diff --git a/.deploy/Dockerfile b/.deploy/Dockerfile
index f4b99de..b26334e 100644
--- a/.deploy/Dockerfile
+++ b/.deploy/Dockerfile
@@ -1,6 +1,6 @@
 FROM amazoncorretto:17-alpine-jdk
 
-ARG TARGET_JAR=/api/build/libs/api.jar
+ARG TARGET_JAR=/api/build/libs/app.jar
 
 COPY ${TARGET_JAR} /app.jar
 
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..f51918e
--- /dev/null
+++ b/README.md
@@ -0,0 +1,19 @@
+# Lettering Backend
+
+
+
+## System Architecture
+
+
+### Overview
+
+
+```markdown
+.
+├── app/
+│   └── domain/
+│       ├── api
+│       ├── controller
+│       └── dto
+└── core
+```
\ No newline at end of file
diff --git a/api/build.gradle.kts b/app/build.gradle.kts
similarity index 100%
rename from api/build.gradle.kts
rename to app/build.gradle.kts
diff --git a/api/src/main/kotlin/com/asap/api/ApiApplication.kt b/app/src/main/kotlin/com/asap/app/AppApplication.kt
similarity index 63%
rename from api/src/main/kotlin/com/asap/api/ApiApplication.kt
rename to app/src/main/kotlin/com/asap/app/AppApplication.kt
index 61e8bee..26dc975 100644
--- a/api/src/main/kotlin/com/asap/api/ApiApplication.kt
+++ b/app/src/main/kotlin/com/asap/app/AppApplication.kt
@@ -1,13 +1,13 @@
-package com.asap.api
+package com.asap.app
 
 import org.springframework.boot.SpringApplication
 import org.springframework.boot.autoconfigure.SpringBootApplication
 
