+    readonly [P in keyof T]: DeepReadonly<T[P]>;
+};
+
+/**
+ * Like `Partial` but requires at least one property to be present.
+ */
+export type AtLeastOne<T, U = { [K in keyof T]: Pick<T, K> }> = Partial<T> & U[keyof U];
+
+/**
+ * Returns a union type of the keys of the input Object type whose values are assignable to the given Item type.
+ * Based on https://stackoverflow.com/a/57862073
+ */
+export type Assignable<Object, Item> = {
+    [Key in keyof Object]: Object[Key] extends Item ? Key : never;
+}[keyof Object];
+
+/**
+ * Like `Partial` but for applied to all nested objects.
+ * Based on https://dev.to/perennialautodidact/adventures-in-typescript-deeppartial-2f2a
+ */
+export type DeepPartial<T> = T extends object
+    ? {
+          [P in keyof T]?: DeepPartial<T[P]>;
+      }
+    : T;
diff --git a/packages/shared-types/package.json b/packages/shared-types/package.json
new file mode 100644
index 0000000000..6fd62d3c30
--- /dev/null
+++ b/packages/shared-types/package.json
@@ -0,0 +1,20 @@
+{
+    "name": "shared-types",
+    "type": "module",
+    "version": "0.0.0",
+    "private": true,
+    "description": "Shared types for Element Web & Desktop",
+    "author": "element-hq",
+    "license": "SEE LICENSE IN README.md",
+    "main": "./lib/index.js",
+    "types": "./lib/index.d.ts",
+    "files": [
+        "lib"
+    ],
+    "scripts": {
+        "lint:types": "tsc --noEmit"
+    },
+    "devDependencies": {
+        "typescript": "catalog:"
+    }
+}
diff --git a/packages/shared-types/tsconfig.json b/packages/shared-types/tsconfig.json
new file mode 100644
index 0000000000..b58ee71b24
--- /dev/null
+++ b/packages/shared-types/tsconfig.json
@@ -0,0 +1,13 @@
+{
+    "$schema": "http://json.schemastore.org/tsconfig",
+    "compilerOptions": {
+        "rootDir": "./lib",
+        "target": "esnext",
+        "lib": ["es2024"],
+        "strict": true,
+        "types": [],
+        "allowImportingTsExtensions": true,
+        "noEmit": true
+    },
+    "include": ["lib"]
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 9f6fbc1bf4..f0fa71a38a 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -241,9 +241,6 @@ catalogs:
     react-dom:
       specifier: ^19.0.0
       version: 19.2.7
-    typescript:
-      specifier: 6.0.3
-      version: 6.0.3
     unplugin-dts:
       specifier: 1.0.1
       version: 1.0.1
@@ -284,6 +281,7 @@ overrides:
   protobufjs@7 <7.5.8: 7.6.1
   '@protobufjs/utf8@1 <1.1.1': 1.1.1
   yauzl: ^3.3.1
+  typescript: 6.0.3
 
 packageExtensionsChecksum: sha256-EMEi1vcyzQthk7O/0AcntvnHgJaKCoFBlzp6iX/qNYk=
 
@@ -351,7 +349,7 @@ importers:
         specifier: 0.56.0
         version: 0.56.0
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       vitepress:
         specifier: ^1.6.4
@@ -492,11 +490,14 @@ importers:
       rimraf:
         specifier: ^6.0.0
         version: 6.1.3
+      shared-types:
+        specifier: workspace:*
+        version: link:../../packages/shared-types
       tar:
         specifier: ^7.5.8
         version: 7.5.19
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       vitest:
         specifier: 'catalog:'
@@ -1033,6 +1034,9 @@ importers:
       semver:
         specifier: ^7.5.2
         version: 7.8.5
+      shared-types:
+        specifier: workspace:*
+        version: link:../../packages/shared-types
       source-map-loader:
         specifier: ^5.0.0
         version: 5.0.0(webpack@5.108.3)
@@ -1055,7 +1059,7 @@ importers:
         specifier: ^12.0.0
         version: 12.0.4
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       util:
         specifier: ^0.12.5
@@ -1164,7 +1168,7 @@ importers:
         specifier: 'catalog:'
         version: 19.2.7
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       vite:
         specifier: 'catalog:'
@@ -1213,7 +1217,7 @@ importers:
         specifier: ^12.0.1
         version: 12.0.4
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       vite:
         specifier: 'catalog:'
@@ -1235,7 +1239,7 @@ importers:
         specifier: 25.9.3
         version: 25.9.3
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       vite:
         specifier: 'catalog:'
@@ -1293,7 +1297,7 @@ importers:
         specifier: 'catalog:'
         version: 19.2.7
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       vite:
         specifier: 'catalog:'
@@ -1344,8 +1348,11 @@ importers:
       semver:
         specifier: ^7.6.3
         version: 7.8.5
+      shared-types:
+        specifier: workspace:*
+        version: link:../shared-types
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       unplugin-dts:
         specifier: 'catalog:'
@@ -1400,7 +1407,7 @@ importers:
         specifier: ^4.17.12
         version: 4.17.12
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
 
