diff --git a/fourthSeminar/.gitignore b/fourthSeminar/.gitignore
new file mode 100644
index 0000000..733be1e
--- /dev/null
+++ b/fourthSeminar/.gitignore
@@ -0,0 +1,39 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+application.yaml
\ No newline at end of file
diff --git a/fourthSeminar/build.gradle b/fourthSeminar/build.gradle
new file mode 100644
index 0000000..92ba45c
--- /dev/null
+++ b/fourthSeminar/build.gradle
@@ -0,0 +1,44 @@
+plugins {
+	id 'java'
+	id 'org.springframework.boot' version '2.7.11'
+	id 'io.spring.dependency-management' version '1.0.15.RELEASE'
+}
+
+group = 'sopt.org'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = '11'
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'org.springframework.boot:spring-boot-starter-web'
+	implementation 'org.springframework.boot:spring-boot-starter-validation'
+	compileOnly 'org.projectlombok:lombok'
+	annotationProcessor 'org.projectlombok:lombok'
+	testImplementation 'org.springframework.boot:spring-boot-starter-test'
+
+	// Health Check
+	implementation 'org.springframework.boot:spring-boot-starter-actuator'
+
+	// JPA & Database
+	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
+	implementation 'mysql:mysql-connector-java:8.0.32'
+
+	//JWT
+	implementation group: 'io.jsonwebtoken', name: 'jjwt-api', version: '0.11.2'
+	implementation group: 'io.jsonwebtoken', name: 'jjwt-impl', version: '0.11.2'
+	implementation group: 'io.jsonwebtoken', name: 'jjwt-jackson', version: '0.11.2'
+
+	// S3 AWS
+	implementation group: 'org.springframework.cloud', name: 'spring-cloud-starter-aws', version: '2.2.6.RELEASE'
+
+	// swagger
+	implementation 'org.springdoc:springdoc-openapi-ui:1.7.0'
+
+}
+
+tasks.named('test') {
+	useJUnitPlatform()
+}
diff --git a/fourthSeminar/gradle/wrapper/gradle-wrapper.jar b/fourthSeminar/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..249e583
Binary files /dev/null and b/fourthSeminar/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/fourthSeminar/gradle/wrapper/gradle-wrapper.properties b/fourthSeminar/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..774fae8
--- /dev/null
+++ b/fourthSeminar/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/fourthSeminar/gradlew b/fourthSeminar/gradlew
new file mode 100644
index 0000000..a69d9cb
--- /dev/null
+++ b/fourthSeminar/gradlew
@@ -0,0 +1,240 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/fourthSeminar/gradlew.bat b/fourthSeminar/gradlew.bat
new file mode 100644
index 0000000..53a6b23
--- /dev/null
+++ b/fourthSeminar/gradlew.bat
@@ -0,0 +1,91 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/fourthSeminar/settings.gradle b/fourthSeminar/settings.gradle
new file mode 100644
index 0000000..0e45ef5
--- /dev/null
+++ b/fourthSeminar/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'fourthSeminar'
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/FourthSeminarApplication.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/FourthSeminarApplication.java
new file mode 100644
index 0000000..2ca0b29
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/FourthSeminarApplication.java
@@ -0,0 +1,15 @@
+package sopt.org.fourthSeminar;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
+
+@EnableJpaAuditing
+@SpringBootApplication
+public class FourthSeminarApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(FourthSeminarApplication.class, args);
+	}
+
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/common/advice/ControllerExceptionAdvice.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/common/advice/ControllerExceptionAdvice.java
new file mode 100644
index 0000000..d8ad04c
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/common/advice/ControllerExceptionAdvice.java
@@ -0,0 +1,47 @@
+package sopt.org.fourthSeminar.common.advice;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import sopt.org.fourthSeminar.common.dto.ApiResponse;
+import sopt.org.fourthSeminar.exception.Error;
+import sopt.org.fourthSeminar.exception.model.SoptException;
+
+import java.util.Objects;
+
+//@RestControllerAdvice
+public class ControllerExceptionAdvice {
+
+    /**
+     * 400 BAD_REQUEST
+     */
+
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    protected ApiResponse handleMethodArgumentNotValidException(final MethodArgumentNotValidException e) {
+        FieldError fieldError = Objects.requireNonNull(e.getFieldError());
+        return ApiResponse.error(Error.REQUEST_VALIDATION_EXCEPTION, String.format("%s. (%s)", fieldError.getDefaultMessage(), fieldError.getField()));
+    }
+
+    /**
+     * 500 Internal Server
+     */
+    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+    @ExceptionHandler(Exception.class)
+    protected ApiResponse<Object> handleException(final Exception e) {
+        return ApiResponse.error(Error.INTERNAL_SERVER_ERROR);
+    }
+
+    /**
+     * Sopt custom error
+     */
+    @ExceptionHandler(SoptException.class)
+    protected ResponseEntity<ApiResponse> handleSoptException(SoptException e) {
+        return ResponseEntity.status(e.getHttpStatus())
+                .body(ApiResponse.error(e.getError(), e.getMessage()));
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/common/dto/ApiResponse.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/common/dto/ApiResponse.java
new file mode 100644
index 0000000..125ac0d
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/common/dto/ApiResponse.java
@@ -0,0 +1,34 @@