 @SpringBootApplication
-class ApiApplication {
+class AppApplication {
 
 }
 
 fun main(args: Array<String>) {
-    SpringApplication.run(ApiApplication::class.java, *args)
+    SpringApplication.run(AppApplication::class.java, *args)
 }
diff --git a/app/src/main/kotlin/com/asap/app/auth/api/AuthApi.kt b/app/src/main/kotlin/com/asap/app/auth/api/AuthApi.kt
new file mode 100644
index 0000000..bcd4ea8
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/auth/api/AuthApi.kt
@@ -0,0 +1,51 @@
+package com.asap.app.auth.api
+
+import com.asap.app.auth.dto.SocialLoginRequest
+import com.asap.app.auth.dto.SocialLoginResponse
+import io.swagger.v3.oas.annotations.Operation
+import io.swagger.v3.oas.annotations.media.Content
+import io.swagger.v3.oas.annotations.media.Schema
+import io.swagger.v3.oas.annotations.responses.ApiResponse
+import io.swagger.v3.oas.annotations.responses.ApiResponses
+import io.swagger.v3.oas.annotations.tags.Tag
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+
+@Tag(name = "Auth", description = "Auth API")
+@RequestMapping("/api/v1/auth")
+interface AuthApi {
+
+    @Operation(summary = "소셜 로그인")
+    @PostMapping("/login/{provider}")
+    @ApiResponses(
+        value = [
+            ApiResponse(
+                responseCode = "200",
+                description = "기존 회원 로그인 성공",
+                content = [
+                    Content(
+                        mediaType = "application/json",
+                        schema = Schema(implementation = SocialLoginResponse.Success::class)
+                    )
+                ]
+            ),
+            ApiResponse(
+                responseCode = "401",
+                description = "신규 회원 가입 필요",
+                content = [
+                    Content(
+                        mediaType = "application/json",
+                        schema = Schema(implementation = SocialLoginResponse.NonRegistered::class)
+                    )
+                ]
+            )
+        ]
+    )
+    fun socialLogin(
+        @PathVariable provider: String,
+        @RequestBody request: SocialLoginRequest
+    ): ResponseEntity<SocialLoginResponse>
+}
\ No newline at end of file
diff --git a/app/src/main/kotlin/com/asap/app/auth/controller/AuthController.kt b/app/src/main/kotlin/com/asap/app/auth/controller/AuthController.kt
new file mode 100644
index 0000000..341a233
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/auth/controller/AuthController.kt
@@ -0,0 +1,28 @@
+package com.asap.app.auth.controller
+
+import com.asap.app.auth.api.AuthApi
+import com.asap.app.auth.dto.SocialLoginRequest
+import com.asap.app.auth.dto.SocialLoginResponse
+import org.springframework.http.HttpStatus
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+class AuthController(
+) : AuthApi {
+
+    override fun socialLogin(
+        provider: String,
+        request: SocialLoginRequest
+    ): ResponseEntity<SocialLoginResponse> {
+        when (request.accessToken) {
+            "nonRegistered" -> return ResponseEntity.status(HttpStatus.UNAUTHORIZED)
+                .body(SocialLoginResponse.NonRegistered("registerToken"))
+
+            "registered" -> return ResponseEntity
+                .ok(SocialLoginResponse.Success("accessToken", "refreshToken"))
+
+            else -> return ResponseEntity.badRequest().build()
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/kotlin/com/asap/app/auth/dto/SocialLoginRequest.kt b/app/src/main/kotlin/com/asap/app/auth/dto/SocialLoginRequest.kt
new file mode 100644
index 0000000..2007225
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/auth/dto/SocialLoginRequest.kt
@@ -0,0 +1,9 @@
+package com.asap.app.auth.dto
+
+import io.swagger.v3.oas.annotations.media.Schema
+
+@Schema(description = "소셜 로그인 요청")
+data class SocialLoginRequest(
+    @Schema(description = "oauth access token")
+    val accessToken: String,
+)
diff --git a/app/src/main/kotlin/com/asap/app/auth/dto/SocialLoginResponse.kt b/app/src/main/kotlin/com/asap/app/auth/dto/SocialLoginResponse.kt
new file mode 100644
index 0000000..60dda7f
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/auth/dto/SocialLoginResponse.kt
@@ -0,0 +1,28 @@
+package com.asap.app.auth.dto
+
+import io.swagger.v3.oas.annotations.media.Schema
+
+@Schema(
+    description = "소셜 로그인 응답",
+    oneOf = [
+        SocialLoginResponse.Success::class,
+        SocialLoginResponse.NonRegistered::class
+    ]
+)
+sealed class SocialLoginResponse{
+
+    @Schema(description = "기존 회원 로그인 성공")
+    data class Success(
+        @Schema(description = "access token")
+        val accessToken: String,
+        @Schema(description = "refresh token")
+        val refreshToken: String
+    ) : SocialLoginResponse()
+
+
+    @Schema(description = "신규 회원 가입 필요")
+    data class NonRegistered(
+        @Schema(description = "register token, 회원가입을 위한 토큰")
+        val registerToken: String
+    ) : SocialLoginResponse()
