diff --git a/src/app/api/auth/check-email/route.ts b/src/app/api/auth/check-email/route.ts
index 54a4bf6..5f042cc 100644
--- a/src/app/api/auth/check-email/route.ts
+++ b/src/app/api/auth/check-email/route.ts
@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from "next/server";
 import { createPublicAuthServerAxios } from "@/lib/api/server";
+import { AUTH_ENDPOINT } from "@/lib/api/constants";
 
 export async function GET(request: NextRequest) {
   try {
@@ -20,7 +21,7 @@ export async function GET(request: NextRequest) {
     // 로컬 게이트웨이(localhost:8099)를 통해 /das/**로 라우팅됩니다
     const serverAxios = createPublicAuthServerAxios();
     const response = await serverAxios.get(
-      `/das/api/auth/check-email?email=${encodeURIComponent(email)}`
+      `${AUTH_ENDPOINT}/check-email?email=${encodeURIComponent(email)}`
     );
 
     return NextResponse.json(response.data);
diff --git a/src/app/api/auth/check-nickname/route.ts b/src/app/api/auth/check-nickname/route.ts
index e66b874..cac6f3e 100644
--- a/src/app/api/auth/check-nickname/route.ts
+++ b/src/app/api/auth/check-nickname/route.ts
@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from "next/server";
 import { createPublicAuthServerAxios } from "@/lib/api/server";
+import { AUTH_ENDPOINT } from "@/lib/api/constants";
 
 export async function GET(request: NextRequest) {
   try {
@@ -20,7 +21,7 @@ export async function GET(request: NextRequest) {
     // 로컬 게이트웨이(localhost:8099)를 통해 /das/**로 라우팅됩니다
     const serverAxios = createPublicAuthServerAxios();
     const response = await serverAxios.get(
-      `/das/api/auth/check-nickname?nickname=${encodeURIComponent(nickname)}`
+      `${AUTH_ENDPOINT}/check-nickname?nickname=${encodeURIComponent(nickname)}`
     );
 
     return NextResponse.json(response.data);
diff --git a/src/app/api/auth/login/route.ts b/src/app/api/auth/login/route.ts
index 8f554c0..9ca53ea 100644
--- a/src/app/api/auth/login/route.ts
+++ b/src/app/api/auth/login/route.ts
@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from "next/server";
 import { createAuthServerAxios } from "@/lib/api/server";
+import { AUTH_ENDPOINT } from "@/lib/api/constants";
 
 export async function POST(request: NextRequest) {
   try {
@@ -9,7 +10,7 @@ export async function POST(request: NextRequest) {
     // Auth Server로 로그인 요청
     // 로컬 게이트웨이(localhost:8099)를 통해 /das/**로 라우팅됩니다
     const serverAxios = createAuthServerAxios(request);
-    const response = await serverAxios.post("/das/api/auth/login", {
+    const response = await serverAxios.post(`${AUTH_ENDPOINT}/login`, {
       email,
       password,
     });
diff --git a/src/app/api/auth/me/route.ts b/src/app/api/auth/me/route.ts
index f1b61bc..61217e5 100644
--- a/src/app/api/auth/me/route.ts
+++ b/src/app/api/auth/me/route.ts
@@ -1,7 +1,17 @@
+import { USER_ENDPOINT } from "@/lib/api/constants";
+import { createAuthServerAxios } from "@/lib/api/server";
 import { NextRequest, NextResponse } from "next/server";
 
 export async function GET(request: NextRequest) {
   try {
+    const serverAxios = createAuthServerAxios(request);
+    const response = await serverAxios.get(`${USER_ENDPOINT}/info`);
+
+    console.log("User info response:", response.data);
+
+    return NextResponse.json(response.data);
+
+    /*
     // 쿠키에서 access_token 확인
     const accessToken = request.cookies.get("access_token")?.value;
 