+package sopt.org.fourthSeminar.common.dto;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import sopt.org.fourthSeminar.exception.Success;
+import sopt.org.fourthSeminar.exception.Error;
+
+@Getter
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class ApiResponse<T> {
+
+    private final int code;
+    private final String message;
+    private T data;
+
+    public static ApiResponse success(Success success) {
+        return new ApiResponse<>(success.getHttpStatusCode(), success.getMessage());
+    }
+
+    public static <T> ApiResponse<T> success(Success success, T data) {
+        return new ApiResponse<T>(success.getHttpStatusCode(), success.getMessage(), data);
+    }
+
+    public static ApiResponse error(Error error) {
+        return new ApiResponse<>(error.getHttpStatusCode(), error.getMessage());
+    }
+
+    public static ApiResponse error(Error error, String message) {
+        return new ApiResponse<>(error.getHttpStatusCode(), message);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/WebConfig.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/WebConfig.java
new file mode 100644
index 0000000..baba9e2
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/WebConfig.java
@@ -0,0 +1,21 @@
+package sopt.org.fourthSeminar.config;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import sopt.org.fourthSeminar.config.resolver.UserIdResolver;
+
+import java.util.List;
+
+@RequiredArgsConstructor
+@Configuration
+public class WebConfig implements WebMvcConfigurer {
+
+    private final UserIdResolver userIdResolver;
+
+    @Override
+    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+        resolvers.add(userIdResolver);
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/jwt/JwtService.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/jwt/JwtService.java
new file mode 100644
index 0000000..5c5a398
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/jwt/JwtService.java
@@ -0,0 +1,80 @@
+package sopt.org.fourthSeminar.config.jwt;
+
+import io.jsonwebtoken.*;
+import io.jsonwebtoken.security.Keys;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+import sopt.org.fourthSeminar.exception.Error;
+import sopt.org.fourthSeminar.exception.model.UnauthorizedException;
+
+
+import javax.annotation.PostConstruct;
+import java.nio.charset.StandardCharsets;
+import java.security.Key;
+import java.util.Base64;
+import java.util.Date;
+
+@Service
+public class JwtService {
+
+    @Value(value = "${jwt.secret}")
+    private String jwtSecret;
+
+    @PostConstruct
+    protected void init() {
+        jwtSecret = Base64.getEncoder()
+                .encodeToString(jwtSecret.getBytes(StandardCharsets.UTF_8));
+    }
+
+    // JWT 토큰 발급
+    public String issuedToken(String userId) {
+        final Date now = new Date();
+
+        // 클레임 생성
+        final Claims claims = Jwts.claims()
+                .setSubject("access_token")
+                .setIssuedAt(now)
+                .setExpiration(new Date(now.getTime() + 120 * 60 * 1000L));
+
+        //private claim 등록
+        claims.put("userId", userId);
+
+        return Jwts.builder()
+                .setHeaderParam(Header.TYPE , Header.JWT_TYPE)
+                .setClaims(claims)
+                .signWith(getSigningKey())
+                .compact();
+    }
+
+    private Key getSigningKey() {
+        final byte[] keyBytes = jwtSecret.getBytes(StandardCharsets.UTF_8);
+        return Keys.hmacShaKeyFor(keyBytes);
+    }
+
+    // JWT 토큰 검증
+    public boolean verifyToken(String token) {
+        try {
+            final Claims claims = getBody(token);
+            return true;
+        } catch (RuntimeException e) {
+            if (e instanceof ExpiredJwtException) {
+                throw new UnauthorizedException(Error.TOKEN_TIME_EXPIRED_EXCEPTION, Error.TOKEN_TIME_EXPIRED_EXCEPTION.getMessage());
+            }
+            return false;
+        }
+    }
+
+    private Claims getBody(final String token) {
+        return Jwts.parserBuilder()
+                .setSigningKey(getSigningKey())
+                .build()
+                .parseClaimsJws(token)
+                .getBody();
+    }
+
+    // JWT 토큰 내용 확인
+    public String getJwtContents(String token) {
+        final Claims claims = getBody(token);
+        return (String) claims.get("userId");
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/resolver/UserId.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/resolver/UserId.java
new file mode 100644
index 0000000..9938d25
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/resolver/UserId.java
@@ -0,0 +1,11 @@
+package sopt.org.fourthSeminar.config.resolver;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface UserId {
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/resolver/UserIdResolver.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/resolver/UserIdResolver.java
new file mode 100644
index 0000000..cbd57ee
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/resolver/UserIdResolver.java
@@ -0,0 +1,44 @@
+package sopt.org.fourthSeminar.config.resolver;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.core.MethodParameter;
+import org.springframework.stereotype.Component;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
+import sopt.org.fourthSeminar.config.jwt.JwtService;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.validation.constraints.NotNull;
+
+@RequiredArgsConstructor
+@Component
