diff --git a/src/app/api/[...path]/route.ts b/src/app/api/[...path]/route.ts
index dc72c507..b484b9c2 100644
--- a/src/app/api/[...path]/route.ts
+++ b/src/app/api/[...path]/route.ts
@@ -8,7 +8,7 @@ type RouteParams = {
 
 async function proxyToBackend(request: NextRequest, params: RouteParams) {
   try {
-    const path = `/${(params.path ?? []).join('/')}`;
+    const path = `/api/${(params.path ?? []).join('/')}`;
     const targetUrl = new URL(path + request.nextUrl.search, process.env.BACKEND_BASE_URL);
 
     const proxyRequest = new Request(targetUrl, request);
diff --git a/src/app/api/auth/_authFetch.ts b/src/app/api/auth/_authFetch.ts
index 207bdaaa..f848e0e8 100644
--- a/src/app/api/auth/_authFetch.ts
+++ b/src/app/api/auth/_authFetch.ts
@@ -3,7 +3,7 @@ type AuthFetchInit = RequestInit & {
 };
 
 export async function authFetch(path: string, init: AuthFetchInit = {}) {
-  const url = new URL(path, process.env.BACKEND_BASE_URL);
+  const url = new URL(`api/${path}`, process.env.BACKEND_BASE_URL);
 
   const headers = new Headers(init.headers ?? {});
 
diff --git a/src/app/api/auth/logout/route.ts b/src/app/api/auth/logout/route.ts
index cd2b5c48..d16650b6 100644
--- a/src/app/api/auth/logout/route.ts
+++ b/src/app/api/auth/logout/route.ts
@@ -14,12 +14,11 @@ export async function POST(request: NextRequest) {
       },
     });
 
-    if (!response.ok) {
-      const data = await response.json().catch(() => null);
-      return NextResponse.json(data ?? { message: 'Logout failed' }, { status: response.status });
-    }
+    const res = response.ok
+      ? NextResponse.json({ ok: true })
+      : NextResponse.json({ message: 'Logout failed' }, { status: response.status });
 
-    const res = NextResponse.json({ ok: true });
+    // 백엔드 응답과 무관하게 쿠키는 항상 삭제 (토큰 만료 상태에서도 로그아웃 가능하도록)
     res.cookies.delete({ name: ACCESS_TOKEN_KEY, path: '/' });
     res.cookies.delete({ name: REFRESH_TOKEN_KEY, path: '/' });
     return res;
diff --git a/src/middleware.ts b/src/middleware.ts
index b2dfb0dd..1e5e914d 100644
--- a/src/middleware.ts
+++ b/src/middleware.ts
@@ -121,7 +121,7 @@ export async function middleware(request: NextRequest) {
         const accessTokenValue = getAccessTokenFromCookies(request);
 
         const response = await fetch(
-          new URL(`${API_URL.LESSON_DETAIL}/${lessonId}`, process.env.NEXT_PUBLIC_DEV_BASE_URL),
+          new URL(`api/${API_URL.LESSON_DETAIL}/${lessonId}`, process.env.NEXT_PUBLIC_DEV_BASE_URL),
           {
             method: 'GET',
             headers: {
diff --git a/src/shared/apis/kyInstance.ts b/src/shared/apis/kyInstance.ts
index 92f27a5e..2bb4c99f 100644
--- a/src/shared/apis/kyInstance.ts
+++ b/src/shared/apis/kyInstance.ts
@@ -5,7 +5,10 @@ import { afterResponse } from '@/shared/apis/afterResponse';
 const getPrefixUrl = (): string => {
   if (isServer) {
     const base = process.env.BACKEND_BASE_URL;
-    if (base) return base.endsWith('/') ? base.slice(0, -1) : base;
+    if (base) {
+      const normalized = base.endsWith('/') ? base.slice(0, -1) : base;
+      return `${normalized}/api`;
+    }
   }
   return '/api';
 };
diff --git a/src/shared/constants/apiURL.ts b/src/shared/constants/apiURL.ts
index b15bf721..d36d5b50 100644
--- a/src/shared/constants/apiURL.ts
+++ b/src/shared/constants/apiURL.ts
@@ -2,66 +2,66 @@ import type { LessonStatus } from '@/app/my/(instructor)/manage-classes/types/le
 import type { ReservationStatus } from '@/app/my/(student)/classes/types/reservationStatus';
 
