diff --git a/package-lock.json b/package-lock.json
index ca6697d..03f1656 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,9 +9,9 @@
       "version": "1.0.0",
       "license": "MIT",
       "dependencies": {
-        "@event-driven-io/emmett-esdb": "0.10.0",
-        "@event-driven-io/emmett-expressjs": "0.10.0",
-        "@event-driven-io/emmett-testcontainers": "0.10.0"
+        "@event-driven-io/emmett-esdb": "0.11.0",
+        "@event-driven-io/emmett-expressjs": "0.11.0",
+        "@event-driven-io/emmett-testcontainers": "0.11.0"
       },
       "devDependencies": {
         "@types/node": "20.11.30",
@@ -490,9 +490,9 @@
       }
     },
     "node_modules/@event-driven-io/emmett": {
-      "version": "0.10.0",
-      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett/-/emmett-0.10.0.tgz",
-      "integrity": "sha512-QcLNm34COaWUn+Taawg6cq6mOoeU9L19cGbebwBrEoVpcxmEtYv2nubgQ8ui48ypa3C7IEu77BIGcd3Z6mXP0A==",
+      "version": "0.11.0",
+      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett/-/emmett-0.11.0.tgz",
+      "integrity": "sha512-/jtSkDUBe9SUFokJ7LuCcEbdgIYutigi7n58WxjBHxRFlXB/dzvmSUr6mEo8ODRssCAXU8XYEH2zOmVo2fC+EQ==",
       "peerDependencies": {
         "@types/async-retry": "^1.4.8",
         "@types/uuid": "^9.0.8",
@@ -502,20 +502,20 @@
       }
     },
     "node_modules/@event-driven-io/emmett-esdb": {
-      "version": "0.10.0",
-      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett-esdb/-/emmett-esdb-0.10.0.tgz",
-      "integrity": "sha512-/0JTi1OyeWhcReoN5I+DxvJ0iLMMl8jnpr0DqABho9o6lmWhzEz2a2A1tTENu6AxjYBkirsIGjpYuDK89sjY2Q==",
+      "version": "0.11.0",
+      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett-esdb/-/emmett-esdb-0.11.0.tgz",
+      "integrity": "sha512-Q10j/paDLc1LC05dFhWqgRuvmKbXAEvZ3O/vK+ySrAQgTa0cWVHQfuZi0wdGBhShpAKZmBsAKlDHt2V3onjSUw==",
       "peerDependencies": {
-        "@event-driven-io/emmett": "0.10.0",
+        "@event-driven-io/emmett": "0.11.0",
         "@eventstore/db-client": "^6.1.0"
       }
     },
     "node_modules/@event-driven-io/emmett-expressjs": {
-      "version": "0.10.0",
-      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett-expressjs/-/emmett-expressjs-0.10.0.tgz",
-      "integrity": "sha512-cedwMNBTKjW6YpOrtfV0ozsLD1cLodnE6dlRMXsA6hZKZ0V33oCfalOzMKLH/9pcosypfpgap5QgWjy+F1lxHg==",
+      "version": "0.11.0",
+      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett-expressjs/-/emmett-expressjs-0.11.0.tgz",
+      "integrity": "sha512-+lw5dNgU11Q8hiHHbE+dM1WtJEiiIYRDnGSCM0+l0InyyDncK/+kdiofw4gUkKM04w3oLJDWHabDOX1SliRoxw==",
       "peerDependencies": {
-        "@event-driven-io/emmett": "0.10.0",
+        "@event-driven-io/emmett": "0.11.0",
         "@types/express": "4.17.21",
         "@types/supertest": "6.0.2",
         "express": "4.19.2",
@@ -525,11 +525,11 @@
       }
     },
     "node_modules/@event-driven-io/emmett-testcontainers": {
-      "version": "0.10.0",
-      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett-testcontainers/-/emmett-testcontainers-0.10.0.tgz",
-      "integrity": "sha512-PnH896jrfKvhGIx6YPB93IO8Cd8X56bCec5S8+2stRB2DesLx3yHPh+V5p7NSGwZ3fMJP3XfoZg6rZMZn6JaKg==",