+public class UserIdResolver implements HandlerMethodArgumentResolver {
+
+    private final JwtService jwtService;
+
+    @Override
+    public boolean supportsParameter(MethodParameter parameter) {
+        return parameter.hasParameterAnnotation(UserId.class) && Long.class.equals(parameter.getParameterType());
+    }
+
+    @Override
+    public Object resolveArgument(@NotNull MethodParameter parameter, ModelAndViewContainer modelAndViewContainer, @NotNull NativeWebRequest webRequest, WebDataBinderFactory binderFactory) {
+        final HttpServletRequest request = (HttpServletRequest) webRequest.getNativeRequest();
+        final String token = request.getHeader("Authorization").split(" ")[1];
+
+        // 토큰 검증
+        if (!jwtService.verifyToken(token)) {
+            throw new RuntimeException(String.format("USER_ID를 가져오지 못했습니다. (%s - %s)", parameter.getClass(), parameter.getMethod()));
+        }
+
+        // 유저 아이디 반환
+        final String tokenContents = jwtService.getJwtContents(token);
+        try {
+            return Long.parseLong(tokenContents);
+        } catch (NumberFormatException e) {
+            throw new RuntimeException(String.format("USER_ID를 가져오지 못했습니다. (%s - %s)", parameter.getClass(), parameter.getMethod()));
+        }
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/swagger/SwaggerConfig.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/swagger/SwaggerConfig.java
new file mode 100644
index 0000000..05bc5ea
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/config/swagger/SwaggerConfig.java
@@ -0,0 +1,31 @@
+package sopt.org.fourthSeminar.config.swagger;
+
+import io.swagger.v3.oas.annotations.enums.SecuritySchemeType;
+import io.swagger.v3.oas.annotations.security.SecurityScheme;
+import io.swagger.v3.oas.models.Components;
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.info.Info;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@SecurityScheme(
+        name = "JWT Auth",
+        type = SecuritySchemeType.HTTP,
+        bearerFormat = "JWT",
+        scheme = "bearer"
+)
+public class SwaggerConfig {
+
+    @Bean
+    public OpenAPI openAPI() {
+        Info info = new Info()
+                .title("SOPT32nd Seminar project")
+                .description("SOPT32nd Seminar project API Document")
+                .version("1.0.0");
+
+        return new OpenAPI()
+                .components(new Components())
+                .info(info);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/BoardController.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/BoardController.java
new file mode 100644
index 0000000..06b37fe
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/BoardController.java
@@ -0,0 +1,39 @@
+package sopt.org.fourthSeminar.controller;
+
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.*;
+import sopt.org.fourthSeminar.common.dto.ApiResponse;
+import sopt.org.fourthSeminar.config.jwt.JwtService;
+import sopt.org.fourthSeminar.config.resolver.UserId;
+import sopt.org.fourthSeminar.controller.dto.request.BoardImageListRequestDto;
+import sopt.org.fourthSeminar.controller.dto.request.BoardRequestDto;
+import sopt.org.fourthSeminar.exception.Success;
+import sopt.org.fourthSeminar.external.client.aws.S3Service;
+import sopt.org.fourthSeminar.service.BoardService;
+
+import javax.validation.Valid;
+import java.util.List;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/board")
+@SecurityRequirement(name = "JWT Auth")
+public class BoardController {
+
+    private final BoardService boardService;
+    private final JwtService jwtService;
+    private final S3Service s3Service;
+
+    @PostMapping(value = "/create", consumes = MediaType.MULTIPART_FORM_DATA_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
+    @ResponseStatus(HttpStatus.CREATED)
+    public ApiResponse create(
+            @UserId Long userId,
+            @ModelAttribute @Valid final BoardImageListRequestDto request) {
+        List<String> boardThumbnailImageUrlList = s3Service.uploadImages(request.getBoardImages(), "board");
+        boardService.create(userId, boardThumbnailImageUrlList, request);
+        return ApiResponse.success(Success.CREATE_BOARD_SUCCESS);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/UserController.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/UserController.java
new file mode 100644
index 0000000..4d077be
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/UserController.java
@@ -0,0 +1,43 @@
+package sopt.org.fourthSeminar.controller;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.*;
+import sopt.org.fourthSeminar.common.dto.ApiResponse;
+import sopt.org.fourthSeminar.config.jwt.JwtService;
+import sopt.org.fourthSeminar.controller.dto.request.UserLoginRequestDto;
+import sopt.org.fourthSeminar.controller.dto.request.UserRequestDto;
+import sopt.org.fourthSeminar.controller.dto.response.UserLoginResponseDto;
+import sopt.org.fourthSeminar.controller.dto.response.UserResponseDto;
+import sopt.org.fourthSeminar.exception.Success;
+import sopt.org.fourthSeminar.service.UserService;
+
+import javax.validation.Valid;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/user")
+@Tag(name = "User", description = "유저 API Document")
+public class UserController {
+
+    private final UserService userService;
+    private final JwtService jwtService;
+
+    @PostMapping("/signup")
+    @ResponseStatus(HttpStatus.CREATED)
+    @Operation(summary = "유저 생성 API", description = "유저를 서버에 등록합니다.")
