diff --git a/.env.sample b/.env.sample
index d5e995bc..97457612 100644
--- a/.env.sample
+++ b/.env.sample
@@ -4,8 +4,8 @@ DATABASE_URL="postgresql://ft_transcendence:supersecretpassword@db/ft_transcende
 NEXT_PUBLIC_API_ENDPOINT="https://localhost"
 NEXT_PUBLIC_UPLOADS_BASE="https://localhost"
 NEXT_PUBLIC_WS_ENDPOINT="wss://localhost"
-API_42_UID="u-s4t2ud-94c0c5cf7592264ccffbc786dac656324fd173fd328b1bc442dbf9e2d1f316a1"
-API_42_SECRET="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"
+API_42_UID="u-s4t2ud-something-something"
+API_42_SECRET="s-s4t2ud-something-something"
 API_42_CALLBACK="https://localhost/api/auth/42/callback"
 FRONTEND_ORIGIN="https://localhost"
 JWT_SECRET="super secret key :)"
diff --git a/.vscode/settings.json b/.vscode/settings.json
index b71f6adb..5ac57d3d 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -10,7 +10,7 @@
     "editor.defaultFormatter": "esbenp.prettier-vscode",
   },
   "editor.codeActionsOnSave": {
-    "source.organizeImports": true,
+    "source.organizeImports": "explicit"
   },
   "[prisma]": {
     "editor.formatOnSave": true,
diff --git a/project/backend/.env.sample.dev b/project/backend/.env.sample.dev
index 8bd7c70c..11b84121 100644
--- a/project/backend/.env.sample.dev
+++ b/project/backend/.env.sample.dev
@@ -2,8 +2,8 @@ NODE_ENV="development"
 PORT=60080
 DATABASE_URL="postgresql://ft_transcendence:supersecretpassword@localhost:65432/ft_transcendence?schema=public"
 # TODO: regenerate/replace API secret later
-API_42_UID="u-s4t2ud-94c0c5cf7592264ccffbc786dac656324fd173fd328b1bc442dbf9e2d1f316a1"
-API_42_SECRET="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"
+API_42_UID="u-s4t2ud-something-something"
+API_42_SECRET="s-s4t2ud-something-something"
 API_42_CALLBACK="http://localhost:53000/api/auth/42/callback"
 FRONTEND_ORIGIN="http://localhost:53000"
 JWT_SECRET="super secret key :)"
diff --git a/project/backend/src/channel/dto/message-pagination.dto.ts b/project/backend/src/channel/dto/message-pagination.dto.ts
index c83976a0..9c2b9372 100644
--- a/project/backend/src/channel/dto/message-pagination.dto.ts
+++ b/project/backend/src/channel/dto/message-pagination.dto.ts
@@ -16,11 +16,11 @@ export class MessagePaginationDto {
   @ApiProperty({
     description: '페이지당 메시지 수',
     required: false,
-    default: 10,
     example: 10,
   })
   @Type(() => Number)
+  @IsOptional()
   @IsInt()
   @Min(1)
-  pageSize: number = 10;
+  pageSize?: number;
 }
diff --git a/project/backend/src/users/dto/update-user.dto.ts b/project/backend/src/users/dto/update-user.dto.ts
index c8188b8c..6ba8135b 100644
--- a/project/backend/src/users/dto/update-user.dto.ts
+++ b/project/backend/src/users/dto/update-user.dto.ts
@@ -1,5 +1,5 @@
 import { ApiPropertyOptional } from '@nestjs/swagger';
-import { IsOptional, IsString, Matches } from 'class-validator';
+import { IsOptional, IsString, Matches, MaxLength } from 'class-validator';
 
 export class UpdateUserDto {
   @ApiPropertyOptional({
@@ -25,5 +25,6 @@ export class UpdateUserDto {
   @ApiPropertyOptional({ description: '프로필 상태 메세지', required: false })
   @IsOptional()
   @IsString()
+  @MaxLength(100)
   statusMessage?: string;
 }
diff --git a/project/frontend/src/components/profile/ProfileEditModal.tsx b/project/frontend/src/components/profile/ProfileEditModal.tsx
index aaddd315..c783ac43 100644
--- a/project/frontend/src/components/profile/ProfileEditModal.tsx
+++ b/project/frontend/src/components/profile/ProfileEditModal.tsx
@@ -44,13 +44,8 @@ export const ProfileEditModal: React.FC<ModalProfileProps> = ({
       });
       fetchData();
       onClose();
-    } catch (error) {
-      if (error instanceof Error) {
-        alert(`${error.message}`);
-        console.error('Error saving changes:', error);
-      } else {
-        console.error('Non-Error type error:', error);
-      }
+    } catch (error: any) {
+      alert(error?.error?.message ?? '프로필 수정에 실패했습니다.');
     }
   }, [api, newData, onClose, fetchData]);
 
