diff --git a/.coderabbit.yaml b/.coderabbit.yaml
index 2c7348d5..a3674c36 100644
--- a/.coderabbit.yaml
+++ b/.coderabbit.yaml
@@ -6,7 +6,7 @@ reviews:
   high_level_summary: true
   poem: false
   review_status: true
-  collapse_walkthrough: true
+  collapse_walkthrough: false
   auto_review:
     enabled: true
     drafts: false
diff --git a/.github/workflows/ci-pr.yml b/.github/workflows/ci-pr.yml
index 8558dd2d..9cdf1d12 100644
--- a/.github/workflows/ci-pr.yml
+++ b/.github/workflows/ci-pr.yml
@@ -31,6 +31,7 @@ jobs:
           echo "${{ secrets.DEV_SECRET_PROPERTIES }}" > ./secret/application-dev-secret.properties
           echo "${{ secrets.PROD_SECRET_PROPERTIES }}" > ./secret/application-prod-secret.properties
           echo "${{ secrets.TEST_SECRET_PROPERTIES }}" > ./secret/application-test-secret.properties
+          echo "${{ secrets.APPLE_AUTH_KEY }}" > ./secret/AuthKey.p8
           chmod 600 ./secret/*
 
       - name: Set up JDK 21
diff --git a/.github/workflows/dev-ci-cd.yml b/.github/workflows/dev-ci-cd.yml
index 3b8b3941..b5b5dbce 100644
--- a/.github/workflows/dev-ci-cd.yml
+++ b/.github/workflows/dev-ci-cd.yml
@@ -29,6 +29,7 @@ jobs:
           mkdir ./secret
           echo "${{ secrets.DEV_SECRET_PROPERTIES }}" > ./secret/application-dev-secret.properties
           echo "${{ secrets.TEST_SECRET_PROPERTIES }}" > ./secret/application-test-secret.properties
+          echo "${{ secrets.APPLE_AUTH_KEY }}" > ./secret/AuthKey.p8
           chmod 600 ./secret/*
 
       - name: Set up Docker Buildx
diff --git a/.github/workflows/prod-ci-cd.yml b/.github/workflows/prod-ci-cd.yml
index e2050472..2d57c9cf 100644
--- a/.github/workflows/prod-ci-cd.yml
+++ b/.github/workflows/prod-ci-cd.yml
@@ -29,6 +29,7 @@ jobs:
           mkdir ./secret
           echo "${{ secrets.PROD_SECRET_PROPERTIES }}" > ./secret/application-prod-secret.properties
           echo "${{ secrets.TEST_SECRET_PROPERTIES }}" > ./secret/application-test-secret.properties
+          echo "${{ secrets.APPLE_AUTH_KEY }}" > ./secret/AuthKey.p8
           chmod 600 ./secret/*
 
       - name: Set up Docker Buildx
diff --git a/apis/build.gradle.kts b/apis/build.gradle.kts
index 6f766de9..96e2b325 100644
--- a/apis/build.gradle.kts
+++ b/apis/build.gradle.kts
@@ -11,6 +11,7 @@ dependencies {
     implementation(Dependencies.Spring.BOOT_STARTER_SECURITY)
     implementation(Dependencies.Spring.BOOT_STARTER_VALIDATION)
     implementation(Dependencies.Spring.BOOT_STARTER_ACTUATOR)
+    implementation(Dependencies.Spring.BOOT_STARTER_OAUTH2_CLIENT)
 
     implementation(Dependencies.Database.MYSQL_CONNECTOR)
 
@@ -18,6 +19,11 @@ dependencies {
 
     implementation(Dependencies.Logging.KOTLIN_LOGGING)
 
+    implementation(Dependencies.BouncyCastle.BC_PROV)
+    implementation(Dependencies.BouncyCastle.BC_PKIX)
+
+    annotationProcessor(Dependencies.Spring.CONFIGURATION_PROCESSOR)
+
     testImplementation(Dependencies.Spring.BOOT_STARTER_TEST)
     testImplementation(Dependencies.TestContainers.MYSQL)
     testImplementation(Dependencies.TestContainers.JUNIT_JUPITER)
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthController.kt b/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthController.kt
index 5dff07fc..0bccabfc 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthController.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthController.kt
@@ -12,9 +12,6 @@ import org.yapp.apis.auth.dto.response.UserProfileResponse
 import org.yapp.apis.auth.usecase.AuthUseCase
 import java.util.*
 
-/**
- * Implementation of the authentication controller API.
- */
 @RestController
 @RequestMapping("/api/v1/auth")
 class AuthController(
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthControllerApi.kt b/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthControllerApi.kt
index 4431f5bd..20ea6d73 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthControllerApi.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/controller/AuthControllerApi.kt
@@ -21,28 +21,28 @@ import org.yapp.apis.auth.dto.response.UserProfileResponse
 import org.yapp.globalutils.exception.ErrorResponse
 import java.util.*
 
-@Tag(name = "Authentication", description = "Authentication API")
+@Tag(name = "Authentication", description = "인증 관련 API")
 interface AuthControllerApi {
 
     @Operation(
-        summary = "Sign in or sign up with social login",
-        description = "Sign in a user with social login credentials (Kakao or Apple). If the user doesn't exist, they will be automatically registered."
+        summary = "소셜 로그인",
+        description = "카카오 또는 애플 계정으로 로그인합니다. 사용자가 존재하지 않으면 자동으로 회원가입됩니다."
     )
     @ApiResponses(
         value = [
             ApiResponse(
                 responseCode = "200",
-                description = "Successful sign in or sign up",
+                description = "로그인/회원가입 성공",
                 content = [Content(schema = Schema(implementation = AuthResponse::class))]
             ),
             ApiResponse(
                 responseCode = "400",
-                description = "Invalid request or credentials",
+                description = "잘못된 요청 또는 인증 정보",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             ),
             ApiResponse(
                 responseCode = "409",
-                description = "Email already in use with a different account",
+                description = "이미 다른 계정으로 사용 중인 이메일",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             )
         ]
@@ -51,24 +51,24 @@ interface AuthControllerApi {
     fun signIn(@RequestBody @Valid request: SocialLoginRequest): ResponseEntity<AuthResponse>
 
     @Operation(
-        summary = "Refresh token",
-        description = "Refresh an access token using a refresh token. Returns both a new access token and a new refresh token."
+        summary = "토큰 갱신",
+        description = "리프레시 토큰을 사용하여 액세스 토큰을 갱신합니다. 새로운 액세스 토큰과 리프레시 토큰을 반환합니다."
     )
     @ApiResponses(
         value = [
             ApiResponse(
                 responseCode = "200",
-                description = "Successful token refresh",
+                description = "토큰 갱신 성공",
                 content = [Content(schema = Schema(implementation = AuthResponse::class))]
             ),
             ApiResponse(
                 responseCode = "400",
-                description = "Invalid refresh token",
+                description = "유효하지 않은 리프레시 토큰",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             ),
             ApiResponse(
                 responseCode = "404",
-                description = "Refresh token not found",
+                description = "리프레시 토큰을 찾을 수 없음",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             )
         ]
@@ -76,13 +76,13 @@ interface AuthControllerApi {
     @PostMapping("/refresh")
     fun refreshToken(@RequestBody @Valid request: TokenRefreshRequest): ResponseEntity<AuthResponse>
 
-    @Operation(summary = "Sign out", description = "Sign out a user by invalidating their refresh token")
+    @Operation(summary = "로그아웃", description = "리프레시 토큰을 무효화하여 사용자를 로그아웃합니다")
     @ApiResponses(
         value = [
-            ApiResponse(responseCode = "204", description = "Successful sign out"),
+            ApiResponse(responseCode = "204", description = "로그아웃 성공"),
             ApiResponse(
                 responseCode = "400",
-                description = "Invalid user ID",
+                description = "유효하지 않은 사용자 ID",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             )
         ]
@@ -90,17 +90,17 @@ interface AuthControllerApi {
     @PostMapping("/signout")
     fun signOut(@AuthenticationPrincipal userId: UUID): ResponseEntity<Unit>
 