+    public ApiResponse<UserResponseDto> create(@RequestBody @Valid final UserRequestDto request) {
+        return ApiResponse.success(Success.SIGNUP_SUCCESS, userService.create(request));
+    }
+
+    @PostMapping("/login")
+    @ResponseStatus(HttpStatus.OK)
+    @Operation(summary = "유저 로그인 API", description = "유저가 서버에 로그인을 요청합니다.")
+    public ApiResponse<UserLoginResponseDto> login(@RequestBody @Valid final UserLoginRequestDto request) {
+        final Long userId = userService.login(request);
+        final String token = jwtService.issuedToken(String.valueOf(userId));
+        return ApiResponse.success(Success.LOGIN_SUCCESS, UserLoginResponseDto.of(userId, token));
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/BoardImageListRequestDto.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/BoardImageListRequestDto.java
new file mode 100644
index 0000000..989ee7a
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/BoardImageListRequestDto.java
@@ -0,0 +1,23 @@
+package sopt.org.fourthSeminar.controller.dto.request;
+
+import lombok.*;
+import org.springframework.web.multipart.MultipartFile;
+
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+import java.util.List;
+
+@Getter
+@Setter // ?
+public class BoardImageListRequestDto {
+    private List<MultipartFile> boardImages;
+
+    @NotBlank
+    private String title;
+
+    @NotBlank
+    private String content;
+
+    @NotNull
+    private Boolean isPublic;
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/BoardRequestDto.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/BoardRequestDto.java
new file mode 100644
index 0000000..7034d6b
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/BoardRequestDto.java
@@ -0,0 +1,27 @@
+package sopt.org.fourthSeminar.controller.dto.request;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.springframework.web.multipart.MultipartFile;
+
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@AllArgsConstructor
+public class BoardRequestDto {
+    @NotNull
+    private MultipartFile thumbnail;
+
+    @NotBlank
+    private String title;
+
+    @NotBlank
+    private String content;
+
+    @NotNull
+    private Boolean isPublic;
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/UserLoginRequestDto.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/UserLoginRequestDto.java
new file mode 100644
index 0000000..f019bce
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/UserLoginRequestDto.java
@@ -0,0 +1,26 @@
+package sopt.org.fourthSeminar.controller.dto.request;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.validation.constraints.Email;
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Pattern;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class UserLoginRequestDto {
+
+    @Email(message = "이메일 형식에 맞지 않습니다")
+    @NotBlank
+    private String email;
+
+    @NotNull
+    @Pattern(
+            regexp="(?=.*[0-9])(?=.*[a-zA-Z])(?=.*\\W)(?=\\S+$).{8,20}",
+            message = "비밀번호는 영문 대,소문자와 숫자, 특수기호가 적어도 1개 이상씩 포함된 8자 ~ 20자의 비밀번호여야 합니다"
+    )
+    private String password;
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/UserRequestDto.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/UserRequestDto.java
new file mode 100644
index 0000000..2ddb276
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/request/UserRequestDto.java
@@ -0,0 +1,35 @@
+package sopt.org.fourthSeminar.controller.dto.request;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.validation.constraints.Email;
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Pattern;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@Schema(description = "유저 생성 DTO")
+public class UserRequestDto {
+
+    @NotBlank
+    @Pattern(regexp = "^[가-힣a-zA-Z]{2,10}$", message = "닉네임 형식에 맞지 않습니다")
+    @Schema(description = "유저 닉네임")
+    private String nickname;
+
+    @Email(message = "이메일 형식에 맞지 않습니다")
+    @NotBlank
+    @Schema(description = "유저 이메일")
+    private String email;
+
+    @NotNull
+    @Pattern(
+            regexp="(?=.*[0-9])(?=.*[a-zA-Z])(?=.*\\W)(?=\\S+$).{8,20}",
+            message = "비밀번호는 영문 대,소문자와 숫자, 특수기호가 적어도 1개 이상씩 포함된 8자 ~ 20자의 비밀번호여야 합니다"
+    )
+    @Schema(description = "유저 비밀번호")
+    private String password;
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/response/UserLoginResponseDto.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/response/UserLoginResponseDto.java
new file mode 100644
index 0000000..28f84c8
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/response/UserLoginResponseDto.java
@@ -0,0 +1,18 @@
+package sopt.org.fourthSeminar.controller.dto.response;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class UserLoginResponseDto {
+    private Long userId;
+    private String accessToken;
+
+    public static UserLoginResponseDto of(Long userId, String accessToken) {
+        return new UserLoginResponseDto(userId, accessToken);
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/response/UserResponseDto.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/response/UserResponseDto.java
new file mode 100644
index 0000000..c0ea83d
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/controller/dto/response/UserResponseDto.java