@@ -28,7 +38,6 @@ export async function GET(request: NextRequest) {
       return NextResponse.json({
         success: true,
         data: {
-          userId: payload.userId,
           email: payload.sub,
           nickname: payload.nickname || "사용자",
           profileImageUrl: null,
@@ -43,6 +52,7 @@ export async function GET(request: NextRequest) {
         { status: 401 }
       );
     }
+    */
   } catch (error) {
     console.error("사용자 정보 조회 API 에러:", error);
     return NextResponse.json(
diff --git a/src/app/api/auth/signup/route.ts b/src/app/api/auth/signup/route.ts
index e875366..f84b833 100644
--- a/src/app/api/auth/signup/route.ts
+++ b/src/app/api/auth/signup/route.ts
@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from "next/server";
 import { createPublicAuthServerAxios } from "@/lib/api/server";
+import { AUTH_ENDPOINT } from "@/lib/api/constants";
 
 export async function POST(request: NextRequest) {
   try {
@@ -9,13 +10,25 @@ export async function POST(request: NextRequest) {
     // 로컬 게이트웨이(localhost:8099)를 통해 /das/**로 라우팅됩니다
     // multipart/form-data로 전송
     const serverAxios = createPublicAuthServerAxios();
-    const response = await serverAxios.post("/das/api/auth/signup", formData, {
+    const response = await serverAxios.post(`${AUTH_ENDPOINT}/signup`, formData, {
       headers: {
         "Content-Type": "multipart/form-data",
       },
     });
 
-    return NextResponse.json(response.data);
+    const nextResponse = NextResponse.json(response.data);
+
+    const cookies = response.headers["set-cookie"];
+    if (cookies) {
+      if (Array.isArray(cookies)) {
+        cookies.forEach((cookie) => nextResponse.headers.append("Set-Cookie", cookie));
+      } else {
+        nextResponse.headers.set("Set-Cookie", cookies);
+      }
+    }
+
+    return nextResponse;
+
   } catch (error: unknown) {
     console.error("회원가입 API 에러:", error);
 
diff --git a/src/app/api/auth/signup/social/route.ts b/src/app/api/auth/signup/social/route.ts
index bff70da..9109b76 100644
--- a/src/app/api/auth/signup/social/route.ts
+++ b/src/app/api/auth/signup/social/route.ts
@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from "next/server";
 import { createPublicAuthServerAxios } from "@/lib/api/server";
+import { AUTH_ENDPOINT } from "@/lib/api/constants";
 
 export async function POST(request: NextRequest) {
   try {
@@ -8,13 +9,25 @@ export async function POST(request: NextRequest) {
 
     // Auth Server로 소셜 회원가입 요청
     const serverAxios = createPublicAuthServerAxios();
-    const response = await serverAxios.post("/das/api/auth/signup/social", formData, {
+    const response = await serverAxios.post(`${AUTH_ENDPOINT}/signup/social`, formData, {
       headers: {
         "Content-Type": "multipart/form-data",
       },
     });
 
-    return NextResponse.json(response.data);
+    const nextResponse = NextResponse.json(response.data);
+
+    const cookies = response.headers["set-cookie"];
+    if (cookies) {
+      if (Array.isArray(cookies)) {
+        cookies.forEach((cookie) => nextResponse.headers.append("Set-Cookie", cookie));
+      } else {
+        nextResponse.headers.set("Set-Cookie", cookies);
+      }
+    }
+
+    return nextResponse;
+
   } catch (error: unknown) {
     console.error("소셜 회원가입 API 에러:", error);
 