-    @Operation(summary = "Get user profile", description = "Retrieves profile information for the given user ID.")
+    @Operation(summary = "사용자 프로필 조회", description = "현재 로그인한 사용자의 프로필 정보를 조회합니다.")
     @ApiResponses(
         value = [
             ApiResponse(
                 responseCode = "200",
-                description = "User profile retrieved successfully",
+                description = "사용자 프로필 조회 성공",
                 content = [Content(schema = Schema(implementation = UserProfileResponse::class))]
             ),
             ApiResponse(
                 responseCode = "404",
-                description = "User not found",
+                description = "사용자를 찾을 수 없음",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             )
         ]
@@ -108,17 +108,17 @@ interface AuthControllerApi {
     @GetMapping("/me")
     fun getUserProfile(@AuthenticationPrincipal userId: UUID): ResponseEntity<UserProfileResponse>
 
-    @Operation(summary = "Update terms agreement", description = "Updates the user's terms agreement status")
+    @Operation(summary = "약관 동의 상태 수정", description = "사용자의 약관 동의 상태를 업데이트합니다")
     @ApiResponses(
         value = [
             ApiResponse(
                 responseCode = "200",
-                description = "Terms agreement status updated successfully",
+                description = "약관 동의 상태 업데이트 성공",
                 content = [Content(schema = Schema(implementation = UserProfileResponse::class))]
             ),
             ApiResponse(
                 responseCode = "404",
-                description = "User not found",
+                description = "사용자를 찾을 수 없음",
                 content = [Content(schema = Schema(implementation = ErrorResponse::class))]
             )
         ]
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/FindOrCreateUserRequest.kt b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/FindOrCreateUserRequest.kt
index 8132dfa9..9642ee30 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/FindOrCreateUserRequest.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/FindOrCreateUserRequest.kt
@@ -4,7 +4,7 @@ import io.swagger.v3.oas.annotations.media.Schema
 import jakarta.validation.constraints.NotBlank
 import jakarta.validation.constraints.NotNull
 import org.yapp.apis.auth.dto.response.UserCreateInfoResponse
-import org.yapp.apis.util.NicknameGenerator
+import org.yapp.apis.auth.util.NicknameGenerator
 import org.yapp.domain.user.ProviderType
 
 @Schema(
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SaveAppleRefreshTokenRequest.kt b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SaveAppleRefreshTokenRequest.kt
new file mode 100644
index 00000000..0e4e9273
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SaveAppleRefreshTokenRequest.kt
@@ -0,0 +1,50 @@
+package org.yapp.apis.auth.dto.request
+
+import io.swagger.v3.oas.annotations.media.Schema
+import jakarta.validation.constraints.NotBlank
+import jakarta.validation.constraints.NotNull
+import org.yapp.apis.auth.dto.response.CreateUserResponse
+import org.yapp.apis.auth.strategy.AppleAuthCredentials
+import java.util.UUID
+
+@Schema(
+    name = "SaveAppleRefreshTokenRequest",
+    description = "Request DTO for saving Apple refresh token with user ID and authorization code"
+)
+data class SaveAppleRefreshTokenRequest private constructor(
+    @Schema(
+        description = "Unique identifier of the user",
+        example = "a1b2c3d4-e5f6-7890-1234-56789abcdef0"
+    )
+    @field:NotNull(message = "userId must not be null")
+    val userId: UUID? = null,
+
+    @Schema(
+        description = "Authorization code from Apple OAuth process",
+        example = "cdef1234-abcd-5678-efgh-9012ijklmnop"
+    )
+    @field:NotBlank(message = "authorizationCode must not be blank")
+    val authorizationCode: String? = null,
+
+    @Schema(
+        description = "Apple refresh token, nullable if not issued yet",
+        example = "apple-refresh-token-example"
+    )
+    val appleRefreshToken: String? = null
+) {
+    fun validUserId(): UUID = userId!!
+    fun validAuthorizationCode(): String = authorizationCode!!
+
+    companion object {
+        fun of(
+            userResponse: CreateUserResponse,
+            credentials: AppleAuthCredentials
+        ): SaveAppleRefreshTokenRequest {
+            return SaveAppleRefreshTokenRequest(
+                userId = userResponse.id,
+                authorizationCode = credentials.authorizationCode,
+                appleRefreshToken = userResponse.appleRefreshToken
+            )
+        }
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SocialLoginRequest.kt b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SocialLoginRequest.kt
index 3adae361..61238588 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SocialLoginRequest.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/SocialLoginRequest.kt
@@ -28,7 +28,14 @@ data class SocialLoginRequest private constructor(
         required = true
     )
     @field:NotBlank(message = "OAuth token is required")
-    val oauthToken: String? = null
+    val oauthToken: String? = null,
+
+    @Schema(
+        description = "Authorization code used to issue Apple access/refresh tokens (required only for Apple login)",
+        example = "c322a426...",
+        required = false
+    )
+    val authorizationCode: String? = null
 ) {
     fun validProviderType(): String = providerType!!
     fun validOauthToken(): String = oauthToken!!
@@ -46,7 +53,11 @@ data class SocialLoginRequest private constructor(
 
             return when (provider) {
                 ProviderType.KAKAO -> KakaoAuthCredentials(request.validOauthToken())
-                ProviderType.APPLE -> AppleAuthCredentials(request.validOauthToken())
+                ProviderType.APPLE -> {
+                    val authCode = request.authorizationCode
+                        ?: throw AuthException(AuthErrorCode.INVALID_REQUEST, "Apple login requires an authorization code.")
+                    AppleAuthCredentials(request.validOauthToken(), authCode)
+                }
             }
         }
     }
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/TermsAgreementRequest.kt b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/TermsAgreementRequest.kt
index 766adf15..cd8197f2 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/TermsAgreementRequest.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/dto/request/TermsAgreementRequest.kt
@@ -6,9 +6,8 @@ import jakarta.validation.constraints.NotNull
 @Schema(description = "Request to update terms agreement status")
 data class TermsAgreementRequest private constructor(
     @Schema(description = "Whether the user agrees to the terms of service", example = "true", required = true)
+    @field:NotNull(message = "termsAgreed must not be null")
     val termsAgreed: Boolean? = null
-
-
 ) {
     fun validTermsAgreed(): Boolean = termsAgreed!!
 }
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/dto/response/CreateUserResponse.kt b/apis/src/main/kotlin/org/yapp/apis/auth/dto/response/CreateUserResponse.kt
index a984ba39..687f177e 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/dto/response/CreateUserResponse.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/dto/response/CreateUserResponse.kt
@@ -1,9 +1,9 @@
 package org.yapp.apis.auth.dto.response
 
 import io.swagger.v3.oas.annotations.media.Schema
-import org.yapp.domain.user.vo.UserIdentityVO
+import org.yapp.domain.user.vo.UserAuthVO
 import org.yapp.globalutils.auth.Role
-import java.util.UUID
+import java.util.*
 
 @Schema(
     name = "CreateUserResponse",
@@ -20,13 +20,20 @@ data class CreateUserResponse private constructor(
         description = "사용자 역할",
         example = "USER"
     )
-    val role: Role
+    val role: Role,
+
+    @Schema(
+        description = "Apple Refresh Token (Apple 유저인 경우에만 존재)",
+        nullable = true
+    )
+    val appleRefreshToken: String?
 ) {
     companion object {
-        fun from(identity: UserIdentityVO): CreateUserResponse {
+        fun from(auth: UserAuthVO): CreateUserResponse {
             return CreateUserResponse(
-                id = identity.id.value,
-                role = identity.role
+                id = auth.id.value,
+                role = auth.role,
+                appleRefreshToken = auth.appleRefreshToken
             )
         }
     }
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/exception/AuthErrorCode.kt b/apis/src/main/kotlin/org/yapp/apis/auth/exception/AuthErrorCode.kt
index 1e98a1d2..45bebdc4 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/exception/AuthErrorCode.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/exception/AuthErrorCode.kt
@@ -3,9 +3,6 @@ package org.yapp.apis.auth.exception
 import org.springframework.http.HttpStatus
 import org.yapp.globalutils.exception.BaseErrorCode
 