@@ -0,0 +1,19 @@
+package sopt.org.fourthSeminar.controller.dto.response;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class UserResponseDto {
+
+    private Long userId;
+    private String nickname;
+
+    public static UserResponseDto of(Long userId, String nickname) {
+        return new UserResponseDto(userId, nickname);
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/AuditingTimeEntity.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/AuditingTimeEntity.java
new file mode 100644
index 0000000..1c38228
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/AuditingTimeEntity.java
@@ -0,0 +1,23 @@
+package sopt.org.fourthSeminar.domain;
+
+import lombok.Getter;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.annotation.LastModifiedDate;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
+
+import javax.persistence.EntityListeners;
+import javax.persistence.MappedSuperclass;
+import java.time.LocalDateTime;
+
+//상속받아서 쓰는 거고, 따로 이것만 객체생성할 필요가 없기 때문에 abstract
+@Getter
+@MappedSuperclass
+@EntityListeners(AuditingEntityListener.class)
+public abstract class AuditingTimeEntity {
+
+    @CreatedDate
+    private LocalDateTime createdAt;
+
+    @LastModifiedDate
+    private LocalDateTime updatedAt;
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/Board.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/Board.java
new file mode 100644
index 0000000..8088312
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/Board.java
@@ -0,0 +1,45 @@
+package sopt.org.fourthSeminar.domain;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.*;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class Board extends AuditingTimeEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false, foreignKey = @ForeignKey(ConstraintMode.CONSTRAINT))
+    private User user;
+
+    @Column
+    private String thumbnail;
+
+    @Column(nullable = false)
+    private String title;
+
+    @Column(nullable = false)
+    private String content;
+
+    @Column(nullable = false)
+    private Boolean isPublic;
+
+    private Board(User user, String title, String content, Boolean isPublic) {
+        this.user = user;
+        //this.thumbnail = thumbnail;
+        this.title =title;
+        this.content = content;
+        this.isPublic = isPublic;
+    }
+
+    public static Board newInstance(User user, String title, String content, Boolean isPublic) {
+        return new Board(user, title, content, isPublic);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/Image.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/Image.java
new file mode 100644
index 0000000..a2effa5
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/Image.java
@@ -0,0 +1,33 @@
+package sopt.org.fourthSeminar.domain;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.*;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class Image extends AuditingTimeEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "board_id", nullable = false, foreignKey = @ForeignKey(ConstraintMode.CONSTRAINT))
+    private Board board;
+
+    @Column(nullable = false)
+    private String imageUrl;
+
+    private Image(Board board, String imageUrl) {
+        this.board = board;
+        this.imageUrl = imageUrl;
+    }
+
+    public static Image newInstance(Board board, String imageUrl) {
+        return new Image(board, imageUrl);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/User.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/User.java
new file mode 100644
index 0000000..9a1bfb4
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/domain/User.java
@@ -0,0 +1,36 @@
+package sopt.org.fourthSeminar.domain;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.*;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class User extends AuditingTimeEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(nullable = false)
+    private String nickname;
+
+    @Column(nullable = false)
+    private String email;
+
+    @Column(nullable = false)
+    private String password;
+
+    private User(String nickname, String email, String password) {
+        this.nickname = nickname;
+        this.email = email;
+        this.password = password;
+    }
+
+    public static User newInstance(String nickname, String email, String password) {
+        return new User(nickname, email, password);
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/Error.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/Error.java
new file mode 100644
index 0000000..ef60a12
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/Error.java
@@ -0,0 +1,49 @@
+package sopt.org.fourthSeminar.exception;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public enum Error {
+
+    /**
+     * 400 BAD REQUEST
+     */
+    REQUEST_VALIDATION_EXCEPTION(HttpStatus.BAD_REQUEST, "잘못된 요청입니다"),
+
+    /**
+     * 404 NOT FOUND
+     */
+    NOT_FOUND_USER_EXCEPTION(HttpStatus.NOT_FOUND, "존재하지 않는 유저입니다"),
+    NOT_FOUND_SAVE_IMAGE_EXCEPTION(HttpStatus.NOT_FOUND, "존재하지 않는 이미지입니다."),
+    NOT_FOUND_IMAGE_EXCEPTION(HttpStatus.NOT_FOUND, "이미지 어쩌구"),
+    INVALID_MULTIPART_EXTENSION_EXCEPTION(HttpStatus.MULTI_STATUS, "이미지 어쩌구"),
+
+    /**
+     * 409 CONFLICT
+     */
