diff --git a/src/canvas/canvas.service.ts b/src/canvas/canvas.service.ts
index 07e379a..a383d87 100644
--- a/src/canvas/canvas.service.ts
+++ b/src/canvas/canvas.service.ts
@@ -420,8 +420,8 @@ export class CanvasService {
   }): Promise<DrawPixelResponse> {
     // 캔버스 타입 조회
     const canvasType = await this.getCanvasType(canvas_id);
-    // 게임 모드면 쿨다운 1초, 그 외는 10초
-    const cooldownSeconds = canvasType === 'game_calculation' ? 1 : 10;
+    // 게임 모드면 쿨다운 1초, 그 외는 3초
+    const cooldownSeconds = canvasType === 'game_calculation' ? 1 : 3;
     console.log(
       `[CanvasService] 쿨다운 설정: canvasType=${canvasType}, cooldownSeconds=${cooldownSeconds}`
     );
diff --git a/src/user/dto/create-guest.dto.ts b/src/user/dto/create-guest.dto.ts
new file mode 100644
index 0000000..a009d67
--- /dev/null
+++ b/src/user/dto/create-guest.dto.ts
@@ -0,0 +1,9 @@
+import { ApiProperty } from '@nestjs/swagger';
+
+export class CreateGuestDto {
+  @ApiProperty({
+    example: 'guest123',
+    description: '게스트 닉네임',
+  })
+  userName: string;
+} 
\ No newline at end of file
diff --git a/src/user/entity/user.entity.ts b/src/user/entity/user.entity.ts
index 7f38268..6fe1910 100644
--- a/src/user/entity/user.entity.ts
+++ b/src/user/entity/user.entity.ts
@@ -14,8 +14,8 @@ export class User {
   @Column({ name: 'email', unique: true, nullable: false })
   email: string;
 
-  @Column({ name: 'password', nullable: true })
-  password: string;
+  @Column({ name: 'password', nullable: true, type: 'varchar', length: 100 })
+  password: string | null;
 
   @Column({ name: 'created_at', type: 'timestamp' })
   createdAt: Date;
diff --git a/src/user/user.controller.ts b/src/user/user.controller.ts
index 44eb9dd..6be7ffd 100644
--- a/src/user/user.controller.ts
+++ b/src/user/user.controller.ts
@@ -25,6 +25,7 @@ import { OAuthCallbackDto } from './dto/oauth_callback_dto.dto';
 import { JwtAuthGuard } from 'src/auth/jwt.guard';
 import { AuthRequest } from 'src/interface/AuthRequest.interface';
 import { SignedCookies } from 'src/interface/SignedCookies.interface';
+import { CreateGuestDto } from './dto/create-guest.dto';
 
 @ApiTags('api/user')
 @Controller('api/user')
@@ -74,6 +75,27 @@ export class UserController {
     }
   }
 
+  @Post('signup')
+  @ApiOperation({ summary: '게스트 회원가입(로그인) API' })
+  async guestSignUp(
+    @Body() createGuestDto: CreateGuestDto,
+    @Res({ passthrough: true }) res: Response
+  ) {
+    const result = await this.userService.guestSignUp(createGuestDto.userName);
+    // access_token을 헤더로, refresh_token을 쿠키로 내려줌 (OAuth와 동일)
+    res.setHeader('Authorization', `Bearer ${result.access_token}`);
+    res.cookie('refresh_token', result.refresh_token, {
+      httpOnly: true,
+      secure: true,
+      sameSite: 'none',
+      maxAge: 1 * 24 * 60 * 60 * 1000, // 1일
+      signed: true,
+    });
+    // 응답 바디에는 토큰 정보 포함하지 않고, 나머지 정보만 반환
+    const { access_token, refresh_token, ...rest } = result;
+    return rest;
+  }
+
   @Get('info')
   @ApiOperation({ summary: '마이페이지 API' })
   @UseGuards(JwtAuthGuard)
diff --git a/src/user/user.service.ts b/src/user/user.service.ts
index 41dbf52..c41ac55 100644
--- a/src/user/user.service.ts
+++ b/src/user/user.service.ts
@@ -11,6 +11,7 @@ import { AuthService } from 'src/auth/auth.service';
 import { JwtService } from '@nestjs/jwt';
 import Redis from 'ioredis';
 import { JwtPayload } from '../interface/JwtPaylod.interface';
+import { v4 as uuidv4 } from 'uuid';
 
 interface CommonTokenResponse {
   access_token: string;
@@ -250,4 +251,34 @@ export class UserService {
       throw new NotFoundException('로그아웃 실패: 레디스에서 토큰 삭제 실패');
     }
   }
+
+  async guestSignUp(userName: string) {
+    // uuid로 이메일 생성
+    const uuid = uuidv4();
+    const email = `${uuid}@guest.local`;
+    // 이메일 중복 체크
+    const exist = await this.userRepository.findOne({ where: { email } });
+    if (exist) {
+      throw new Error('이미 존재하는 이메일입니다.');
+    }
+    const now = new Date();
+    const newUser = this.userRepository.create({
+      email: email,
+      password: null,
+      createdAt: now,
+      updatedAt: now,
+      userName: userName,
+    });
+    const saved: User = await this.userRepository.save(newUser);
+    const token = await this.authService.generateJWT(saved.id, saved.userName);
+    return {
+      isSuccess: true,
+      code: '200',
+      message: '요청에 성공하였습니다.',
+      createdAt: now.toISOString(),
+      data: 'Join Success',
+      access_token: token.access_token,
+      refresh_token: token.refresh_token,
+    };
+  }
 }