-/**
- * Error codes for authentication-related errors.
- */
 enum class AuthErrorCode(
     private val httpStatus: HttpStatus,
     private val code: String,
@@ -13,23 +10,44 @@ enum class AuthErrorCode(
 ) : BaseErrorCode {
 
     /* 400 BAD_REQUEST  */
-    UNSUPPORTED_PROVIDER_TYPE(HttpStatus.BAD_REQUEST, "AUTH_005", "Unsupported provider type."),
-    INVALID_CREDENTIALS(HttpStatus.BAD_REQUEST, "AUTH_006", "Invalid credentials."),
-    EMAIL_NOT_FOUND(HttpStatus.BAD_REQUEST, "AUTH_007", "Email not found."),
-    INVALID_ID_TOKEN_FORMAT(HttpStatus.BAD_REQUEST, "AUTH_008", "Invalid ID token format."),
-    SUBJECT_NOT_FOUND(HttpStatus.BAD_REQUEST, "AUTH_009", "Subject not found in ID token."),
-    FAILED_TO_PARSE_ID_TOKEN(HttpStatus.BAD_REQUEST, "AUTH_010", "Failed to parse ID token."),
-    FAILED_TO_GET_USER_INFO(HttpStatus.BAD_REQUEST, "AUTH_011", "Failed to get user info from provider."),
-    USER_NOT_FOUND(HttpStatus.BAD_REQUEST, "AUTH_012", "User not found."),
+    UNSUPPORTED_PROVIDER_TYPE(HttpStatus.BAD_REQUEST, "AUTH_400_01", "지원되지 않는 공급자 타입입니다."),
+    INVALID_CREDENTIALS(HttpStatus.BAD_REQUEST, "AUTH_400_02", "잘못된 인증 정보입니다."),
+    INVALID_REQUEST(HttpStatus.BAD_REQUEST, "AUTH_400_03", "잘못된 요청입니다."),
+    INVALID_ID_TOKEN_FORMAT(HttpStatus.BAD_REQUEST, "AUTH_400_04", "잘못된 ID 토큰 형식입니다."),
+    SUBJECT_NOT_FOUND(HttpStatus.BAD_REQUEST, "AUTH_400_05", "ID 토큰에서 주체를 찾을 수 없습니다."),
+    FAILED_TO_PARSE_ID_TOKEN(HttpStatus.BAD_REQUEST, "AUTH_400_06", "ID 토큰 파싱에 실패했습니다."),
+    FAILED_TO_GET_USER_INFO(HttpStatus.BAD_REQUEST, "AUTH_400_07", "공급자로부터 사용자 정보를 가져오는데 실패했습니다."),
+    USER_NOT_FOUND(HttpStatus.BAD_REQUEST, "AUTH_400_08", "사용자를 찾을 수 없습니다."),
+    EMAIL_NOT_FOUND(HttpStatus.BAD_REQUEST, "AUTH_400_09", "이메일을 찾을 수 없습니다."),
+    INVALID_APPLE_ID_TOKEN(HttpStatus.BAD_REQUEST, "AUTH_400_10", "유효하지 않은 Apple ID 토큰입니다."),
 
     /* 401 UNAUTHORIZED */
-    INVALID_REFRESH_TOKEN(HttpStatus.UNAUTHORIZED, "AUTH_002", "Invalid refresh token."),
-    REFRESH_TOKEN_NOT_FOUND(HttpStatus.UNAUTHORIZED, "AUTH_003", "Refresh token not found."),
-    INVALID_ACCESS_TOKEN(HttpStatus.UNAUTHORIZED, "AUTH_004", "Invalid access token."),
+    INVALID_OAUTH_TOKEN(HttpStatus.UNAUTHORIZED, "AUTH_401_01", "잘못된 소셜 OAuth 토큰입니다."),
+    INVALID_REFRESH_TOKEN(HttpStatus.UNAUTHORIZED, "AUTH_401_02", "잘못된 리프레시 토큰입니다."),
+    REFRESH_TOKEN_NOT_FOUND(HttpStatus.UNAUTHORIZED, "AUTH_401_03", "리프레시 토큰을 찾을 수 없습니다."),
+    INVALID_ACCESS_TOKEN(HttpStatus.UNAUTHORIZED, "AUTH_401_04", "잘못된 액세스 토큰입니다."),
+
+    /* 403 FORBIDDEN */
+    INSUFFICIENT_PERMISSIONS(HttpStatus.FORBIDDEN, "AUTH_403_01", "요청된 리소스에 대한 권한이 부족합니다."),
 
     /* 409 CONFLICT */
-    EMAIL_ALREADY_IN_USE(HttpStatus.CONFLICT, "AUTH_001", "Email already in use with a different account.");
+    EMAIL_ALREADY_IN_USE(HttpStatus.CONFLICT, "AUTH_409_01", "이미 다른 계정에서 사용 중인 이메일입니다."),
 
+    /* 500 INTERNAL_SERVER_ERROR */
+    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "AUTH_500_01", "내부 서버 오류입니다."),
+    FAILED_TO_LOAD_PRIVATE_KEY(HttpStatus.INTERNAL_SERVER_ERROR, "AUTH_500_02", "Apple 개인키 로드에 실패했습니다."),
+    INVALID_PRIVATE_KEY_FORMAT(HttpStatus.INTERNAL_SERVER_ERROR, "AUTH_500_03", "잘못된 개인키 형식입니다."),
+    FAILED_TO_COMMUNICATE_WITH_PROVIDER(
+        HttpStatus.INTERNAL_SERVER_ERROR,
+        "AUTH_500_04",
+        "외부 공급자와의 통신에 실패했습니다."
+    ),
+    OAUTH_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "AUTH_500_05", "소셜 OAuth 서버 오류입니다."),
+    MISSING_APPLE_REFRESH_TOKEN(
+        HttpStatus.INTERNAL_SERVER_ERROR,
+        "AUTH_500_06",
+        "Apple에서 초기 로그인 시 리프레시 토큰을 제공하지 않았습니다."
+    );
 