+    ALREADY_EXIST_USER_EXCEPTION(HttpStatus.CONFLICT, "이미 존재하는 유저입니다"),
+
+
+    /**
+     * 500 INTERNAL SERVER ERROR
+     */
+    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "알 수 없는 서버 에러가 발생했습니다"),
+
+    /**
+     *
+     */
+    TOKEN_TIME_EXPIRED_EXCEPTION(HttpStatus.UNAUTHORIZED, "권한 없어요"),
+    INVALID_PASSWORD_EXCEPTION(HttpStatus.UNAUTHORIZED, "권한 없어요")
+    ;
+
+    private final HttpStatus httpStatus;
+    private final String message;
+
+    public int getHttpStatusCode() {
+        return httpStatus.value();
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/Success.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/Success.java
new file mode 100644
index 0000000..bf6b366
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/Success.java
@@ -0,0 +1,27 @@
+package sopt.org.fourthSeminar.exception;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+@AllArgsConstructor(access =  AccessLevel.PRIVATE)
+public enum Success {
+
+    /**
+     * 201 CREATED
+     */
+    SIGNUP_SUCCESS(HttpStatus.CREATED, "회원가입이 완료됐습니다."),
+    CREATE_BOARD_SUCCESS(HttpStatus.CREATED, "게시물 생성이 완료됐습니다."),
+
+    LOGIN_SUCCESS(HttpStatus.OK, "로그인 성공"),
+    ;
+
+    private final HttpStatus httpStatus;
+    private final String message;
+
+    public int getHttpStatusCode() {
+        return httpStatus.value();
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/BadRequestException.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/BadRequestException.java
new file mode 100644
index 0000000..ffdc94e
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/BadRequestException.java
@@ -0,0 +1,9 @@
+package sopt.org.fourthSeminar.exception.model;
+
+import sopt.org.fourthSeminar.exception.Error;
+
+public class BadRequestException extends SoptException {
+    public BadRequestException(Error error, String message) {
+        super(error, message);
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/ConflictException.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/ConflictException.java
new file mode 100644
index 0000000..d4fe6f7
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/ConflictException.java
@@ -0,0 +1,9 @@
+package sopt.org.fourthSeminar.exception.model;
+
+import sopt.org.fourthSeminar.exception.Error;
+
+public class ConflictException extends SoptException {
+    public ConflictException(Error error, String message) {
+        super(error, message);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/NotFoundException.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/NotFoundException.java
new file mode 100644
index 0000000..ee123ba
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/NotFoundException.java
@@ -0,0 +1,9 @@
+package sopt.org.fourthSeminar.exception.model;
+
+import sopt.org.fourthSeminar.exception.Error;
+
+public class NotFoundException extends SoptException {
+    public NotFoundException(Error error, String message) {
+        super(error, message);
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/SoptException.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/SoptException.java
new file mode 100644
index 0000000..b685566
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/SoptException.java
@@ -0,0 +1,19 @@
+package sopt.org.fourthSeminar.exception.model;
+
+import lombok.Getter;
+import sopt.org.fourthSeminar.exception.Error;
+
+@Getter
+public class SoptException extends RuntimeException {
+
+    private final Error error;
+
+    public SoptException(Error error, String message) {
+        super(message);
+        this.error = error;
+    }
+
+    public int getHttpStatus() {
+        return error.getHttpStatusCode();
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/UnauthorizedException.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/UnauthorizedException.java
new file mode 100644
index 0000000..c27cab4
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/exception/model/UnauthorizedException.java
@@ -0,0 +1,9 @@
+package sopt.org.fourthSeminar.exception.model;
+
+import sopt.org.fourthSeminar.exception.Error;
+
+public class UnauthorizedException extends SoptException {
+    public UnauthorizedException(Error error, String message) {
+        super(error, message);
+    }
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/external/client/aws/S3Service.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/external/client/aws/S3Service.java
new file mode 100644
index 0000000..e625f5b
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/external/client/aws/S3Service.java
@@ -0,0 +1,95 @@
+package sopt.org.fourthSeminar.external.client.aws;
+
+import com.amazonaws.auth.AWSStaticCredentialsProvider;
+import com.amazonaws.auth.BasicAWSCredentials;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.AmazonS3Client;
+import com.amazonaws.services.s3.AmazonS3ClientBuilder;
+import com.amazonaws.services.s3.model.CannedAccessControlList;
+import com.amazonaws.services.s3.model.ObjectMetadata;
+import com.amazonaws.services.s3.model.PutObjectRequest;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+import org.springframework.web.multipart.MultipartFile;
+import sopt.org.fourthSeminar.exception.Error;