diff --git a/project/frontend/src/components/sign-in/RegisterUser.tsx b/project/frontend/src/components/sign-in/RegisterUser.tsx
index 3119f2cc..24a9d1a1 100644
--- a/project/frontend/src/components/sign-in/RegisterUser.tsx
+++ b/project/frontend/src/components/sign-in/RegisterUser.tsx
@@ -28,14 +28,14 @@ export default function RegisterUser({
     try {
       await api.authControllerRegister({ nickname, imageUrl });
       router.push('/friend');
-    } catch (error) {
+    } catch (error: any) {
+      error?.error?.message && alert(`${error?.error?.message}`);
       console.error('error', error);
     }
   }, [api, imageUrl, nickname, router]);
 
   return (
     <div className="w-xl h-xl bg-light-background border-2 border-dark-purple rounded-lg flex flex-col gap-xl justify-center items-start p-xl">
-      {/* <form encType="multipart/form-data"> */}
       <p className="font-semibold text-h3">선택한 닉네임: {nickname}</p>
       <div className="flex flex-row items-center">
         <p className="font-semibold text-h3">선택한 아바타: </p>
@@ -47,7 +47,6 @@ export default function RegisterUser({
           height={100}
         />
       </div>
-      {/* </form> */}
       <div className="self-end">
         <Button onClick={handleSubmitClick}>가입하기!</Button>
       </div>
diff --git a/project/frontend/src/hooks/chat/useSocket.ts b/project/frontend/src/hooks/chat/useSocket.ts
index ceab99b1..5fbb39bd 100644
--- a/project/frontend/src/hooks/chat/useSocket.ts
+++ b/project/frontend/src/hooks/chat/useSocket.ts
@@ -1,3 +1,4 @@
+import useToast from '@/components/common/useToast';
 import {
   MessageContentInterface,
   messageType,
@@ -14,7 +15,7 @@ export const useSocket = (
   render: object,
 ) => {
   const router = useRouter();
-  // const { openMessage } = useToast();
+  const { openMessage } = useToast();
   useEffect(() => {
     const socket = getSocket();
     const localMe = localStorage.getItem('me');
@@ -65,7 +66,7 @@ export const useSocket = (
     ) => {
       socket.on('leave', (res: any) => {
         if (res.data.member.id === meId) {
-          // openMessage('채널에서 나갔습니다!');
+          openMessage('채널에서 나갔습니다!');
           router.replace('/channel');
         } else {
           setMessageWithScrollTarget(render, setMessages, res);
@@ -94,9 +95,9 @@ export const useSocket = (
         ) {
           if (targetUserId === meId && channelId === res.data.channelId) {
             if (res.data.actionType === 'KICK') {
-              // openMessage('방장이 나가라고 합니다!');
+              openMessage('방장이 나가라고 합니다!');
             } else {
-              // openMessage('방장이 채널에서 차단했습니다!');
+              openMessage('방장이 채널에서 차단했습니다!');
             }
             router.replace('/channel');
           }
@@ -105,13 +106,13 @@ export const useSocket = (
           channelId === res.data.channelId &&
           targetUserId === meId
         ) {
-          // openMessage('관리자가 되었습니다!');
+          openMessage('관리자가 되었습니다!');
         } else if (
           res.data.actionType === 'MUTE' &&
           targetUserId === meId &&
           channelId === res.data.channelId
         ) {
-          // openMessage('방장이 1분간 조용히 하래요 ㅠ');
+          openMessage('방장이 1분간 조용히 하래요 ㅠ');
         }
       });
     };
@@ -130,5 +131,5 @@ export const useSocket = (
       socket.off('join');
       socket.off('kickBanPromote');
     };
-  }, [type, setMessages, channelId, router, targetName, render]);
+  }, [type, setMessages, channelId, router, targetName, render, openMessage]);
 };