   packages/shared-components:
@@ -1602,7 +1609,7 @@ importers:
         specifier: ^4.1.2
         version: 4.1.3(typedoc@0.28.19(typescript@6.0.3))
       typescript:
-        specifier: 'catalog:'
+        specifier: 6.0.3
         version: 6.0.3
       unplugin-dts:
         specifier: 'catalog:'
@@ -1617,6 +1624,12 @@ importers:
         specifier: 'catalog:'
         version: 4.1.9(@opentelemetry/api@1.9.1)(@types/node@25.9.3)(@vitest/browser-playwright@4.1.9)(@vitest/coverage-v8@4.1.9)(happy-dom@20.10.6)(jsdom@26.1.0(patch_hash=040623e87b1c8b676c2a705513c0276c0704dd1b23fc3a1bb77cde8128b64b5f))(vite@8.1.3(@types/node@25.9.3)(esbuild@0.27.4)(jiti@2.7.0)(sugarss@5.0.1(postcss@8.5.16))(terser@5.48.0)(yaml@2.8.4))
 
+  packages/shared-types:
+    devDependencies:
+      typescript:
+        specifier: 6.0.3
+        version: 6.0.3
+
 packages:
 
   '@action-validator/cli@0.6.0':
@@ -3383,7 +3396,7 @@ packages:
   '@joshwooding/vite-plugin-react-docgen-typescript@0.7.0':
     resolution: {integrity: sha512-qvsTEwEFefhdirGOPnu9Wp6ChfIwy2dBCRuETU3uE+4cC+PFoxMSiiEhxk4lOluA34eARHA0OxqsEUYDqRMgeQ==}
     peerDependencies:
-      typescript: '>= 4.3.x'
+      typescript: 6.0.3
       vite: ^3.0.0 || ^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0
     peerDependenciesMeta:
       typescript:
@@ -5573,7 +5586,7 @@ packages:
       react: ^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0
       react-dom: ^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0
       storybook: ^10.4.6
-      typescript: '>= 4.9.x'
+      typescript: 6.0.3
     peerDependenciesMeta:
       '@types/react':
         optional: true
@@ -6148,32 +6161,32 @@ packages:
     peerDependencies:
       '@typescript-eslint/parser': ^8.61.0
       eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/parser@8.62.1':
     resolution: {integrity: sha512-sPhE4iHuJDSvoAiec+Ro8JyXw8f0ql13HFR82P99nCm9GwTEKG0KYLvDe6REk8BCXuit6vJAv/Yxg5ABaNS2rA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/project-service@8.61.0':
     resolution: {integrity: sha512-DV42F7MLJO6Rax7SK1yg43tcnEfGUrurSpSxKuVX+a3RCTzBlH3fuxprrOJXKCJGAaw82xXocikJ0uQaqwXgGA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/project-service@8.61.1':
     resolution: {integrity: sha512-PrC4JYGmR241lYnfhmKGTXkFqv8+ymbTFgSAY0fVXpY82/QkMw5TZPl+vGzuDDU2QYJk9fIDOBTntF+yDv9LEA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/project-service@8.62.1':
     resolution: {integrity: sha512-yQ3RgY5RkSBpsNS1Bx/JQEcA24FOSdfGktoyprAr5u18390UQdtVcfnEv4nIrIshNnavlVyZBKxQwT1fIAE6cg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/scope-manager@8.61.0':
     resolution: {integrity: sha512-IWdXFHFSb6mlC3HPc7QsLDm5zYEbUla6trDEHf32D3/dnuUyXd87plScSNXSbm0/RxMvObpI17sv/EDTGrGZkA==}
@@ -6191,26 +6204,26 @@ packages:
     resolution: {integrity: sha512-O5Amvdv9ztMpxpf+vmFULGG78IE6Qwdr3bCGvqwG4nwc9H2qXkOYJJnRbRHyMkQTjv1d03olqwwwzHLMqpFePQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/tsconfig-utils@8.61.1':
     resolution: {integrity: sha512-UN/H4di+OO7EWx2ovME+8t31YO+KVnK0RRKEHR3kOt21/Ay8BOq3M1OMvWs5vNiqcFCYGYoxK3MXPZzmMUE+yg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/tsconfig-utils@8.62.1':
     resolution: {integrity: sha512-xadytJqX9vJVQ2fdQjkcIVigwaOJNWkpjdLt6cEQ+xPnrI1fkp+/jZE/I97k9KUjqtpd25i0HeyZf3T6dutv2g==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/type-utils@8.61.0':
     resolution: {integrity: sha512-TuBiQYIkd97yBfInHCTKVYMbX4kvEmpOEuixIuzCU9p8BGT1SfyyO0d0IfDMbPIHcjn/hWnusUX5e8v5Xg+X8A==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/types@8.61.0':
     resolution: {integrity: sha512-9QTQpZ5Iin4CdIodfbDQFSeiSJKidgYJYug1P9CC2xWgUTvlmixViqDZNciMjwLBZyJnG4tGmPl97rVAFb1AJg==}
@@ -6228,33 +6241,33 @@ packages:
     resolution: {integrity: sha512-42zatd5qSvvcV1JdDBCLxYRznvP4eIHpPoZXdkPFnAmanA4FuZ5dibSnCBggY8hQnqajPpoGjXFdZ7fIJKQnlA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/typescript-estree@8.61.1':
     resolution: {integrity: sha512-u+oQD3BqYWPc8YV9Zab4vaJElJuwOLPRc10Jm1o/qS+6Qwen14HCWwx0Seo4LnSn2wxea2Ik8DxPt2/FHmuhrg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/typescript-estree@8.62.1':
     resolution: {integrity: sha512-xMcW9oP9u7fAMXYs9A65CVmtLQe2r//oXINHfi8HV+oiqhih17sbLdhXr4540YWlgpDKQdY854OL5ZrdCiQsAA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/utils@8.61.0':
     resolution: {integrity: sha512-3bzFt7ImFMW/jVYwJamDoe/dMOdFLSC6pom6rRjdh4SZJEYupyMzem8e7vKZLclLfpHjlwSAXOUxtKxGXUiLqA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/utils@8.61.1':
     resolution: {integrity: sha512-1+P/3Dj6jvtybE1q0HQ6yBt/gq+oKJyLdEv4HdnqasaEXRSYCAsD59mXEVQnM/ULNdQxbX77tdG4jPRjIS6knA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
-      typescript: '>=4.8.4 <6.1.0'
+      typescript: 6.0.3
 