 export const API_URL = {
-  AUTH_LOGIN: 'api/v1/auth/login',
-  AUTH_REISSUE: 'api/v1/auth/reissue',
-  AUTH_LOGOUT: 'api/v1/auth/logout',
-  AUTH_PHONE_REQUEST: 'api/v1/auth/phone/request',
-  AUTH_PHONE_VERIFY: 'api/v1/auth/phone/verify',
+  AUTH_LOGIN: 'v1/auth/login',
+  AUTH_REISSUE: 'v1/auth/reissue',
+  AUTH_LOGOUT: 'v1/auth/logout',
+  AUTH_PHONE_REQUEST: 'v1/auth/phone/request',
+  AUTH_PHONE_VERIFY: 'v1/auth/phone/verify',
 
-  MEMBERS_VALIDATE_WITHDRAW: 'api/v1/auth/validate-withdraw',
-  MEMBERS_WITHDRAW: 'api/v1/auth/withdraw',
-  MEMBERS_ONBOARD: 'api/v1/members/onboard',
-  MEMBERS_ME: 'api/v1/members/me',
+  MEMBERS_VALIDATE_WITHDRAW: 'v1/auth/validate-withdraw',
+  MEMBERS_WITHDRAW: 'v1/auth/withdraw',
+  MEMBERS_ONBOARD: 'v1/members/onboard',
+  MEMBERS_ME: 'v1/members/me',
   MEMBERS_RESERVATIONS: (status: ReservationStatus) => {
-    return status === 'ALL' ? 'api/v1/members/me/reservations' : `api/v1/members/me/reservations?status=${status}`;
+    return status === 'ALL' ? 'v1/members/me/reservations' : `v1/members/me/reservations?status=${status}`;
   },
-  MEMBERS_RESERVATIONS_CLASS_CARD: 'api/v1/members/me/reservations/{reservationId}/class-card',
-  MEMBERS_RESERVATIONS_CANCEL: 'api/v1/members/me/reservations/{reservationId}/cancel',
-  MEMBERS_RESERVATIONS_STATISTICS: 'api/v1/members/me/reservations/statistics',
-  MEMBERS_RESERVATION_DETAIL: 'api/v1/members/me/reservations',
+  MEMBERS_RESERVATIONS_CLASS_CARD: 'v1/members/me/reservations/{reservationId}/class-card',
+  MEMBERS_RESERVATIONS_CANCEL: 'v1/members/me/reservations/{reservationId}/cancel',
+  MEMBERS_RESERVATIONS_STATISTICS: 'v1/members/me/reservations/statistics',
+  MEMBERS_RESERVATION_DETAIL: 'v1/members/me/reservations',
 
-  TEACHERS: 'api/v1/teachers',
-  TEACHER_DETAIL: 'api/v1/teachers',
-  TEACHERS_ME: 'api/v1/teachers/me',
-  TEACHERS_LESSONS_DETAIL: 'api/v1/teachers/me/lessons',
+  TEACHERS: 'v1/teachers',
+  TEACHER_DETAIL: 'v1/teachers',
+  TEACHERS_ME: 'v1/teachers/me',
+  TEACHERS_LESSONS_DETAIL: 'v1/teachers/me/lessons',
   TEACHERS_LESSONS: (status: LessonStatus) => {
-    return status === 'ALL' ? 'api/v1/teachers/me/lessons' : `api/v1/teachers/me/lessons?status=${status}`;
+    return status === 'ALL' ? 'v1/teachers/me/lessons' : `v1/teachers/me/lessons?status=${status}`;
   },
-  TEACHER_DETAIL_INTRODUCTION: 'api/v1/teachers/me/detail',
-  TEACHER_ME_THUMBNAILS: 'api/v1/teachers/me/lessons/thumbnails',
-  TEACHER_ME_ACCOUNT: 'api/v1/teachers/me/account',
-  TEACHERS_POPULAR: 'api/v1/teachers/popular',
-  TEACHERS_SEARCH: 'api/v1/teachers?keyword=:keyword',
-  TEACHERS_LESSON_STATUS: 'api/v1/teachers/me/lessons/status',
+  TEACHER_DETAIL_INTRODUCTION: 'v1/teachers/me/detail',
+  TEACHER_ME_THUMBNAILS: 'v1/teachers/me/lessons/thumbnails',
+  TEACHER_ME_ACCOUNT: 'v1/teachers/me/account',
+  TEACHERS_POPULAR: 'v1/teachers/popular',
+  TEACHERS_SEARCH: 'v1/teachers?keyword=:keyword',
+  TEACHERS_LESSON_STATUS: 'v1/teachers/me/lessons/status',
   TEACHERS_LESSON_CHANGE_APPROVE: (lessonId: number, reservationId: number) =>
-    `api/v1/teachers/me/lessons/${lessonId}/${reservationId}/change-approve`,
+    `v1/teachers/me/lessons/${lessonId}/${reservationId}/change-approve`,
   TEACHERS_LESSON_CHANGE_CANCEL: (lessonId: number, reservationId: number) =>
-    `api/v1/teachers/me/lessons/${lessonId}/${reservationId}/change-cancel`,
-  TEACHER_NICKNAME_VALIDATION: 'api/v1/teachers/nickname-validation',
+    `v1/teachers/me/lessons/${lessonId}/${reservationId}/change-cancel`,
+  TEACHER_NICKNAME_VALIDATION: 'v1/teachers/nickname-validation',
 