     override fun getHttpStatus(): HttpStatus = httpStatus
     override fun getCode(): String = code
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/helper/AppleJwtHelper.kt b/apis/src/main/kotlin/org/yapp/apis/auth/helper/AppleJwtHelper.kt
deleted file mode 100644
index 4c3eeacd..00000000
--- a/apis/src/main/kotlin/org/yapp/apis/auth/helper/AppleJwtHelper.kt
+++ /dev/null
@@ -1,75 +0,0 @@
-package org.yapp.apis.auth.helper
-
-import com.fasterxml.jackson.core.JsonProcessingException
-import com.fasterxml.jackson.databind.ObjectMapper
-import mu.KotlinLogging
-import org.yapp.apis.auth.exception.AuthErrorCode
-import org.yapp.apis.auth.exception.AuthException
-import org.yapp.globalutils.annotation.Helper
-import java.util.*
-
-@Helper
-class AppleJwtHelper(
-    private val objectMapper: ObjectMapper
-) {
-    private val log = KotlinLogging.logger {}
-
-    companion object {
-        private const val JWT_PARTS_COUNT = 3
-        private const val JWT_PAYLOAD_INDEX = 1
-    }
-
-    fun parseIdToken(idToken: String): AppleIdTokenPayload {
-        return try {
-            val parts = idToken.split(".")
-            require(parts.size == JWT_PARTS_COUNT) {
-                "Invalid JWT format: expected $JWT_PARTS_COUNT parts but got ${parts.size}"
-            }
-
-            val decodedPayload = decodeBase64UrlSafe(parts[JWT_PAYLOAD_INDEX])
-            val payloadJson = String(decodedPayload, Charsets.UTF_8)
-
-            objectMapper.readValue(payloadJson, AppleIdTokenPayload::class.java)
-
-        } catch (e: IllegalArgumentException) {
-            log.error("Invalid Apple ID token format", e)
-            throw AuthException(
-                AuthErrorCode.INVALID_ID_TOKEN_FORMAT,
-                "Invalid token format: ${e.message}"
-            )
-        } catch (e: JsonProcessingException) {
-            log.error("Failed to parse Apple ID token JSON", e)
-            throw AuthException(
-                AuthErrorCode.FAILED_TO_PARSE_ID_TOKEN,
-                "Failed to parse JSON: ${e.message}"
-            )
-        } catch (e: Exception) {
-            log.error("Failed to parse Apple ID token", e)
-            throw AuthException(
-                AuthErrorCode.FAILED_TO_PARSE_ID_TOKEN,
-                "Failed to parse token: ${e.message}"
-            )
-        }
-    }
-
-    private fun decodeBase64UrlSafe(encoded: String): ByteArray {
-        return try {
-            Base64.getUrlDecoder().decode(encoded)
-        } catch (e: IllegalArgumentException) {
-            throw AuthException(
-                AuthErrorCode.INVALID_ID_TOKEN_FORMAT,
-                "Invalid Base64 encoding: ${e.message}"
-            )
-        }
-    }
-
-    data class AppleIdTokenPayload(
-        val sub: String,
-        val email: String?,
-        val name: String?
-    ) {
-        init {
-            require(sub.isNotBlank()) { "Subject cannot be blank" }
-        }
-    }
-}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/helper/AuthTokenHelper.kt b/apis/src/main/kotlin/org/yapp/apis/auth/helper/AuthTokenHelper.kt
deleted file mode 100644
index 8c3d96f4..00000000
--- a/apis/src/main/kotlin/org/yapp/apis/auth/helper/AuthTokenHelper.kt
+++ /dev/null
@@ -1,45 +0,0 @@
-package org.yapp.apis.auth.helper
-
-import org.yapp.apis.auth.dto.request.DeleteTokenRequest
-import org.yapp.apis.auth.dto.request.GenerateTokenPairRequest
-import org.yapp.apis.auth.dto.request.TokenGenerateRequest
-import org.yapp.apis.auth.dto.request.TokenRefreshRequest
-import org.yapp.apis.auth.dto.response.TokenPairResponse
-import org.yapp.apis.auth.dto.response.UserIdResponse
-import org.yapp.apis.auth.service.TokenService
-import org.yapp.gateway.jwt.JwtTokenService
-import org.yapp.globalutils.annotation.Helper
-
-@Helper
-class AuthTokenHelper(
-    private val tokenService: TokenService,
-    private val jwtTokenService: JwtTokenService
-) {
-    fun generateTokenPair(generateTokenPairRequest: GenerateTokenPairRequest): TokenPairResponse {
-        val userId = generateTokenPairRequest.validUserId()
-        val role = generateTokenPairRequest.validRole()
-
-        val accessToken = jwtTokenService.generateAccessToken(userId, role)
-        val refreshToken = jwtTokenService.generateRefreshToken(userId)
-        val expiration = jwtTokenService.getRefreshTokenExpiration()
-
-        val refreshTokenResponse = tokenService.saveRefreshToken(
-            TokenGenerateRequest.of(userId, refreshToken, expiration)
-        )
-
-        return TokenPairResponse.of(accessToken, refreshTokenResponse.refreshToken)
-    }
-
-    fun validateAndGetUserIdFromRefreshToken(tokenRefreshRequest: TokenRefreshRequest): UserIdResponse {
-        tokenService.validateRefreshToken(tokenRefreshRequest.validRefreshToken())
-        return tokenService.getUserIdByToken(tokenRefreshRequest)
-    }
-
-    fun deleteTokenForReissue(tokenRefreshRequest: TokenRefreshRequest) {
-        tokenService.deleteRefreshTokenByToken(tokenRefreshRequest.validRefreshToken())
-    }
-
-    fun deleteTokenForSignOut(deleteTokenRequest: DeleteTokenRequest) {
-        tokenService.deleteRefreshTokenByToken(deleteTokenRequest.validRefreshToken())
-    }
-}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/helper/KakaoApiHelper.kt b/apis/src/main/kotlin/org/yapp/apis/auth/helper/KakaoApiHelper.kt
deleted file mode 100644
index ce17f076..00000000
--- a/apis/src/main/kotlin/org/yapp/apis/auth/helper/KakaoApiHelper.kt
+++ /dev/null
@@ -1,29 +0,0 @@
-package org.yapp.apis.auth.helper
-
-import mu.KotlinLogging
-import org.yapp.apis.auth.exception.AuthErrorCode
-import org.yapp.apis.auth.exception.AuthException
-import org.yapp.globalutils.annotation.Helper
-import org.yapp.infra.external.oauth.kakao.KakaoApi
-import org.yapp.infra.external.oauth.kakao.response.KakaoUserInfo
-
-@Helper
-class KakaoApiHelper(
-    private val kakaoApi: KakaoApi
-) {
-    private val log = KotlinLogging.logger {}
-
-    fun getUserInfo(accessToken: String): KakaoUserInfo {
-        return kakaoApi.fetchUserInfo(accessToken)
-            .onSuccess { userInfo ->
-                log.info("Successfully fetched Kakao user info for userId: ${userInfo.id}")
-            }
-            .getOrElse { exception ->
-                log.error("Failed to fetch Kakao user info", exception)
-                throw AuthException(
-                    AuthErrorCode.FAILED_TO_GET_USER_INFO,
-                    "Failed to call Kakao API: ${exception.message}"
-                )
-            }
-    }
-}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/AppleClientSecretGenerator.kt b/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/AppleClientSecretGenerator.kt
new file mode 100644
index 00000000..e4f2dd48
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/AppleClientSecretGenerator.kt
@@ -0,0 +1,37 @@
+package org.yapp.apis.auth.helper.apple
+
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.security.oauth2.jose.jws.SignatureAlgorithm
+import org.springframework.security.oauth2.jwt.JwsHeader
+import org.springframework.security.oauth2.jwt.JwtClaimsSet
+import org.springframework.security.oauth2.jwt.JwtEncoder
+import org.springframework.security.oauth2.jwt.JwtEncoderParameters
+import org.yapp.apis.config.AppleOauthProperties
+import org.yapp.globalutils.annotation.Helper
+import java.time.Instant
+import java.time.temporal.ChronoUnit
+
+@Helper
+class AppleClientSecretGenerator(
+    private val appleProperties: AppleOauthProperties,
+    @Qualifier("appleJwtEncoder")
+    private val jwtEncoder: JwtEncoder,
+) {
+    fun generateClientSecret(): String {
+        val header = JwsHeader.with(SignatureAlgorithm.ES256)
+            .keyId(appleProperties.keyId)
+            .build()
+
+        val claims = JwtClaimsSet.builder()
+            .issuer(appleProperties.teamId)
+            .subject(appleProperties.clientId)
+            .audience(listOf(appleProperties.audience))
+            .issuedAt(Instant.now())
+            .expiresAt(Instant.now().plus(5, ChronoUnit.MINUTES))
+            .build()
+
+        val encoderParameters = JwtEncoderParameters.from(header, claims)
+
+        return jwtEncoder.encode(encoderParameters).tokenValue
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/AppleIdTokenProcessor.kt b/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/AppleIdTokenProcessor.kt
new file mode 100644
index 00000000..5ddf3f20
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/AppleIdTokenProcessor.kt
@@ -0,0 +1,32 @@
+package org.yapp.apis.auth.helper.apple
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.security.oauth2.jwt.Jwt
+import org.springframework.security.oauth2.jwt.JwtDecoder
+import org.yapp.apis.auth.exception.AuthErrorCode
+import org.yapp.apis.auth.exception.AuthException
+import org.yapp.globalutils.annotation.Helper
+
+@Helper
+class AppleIdTokenProcessor(
+    @Qualifier("appleIdTokenDecoder")
+    private val jwtDecoder: JwtDecoder,
+    private val objectMapper: ObjectMapper
+) {
+    fun parseAndValidate(idToken: String): AppleIdTokenPayload {
+        try {
+            val decodedJwt: Jwt = jwtDecoder.decode(idToken)
+            val claims = decodedJwt.claims
+
+            return objectMapper.convertValue(claims, AppleIdTokenPayload::class.java)
+        } catch (e: Exception) {
+            throw AuthException(AuthErrorCode.INVALID_APPLE_ID_TOKEN, e.message)
+        }
+    }
+
+    data class AppleIdTokenPayload(
+        val sub: String,
+        val email: String?
+    )
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/ApplePrivateKeyLoader.kt b/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/ApplePrivateKeyLoader.kt