+import sopt.org.fourthSeminar.exception.model.BadRequestException;
+import sopt.org.fourthSeminar.exception.model.NotFoundException;
+
+import javax.annotation.PostConstruct;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+public class S3Service {
+    private final AmazonS3 amazonS3;
+
+    @Value("${cloud.aws.credentials.accessKey}")
+    private String accessKey;
+
+    @Value("${cloud.aws.credentials.secretKey}")
+    private String secretKey;
+
+    @Value("${cloud.aws.s3.bucket}")
+    private String bucket;
+
+    @Value("${cloud.aws.region.static}")
+    private String region;
+
+    @PostConstruct
+    public AmazonS3Client amazonS3Client() {
+        BasicAWSCredentials awsCredentials = new BasicAWSCredentials(accessKey, secretKey);
+        return (AmazonS3Client) AmazonS3ClientBuilder.standard()
+                .withRegion(region)
+                .withCredentials(new AWSStaticCredentialsProvider(awsCredentials))
+                .build();
+    }
+
+    public String uploadImage(MultipartFile multipartFile, String folder) {
+        String fileName = createFileName(multipartFile.getOriginalFilename());
+        ObjectMetadata objectMetadata = new ObjectMetadata();
+        objectMetadata.setContentLength(multipartFile.getSize());
+        objectMetadata.setContentType(multipartFile.getContentType());
+
+        try(InputStream inputStream = multipartFile.getInputStream()) {
+            amazonS3.putObject(new PutObjectRequest(bucket+"/"+ folder + "/image", fileName, inputStream, objectMetadata)
+                    .withCannedAcl(CannedAccessControlList.PublicRead));
+            return amazonS3.getUrl(bucket+"/"+ folder + "/image", fileName).toString();
+        } catch(IOException e) {
+            throw new NotFoundException(Error.NOT_FOUND_SAVE_IMAGE_EXCEPTION, Error.NOT_FOUND_SAVE_IMAGE_EXCEPTION.getMessage());
+        }
+    }
+
+    public List<String> uploadImages(List<MultipartFile> multipartFileList, String folder) {
+        return multipartFileList.stream().map(multipartFile -> uploadImage(multipartFile, folder)).collect(Collectors.toList());
+    }
+
+    // 파일명 (중복 방지)
+    private String createFileName(String fileName) {
+        return UUID.randomUUID().toString().concat(getFileExtension(fileName));
+    }
+
+    // 파일 유효성 검사
+    private String getFileExtension(String fileName) {
+        if (fileName.length() == 0) {
+            throw new NotFoundException(Error.NOT_FOUND_IMAGE_EXCEPTION, Error.NOT_FOUND_USER_EXCEPTION.getMessage());
+        }
+        ArrayList<String> fileValidate = new ArrayList<>();
+        fileValidate.add(".jpg");
+        fileValidate.add(".jpeg");
+        fileValidate.add(".png");
+        fileValidate.add(".JPG");
+        fileValidate.add(".JPEG");
+        fileValidate.add(".PNG");
+        String idxFileName = fileName.substring(fileName.lastIndexOf("."));
+        if (!fileValidate.contains(idxFileName)) {
+            throw new BadRequestException(Error.INVALID_MULTIPART_EXTENSION_EXCEPTION, Error.INVALID_MULTIPART_EXTENSION_EXCEPTION.getMessage());
+        }
+        return fileName.substring(fileName.lastIndexOf("."));
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/BoardRepository.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/BoardRepository.java
new file mode 100644
index 0000000..383190f
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/BoardRepository.java
@@ -0,0 +1,16 @@
+package sopt.org.fourthSeminar.infrastructure;
+
+import org.springframework.data.repository.Repository;
+import sopt.org.fourthSeminar.domain.Board;
+
+public interface BoardRepository extends Repository<Board, Long> {
+
+    // CREATE
+    void save(Board board);
+
+    // READ
+
+    // UPDATE
+
+    // DELETE
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/ImageRepository.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/ImageRepository.java
new file mode 100644
index 0000000..b3fc1fa
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/ImageRepository.java
@@ -0,0 +1,9 @@
+package sopt.org.fourthSeminar.infrastructure;
+
+import org.springframework.data.repository.Repository;
+import sopt.org.fourthSeminar.domain.Image;
+
+public interface ImageRepository extends Repository<Image, Long> {
+    // CREATE
+    void save(Image image);
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/UserRepository.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/UserRepository.java
new file mode 100644
index 0000000..1116270
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/infrastructure/UserRepository.java
@@ -0,0 +1,21 @@
+package sopt.org.fourthSeminar.infrastructure;
+
+import org.springframework.data.repository.Repository;
+import sopt.org.fourthSeminar.domain.User;
+
+import java.util.Optional;
+
+public interface UserRepository extends Repository<User, Long> {
+
+    // CREATE
+    void save(User user);
+
+    // READ
+    Optional<User> findByEmail(String email);
+    boolean existsByEmail(String email);
+    Optional<User> findById(Long userId);
+
+    // UPDATE
+
+    // DELETE
+}
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/service/BoardService.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/service/BoardService.java