   '@typescript-eslint/visitor-keys@8.61.0':
     resolution: {integrity: sha512-QVLZu3ZPQEE+HICQyAMZ2yLQhxf0meY/wx6Hx14YcTNj13JB3qHlX3lJ02L3fLGHgERRH71kvYDwiXIguT3AjQ==}
@@ -7670,7 +7683,7 @@ packages:
     resolution: {integrity: sha512-kcZ6+W5QzcJ3P1Mt+83OUv/oHFqZHIx8DuxG6eZ5RGMERoLqp4BuGjhHLYGK+Kf5XVkQvqBSmAy/nGWN3qDgEA==}
     engines: {node: '>=14'}
     peerDependencies:
-      typescript: '>=4.9.5'
+      typescript: 6.0.3
     peerDependenciesMeta:
       typescript:
         optional: true
@@ -7679,7 +7692,7 @@ packages:
     resolution: {integrity: sha512-gtTZxTDau1wL7Y7zifc2dd8jHSK/k6BTx/2Xp/BpdlAdnlYWFVt7qhJqgwi7637yRwRQ3qL4ZidbB4I8tA5VOg==}
     engines: {node: '>=14'}
     peerDependencies:
-      typescript: '>=4.9.5'
+      typescript: 6.0.3
     peerDependenciesMeta:
       typescript:
         optional: true
@@ -8620,7 +8633,7 @@ packages:
       '@typescript-eslint/eslint-plugin': ^8.0.0
       eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
       jest: '*'
-      typescript: '>=4.8.4 <7.0.0'
+      typescript: 6.0.3
     peerDependenciesMeta:
       '@typescript-eslint/eslint-plugin':
         optional: true
@@ -8655,7 +8668,7 @@ packages:
       eslint-plugin-react-hooks: '*'
       eslint-plugin-unicorn: <57
       prettier: '*'
-      typescript: '*'
+      typescript: 6.0.3
 
   eslint-plugin-n@17.24.0:
     resolution: {integrity: sha512-/gC7/KAYmfNnPNOb3eu8vw+TdVnV0zhdQwexsw6FLXbhzroVj20vRn2qL8lDWDGnAQ2J8DhdfvXxX9EoxvERvw==}
@@ -11966,7 +11979,7 @@ packages:
   react-docgen-typescript@2.4.0:
     resolution: {integrity: sha512-ZtAp5XTO5HRzQctjPU0ybY0RRCQO19X/8fxn3w7y2VVTUbGHDKULPTL4ky3vB05euSgG5NpALhEhDPvQ56wvXg==}
     peerDependencies:
-      typescript: '>= 4.3.x'
+      typescript: 6.0.3
 
