diff --git a/apps/cs/app/api/proxy/[...url]/route.ts b/apps/cs/app/api/proxy/[...url]/route.ts
index abd3ae007..0929ca57c 100644
--- a/apps/cs/app/api/proxy/[...url]/route.ts
+++ b/apps/cs/app/api/proxy/[...url]/route.ts
@@ -2,6 +2,7 @@ import {
   ACCESS_TOKEN,
   AUTH_USER_ID,
   CLAIM_NAME,
+  COOKIE_DOMAIN,
   REFRESH_TOKEN,
   SERVER_API_URL,
   SITE_ID,
@@ -60,18 +61,11 @@ async function handler(
         [AUTH_USER_ID]: userId,
       });
 
-      const forwardedHost = request.headers.get("x-forwarded-host");
-      const host = request.headers.get("host");
-      const actualHost = forwardedHost || host || new URL(request.url).hostname.toString();
-      
-      // 운영 환경에서 domain 설정
-      const domain = actualHost.includes("hasuon.or.kr") ? ".hasuon.or.kr" : actualHost;
-
       if (refreshToken) {
-        cookieStore.set(REFRESH_TOKEN, refreshToken, {
+        response.cookies.set(REFRESH_TOKEN, refreshToken, {
           httpOnly: true,
           sameSite: "strict",
-          domain: domain,
+          domain: getCookieDomain(),
           path: "/",
         });
       }
@@ -91,7 +85,6 @@ async function handler(
   }
 }
 
-
 export async function POST(
   request: Request,
   props: { params: Promise<{ url: string[] }> },
@@ -107,3 +100,14 @@ export async function PUT(
   const params = await props.params;
   return handler(request, params, "PUT");
 }
+
+function getCookieDomain(): string | undefined {
+  if (typeof window === "undefined") return undefined;
+
+  if (COOKIE_DOMAIN) return COOKIE_DOMAIN;
+
+  const { hostname } = window.location;
+  if (hostname === "localhost" || hostname === "127.0.0.1") return undefined;
+
+  return hostname;
+}
diff --git a/apps/cs/src/app/providers/app-provider.tsx b/apps/cs/src/app/providers/app-provider.tsx
index efd1f308e..31d14ac79 100644
--- a/apps/cs/src/app/providers/app-provider.tsx
+++ b/apps/cs/src/app/providers/app-provider.tsx
@@ -14,8 +14,9 @@ import { ConfirmDialog } from "@/shared/ui/confirm-dialog";
 import { SelectPromptDialog } from "@/shared/ui/select-prompt-dialog";
 import { PromptProvider, StoreProvider } from "@/shared/providers";
 
+const queryClient = new QueryClient();
+
 const AppProvider = ({ children }: Readonly<{ children: React.ReactNode }>) => {
-  const queryClient = new QueryClient();
   return (
     <QueryClientProvider client={queryClient}>
       <StoreProvider>
diff --git a/apps/cs/src/entities/auth/api/login-service.ts b/apps/cs/src/entities/auth/api/login-service.ts
index 671c8bb4c..6922efbbe 100644
--- a/apps/cs/src/entities/auth/api/login-service.ts
+++ b/apps/cs/src/entities/auth/api/login-service.ts
@@ -1,96 +1,105 @@
-import { AxiosError } from "axios";
 import {
   ENDPOINT,
-  JWT_EXPIRATION_TIME,
+  CLAIM_NAME,
   ACCESS_TOKEN,
   AUTH_USER_ID,
-  CLAIM_NAME,
 } from "@/shared/config";
-import type { LoginService, ILogin } from "../model/login-interface";
-import { tokenManager } from "../lib/token-manager";
+import type { ILogin } from "../model/login-interface";
+import {
+  setToken,
+  clearAuthToken,
+  setupRefreshTimer,
+} from "../lib/token-manager";
+import { getRemainingMs } from "../lib/jwt-utils";
 