new file mode 100644
index 0000000..036556c
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/service/BoardService.java
@@ -0,0 +1,63 @@
+package sopt.org.fourthSeminar.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import sopt.org.fourthSeminar.controller.dto.request.BoardImageListRequestDto;
+import sopt.org.fourthSeminar.controller.dto.request.BoardRequestDto;
+import sopt.org.fourthSeminar.domain.Board;
+import sopt.org.fourthSeminar.domain.Image;
+import sopt.org.fourthSeminar.domain.User;
+import sopt.org.fourthSeminar.exception.Error;
+import sopt.org.fourthSeminar.exception.model.NotFoundException;
+import sopt.org.fourthSeminar.infrastructure.BoardRepository;
+import sopt.org.fourthSeminar.infrastructure.ImageRepository;
+import sopt.org.fourthSeminar.infrastructure.UserRepository;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class BoardService {
+
+    private final UserRepository userRepository;
+    private final BoardRepository boardRepository;
+    private final ImageRepository imageRepository;
+
+//    @Transactional
+//    public void create(Long userId, String boardThumbnailImageUrl, BoardRequestDto request) {
+//        User user = userRepository.findById(userId)
+//                .orElseThrow(() -> new NotFoundException(Error.NOT_FOUND_USER_EXCEPTION, Error.NOT_FOUND_USER_EXCEPTION.getMessage()));
+//
+//        Board newBoard = Board.newInstance(
+//                user,
+//                boardThumbnailImageUrl,
+//                request.getTitle(),
+//                request.getContent(),
+//                request.getIsPublic()
+//        );
+//
+//        boardRepository.save(newBoard);
+//    }
+
+    @Transactional
+    public void create(Long userId, List<String> boardImageUrlList, BoardImageListRequestDto request) {
+        User user = userRepository.findById(userId)
+                .orElseThrow(() -> new NotFoundException(Error.NOT_FOUND_USER_EXCEPTION, Error.NOT_FOUND_USER_EXCEPTION.getMessage()));
+
+        // 게시글 생성
+        Board newBoard = Board.newInstance(
+                user,
+                request.getTitle(),
+                request.getContent(),
+                request.getIsPublic()
+        );
+
+        boardRepository.save(newBoard);
+
+        // 이미지 생성
+        for (String boardImageUrl: boardImageUrlList) {
+            imageRepository.save(Image.newInstance(newBoard, boardImageUrl));
+        }
+    }
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/main/java/sopt/org/fourthSeminar/service/UserService.java b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/service/UserService.java
new file mode 100644
index 0000000..c1a124b
--- /dev/null
+++ b/fourthSeminar/src/main/java/sopt/org/fourthSeminar/service/UserService.java
@@ -0,0 +1,51 @@
+package sopt.org.fourthSeminar.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import sopt.org.fourthSeminar.controller.dto.request.UserLoginRequestDto;
+import sopt.org.fourthSeminar.controller.dto.request.UserRequestDto;
+import sopt.org.fourthSeminar.controller.dto.response.UserResponseDto;
+import sopt.org.fourthSeminar.domain.User;
+import sopt.org.fourthSeminar.exception.Error;
+import sopt.org.fourthSeminar.exception.model.BadRequestException;
+import sopt.org.fourthSeminar.exception.model.ConflictException;
+import sopt.org.fourthSeminar.exception.model.NotFoundException;
+import sopt.org.fourthSeminar.infrastructure.UserRepository;
+
+@Service
+@RequiredArgsConstructor
+public class UserService {
+
+    private final UserRepository userRepository;
+
+    @Transactional
+    public UserResponseDto create(UserRequestDto request) {
+        if (userRepository.existsByEmail(request.getEmail())) {
+            throw new ConflictException(Error.ALREADY_EXIST_USER_EXCEPTION, Error.ALREADY_EXIST_USER_EXCEPTION.getMessage());
+        }
+
+        User newUser = User.newInstance(
+                request.getNickname(),
+                request.getEmail(),
+                request.getPassword()
+        );
+
+        userRepository.save(newUser);
+
+        return UserResponseDto.of(newUser.getId(), newUser.getNickname());
+    }
+
+    @Transactional
+    public Long login(UserLoginRequestDto request) {
+        User user = userRepository.findByEmail(request.getEmail())
+                .orElseThrow(() -> new NotFoundException(Error.NOT_FOUND_USER_EXCEPTION, Error.NOT_FOUND_USER_EXCEPTION.getMessage()));
+
+        if (!user.getPassword().equals(request.getPassword())) {
+            throw new BadRequestException(Error.INVALID_PASSWORD_EXCEPTION, Error.INVALID_PASSWORD_EXCEPTION.getMessage());
+        }
+
+        return user.getId();
+    }
+
+}
\ No newline at end of file
diff --git a/fourthSeminar/src/test/java/sopt/org/fourthSeminar/FourthSeminarApplicationTests.java b/fourthSeminar/src/test/java/sopt/org/fourthSeminar/FourthSeminarApplicationTests.java
new file mode 100644
index 0000000..81ef130
--- /dev/null
+++ b/fourthSeminar/src/test/java/sopt/org/fourthSeminar/FourthSeminarApplicationTests.java
@@ -0,0 +1,13 @@
+package sopt.org.fourthSeminar;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class FourthSeminarApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}