-  LESSONS: 'api/v1/lessons',
-  LESSON_DETAIL: 'api/v1/lessons',
-  LESSON_UPDATE: 'api/v1/lessons',
-  LESSONS_LATEST: 'api/v1/lessons/latest',
-  LESSONS_POPULAR_GENRES: 'api/v1/lessons/popular-genres',
-  LESSONS_UPCOMING: 'api/v1/lessons/upcoming',
-  LESSONS_FAVORITES: 'api/v1/lessons/favorites/{lessonId}',
-  LESSON_RESERVE_PROGRESS: 'api/v1/lessons',
-  LESSON_RESERVATION: 'api/v2/lessons',
-  LESSON_RESERVATION_STATUS: 'api/v1/members/me/reservations/status',
+  LESSONS: 'v1/lessons',
+  LESSON_DETAIL: 'v1/lessons',
+  LESSON_UPDATE: 'v1/lessons',
+  LESSONS_LATEST: 'v1/lessons/latest',
+  LESSONS_POPULAR_GENRES: 'v1/lessons/popular-genres',
+  LESSONS_UPCOMING: 'v1/lessons/upcoming',
+  LESSONS_FAVORITES: 'v1/lessons/favorites/{lessonId}',
+  LESSON_RESERVE_PROGRESS: 'v1/lessons',
+  LESSON_RESERVATION: 'v2/lessons',
+  LESSON_RESERVATION_STATUS: 'v1/members/me/reservations/status',
 
-  MY_PAGE_FAVORITES: 'api/v1/mypage/favorites',
-  MY_PAGE_LESSONS: 'api/v1/mypage/lessons',
-  MY_PAGE_LESSON_DETAIL: 'api/v1/mypage/lessons/{lessonId}',
+  MY_PAGE_FAVORITES: 'v1/mypage/favorites',
+  MY_PAGE_LESSONS: 'v1/mypage/lessons',
+  MY_PAGE_LESSON_DETAIL: 'v1/mypage/lessons/{lessonId}',
 
-  ADVERTISEMENTS: 'api/v1/advertisements',
-  BANKS: 'api/v1/bank',
+  ADVERTISEMENTS: 'v1/advertisements',
+  BANKS: 'v1/bank',
 
   SEARCH_LESSONS:
-    'api/v1/lessons?genre=:genre&level=:level&startDate=:startDate&endDate=:endDate&sortOption=:sortOption&keyword=:keyword',
+    'v1/lessons?genre=:genre&level=:level&startDate=:startDate&endDate=:endDate&sortOption=:sortOption&keyword=:keyword',
 
-  LOCATIONS: 'api/v1/locations',
+  LOCATIONS: 'v1/locations',
 
-  AUTH_ROLE: 'api/v1/auth/role',
-  IMAGES: 'api/v1/images',
+  AUTH_ROLE: 'v1/auth/role',
+  IMAGES: 'v1/images',
 };