-export class LoginApiService implements LoginService {
-  private static instance: LoginApiService;
-
-  private constructor() {}
-
-  public static getInstance(): LoginApiService {
-    if (!LoginApiService.instance) {
-      LoginApiService.instance = new LoginApiService();
-    }
-    return LoginApiService.instance;
-  }
-
-  public async login(payload: ILogin): Promise<void> {
-    try {
-      const response = await fetch(`/api/proxy${ENDPOINT.USER_SERVICE.LOGIN}`, {
-        method: "POST",
-        body: JSON.stringify({
-          userId: payload.userId,
-          password: payload.password,
-        }),
-      });
-
-      const data = await response.json();
-      console.log('data ', data)
-      const accessToken = data[ACCESS_TOKEN];
-      const tokenId = data[AUTH_USER_ID];
-
-      if (!accessToken || !tokenId) {
-        if (data.message == 'Invalid Credentials' ) {
-          throw new Error('아이디와 비밀번호가 일치하지 않습니다.');
-        } else if (data.message == 'User not found') {
-          throw new Error('존재하지 않는 아이디입니다.');
-        } else if (data.message == 'User is not active') {
-          throw new Error('활성화되지 않은 계정입니다.');
-        } else if (data.message == 'User is not verified') {
-          throw new Error('이메일 인증이 필요합니다.');
-        } else {
-          throw new Error(data.message);
-        } 
-      }
-
-      tokenManager.setToken(CLAIM_NAME, accessToken);
-      tokenManager.setToken(AUTH_USER_ID, tokenId);
-      tokenManager.setupRefreshTimer(
-        () => this.silentRefresh(),
-        JWT_EXPIRATION_TIME,
-      );
-    } catch (error) {
-      if (error instanceof AxiosError) {
-        throw new Error(`Login 실패 ${error.response?.data?.message}`);
-      }
-      throw new Error(`Login 실패 ${error}`);
-    }
-  }
-
-  public async silentRefresh(): Promise<void> {
-    try {
-      const response = await fetch(
-        `/api/proxy${ENDPOINT.USER_SERVICE.SILENT_REFRESH}`,
-        { method: "PUT" },
-      );
-
-      const data = await response.json();
-      const accessToken = data[ACCESS_TOKEN];
-      const tokenId = data[AUTH_USER_ID];
-
-      if (!accessToken || !tokenId) {
-        throw new Error("Missing required authentication tokens");
-      }
-
-      tokenManager.setToken(CLAIM_NAME, accessToken);
-      tokenManager.setToken(AUTH_USER_ID, tokenId);
-    } catch (error) {
-      tokenManager.clearAuthToken();
-      if (error instanceof AxiosError) {
-        throw new Error(
-          `Silent refresh failed: ${error.response?.data?.message}`,
-        );
-      }
-      throw new Error(`Silent refresh failed: ${error}`);
-    }
+function resolveLoginError(message: string | undefined): string {
+  switch (message) {
+    case "Invalid Credentials":
+      return "아이디와 비밀번호가 일치하지 않습니다.";
+    case "User not found":
+      return "존재하지 않는 아이디입니다.";
+    case "User is not active":
+      return "활성화되지 않은 계정입니다.";
+    case "User is not verified":
+      return "이메일 인증이 필요합니다.";
+    default:
+      return message ?? "로그인에 실패했습니다.";
   }
 }
 
-export const LoginApi = LoginApiService.getInstance();
+export async function login(payload: ILogin): Promise<void> {
+  const response = await fetch(`/api/proxy${ENDPOINT.USER_SERVICE.LOGIN}`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(payload),
+  });
+
+  const data = await response.json();
+
+  if (!response.ok) {
+    throw new Error(resolveLoginError(data?.message));
+  }
+
+  const accessToken = data[ACCESS_TOKEN] as string | undefined;
+  const tokenId = data[AUTH_USER_ID] as string | undefined;
+
+  if (!accessToken || !tokenId) {
+    throw new Error("인증 토큰을 받지 못했습니다.");
+  }
+
+  setToken(CLAIM_NAME, accessToken);
+  setToken(AUTH_USER_ID, tokenId);
+
+  const remainingMs = getRemainingMs(accessToken);
+  if (remainingMs > 0) {
+    setupRefreshTimer(silentRefresh, remainingMs);
+  }
+}
+
+export async function silentRefresh(): Promise<void> {
+  console.log(`[silentRefresh] Called at ${new Date().toISOString()}`);
+  try {
+    const response = await fetch(
+      `/api/proxy${ENDPOINT.USER_SERVICE.SILENT_REFRESH}`,
+      { method: "PUT" },
+    );
+
+    const data = await response.json();
+
+    if (!response.ok) {
+      throw new Error(data?.message ?? "토큰 갱신에 실패했습니다.");
+    }
+
+    const accessToken = data[ACCESS_TOKEN] as string | undefined;
+    const tokenId = data[AUTH_USER_ID] as string | undefined;
+
+    if (!accessToken || !tokenId) {
+      throw new Error("갱신된 인증 토큰을 받지 못했습니다.");
+    }
+
+    setToken(CLAIM_NAME, accessToken);
+    setToken(AUTH_USER_ID, tokenId);
+
+    const remainingMs = getRemainingMs(accessToken);
+    if (remainingMs > 0) {
+      setupRefreshTimer(silentRefresh, remainingMs);
+    }
+  } catch (error) {
+    console.error(
+      `[silentRefresh] Failed at ${new Date().toISOString()}`,
+      error,
+    );
+    clearAuthToken();
+    if (typeof window !== "undefined") {
+      window.dispatchEvent(new CustomEvent("auth:logout"));
+    }
+    // re-throw하지 않음: setupRefreshTimer 콜백의 catch와 이중 처리 방지
+  }
+}
+
+export async function logout(): Promise<void> {
+  clearAuthToken();
+  if (typeof window !== "undefined") {
+    window.dispatchEvent(new CustomEvent("auth:logout"));
+  }
+}
diff --git a/apps/cs/src/entities/auth/index.ts b/apps/cs/src/entities/auth/index.ts
index 97e142225..b4cb7d202 100644
--- a/apps/cs/src/entities/auth/index.ts
+++ b/apps/cs/src/entities/auth/index.ts
@@ -1,2 +1,2 @@
-export { LoginApi } from "./api/login-service";
+export { login, silentRefresh, logout } from "./api/login-service";
 export { AuthWrapper } from "./lib/auth-wrapper";
diff --git a/apps/cs/src/entities/auth/lib/auth-wrapper.tsx b/apps/cs/src/entities/auth/lib/auth-wrapper.tsx
index 57ae75c34..ba6627d8a 100644
--- a/apps/cs/src/entities/auth/lib/auth-wrapper.tsx
+++ b/apps/cs/src/entities/auth/lib/auth-wrapper.tsx
@@ -1,47 +1,80 @@
 "use client";
 