new file mode 100644
index 00000000..94221b1b
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/helper/apple/ApplePrivateKeyLoader.kt
@@ -0,0 +1,39 @@
+package org.yapp.apis.auth.helper.apple
+
+import org.springframework.context.annotation.Profile
+import org.springframework.core.io.ResourceLoader
+import org.yapp.apis.auth.exception.AuthErrorCode
+import org.yapp.apis.auth.exception.AuthException
+import org.yapp.apis.auth.util.AppleKeyParser
+import org.yapp.apis.config.AppleOauthProperties
+import org.yapp.globalutils.annotation.Helper
+import java.security.KeyPair
+
+@Helper
+@Profile("!test")
+class ApplePrivateKeyLoader(
+    private val appleProperties: AppleOauthProperties,
+    private val resourceLoader: ResourceLoader,
+) {
+    val keyPair: KeyPair = loadKeyPair()
+
+    private fun loadKeyPair(): KeyPair {
+        val resource = resourceLoader.getResource(appleProperties.keyPath)
+        if (!resource.exists()) {
+            throw AuthException(
+                AuthErrorCode.FAILED_TO_LOAD_PRIVATE_KEY,
+                "Apple private key file not found at path: ${appleProperties.keyPath}"
+            )
+        }
+
+        return try {
+            val pemString = resource.inputStream.bufferedReader().use { it.readText() }
+            AppleKeyParser.parseKeyPair(pemString)
+        } catch (e: IllegalArgumentException) {
+            throw AuthException(
+                AuthErrorCode.INVALID_PRIVATE_KEY_FORMAT,
+                "Failed to parse Apple private key: ${e.message}",
+            )
+        }
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/manager/AppleApiManager.kt b/apis/src/main/kotlin/org/yapp/apis/auth/manager/AppleApiManager.kt
new file mode 100644
index 00000000..1612c7f7
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/manager/AppleApiManager.kt
@@ -0,0 +1,38 @@
+package org.yapp.apis.auth.manager
+
+import mu.KotlinLogging
+import org.springframework.stereotype.Component
+import org.yapp.apis.auth.exception.AuthErrorCode
+import org.yapp.apis.auth.exception.AuthException
+import org.yapp.apis.auth.helper.apple.AppleClientSecretGenerator
+import org.yapp.apis.config.AppleOauthProperties
+import org.yapp.infra.external.oauth.apple.AppleApi
+import org.yapp.infra.external.oauth.apple.response.AppleTokenResponse
+
+@Component
+class AppleApiManager(
+    private val appleApi: AppleApi,
+    private val properties: AppleOauthProperties,
+    private val appleClientSecretGenerator: AppleClientSecretGenerator
+) {
+    private val log = KotlinLogging.logger {}
+
+    fun fetchAppleOauthTokens(authorizationCode: String): AppleTokenResponse {
+        val clientSecret = appleClientSecretGenerator.generateClientSecret()
+
+        return appleApi.getOauthTokens(
+            clientId = properties.clientId,
+            clientSecret = clientSecret,
+            code = authorizationCode
+        ).onSuccess { response ->
+            log.info {
+                "Successfully fetched Apple OAuth tokens. user_id=${response.idToken.substring(0, 20)}..."
+            }
+        }.getOrElse { originalError ->
+            log.error(originalError) { "Failed to fetch Apple OAuth tokens." }
+            throw AuthException(
+                AuthErrorCode.OAUTH_SERVER_ERROR, "Failed to communicate with Apple OAuth server."
+            )
+        }
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/manager/KakaoApiManager.kt b/apis/src/main/kotlin/org/yapp/apis/auth/manager/KakaoApiManager.kt
new file mode 100644
index 00000000..b93a5acd
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/manager/KakaoApiManager.kt
@@ -0,0 +1,45 @@
+package org.yapp.apis.auth.manager
+
+import mu.KotlinLogging
+import org.springframework.stereotype.Component
+import org.springframework.web.client.HttpClientErrorException
+import org.springframework.web.client.HttpServerErrorException
+import org.yapp.apis.auth.exception.AuthErrorCode
+import org.yapp.apis.auth.exception.AuthException
+import org.yapp.infra.external.oauth.kakao.KakaoApi
+import org.yapp.infra.external.oauth.kakao.response.KakaoUserInfo
+
+@Component
+class KakaoApiManager(
+    private val kakaoApi: KakaoApi
+) {
+    private val log = KotlinLogging.logger {}
+
+    fun getUserInfo(accessToken: String): KakaoUserInfo {
+        return kakaoApi.fetchUserInfo(accessToken)
+            .onSuccess { userInfo ->
+                log.info("Successfully fetched Kakao user info for userId: ${userInfo.id}")
+            }
+            .getOrElse { exception ->
+                log.error("Failed to fetch Kakao user info", exception)
+
+                when (exception) {
+                    is HttpClientErrorException -> {
+                        throw AuthException(
+                            AuthErrorCode.INVALID_OAUTH_TOKEN,
+                            "Invalid Kakao OAuth token."
+                        )
+                    }
+
+                    is HttpServerErrorException, is Exception -> {
+                        throw AuthException(
+                            AuthErrorCode.OAUTH_SERVER_ERROR,
+                            "Failed to communicate with Kakao server."
+                        )
+                    }
+
+                    else -> throw exception
+                }
+            }
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/service/AppleAuthService.kt b/apis/src/main/kotlin/org/yapp/apis/auth/service/AppleAuthService.kt
new file mode 100644
index 00000000..b147b179
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/service/AppleAuthService.kt
@@ -0,0 +1,28 @@
+package org.yapp.apis.auth.service
+
+import jakarta.validation.Valid
+import org.springframework.stereotype.Service
+import org.springframework.validation.annotation.Validated
+import org.yapp.apis.auth.dto.request.SaveAppleRefreshTokenRequest
+import org.yapp.apis.auth.exception.AuthErrorCode
+import org.yapp.apis.auth.exception.AuthException
+import org.yapp.apis.auth.manager.AppleApiManager
+import org.yapp.domain.user.UserDomainService
+
+@Service
+@Validated
+class AppleAuthService(
+    private val appleApiManager: AppleApiManager,
+    private val userDomainService: UserDomainService
+) {
+    fun saveAppleRefreshTokenIfMissing(@Valid request: SaveAppleRefreshTokenRequest) {
+        if (request.appleRefreshToken == null) {
+            val tokenResponse = appleApiManager.fetchAppleOauthTokens(request.validAuthorizationCode())
+
+            val refreshToken = tokenResponse.refreshToken
+                ?: throw AuthException(AuthErrorCode.MISSING_APPLE_REFRESH_TOKEN)
+
+            userDomainService.updateAppleRefreshToken(request.validUserId(), refreshToken)
+        }
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/service/AuthTokenService.kt b/apis/src/main/kotlin/org/yapp/apis/auth/service/AuthTokenService.kt
new file mode 100644
index 00000000..4ee67f36
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/service/AuthTokenService.kt
@@ -0,0 +1,47 @@
+package org.yapp.apis.auth.service
+
+import jakarta.validation.Valid
+import org.springframework.stereotype.Service
+import org.springframework.validation.annotation.Validated
+import org.yapp.apis.auth.dto.request.DeleteTokenRequest
+import org.yapp.apis.auth.dto.request.GenerateTokenPairRequest
+import org.yapp.apis.auth.dto.request.TokenGenerateRequest
+import org.yapp.apis.auth.dto.request.TokenRefreshRequest
+import org.yapp.apis.auth.dto.response.TokenPairResponse
+import org.yapp.apis.auth.dto.response.UserIdResponse
+import org.yapp.gateway.jwt.JwtTokenService
+
+@Service
+@Validated
+class AuthTokenService(
+    private val refreshTokenService: RefreshTokenService,
+    private val jwtTokenService: JwtTokenService
+) {
+    fun generateTokenPair(@Valid generateTokenPairRequest: GenerateTokenPairRequest): TokenPairResponse {
+        val userId = generateTokenPairRequest.validUserId()
+        val role = generateTokenPairRequest.validRole()
+
+        val accessToken = jwtTokenService.generateAccessToken(userId, role)
+        val refreshToken = jwtTokenService.generateRefreshToken(userId)
+        val expiration = jwtTokenService.getRefreshTokenExpiration()
+
+        val refreshTokenResponse = refreshTokenService.saveRefreshToken(
+            TokenGenerateRequest.of(userId, refreshToken, expiration)
+        )
+
+        return TokenPairResponse.of(accessToken, refreshTokenResponse.refreshToken)
+    }
+
+    fun validateAndGetUserIdFromRefreshToken(@Valid tokenRefreshRequest: TokenRefreshRequest): UserIdResponse {
+        refreshTokenService.validateRefreshToken(tokenRefreshRequest.validRefreshToken())
+        return refreshTokenService.getUserIdByToken(tokenRefreshRequest)
+    }
+
+    fun deleteTokenForReissue(@Valid tokenRefreshRequest: TokenRefreshRequest) {
+        refreshTokenService.deleteRefreshTokenByToken(tokenRefreshRequest.validRefreshToken())
+    }
+
+    fun deleteTokenForSignOut(@Valid deleteTokenRequest: DeleteTokenRequest) {
+        refreshTokenService.deleteRefreshTokenByToken(deleteTokenRequest.validRefreshToken())
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/service/TokenService.kt b/apis/src/main/kotlin/org/yapp/apis/auth/service/RefreshTokenService.kt
similarity index 92%
rename from apis/src/main/kotlin/org/yapp/apis/auth/service/TokenService.kt
rename to apis/src/main/kotlin/org/yapp/apis/auth/service/RefreshTokenService.kt
index 93b49fde..fee4ef7b 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/service/TokenService.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/service/RefreshTokenService.kt
@@ -12,7 +12,7 @@ import java.util.*
 