+      "version": "0.11.0",
+      "resolved": "https://registry.npmjs.org/@event-driven-io/emmett-testcontainers/-/emmett-testcontainers-0.11.0.tgz",
+      "integrity": "sha512-HHoCgILTcujOv9KwVJBDUr545KUSLoaNWHB4I5jWGzYzvum7eu/CUmqP6xuff8iGz5O/cXvn7LoE069dIY2uZQ==",
       "dependencies": {
-        "@event-driven-io/emmett": "0.10.0",
+        "@event-driven-io/emmett": "0.11.0",
         "testcontainers": "^10.7.2"
       }
     },
diff --git a/package.json b/package.json
index 382f946..d6d9f6f 100644
--- a/package.json
+++ b/package.json
@@ -38,9 +38,9 @@
   },
   "homepage": "https://github.com/oskardudycz/EventSourcing.NodeJS#readme",
   "dependencies": {
-    "@event-driven-io/emmett-esdb": "0.10.0",
-    "@event-driven-io/emmett-expressjs": "0.10.0",
-    "@event-driven-io/emmett-testcontainers": "0.10.0"
+    "@event-driven-io/emmett-esdb": "0.11.0",
+    "@event-driven-io/emmett-expressjs": "0.11.0",
+    "@event-driven-io/emmett-testcontainers": "0.11.0"
   },
   "devDependencies": {
     "@types/node": "20.11.30",
diff --git a/src/guestStayAccounts/api/api.e2e.spec.ts b/src/guestStayAccounts/api/api.e2e.spec.ts
index d3a5251..a3e5953 100644
--- a/src/guestStayAccounts/api/api.e2e.spec.ts
+++ b/src/guestStayAccounts/api/api.e2e.spec.ts
@@ -220,6 +220,6 @@ describe('guestStayAccount E2E', () => {
     void it(`doesn't checkout`, () =>
       given(...checkedOutAccount)
         .when(checkOut)
-        .then([expectError(403, { detail: `NotOpened` })]));
+        .then([expectError(403, { detail: `NotCheckedIn` })]));
   });
 });
diff --git a/src/guestStayAccounts/api/api.int.spec.ts b/src/guestStayAccounts/api/api.int.spec.ts
index b6472c7..724fad6 100644
--- a/src/guestStayAccounts/api/api.int.spec.ts
+++ b/src/guestStayAccounts/api/api.int.spec.ts
@@ -2,6 +2,7 @@ import {
   formatDateToUtcYYYYMMDD,
   getInMemoryEventStore,
   type EventStore,
+  type TestEventStream,
 } from '@event-driven-io/emmett';
 import {
   ApiSpecification,
@@ -12,7 +13,6 @@ import {
   getApplication,
   type TestRequest,
 } from '@event-driven-io/emmett-expressjs';
-import type { TestEventStream } from '@event-driven-io/emmett-expressjs/dist/testing/utils';
 import { randomUUID } from 'node:crypto';
 import { beforeEach, describe, it } from 'node:test';
 import {
@@ -426,14 +426,14 @@ void describe('Guest stay account', () => {
       given(checkedOutAccount)
         .when(checkOut)
         .then([
-          expectError(403, { detail: `NotOpened` }),
+          expectError(403, { detail: `NotCheckedIn` }),
           expectNewEvents(guestStayAccountId, [
             {
               type: 'GuestCheckoutFailed',
               data: {
                 guestStayAccountId,
                 groupCheckoutId: undefined,
-                reason: 'NotOpened',
+                reason: 'NotCheckedIn',
                 failedAt: now,
               },
             },
diff --git a/src/guestStayAccounts/api/api.ts b/src/guestStayAccounts/api/api.ts
index 864eb7f..94b9759 100644
--- a/src/guestStayAccounts/api/api.ts
+++ b/src/guestStayAccounts/api/api.ts
@@ -55,7 +55,7 @@ type CheckOutRequest = Request<
   unknown
 >;
 