 import { useEffect } from "react";
+import { useRouter } from "next/navigation";
+import { isAxiosError } from "axios";
 import { client } from "@/shared/api";
 import type { IUserInfo } from "@/shared/store";
-import { getCookie, useUserStore } from "@/shared/lib";
+import { useUserStore } from "@/shared/lib";
 import { isAtLoginRedirectUrl } from "@common/network";
 import {
   ENDPOINT,
   AUTH_USER_ID,
   AUTH_LOGIN_REDIRECT_URL,
+  CLAIM_NAME,
 } from "@/shared/config";
+import { getToken, setupRefreshTimer } from "./token-manager";
+import { getRemainingMs } from "./jwt-utils";
+import { silentRefresh } from "../api/login-service";
 
 const AuthWrapper = ({ children }: { children: React.ReactNode }) => {
-  const { userInfo, setUserInfo } = useUserStore((state) => state);
-
-  async function authCheck() {
-    if (isAtLoginRedirectUrl(AUTH_LOGIN_REDIRECT_URL)) {
-      return;
-    }
-
-    const userId = getCookie(AUTH_USER_ID);
-    if (!userId) {
-      throw new Error("Missing required authentication tokens");
-    }
-
-    const response = await client.get<IUserInfo>(
-      `${ENDPOINT.USER_SERVICE.USERS}/info/me`,
-    );
-    if (!userInfo) setUserInfo(response.data);
-  }
+  const router = useRouter();
+  const userInfo = useUserStore((state) => state.userInfo);
+  const setUserInfo = useUserStore((state) => state.setUserInfo);
 
   useEffect(() => {
-    (async () => {
-      try {
-        await authCheck();
-      } catch (error) {
-        console.error(error);
-        setUserInfo(null);
-        if (!isAtLoginRedirectUrl(AUTH_LOGIN_REDIRECT_URL)) {
-          window.location.assign(AUTH_LOGIN_REDIRECT_URL);
-        }
+    // 페이지 새로고침 시 silentRefresh 타이머 복구
+    const token = getToken(CLAIM_NAME);
+    if (token) {
+      const remainingMs = getRemainingMs(token);
+      if (remainingMs > 0) {
+        console.log(
+          `[AuthWrapper] Refresh timer set: ${remainingMs}ms (${remainingMs / 1000}s)`,
+        );
+        setupRefreshTimer(silentRefresh, remainingMs);
       }
-    })();
+    }
+
+    if (isAtLoginRedirectUrl(AUTH_LOGIN_REDIRECT_URL)) return;
+
+    async function authCheck() {
+      const userId = getToken(AUTH_USER_ID);
+      if (!userId) {
+        router.replace(AUTH_LOGIN_REDIRECT_URL);
+        return;
+      }
+
+      if (userInfo) return;
+
+      const response = await client.get<IUserInfo>(
+        `${ENDPOINT.USER_SERVICE.USERS}/info/me`,
+      );
+      setUserInfo(response.data);
+    }
+
+    authCheck().catch((error) => {
+      // 401은 @common/network error-interceptor에서 이미 리다이렉트 처리됨
+      if (isAxiosError(error) && error.response?.status === 401) return;
+
+      console.error(error);
+      setUserInfo(null);
+      if (!isAtLoginRedirectUrl(AUTH_LOGIN_REDIRECT_URL)) {
+        router.replace(AUTH_LOGIN_REDIRECT_URL);
+      }
+    });
+  }, []);
+
+  // silentRefresh 실패 시 auth:logout 이벤트를 수신해 로그인으로 이동
+  useEffect(() => {
+    function handleAuthLogout() {
+      setUserInfo(null);
+      if (!isAtLoginRedirectUrl(AUTH_LOGIN_REDIRECT_URL)) {
+        router.replace(AUTH_LOGIN_REDIRECT_URL);
+      }
+    }
+
+    window.addEventListener("auth:logout", handleAuthLogout);
+    return () => window.removeEventListener("auth:logout", handleAuthLogout);
   }, []);
 
