diff --git a/apps/cs/src/entities/auth/api/auth-service.ts b/apps/cs/src/entities/auth/api/auth-service.ts
index e48569677..9837aac8e 100644
--- a/apps/cs/src/entities/auth/api/auth-service.ts
+++ b/apps/cs/src/entities/auth/api/auth-service.ts
@@ -1,16 +1,17 @@
-import { getRemainingMs } from "@common/auth";
 import {
-  ENDPOINT,
-  CLAIM_NAME,
   ACCESS_TOKEN,
   AUTH_USER_ID,
+  CLAIM_NAME,
+  ENDPOINT,
 } from "@/shared/config";
-import type { ILogin } from "../model/auth-interface";
+import { getRemainingMs } from "@common/auth";
+
 import {
-  setToken,
   clearAuthToken,
+  setToken,
   setupRefreshTimer,
 } from "../lib/token-manager";
+import type { AuthPayload, AuthService } from "../model/auth-interface";
 
 function resolveLoginError(message: string | undefined): string {
   switch (message) {
@@ -27,7 +28,7 @@ function resolveLoginError(message: string | undefined): string {
   }
 }
 
-export async function login(payload: ILogin): Promise<void> {
+async function login(payload: AuthPayload): Promise<void> {
   const response = await fetch(`/api/proxy${ENDPOINT.USER_SERVICE.LOGIN}`, {
     method: "POST",
     headers: { "Content-Type": "application/json" },
@@ -56,7 +57,7 @@ export async function login(payload: ILogin): Promise<void> {
   }
 }
 
-export async function silentRefresh(): Promise<void> {
+async function silentRefresh(): Promise<void> {
   console.log(`[silentRefresh] Called at ${new Date().toISOString()}`);
   try {
     const response = await fetch(
@@ -97,9 +98,15 @@ export async function silentRefresh(): Promise<void> {
   }
 }
 
-export async function logout(): Promise<void> {
+async function logout(): Promise<void> {
   clearAuthToken();
   if (typeof window !== "undefined") {
     window.dispatchEvent(new CustomEvent("auth:logout"));
   }
 }
+
+export const authService: AuthService = {
+  login,
+  silentRefresh,
+  logout,
+};
diff --git a/apps/cs/src/entities/auth/index.ts b/apps/cs/src/entities/auth/index.ts
index 76b22ca39..7f0d0081a 100644
--- a/apps/cs/src/entities/auth/index.ts
+++ b/apps/cs/src/entities/auth/index.ts
@@ -1,3 +1,3 @@
-export { login, silentRefresh, logout } from "./api/auth-service";
+export { authService } from "./api/auth-service";
 export { AuthWrapper } from "./lib/auth-wrapper";
-export { tokenManager } from "./lib/token-manager";
\ No newline at end of file
+export { tokenManager } from "./lib/token-manager";
diff --git a/apps/cs/src/entities/auth/lib/auth-wrapper.tsx b/apps/cs/src/entities/auth/lib/auth-wrapper.tsx
index 3c4dea9c7..4b6c181a8 100644
--- a/apps/cs/src/entities/auth/lib/auth-wrapper.tsx
+++ b/apps/cs/src/entities/auth/lib/auth-wrapper.tsx
@@ -2,20 +2,24 @@
 
 import { useEffect } from "react";
 import { useRouter } from "next/navigation";
+
 import { isAxiosError } from "axios";
+
+import { client } from "@/shared/api";
+import {
+  AUTH_LOGIN_REDIRECT_URL,
+  AUTH_USER_ID,
+  CLAIM_NAME,
+  ENDPOINT,
+} from "@/shared/config";
+import { useUserStore } from "@/shared/lib";
+import type { IUserInfo } from "@/shared/store";
 import { getRemainingMs } from "@common/auth";
 import { isAtLoginRedirectUrl } from "@common/network";
-import { client } from "@/shared/api";
-import type { IUserInfo } from "@/shared/store";
-import { useUserStore } from "@/shared/lib";
-import {
-  ENDPOINT,
-  AUTH_USER_ID,
-  AUTH_LOGIN_REDIRECT_URL,
-  CLAIM_NAME,
-} from "@/shared/config";
+
+import { authService } from "../api/auth-service";
+
 import { getToken, setupRefreshTimer } from "./token-manager";
-import { silentRefresh } from "../api/auth-service";
 
 const AuthWrapper = ({ children }: { children: React.ReactNode }) => {
   const router = useRouter();
@@ -31,7 +35,7 @@ const AuthWrapper = ({ children }: { children: React.ReactNode }) => {
         console.log(
           `[AuthWrapper] Refresh timer set: ${remainingMs}ms (${remainingMs / 1000}s)`,
         );
-        setupRefreshTimer(silentRefresh, remainingMs);
+        setupRefreshTimer(authService.silentRefresh, remainingMs);
       }
     }
 
diff --git a/apps/cs/src/entities/auth/model/auth-interface.ts b/apps/cs/src/entities/auth/model/auth-interface.ts
index 012f81457..c4b2d2691 100644
--- a/apps/cs/src/entities/auth/model/auth-interface.ts
+++ b/apps/cs/src/entities/auth/model/auth-interface.ts
@@ -1,4 +1,10 @@
-export interface ILogin {
+export interface AuthPayload {
   userId: string;
   password: string;
 }
+
+export interface AuthService {
+  login(payload: AuthPayload): Promise<void>;
+  silentRefresh(): Promise<void>;
+  logout(): 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 fa7b84185..6a7fe120d 100644
--- a/apps/cs/src/pages/auth/login/ui/login-page.tsx
+++ b/apps/cs/src/pages/auth/login/ui/login-page.tsx
@@ -2,8 +2,10 @@
 
 import { useState } from "react";
 import Image from "next/image";
+
+import { authService } from "@/entities/auth";
 import { images } from "@common/assets";
-import { login } from "@/entities/auth";
+
 import "./login.css";
 
 function LoginPage() {
@@ -18,7 +20,7 @@ function LoginPage() {
     const password = formData.get("password") as string;
 
     try {
-      await login({ userId, password });
+      await authService.login({ userId, password });
       window.location.href = "/dashboard";
     } catch (error) {
       const message =
@@ -31,12 +33,14 @@ function LoginPage() {
     <div className="login fx">
       <div className="left_box fx">
         <div className="text">
-        <h1>
+          <h1>
             유역하수도통합플랫폼
             <br />
             <span>하수도플랫폼 통합관리(CMS)시스템</span>
           </h1>
-          <p>유역하수도통합플랫폼 통합관리(CMS)시스템에 오신 것을 환영합니다.</p>
+          <p>
+            유역하수도통합플랫폼 통합관리(CMS)시스템에 오신 것을 환영합니다.
+          </p>
         </div>
         <div className="img">
           <Image src={images.logo} width={229} height={46} alt="logo" />