+}
diff --git a/app/src/main/kotlin/com/asap/app/user/api/UserApi.kt b/app/src/main/kotlin/com/asap/app/user/api/UserApi.kt
new file mode 100644
index 0000000..e1821fc
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/user/api/UserApi.kt
@@ -0,0 +1,39 @@
+package com.asap.app.user.api
+
+import com.asap.app.user.dto.RegisterUserRequest
+import com.asap.app.user.dto.RegisterUserResponse
+import io.swagger.v3.oas.annotations.Operation
+import io.swagger.v3.oas.annotations.media.Content
+import io.swagger.v3.oas.annotations.media.Schema
+import io.swagger.v3.oas.annotations.responses.ApiResponse
+import io.swagger.v3.oas.annotations.responses.ApiResponses
+import io.swagger.v3.oas.annotations.tags.Tag
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+
+@Tag(name = "User", description = "User API")
+@RequestMapping("/api/v1/users")
+interface UserApi {
+
+    @Operation(summary = "회원 가입")
+    @PostMapping()
+    @ApiResponses(
+        value = [
+            ApiResponse(
+                responseCode = "200",
+                description = "회원 가입 성공",
+                content = [
+                    Content(
+                        mediaType = "application/json",
+                        schema = Schema(implementation = RegisterUserResponse::class)
+                    )
+                ]
+            )
+        ]
+    )
+    fun registerUser(
+        @RequestBody request: RegisterUserRequest
+    ): ResponseEntity<RegisterUserResponse>
+}
\ No newline at end of file
diff --git a/app/src/main/kotlin/com/asap/app/user/controller/UserController.kt b/app/src/main/kotlin/com/asap/app/user/controller/UserController.kt
new file mode 100644
index 0000000..c7808f2
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/user/controller/UserController.kt
@@ -0,0 +1,20 @@
+package com.asap.app.user.controller
+
+import com.asap.app.user.api.UserApi
+import com.asap.app.user.dto.RegisterUserRequest
+import com.asap.app.user.dto.RegisterUserResponse
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+class UserController(
+
+) : UserApi{
+
+    override fun registerUser(request: RegisterUserRequest): ResponseEntity<RegisterUserResponse> {
+        when(request.registerToken){
+            "register" -> return ResponseEntity.ok(RegisterUserResponse("accessToken", "refreshToken"))
+            else -> return ResponseEntity.badRequest().build()
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/kotlin/com/asap/app/user/dto/RegisterUserRequest.kt b/app/src/main/kotlin/com/asap/app/user/dto/RegisterUserRequest.kt
new file mode 100644
index 0000000..e22ae89
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/user/dto/RegisterUserRequest.kt
@@ -0,0 +1,19 @@
+package com.asap.app.user.dto
+
+import io.swagger.v3.oas.annotations.media.Schema
+import java.time.LocalDate
+
+@Schema(description = "회원 가입 요청")
+data class RegisterUserRequest(
+    @Schema(description = "register_token, 소셜 로그인이로부터 전달받은 토큰")
+    val registerToken: String,
+    @Schema(description = "서비스 이용약관 동의")
+    val servicePermission: Boolean,
+    @Schema(description = "개인정보 수집 및 이용 동의")
+    val privatePermission: Boolean,
+    @Schema(description = "마케팅 정보 수신 동의")
+    val marketingPermission: Boolean,
+    @Schema(description = "생년 월일, yyyy-MM-dd, 값이 안넘어올 수 있음")
+    val birthday: LocalDate?
+) {
+}
\ No newline at end of file
diff --git a/app/src/main/kotlin/com/asap/app/user/dto/RegisterUserResponse.kt b/app/src/main/kotlin/com/asap/app/user/dto/RegisterUserResponse.kt
new file mode 100644
index 0000000..057e82f
--- /dev/null
+++ b/app/src/main/kotlin/com/asap/app/user/dto/RegisterUserResponse.kt
@@ -0,0 +1,12 @@
+package com.asap.app.user.dto
+
+import io.swagger.v3.oas.annotations.media.Schema
+
+@Schema(description = "회원 가입 응답")
+data class RegisterUserResponse(
+    @Schema(description = "access token")
+    val accessToken: String,
+    @Schema(description = "refresh token")
+    val refreshToken: String
+) {
+}
\ No newline at end of file
diff --git a/api/src/main/resources/application.yml b/app/src/main/resources/application.yml
similarity index 100%
rename from api/src/main/resources/application.yml
rename to app/src/main/resources/application.yml
diff --git a/app/src/test/java/com/asap/app/auth/controller/AuthControllerTest.kt b/app/src/test/java/com/asap/app/auth/controller/AuthControllerTest.kt
new file mode 100644
index 0000000..0e8bbf6
--- /dev/null
+++ b/app/src/test/java/com/asap/app/auth/controller/AuthControllerTest.kt
@@ -0,0 +1,88 @@
+package com.asap.app.auth.controller
+
+import com.asap.app.auth.dto.SocialLoginRequest
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest
+import org.springframework.http.MediaType
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.post
+
+@WebMvcTest(AuthController::class)
+@AutoConfigureMockMvc
+class AuthControllerTest {
+
+    @Autowired
+    private lateinit var mockMvc: MockMvc
+
+    private val objectMapper: ObjectMapper = ObjectMapper()