   return <>{children}</>;
diff --git a/apps/cs/src/entities/auth/lib/jwt-utils.ts b/apps/cs/src/entities/auth/lib/jwt-utils.ts
new file mode 100644
index 000000000..05d2b0ff8
--- /dev/null
+++ b/apps/cs/src/entities/auth/lib/jwt-utils.ts
@@ -0,0 +1,32 @@
+interface JwtPayload {
+  exp?: number;
+  [key: string]: unknown;
+}
+
+/**
+ * JWT 토큰의 exp 클레임(Unix timestamp, 초 단위)을 반환합니다.
+ * 파싱 실패 시 null을 반환합니다.
+ */
+export function getJwtExpiry(token: string): number | null {
+  try {
+    const base64Payload = token.split(".")[1];
+    if (!base64Payload) return null;
+
+    const payload = JSON.parse(atob(base64Payload)) as JwtPayload;
+    return typeof payload.exp === "number" ? payload.exp : null;
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * 토큰 만료 1분 전까지 남은 시간(ms)을 반환합니다.
+ * 이미 만료됐거나 파싱 실패 시 0을 반환합니다.
+ */
+export function getRemainingMs(token: string): number {
+  const exp = getJwtExpiry(token);
+  if (!exp) return 0;
+
+  const remainingMs = exp * 1000 - Date.now() - 60_000;
+  return Math.max(0, remainingMs);
+}
diff --git a/apps/cs/src/entities/auth/lib/token-manager.ts b/apps/cs/src/entities/auth/lib/token-manager.ts
index dd9aea352..bef544141 100644
--- a/apps/cs/src/entities/auth/lib/token-manager.ts
+++ b/apps/cs/src/entities/auth/lib/token-manager.ts
@@ -1,82 +1,62 @@
-import { AUTH_USER_ID, CLAIM_NAME } from "@/shared/config";
+import { AUTH_USER_ID, CLAIM_NAME, COOKIE_DOMAIN } from "@/shared/config";
 import { getCookie, setCookie, removeCookie } from "@/shared/lib";
 
-export class TokenManager {
-  private static instance: TokenManager;
-  private refreshTimer: NodeJS.Timeout | null = null;
+let refreshTimer: ReturnType<typeof setTimeout> | null = null;
 
-  private constructor() {}
-
-  public static getInstance(): TokenManager {
-    if (!TokenManager.instance) {
-      TokenManager.instance = new TokenManager();
-    }
-    return TokenManager.instance;
-  }
-
-  public getToken(key: string): string | undefined {
-    return getCookie(key);
-  }
-
-  public setToken(key: string, value: string): void {
-    const domain = this.getCookieDomain();
-    
-    setCookie(key, value, {
-      secure: window.location.protocol === "https:",
-      sameSite: "lax",
-      domain: domain,
-      path: "/", // 모든 경로에서 접근 가능
-    });
-  }
-
-  
-  private getCookieDomain(): string | undefined {
-    const hostname = window.location.hostname;
-    
-    // 개발 환경에서는 localhost 도메인 사용
-    if (hostname === "localhost" || hostname === "127.0.0.1") {
-      return undefined; // localhost에서는 도메인 설정하지 않음
-    }
-    
-    // 운영 환경에서는 서브도메인을 포함한 최상위 도메인 사용
-    if (hostname.includes("hasuon.or.kr")) {
-      return ".hasuon.or.kr";
-    }
-    
-    // 기타 환경에서는 현재 호스트명 사용
-    return hostname;
-  }
-
-  public removeToken(key: string): void {
-    const domain = this.getCookieDomain();
-    removeCookie(key, { domain, path: "/" });
-  }
-
-  public setupRefreshTimer(
-    callback: () => Promise<void>,
-    expirationTime: number,
-  ): void {
-    if (this.refreshTimer) {
-      clearTimeout(this.refreshTimer);
-    }
-
-    this.refreshTimer = setTimeout(() => {
-      callback().catch((error) => {
-        console.error("Silent refresh failed:", error);
-        this.clearAuthToken();
-      });
-    }, expirationTime - 60000);
-  }
-
-  public clearAuthToken(): void {
-    if (this.refreshTimer) {
-      clearTimeout(this.refreshTimer);
-      this.refreshTimer = null;
-    }
-
-    this.removeToken(CLAIM_NAME);
-    this.removeToken(AUTH_USER_ID);
-  }
+export function getToken(key: string): string | undefined {
+  return getCookie(key);
 }
 
