diff --git a/src/app-bridge/app-bridge-state.test.ts b/src/app-bridge/app-bridge-state.test.ts
index cb1cdd5..7a5fb8b 100644
--- a/src/app-bridge/app-bridge-state.test.ts
+++ b/src/app-bridge/app-bridge-state.test.ts
@@ -12,6 +12,7 @@ describe("app-bridge-state.ts", () => {
       ready: false,
       path: "/",
       theme: "light",
+      locale: "en",
     });
   });
 
@@ -23,10 +24,23 @@ describe("app-bridge-state.ts", () => {
       id: "foo-bar",
       path: "/",
       theme: "light",
+      locale: "pl",
     };
 
     instance.setState(newState);
 
     expect(instance.getState()).toEqual(expect.objectContaining(newState));
   });
+
+  it("Set \"en\" to be initial locale value", () => {
+    expect(new AppBridgeStateContainer().getState().locale).toEqual("en");
+  });
+
+  it("Can be constructed with initial locale", () => {
+    expect(
+      new AppBridgeStateContainer({
+        initialLocale: "pl",
+      }).getState().locale
+    ).toBe("pl");
+  });
 });
diff --git a/src/app-bridge/app-bridge-state.ts b/src/app-bridge/app-bridge-state.ts
index d61c57a..687a60d 100644
--- a/src/app-bridge/app-bridge-state.ts
+++ b/src/app-bridge/app-bridge-state.ts
@@ -7,6 +7,11 @@ export type AppBridgeState = {
   domain: string;
   path: string;
   theme: ThemeType;
+  locale: string;
+};
+
+type Options = {
+  initialLocale?: string;
 };
 
 export class AppBridgeStateContainer {
@@ -16,8 +21,15 @@ export class AppBridgeStateContainer {
     ready: false,
     path: "/",
     theme: "light",
+    locale: "en",
   };
 
+  constructor(options: Options = {}) {
+    if (options.initialLocale) {
+      this.state.locale = options.initialLocale;
+    }
+  }
+
   getState() {
     return this.state;
   }
diff --git a/src/app-bridge/app-bridge.ts b/src/app-bridge/app-bridge.ts
index 6c417eb..11a7faf 100644
--- a/src/app-bridge/app-bridge.ts
+++ b/src/app-bridge/app-bridge.ts
@@ -37,6 +37,12 @@ function eventStateReducer(state: AppBridgeState, event: Events) {
         theme: event.payload.theme,
       };
     }
+    case EventType.localeChanged: {
+      return {
+        ...state,
+        locale: event.payload.locale,
+      };
+    }
     case EventType.response: {
       return state;
     }
@@ -56,6 +62,7 @@ const createEmptySubscribeMap = (): SubscribeMap => ({
   response: {},
   redirect: {},
   theme: {},
+  localeChanged: {},
 });
 
 export type AppBridgeOptions = {
diff --git a/src/app-bridge/events.ts b/src/app-bridge/events.ts
index 2413eb3..259ad9d 100644
--- a/src/app-bridge/events.ts
+++ b/src/app-bridge/events.ts
@@ -7,6 +7,7 @@ export const EventType = {
   response: "response",
   redirect: "redirect",
   theme: "theme",
+  localeChanged: "localeChanged",
 } as const;
 
 export type EventType = Values<typeof EventType>;
@@ -47,7 +48,19 @@ export type ThemeEvent = Event<
   }
 >;
 
-export type Events = HandshakeEvent | DispatchResponseEvent | RedirectEvent | ThemeEvent;
+export type LocaleChangedEvent = Event<
+  "localeChanged",
+  {
+    locale: string;
+  }
+>;
+
+export type Events =
+  | HandshakeEvent
+  | DispatchResponseEvent
+  | RedirectEvent
+  | ThemeEvent
+  | LocaleChangedEvent;
 
 export type PayloadOfEvent<
   TEventType extends EventType,