-type GetShoppingCartRequest = Request<
+type GetGuestStayAccountDetailsRequest = Request<
   Partial<{ guestId: string; roomId: string; checkInDate: string }>,
   unknown,
   unknown
@@ -153,7 +153,7 @@ export const guestStayAccountsApi =
       }),
     );
 
-    // CheckOut Shopping Cart
+    // CheckOut Guest
     router.delete(
       '/guests/:guestId/stays/:roomId/periods/:checkInDate',
       on(async (request: CheckOutRequest) => {
@@ -179,10 +179,10 @@ export const guestStayAccountsApi =
       }),
     );
 
-    // Get Shopping Cart
+    // Get Guest Stay Account Details
     router.get(
       '/guests/:guestId/stays/:roomId/periods/:checkInDate',
-      on(async (request: GetShoppingCartRequest) => {
+      on(async (request: GetGuestStayAccountDetailsRequest) => {
         const guestStayAccountId = parseGuestStayAccountId(request.params);
 
         const result = await getGuestStayDetails(
@@ -192,7 +192,7 @@ export const guestStayAccountsApi =
 
         if (result === null) return NotFound();
 
-        if (result.state.status !== 'Opened') return NotFound();
+        if (result.state.status !== 'CheckedIn') return NotFound();
 
         return OK({
           body: result.state,
diff --git a/src/guestStayAccounts/businessLogic.ts b/src/guestStayAccounts/businessLogic.ts
index 0c20a8d..07073ad 100644
--- a/src/guestStayAccounts/businessLogic.ts
+++ b/src/guestStayAccounts/businessLogic.ts
@@ -2,12 +2,12 @@ import { IllegalStateError, type Command } from '@event-driven-io/emmett';
 import {
   toGuestStayAccountId,
   type ChargeRecorded,
+  type CheckedIn,
   type GuestCheckedIn,
   type GuestCheckedOut,
   type GuestCheckoutFailed,
   type GuestStayAccount,
   type GuestStayAccountEvent,
-  type Opened,
   type PaymentRecorded,
 } from './guestStayAccount';
 
@@ -74,7 +74,7 @@ export const recordCharge = (
   { data: { guestStayAccountId, chargeId, amount }, metadata }: RecordCharge,
   state: GuestStayAccount,
 ): ChargeRecorded => {
-  assertIsOpened(state);
+  assertIsCheckedIn(state);
 
   return {
     type: 'ChargeRecorded',
@@ -91,7 +91,7 @@ export const recordPayment = (
   { data: { guestStayAccountId, paymentId, amount }, metadata }: RecordPayment,
   state: GuestStayAccount,
 ): PaymentRecorded => {
-  assertIsOpened(state);
+  assertIsCheckedIn(state);
 
   return {
     type: 'PaymentRecorded',
@@ -110,13 +110,13 @@ export const checkOut = (
 ): GuestCheckedOut | GuestCheckoutFailed => {
   const now = metadata?.now ?? new Date();
 
-  if (state.status !== 'Opened')
+  if (state.status !== 'CheckedIn')
     return {
       type: 'GuestCheckoutFailed',
       data: {
         guestStayAccountId,
         groupCheckoutId,
-        reason: 'NotOpened',
+        reason: 'NotCheckedIn',
         failedAt: now,
       },
     };
@@ -165,8 +165,8 @@ export const decide = (
   }
 };
 
-const assertDoesNotExist = (state: GuestStayAccount): state is Opened => {
-  if (state.status === 'Opened')
+const assertDoesNotExist = (state: GuestStayAccount): state is CheckedIn => {
+  if (state.status === 'CheckedIn')
     throw new IllegalStateError(`Guest is already checked-in!`);
 
   if (state.status === 'CheckedOut')
@@ -175,7 +175,7 @@ const assertDoesNotExist = (state: GuestStayAccount): state is Opened => {
   return true;
 };
 
-const assertIsOpened = (state: GuestStayAccount): state is Opened => {
+const assertIsCheckedIn = (state: GuestStayAccount): state is CheckedIn => {
   if (state.status === 'NotExisting')
     throw new IllegalStateError(`Guest account doesn't exist!`);
 
diff --git a/src/guestStayAccounts/businessLogic.unit.spec.ts b/src/guestStayAccounts/businessLogic.unit.spec.ts
index 5f03a05..d445e92 100644
--- a/src/guestStayAccounts/businessLogic.unit.spec.ts
+++ b/src/guestStayAccounts/businessLogic.unit.spec.ts
@@ -101,7 +101,7 @@ void describe('Guest Stay Account', () => {
             data: {
               guestStayAccountId,
               groupCheckoutId: undefined,
-              reason: 'NotOpened',
+              reason: 'NotCheckedIn',
               failedAt: now,
             },
           },
@@ -491,7 +491,7 @@ void describe('Guest Stay Account', () => {
             data: {
               guestStayAccountId,
               groupCheckoutId: undefined,
-              reason: 'NotOpened',
+              reason: 'NotCheckedIn',
               failedAt: now,
             },
           },
diff --git a/src/guestStayAccounts/guestStayAccount.ts b/src/guestStayAccounts/guestStayAccount.ts
index e523967..8534639 100644
--- a/src/guestStayAccounts/guestStayAccount.ts
+++ b/src/guestStayAccounts/guestStayAccount.ts
@@ -47,7 +47,7 @@ export type GuestCheckoutFailed = Event<
   'GuestCheckoutFailed',
   {
     guestStayAccountId: string;
-    reason: 'NotOpened' | 'BalanceNotSettled';
+    reason: 'NotCheckedIn' | 'BalanceNotSettled';
     failedAt: Date;
     groupCheckoutId?: string;
   }
@@ -66,11 +66,11 @@ export type GuestStayAccountEvent =
 
 export type NotExisting = { status: 'NotExisting' };
 