 @Service
 @Validated
-class TokenService(
+class RefreshTokenService(
     private val tokenDomainRedisService: TokenDomainRedisService,
 ) {
     fun deleteRefreshTokenByToken(token: String) {
@@ -37,7 +37,7 @@ class TokenService(
         tokenDomainRedisService.validateRefreshTokenByToken(refreshToken)
     }
 
-    fun getUserIdByToken(tokenRefreshRequest: TokenRefreshRequest): UserIdResponse {
+    fun getUserIdByToken(@Valid tokenRefreshRequest: TokenRefreshRequest): UserIdResponse {
         val userId = tokenDomainRedisService.getUserIdByToken(tokenRefreshRequest.validRefreshToken())
         return UserIdResponse.from(userId)
     }
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/service/UserAuthService.kt b/apis/src/main/kotlin/org/yapp/apis/auth/service/UserAuthService.kt
index 6e9160bc..190ecf9f 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/service/UserAuthService.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/service/UserAuthService.kt
@@ -11,7 +11,7 @@ import org.yapp.apis.auth.dto.response.UserProfileResponse
 import org.yapp.apis.auth.exception.AuthErrorCode
 import org.yapp.apis.auth.exception.AuthException
 import org.yapp.domain.user.UserDomainService
-import org.yapp.domain.user.vo.UserIdentityVO
+import org.yapp.domain.user.vo.UserAuthVO
 import java.util.*
 
 @Service
@@ -45,22 +45,23 @@ class UserAuthService(
         userDomainService.findUserByProviderTypeAndProviderId(
             findOrCreateUserRequest.validProviderType(),
             findOrCreateUserRequest.validProviderId()
-        )?.let { return CreateUserResponse.from(it) }
+        )?.let {
+            return CreateUserResponse.from(it)
+        }
 
         userDomainService.findUserByProviderTypeAndProviderIdIncludingDeleted(
             findOrCreateUserRequest.validProviderType(),
             findOrCreateUserRequest.validProviderId()
-        )?.let { deletedUserIdentity ->
-            return CreateUserResponse.from(
-                userDomainService.restoreDeletedUser(deletedUserIdentity.id.value)
-            )
+        )?.let { deletedUserAuth ->
+            val restoredUser = userDomainService.restoreDeletedUser(deletedUserAuth.id.value)
+            return CreateUserResponse.from(restoredUser)
         }
 
         val createdUser = createNewUser(findOrCreateUserRequest)
         return CreateUserResponse.from(createdUser)
     }
 
-    private fun createNewUser(findOrCreateUserRequest: FindOrCreateUserRequest): UserIdentityVO {
+    private fun createNewUser(@Valid findOrCreateUserRequest: FindOrCreateUserRequest): UserAuthVO {
         val email = findOrCreateUserRequest.getOrDefaultEmail()
         val nickname = findOrCreateUserRequest.getOrDefaultNickname()
 
@@ -68,7 +69,7 @@ class UserAuthService(
             throw AuthException(AuthErrorCode.EMAIL_ALREADY_IN_USE, "Email already in use")
         }
 
-        return userDomainService.createNewUser(
+        return userDomainService.createUser(
             email = email,
             nickname = nickname,
             profileImageUrl = findOrCreateUserRequest.profileImageUrl,
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AppleAuthStrategy.kt b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AppleAuthStrategy.kt
index 894452ee..b094550f 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AppleAuthStrategy.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AppleAuthStrategy.kt
@@ -5,34 +5,26 @@ import org.springframework.stereotype.Component
 import org.yapp.apis.auth.dto.response.UserCreateInfoResponse
 import org.yapp.apis.auth.exception.AuthErrorCode
 import org.yapp.apis.auth.exception.AuthException
-import org.yapp.apis.auth.helper.AppleJwtHelper
-import org.yapp.apis.util.NicknameGenerator
+import org.yapp.apis.auth.helper.apple.AppleIdTokenProcessor
+import org.yapp.apis.auth.util.NicknameGenerator
 import org.yapp.domain.user.ProviderType
 