-export const tokenManager = TokenManager.getInstance();
+export function setToken(key: string, value: string): void {
+  const domain = getCookieDomain();
+  const isHttps =
+    typeof window !== "undefined" && window.location.protocol === "https:";
+
+  setCookie(key, value, {
+    secure: isHttps,
+    sameSite: "lax",
+    domain,
+    path: "/",
+  });
+}
+
+export function removeToken(key: string): void {
+  const domain = getCookieDomain();
+  removeCookie(key, { domain, path: "/" });
+}
+
+export function setupRefreshTimer(
+  callback: () => Promise<void>,
+  delayMs: number,
+): void {
+  if (refreshTimer) {
+    clearTimeout(refreshTimer);
+  }
+
+  refreshTimer = setTimeout(() => {
+    callback().catch((error) => {
+      console.error("Silent refresh timer callback failed:", error);
+    });
+  }, delayMs);
+}
+
+export function clearAuthToken(): void {
+  if (refreshTimer) {
+    clearTimeout(refreshTimer);
+    refreshTimer = null;
+  }
+
+  removeToken(CLAIM_NAME);
+  removeToken(AUTH_USER_ID);
+}
+
+function getCookieDomain(): string | undefined {
+  if (typeof window === "undefined") return undefined;
+
+  if (COOKIE_DOMAIN) return COOKIE_DOMAIN;
+
+  const { hostname } = window.location;
+  if (hostname === "localhost" || hostname === "127.0.0.1") return undefined;
+
+  return hostname;
+}
diff --git a/apps/cs/src/entities/auth/model/login-interface.ts b/apps/cs/src/entities/auth/model/login-interface.ts
index 5aaf53044..012f81457 100644
--- a/apps/cs/src/entities/auth/model/login-interface.ts
+++ b/apps/cs/src/entities/auth/model/login-interface.ts
@@ -2,8 +2,3 @@ export interface ILogin {
   userId: string;
   password: string;
 }
-
-export interface LoginService {
-  login(payload: ILogin): Promise<void>;
-  silentRefresh(): Promise<void>;
-}
diff --git a/apps/cs/src/pages/auth/login/ui/login-page.tsx b/apps/cs/src/pages/auth/login/ui/login-page.tsx
index fd1e2f809..90de72f4c 100644
--- a/apps/cs/src/pages/auth/login/ui/login-page.tsx
+++ b/apps/cs/src/pages/auth/login/ui/login-page.tsx
@@ -3,7 +3,7 @@
 import { useState } from "react";
 import Image from "next/image";
 import { images } from "@common/assets";
-import { LoginApi } from "@/entities/auth";
+import { login } from "@/entities/auth";
 import "./login.css";
 
 function LoginPage() {
@@ -18,7 +18,7 @@ function LoginPage() {
     const password = formData.get("password") as string;
 
     try {
-      await LoginApi.login({ userId, password });
+      await login({ userId, password });
       window.location.href = "/dashboard";
     } catch (error) {
       const message =
diff --git a/apps/cs/src/shared/config/env.ts b/apps/cs/src/shared/config/env.ts
index 95d1a4477..5e1392b4d 100644
--- a/apps/cs/src/shared/config/env.ts
+++ b/apps/cs/src/shared/config/env.ts
@@ -11,3 +11,4 @@ export const ACCESS_TOKEN =
 export const REFRESH_TOKEN =
   process.env.NEXT_PUBLIC_REFRESH_TOKEN || "refresh-token";
 export const AUTH_USER_ID = process.env.NEXT_PUBLIC_AUTH_USER_ID || "token-id";
+export const COOKIE_DOMAIN = process.env.NEXT_PUBLIC_COOKIE_DOMAIN;