-export type Opened = { status: 'Opened'; balance: number };
+export type CheckedIn = { status: 'CheckedIn'; balance: number };
 
 export type CheckedOut = { status: 'CheckedOut' };
 
-export type GuestStayAccount = NotExisting | Opened | CheckedOut;
+export type GuestStayAccount = NotExisting | CheckedIn | CheckedOut;
 
 export const initialState = (): GuestStayAccount => ({
   status: 'NotExisting',
@@ -93,11 +93,11 @@ export const evolve = (
   switch (type) {
     case 'GuestCheckedIn': {
       return state.status === 'NotExisting'
-        ? { status: 'Opened', balance: 0 }
+        ? { status: 'CheckedIn', balance: 0 }
         : state;
     }
     case 'ChargeRecorded': {
-      return state.status === 'Opened'
+      return state.status === 'CheckedIn'
         ? {
             ...state,
             balance: state.balance - event.amount,
@@ -105,7 +105,7 @@ export const evolve = (
         : state;
     }
     case 'PaymentRecorded': {
-      return state.status === 'Opened'
+      return state.status === 'CheckedIn'
         ? {
             ...state,
             balance: state.balance + event.amount,
@@ -113,7 +113,7 @@ export const evolve = (
         : state;
     }
     case 'GuestCheckedOut': {
-      return state.status === 'Opened' ? { status: 'CheckedOut' } : state;
+      return state.status === 'CheckedIn' ? { status: 'CheckedOut' } : state;
     }
     case 'GuestCheckoutFailed': {
       return state;
diff --git a/src/guestStayAccounts/guestStayDetails.ts b/src/guestStayAccounts/guestStayDetails.ts
index 0898ded..50a8842 100644
--- a/src/guestStayAccounts/guestStayDetails.ts
+++ b/src/guestStayAccounts/guestStayDetails.ts
@@ -3,11 +3,11 @@ import type { GuestStayAccountEvent } from './guestStayAccount';
 
 export type NotExisting = { status: 'NotExisting' };
 
-export type Opened = {
+export type CheckedIn = {
   id: string;
   guestId: string;
   roomId: string;
-  status: 'Opened' | 'CheckedOut';
+  status: 'CheckedIn' | 'CheckedOut';
   balance: number;
   transactionsCount: number;
   transactions: { id: string; amount: number }[];
@@ -15,7 +15,7 @@ export type Opened = {
   checkedOutAt?: Date;
 };
 
-export type GuestStayDetails = NotExisting | Opened;
+export type GuestStayDetails = NotExisting | CheckedIn;
 
 export const initialState = (): GuestStayDetails => ({
   status: 'NotExisting',
@@ -32,7 +32,7 @@ export const evolve = (
             id: event.guestStayAccountId,
             guestId: event.guestId,
             roomId: event.roomId,
-            status: 'Opened',
+            status: 'CheckedIn',
             balance: 0,
             transactionsCount: 0,
             transactions: [],
@@ -41,7 +41,7 @@ export const evolve = (
         : state;
     }
     case 'ChargeRecorded': {
-      return state.status === 'Opened'
+      return state.status === 'CheckedIn'
         ? {
             ...state,
             balance: state.balance - event.amount,
@@ -54,7 +54,7 @@ export const evolve = (
         : state;
     }
     case 'PaymentRecorded': {
-      return state.status === 'Opened'
+      return state.status === 'CheckedIn'
         ? {
             ...state,
             balance: state.balance + event.amount,
@@ -67,7 +67,7 @@ export const evolve = (
         : state;
     }
     case 'GuestCheckedOut': {
-      return state.status === 'Opened'
+      return state.status === 'CheckedIn'
         ? {
             ...state,
             status: 'CheckedOut',
diff --git a/src/index.ts b/src/index.ts
index 84f087c..ad2a7af 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -13,7 +13,7 @@ const eventStore = getEventStoreDBEventStore(eventStoreDBClient);
 const doesGuestStayExist = (_guestId: string, _roomId: string, _day: Date) =>
   Promise.resolve(true);
 
-const shoppingCarts = guestStayAccountsApi(
+const guestStayAccounts = guestStayAccountsApi(
   eventStore,
   doesGuestStayExist,
   (prefix) => `${prefix}-${randomUUID()}`,
@@ -21,7 +21,7 @@ const shoppingCarts = guestStayAccountsApi(
 );
 
 const application: Application = getApplication({
-  apis: [shoppingCarts],
+  apis: [guestStayAccounts],
 });
 
 startAPI(application);