diff --git a/src/components/auth/SocialSignUpForm.tsx b/src/components/auth/SocialSignUpForm.tsx
index f48cd65..d2153f2 100644
--- a/src/components/auth/SocialSignUpForm.tsx
+++ b/src/components/auth/SocialSignUpForm.tsx
@@ -208,19 +208,24 @@ export default function SocialSignUpForm({
                 <FormControl>
                   <div className="flex flex-col items-center gap-4">
                     {previewUrl ? (
-                      <div className="relative w-32 h-32 rounded-full overflow-hidden border-4 border-gray-200">
-                        <Image
-                          src={previewUrl}
-                          alt="Profile preview"
-                          fill
-                          className="object-cover"
-                        />
+                      <div className="relative w-32 h-32">
+
+                        <div className="w-full h-full rounded-full overflow-hidden border-4 border-gray-200 shadow-sm relative">
+                          <Image
+                            src={previewUrl}
+                            alt="Profile preview"
+                            fill
+                            className="object-cover"
+                          />
+                        </div>
+
                         <button
                           type="button"
                           onClick={removeImage}
-                          className="absolute top-1 right-1 w-6 h-6 bg-red-500 text-white rounded-full flex items-center justify-center hover:bg-red-600 transition-colors"
+                          className="absolute top-1 right-1 w-8 h-8 bg-red-500 text-white rounded-full flex items-center justify-center hover:bg-red-600 transition-all shadow-lg z-10 border-2 border-white"
+                          title="이미지 삭제"
                         >
-                          <X className="w-4 h-4" />
+                          <X className="w-5 h-5" />
                         </button>
                       </div>
                     ) : (
@@ -228,6 +233,7 @@ export default function SocialSignUpForm({
                         <User className="w-12 h-12 text-gray-400" />
                       </div>
                     )}
+
                     <label className="cursor-pointer">
                       <input
                         type="file"
diff --git a/src/lib/api/constants.ts b/src/lib/api/constants.ts
index 96c6262..8ae89ed 100644
--- a/src/lib/api/constants.ts
+++ b/src/lib/api/constants.ts
@@ -7,3 +7,7 @@ export const AUCTION_HISTORY_ENDPOINT = "/oab/auction-history";
 export const BOARDS_ENDPOINT = "/dcs/api/boards";
 export const POSTS_ENDPOINT = "/dcs/api/posts";
 export const COMMENTS_ENDPOINT = "/dcs/api/comments";
+
+// Auth API Endpoints (prefix: /das/api)
+export const AUTH_ENDPOINT = "/das/api/auth";
+export const USER_ENDPOINT = "/das/api/user";
diff --git a/src/lib/api/gateway-selector.ts b/src/lib/api/gateway-selector.ts
index 7861945..7c0d69f 100644
--- a/src/lib/api/gateway-selector.ts
+++ b/src/lib/api/gateway-selector.ts
@@ -83,9 +83,9 @@ export function selectGatewayUrl(path: string): string {
  * 클라이언트 환경 변수를 사용할 수 없으므로 별도 함수 제공
  */
 export function selectServerGatewayUrl(path: string): string {
-  const localUrl = process.env.GATEWAY_LOCAL_URL;
-  const devUrl = process.env.GATEWAY_DEV_URL;
-  const useLocalFor = process.env.USE_LOCAL_GATEWAY_FOR || "";
+  const localUrl = process.env.NEXT_PUBLIC_GATEWAY_LOCAL_URL;
+  const devUrl = process.env.NEXT_PUBLIC_GATEWAY_DEV_URL;
+  const useLocalFor = process.env.NEXT_PUBLIC_USE_LOCAL_GATEWAY_FOR || "";
 
   // 기본값: 개발 서버 게이트웨이
   if (!devUrl) {
diff --git a/src/lib/auth/socialAuth.ts b/src/lib/auth/socialAuth.ts
index 2632dab..dd8e815 100644
--- a/src/lib/auth/socialAuth.ts
+++ b/src/lib/auth/socialAuth.ts
@@ -2,6 +2,8 @@
  * 소셜 로그인/회원가입 유틸리티
  */
 
+import { selectGatewayUrl } from "../api/gateway-selector";
+
 export type SocialProvider = "google" | "kakao" | "naver";
 
 export interface SocialAuthResponse {
@@ -28,8 +30,10 @@ export function initiateSocialLogin(provider: SocialProvider): void {
   const currentUrl = window.location.href;
   sessionStorage.setItem("social_login_return_url", currentUrl);
 
+  const gateWayUrl = selectGatewayUrl("/das");
+
   // 로컬 게이트웨이를 통해 Auth Server의 OAuth2 엔드포인트로 이동
-  const authUrl = `http://localhost:8099/das/oauth2/authorization/${provider}`;
+  const authUrl = `http://${gateWayUrl}/das/oauth2/authorization/${provider}`;
 
   // 새 탭에서 소셜 로그인 팝업 열기 (더 나은 UX)
   const width = 500;