-/**
- * Implementation of AuthStrategy for Apple authentication.
- */
 @Component
 class AppleAuthStrategy(
-    private val appleJwtHelper: AppleJwtHelper
+    private val appleIdTokenProcessor: AppleIdTokenProcessor
 ) : AuthStrategy {
-
     private val log = KotlinLogging.logger {}
 
     override fun getProviderType(): ProviderType = ProviderType.APPLE
 
     override fun authenticate(credentials: AuthCredentials): UserCreateInfoResponse {
-        return try {
-            val appleCredentials = validateCredentials(credentials)
-            val payload = appleJwtHelper.parseIdToken(appleCredentials.idToken)
-            createUserInfo(payload)
-        } catch (exception: Exception) {
-            log.error("Apple authentication failed", exception)
-            when (exception) {
-                is AuthException -> throw exception
-                else -> throw AuthException(AuthErrorCode.FAILED_TO_GET_USER_INFO, exception.message)
-            }
-        }
+        val appleCredentials = validateCredentials(credentials)
+
+        val payload = appleIdTokenProcessor.parseAndValidate(appleCredentials.idToken)
+
+        log.info { "Apple ID Token validated successfully. sub=${payload.sub}, email=${payload.email}" }
+
+        return createUserInfo(payload)
     }
 
     private fun validateCredentials(credentials: AuthCredentials): AppleAuthCredentials {
@@ -43,7 +35,7 @@ class AppleAuthStrategy(
             )
     }
 
-    private fun createUserInfo(payload: AppleJwtHelper.AppleIdTokenPayload): UserCreateInfoResponse {
+    private fun createUserInfo(payload: AppleIdTokenProcessor.AppleIdTokenPayload): UserCreateInfoResponse {
         return UserCreateInfoResponse.of(
             email = payload.email,
             nickname = NicknameGenerator.generate(),
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthCredentials.kt b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthCredentials.kt
index fd89cb96..8ff9fc55 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthCredentials.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthCredentials.kt
@@ -13,7 +13,8 @@ data class KakaoAuthCredentials(
 }
 
 data class AppleAuthCredentials(
-    val idToken: String
+    val idToken: String,
+    val authorizationCode: String
 ) : AuthCredentials() {
     override fun getProviderType(): ProviderType = ProviderType.APPLE
 }
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/service/SocialAuthService.kt b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthStrategyResolver.kt
similarity index 77%
rename from apis/src/main/kotlin/org/yapp/apis/auth/service/SocialAuthService.kt
rename to apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthStrategyResolver.kt
index 6e6c1fa6..97f08b62 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/service/SocialAuthService.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/AuthStrategyResolver.kt
@@ -1,16 +1,13 @@
-package org.yapp.apis.auth.service
+package org.yapp.apis.auth.strategy
 
 import org.springframework.stereotype.Service
-import org.yapp.apis.auth.strategy.AuthCredentials
 import org.yapp.apis.auth.exception.AuthErrorCode
 import org.yapp.apis.auth.exception.AuthException
-import org.yapp.apis.auth.strategy.AuthStrategy
 
 @Service
-class SocialAuthService(
+class AuthStrategyResolver(
     private val strategies: List<AuthStrategy>
 ) {
-
     fun resolve(credentials: AuthCredentials): AuthStrategy {
         return strategies.find { it.getProviderType() == credentials.getProviderType() }
             ?: throw AuthException(
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/strategy/KakaoAuthStrategy.kt b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/KakaoAuthStrategy.kt
index f6f98b94..3d82ef93 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/strategy/KakaoAuthStrategy.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/strategy/KakaoAuthStrategy.kt
@@ -5,17 +5,14 @@ import org.springframework.stereotype.Component
 import org.yapp.apis.auth.dto.response.UserCreateInfoResponse
 import org.yapp.apis.auth.exception.AuthErrorCode
 import org.yapp.apis.auth.exception.AuthException
-import org.yapp.apis.auth.helper.KakaoApiHelper
-import org.yapp.apis.util.NicknameGenerator
+import org.yapp.apis.auth.manager.KakaoApiManager
+import org.yapp.apis.auth.util.NicknameGenerator
 import org.yapp.domain.user.ProviderType
 import org.yapp.infra.external.oauth.kakao.response.KakaoUserInfo
 
-/**
- * Implementation of AuthStrategy for Kakao authentication.
- */
 @Component
 class KakaoAuthStrategy(
-    private val kakaoApiHelper: KakaoApiHelper
+    private val kakaoApiManager: KakaoApiManager
 ) : AuthStrategy {
 
     private val log = KotlinLogging.logger {}
@@ -25,7 +22,7 @@ class KakaoAuthStrategy(
     override fun authenticate(credentials: AuthCredentials): UserCreateInfoResponse {
         return try {
             val kakaoCredentials = validateCredentials(credentials)
-            val kakaoUser = kakaoApiHelper.getUserInfo(kakaoCredentials.accessToken)
+            val kakaoUser = kakaoApiManager.getUserInfo(kakaoCredentials.accessToken)
             createUserInfo(kakaoUser)
         } catch (exception: Exception) {
             log.error("Kakao authentication failed", exception)
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/usecase/AuthUseCase.kt b/apis/src/main/kotlin/org/yapp/apis/auth/usecase/AuthUseCase.kt
index d959ddfb..f572731f 100644
--- a/apis/src/main/kotlin/org/yapp/apis/auth/usecase/AuthUseCase.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/usecase/AuthUseCase.kt
@@ -4,51 +4,61 @@ import org.springframework.transaction.annotation.Transactional
 import org.yapp.apis.auth.dto.request.*
 import org.yapp.apis.auth.dto.response.TokenPairResponse
 import org.yapp.apis.auth.dto.response.UserProfileResponse
-import org.yapp.apis.auth.helper.AuthTokenHelper
-import org.yapp.apis.auth.service.SocialAuthService
-import org.yapp.apis.auth.service.TokenService
+import org.yapp.apis.auth.service.AppleAuthService
+import org.yapp.apis.auth.service.AuthTokenService
+import org.yapp.apis.auth.service.RefreshTokenService
 import org.yapp.apis.auth.service.UserAuthService
+import org.yapp.apis.auth.strategy.AppleAuthCredentials
+import org.yapp.apis.auth.strategy.AuthStrategyResolver
 import org.yapp.globalutils.annotation.UseCase
 import java.util.*
 
 @UseCase
 @Transactional(readOnly = true)
 class AuthUseCase(
-    private val socialAuthService: SocialAuthService,
+    private val authStrategyResolver: AuthStrategyResolver,
     private val userAuthService: UserAuthService,
-    private val tokenService: TokenService,
-    private val authTokenHelper: AuthTokenHelper
+    private val refreshTokenService: RefreshTokenService,
+    private val authTokenService: AuthTokenService,
+    private val appleAuthService: AppleAuthService
 ) {
     @Transactional
     fun signIn(socialLoginRequest: SocialLoginRequest): TokenPairResponse {
         val credentials = SocialLoginRequest.toCredentials(socialLoginRequest)
-        val strategy = socialAuthService.resolve(credentials)
-
+        val strategy = authStrategyResolver.resolve(credentials)
         val userCreateInfoResponse = strategy.authenticate(credentials)
-        val findOrCreateUserRequest = FindOrCreateUserRequest.from(userCreateInfoResponse)
-        val createUserResponse = userAuthService.findOrCreateUser(findOrCreateUserRequest)
-        val generateTokenPairRequest = GenerateTokenPairRequest.from(createUserResponse)
 
-        return authTokenHelper.generateTokenPair(generateTokenPairRequest)
+        val createUserResponse = userAuthService.findOrCreateUser(FindOrCreateUserRequest.from(userCreateInfoResponse))
+
+        if (credentials is AppleAuthCredentials) {
+            appleAuthService.saveAppleRefreshTokenIfMissing(
+                SaveAppleRefreshTokenRequest.of(
+                    createUserResponse,
+                    credentials
+                )
+            )
+        }
+
+        return authTokenService.generateTokenPair(GenerateTokenPairRequest.from(createUserResponse))
     }
 