+
+
+    @Test
+    fun socialLoginSuccessTest(){
+        // given
+        val request = SocialLoginRequest("registered")
+        // when
+        val response = mockMvc.post("/api/v1/auth/login/{provider}", "kakao") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(request)
+        }
+
+        // then
+        response.andExpect {
+            status { isOk() }
+            jsonPath("$.accessToken") {
+                exists()
+                isString()
+                isNotEmpty()
+            }
+            jsonPath("$.refreshToken") {
+                exists()
+                isString()
+                isNotEmpty()
+            }
+        }
+    }
+
+    @Test
+    fun socialLoginNonRegisteredTest(){
+        // given
+        val request = SocialLoginRequest("nonRegistered")
+        // when
+        val response = mockMvc.post("/api/v1/auth/login/{provider}", "kakao") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(request)
+        }
+
+        // then
+        response.andExpect {
+            status { isUnauthorized() }
+            jsonPath("$.registerToken") {
+                exists()
+                isString()
+                isNotEmpty()
+            }
+        }
+    }
+
+
+    @Test
+    fun socialLoginBadRequestTest(){
+        // given
+        val request = SocialLoginRequest("invalid")
+        // when
+        val response = mockMvc.post("/api/v1/auth/login/{provider}", "kakao") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(request)
+        }
+
+        // then
+        response.andExpect {
+            status { isBadRequest() }
+        }
+    }
+
+
+}
\ No newline at end of file
diff --git a/app/src/test/java/com/asap/app/user/controller/UserControllerTest.kt b/app/src/test/java/com/asap/app/user/controller/UserControllerTest.kt
new file mode 100644
index 0000000..e90cdb3
--- /dev/null
+++ b/app/src/test/java/com/asap/app/user/controller/UserControllerTest.kt
@@ -0,0 +1,63 @@
+package com.asap.app.user.controller
+
+import com.asap.app.user.dto.RegisterUserRequest
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest
+import org.springframework.http.MediaType
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.post
+import java.time.LocalDate
+
+@WebMvcTest(UserController::class)
+@AutoConfigureMockMvc
+class UserControllerTest {
+
+    @Autowired
+    private lateinit var mockMvc: MockMvc
+
+    private val objectMapper: ObjectMapper = ObjectMapper().registerModules(JavaTimeModule())
+
+    @Test
+    fun registerUserTest(){
+        // given
+        val request = RegisterUserRequest("register", true, true, true, LocalDate.now())
+        // when
+        val response = mockMvc.post("/api/v1/users") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(request)
+        }
+        // then
+        response.andExpect {
+            status { isOk() }
+            jsonPath("$.accessToken") {
+                exists()
+                isString()
+                isNotEmpty()
+            }
+            jsonPath("$.refreshToken") {
+                exists()
+                isString()
+                isNotEmpty()
+            }
+        }
+    }
+
+    @Test
+    fun registerUserNotExistsRegisterTokenTest(){
+        // given
+        val request = RegisterUserRequest("nonExistsToken", false, true, true, LocalDate.now())
+        // when
+        val response = mockMvc.post("/api/v1/users") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(request)
+        }
+        // then
+        response.andExpect {
+            status { isBadRequest() }
+        }
+    }
+}
\ No newline at end of file
diff --git a/build.gradle.kts b/build.gradle.kts
index f34b9aa..8a5aef6 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -17,6 +17,7 @@ allprojects {
     version = ""
 
     val javaVersion = "17"
+    val kotestVersion = "5.0.0"
 
     tasks.withType<JavaCompile> {
         sourceCompatibility = javaVersion
@@ -30,7 +31,7 @@ allprojects {
     }
 
     tasks.withType<BootJar> {
-        if (project.name == "api") {
+        if (project.name == "app") {
             enabled = true
         } else {
             enabled = false
@@ -59,6 +60,14 @@ allprojects {
         testImplementation("org.springframework.boot:spring-boot-starter-test")
         testImplementation("org.jetbrains.kotlin:kotlin-test-junit5")
         testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+
+
+        // kotest
+        testImplementation("io.kotest:kotest-runner-junit5:$kotestVersion")
+
+        // jackson
+        implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
+        implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310")
     }
 
     kotlin {
diff --git a/settings.gradle.kts b/settings.gradle.kts
index f5234f3..3200b6a 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -1,3 +1,3 @@
 rootProject.name = "Lettering-Backend"
 
-include(":api")
+include(":app")