   react-docgen@8.0.3:
     resolution: {integrity: sha512-aEZ9qP+/M+58x2qgfSFEWH1BxLyHe5+qkLNJOZQb5iGS017jpbRnoKhNRrXPeA6RfBrZO5wZrT9DMC1UqE1f1w==}
@@ -13186,12 +13199,12 @@ packages:
     resolution: {integrity: sha512-OJ/ibxhPlqrMM0UiNHJ/0CKQkoKF243/AEmplt3qpRgkW8VG7IfOS41h7V8TjITqdByHzrjcS/2si+y4lIh8NA==}
     engines: {node: '>=18.12'}
     peerDependencies:
-      typescript: '>=4.8.4'
+      typescript: 6.0.3
 
   ts-declaration-location@1.0.7:
     resolution: {integrity: sha512-EDyGAwH1gO0Ausm9gV6T2nUvBgXT5kGoCMJPllOaooZ+4VvJiKBdZE7wK18N1deEowhcUptS+5GXZK8U/fvpwA==}
     peerDependencies:
-      typescript: '>=4.0.0'
+      typescript: 6.0.3
 
   ts-dedent@2.3.0:
     resolution: {integrity: sha512-JfJeIHke7y2egdGGgRAvpCwYFUsHlM2gPcrVOxFkznt/4uzQ7HFmvE63iFHVLBJNDuyDOQgijDK/tXH/f6Msjg==}
@@ -13271,7 +13284,7 @@ packages:
   type-plus@8.0.0-beta.8:
     resolution: {integrity: sha512-egrpXQq2tV0abCf99+n4SCD/stT76qEwPBI1q7BqiVUe5pHWc+bm4vsOiNR84SmZTv4SoEl9UOZUdkEbS3POdw==}
     peerDependencies:
-      typescript: '>= 5.6.0'
+      typescript: 6.0.3
 
   typed-array-buffer@1.0.3:
     resolution: {integrity: sha512-nAYYwfY3qnzX30IkA6AQZjVbtK6duGontcQm1WSG1MD94YLqK0515GNApXkoxKOWMusVssAHWLh9SeaoefYFGw==}
@@ -13305,12 +13318,7 @@ packages:
     engines: {node: '>= 18', pnpm: '>= 10'}
     hasBin: true
     peerDependencies:
-      typescript: 5.0.x || 5.1.x || 5.2.x || 5.3.x || 5.4.x || 5.5.x || 5.6.x || 5.7.x || 5.8.x || 5.9.x || 6.0.x
-
-  typescript@5.9.3:
-    resolution: {integrity: sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==}
-    engines: {node: '>=14.17'}
-    hasBin: true
+      typescript: 6.0.3
 
   typescript@6.0.3:
     resolution: {integrity: sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==}
@@ -13428,7 +13436,7 @@ packages:
       esbuild: 0.27.4
       rolldown: '*'
       rollup: '>=3'
-      typescript: '>=4'
+      typescript: 6.0.3
       vite: '>=3'
       webpack: ^4 || ^5
     peerDependenciesMeta:
@@ -13730,7 +13738,7 @@ packages:
   vue@3.5.31:
     resolution: {integrity: sha512-iV/sU9SzOlmA/0tygSmjkEN6Jbs3nPoIPFhCMLD2STrjgOU8DX7ZtzMhg4ahVwf5Rp9KoFzcXeB1ZrVbLBp5/Q==}
     peerDependencies:
-      typescript: '*'
+      typescript: 6.0.3
     peerDependenciesMeta:
       typescript:
         optional: true
@@ -14282,7 +14290,7 @@ snapshots:
   '@arcmantle/vite-plugin-import-css-sheet@1.0.14(patch_hash=8019aa9feca17db6bab3483612b4150c911d70b58fddc52bf2d7258a1484a747)':
     dependencies:
       lightningcss: 1.32.0
-      typescript: 5.9.3
+      typescript: 6.0.3
 
   '@asamuzakjp/css-color@3.2.0':
     dependencies:
@@ -16545,7 +16553,7 @@ snapshots:
       resolve: 1.22.12
       semver: 7.7.4
       source-map: 0.6.1
-      typescript: 5.9.3
+      typescript: 6.0.3
     transitivePeerDependencies:
       - '@types/node'
 
@@ -27603,8 +27611,6 @@ snapshots:
       typescript: 6.0.3
       yaml: 2.8.4
 
-  typescript@5.9.3: {}
-
   typescript@6.0.3: {}
 
   ua-parser-js@1.0.40: {}
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index d0919bc43a..2c6c4c227f 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -135,6 +135,8 @@ overrides:
     "@protobufjs/utf8@1 <1.1.1": 1.1.1
     # Workaround for https://github.com/electron/electron/issues/51619
     yauzl: "^3.3.1"
+    # Convince api-extractor to use an up to date Typescript version
+    typescript: "catalog:"
 
 minimumReleaseAgeExclude:
     - "matrix-js-sdk"