     @Transactional
     fun reissueTokenPair(tokenRefreshRequest: TokenRefreshRequest): TokenPairResponse {
-        val userIdResponse = authTokenHelper.validateAndGetUserIdFromRefreshToken(tokenRefreshRequest)
-        authTokenHelper.deleteTokenForReissue(tokenRefreshRequest)
+        val userIdResponse = authTokenService.validateAndGetUserIdFromRefreshToken(tokenRefreshRequest)
+        authTokenService.deleteTokenForReissue(tokenRefreshRequest)
 
         val findUserIdentityRequest = FindUserIdentityRequest.from(userIdResponse)
         val userAuthInfoResponse = userAuthService.findUserIdentityByUserId(findUserIdentityRequest)
         val generateTokenPairRequest = GenerateTokenPairRequest.from(userAuthInfoResponse)
 
-        return authTokenHelper.generateTokenPair(generateTokenPairRequest)
+        return authTokenService.generateTokenPair(generateTokenPairRequest)
     }
 
     @Transactional
     fun signOut(userId: UUID) {
-        val refreshTokenResponse = tokenService.getRefreshTokenByUserId(userId)
+        val refreshTokenResponse = refreshTokenService.getRefreshTokenByUserId(userId)
         val deleteTokenRequest = DeleteTokenRequest.from(refreshTokenResponse)
-        authTokenHelper.deleteTokenForSignOut(deleteTokenRequest)
+        authTokenService.deleteTokenForSignOut(deleteTokenRequest)
     }
 
     fun getUserProfile(userId: UUID): UserProfileResponse {
diff --git a/apis/src/main/kotlin/org/yapp/apis/auth/util/AppleKeyParser.kt b/apis/src/main/kotlin/org/yapp/apis/auth/util/AppleKeyParser.kt
new file mode 100644
index 00000000..0c3eadba
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/util/AppleKeyParser.kt
@@ -0,0 +1,133 @@
+package org.yapp.apis.auth.util
+
+import org.bouncycastle.asn1.pkcs.PrivateKeyInfo
+import org.bouncycastle.jce.provider.BouncyCastleProvider
+import org.bouncycastle.openssl.PEMKeyPair
+import org.bouncycastle.openssl.PEMParser
+import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter
+import java.io.StringReader
+import java.security.KeyFactory
+import java.security.KeyPair
+import java.security.Security
+import java.security.interfaces.ECPrivateKey
+
+/**
+ * Apple JWT 인증에 사용되는 .p8 키 파일 파서
+ * 
+ * Apple Developer Console에서 다운로드한 .p8 키 파일(PKCS#8 형식)을
+ * JWT 서명 및 검증용 Java KeyPair 객체로 변환합니다.
+ * 
+ * 지원하는 PEM 형식:
+ * - PKCS#8 (-----BEGIN PRIVATE KEY-----)
+ * - SEC1 (-----BEGIN EC PRIVATE KEY-----)  
+ * - OpenSSL KeyPair 형식
+ * 
+ * @since 1.0
+ */
+object AppleKeyParser {
+    
+    /**
+     * Apple .p8 키 파일을 파싱하여 KeyPair를 생성합니다.
+     * 
+     * @param pemString PEM 형식의 키 문자열
+     * @return EC KeyPair (P-256 기반)
+     * @throws IllegalArgumentException 키 파싱 실패 시
+     */
+    fun parseKeyPair(pemString: String): KeyPair {
+        ensureBouncyCastleProvider()
+
+        return try {
+            parsePemKeyPair(pemString.trim())
+        } catch (e: Exception) {
+            throw IllegalArgumentException("Failed to parse Apple .p8 key file: ${e.message}", e)
+        }
+    }
+
+    /**
+     * BouncyCastle 보안 제공자가 등록되어 있는지 확인하고 필요시 등록합니다.
+     */
+    private fun ensureBouncyCastleProvider() {
+        if (Security.getProvider(BouncyCastleProvider.PROVIDER_NAME) == null) {
+            Security.addProvider(BouncyCastleProvider())
+        }
+    }
+
+    /**
+     * PEM 문자열을 파싱하여 형식에 맞는 KeyPair를 반환합니다.
+     * 
+     * @param pemString 공백이 제거된 PEM 문자열
+     * @return 파싱된 KeyPair
+     */
+    private fun parsePemKeyPair(pemString: String): KeyPair {
+        PEMParser(StringReader(pemString)).use { pemParser ->
+            val pemObject = pemParser.readObject()
+                ?: throw IllegalArgumentException("No PEM objects found in the provided string")
+
+            val converter = JcaPEMKeyConverter().setProvider(BouncyCastleProvider.PROVIDER_NAME)
+
+            return when (pemObject) {
+                is PEMKeyPair -> {
+                    // OpenSSL 형식 - 개인키와 공개키가 함께 포함된 경우
+                    converter.getKeyPair(pemObject)
+                }
+                
+                is PrivateKeyInfo -> {
+                    // PKCS#8 형식 - Apple .p8 파일의 표준 형식
+                    val privateKey = converter.getPrivateKey(pemObject) as ECPrivateKey
+                    deriveKeyPairFromPrivateKey(privateKey)
+                }
+                
+                is KeyPair -> {
+                    // 이미 KeyPair 객체인 경우
+                    pemObject
+                }
+
+                else -> {
+                    throw IllegalArgumentException(
+                        "Unsupported PEM object type: ${pemObject::class.qualifiedName}. " +
+                                "Expected PKCS#8 private key format."
+                    )
+                }
+            }
+        }
+    }
+
+    /**
+     * EC 개인키로부터 BouncyCastle 표준 방식을 사용하여 안전하게 KeyPair를 유도합니다.
+     * 
+     * @param privateKey EC 개인키
+     * @return 공개키가 유도된 완전한 KeyPair
+     */
+    private fun deriveKeyPairFromPrivateKey(privateKey: ECPrivateKey): KeyPair {
+        val keyFactory = KeyFactory.getInstance("EC", BouncyCastleProvider.PROVIDER_NAME)
+        val publicKey = generatePublicKeyFromPrivateKey(privateKey, keyFactory)
+        
+        return KeyPair(publicKey, privateKey)
+    }
+
+    /**
+     * BouncyCastle EC 수학을 사용하여 개인키로부터 공개키를 생성합니다.
+     * 
+     * @param privateKey EC 개인키
+     * @param keyFactory BouncyCastle EC 키 팩토리
+     * @return 유도된 공개키
+     */
+    private fun generatePublicKeyFromPrivateKey(
+        privateKey: ECPrivateKey,
+        keyFactory: KeyFactory
+    ): java.security.PublicKey {
+        
+        val bcPrivateKey = privateKey as org.bouncycastle.jce.interfaces.ECPrivateKey
+        val bcEcParams = bcPrivateKey.parameters
+        
+        val publicPoint = bcEcParams.g.multiply(bcPrivateKey.d)
+        publicPoint.normalize()
+
+        require(!publicPoint.isInfinity) {
+            "Invalid private key: derived public key point is at infinity"
+        }
+        
+        val bcPublicKeySpec = org.bouncycastle.jce.spec.ECPublicKeySpec(publicPoint, bcEcParams)
+        return keyFactory.generatePublic(bcPublicKeySpec)
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/util/AuthorExtractor.kt b/apis/src/main/kotlin/org/yapp/apis/auth/util/AuthorExtractor.kt
similarity index 100%
rename from apis/src/main/kotlin/org/yapp/apis/util/AuthorExtractor.kt
rename to apis/src/main/kotlin/org/yapp/apis/auth/util/AuthorExtractor.kt
diff --git a/apis/src/main/kotlin/org/yapp/apis/util/IsbnConverter.kt b/apis/src/main/kotlin/org/yapp/apis/auth/util/IsbnConverter.kt
similarity index 100%
rename from apis/src/main/kotlin/org/yapp/apis/util/IsbnConverter.kt
rename to apis/src/main/kotlin/org/yapp/apis/auth/util/IsbnConverter.kt
diff --git a/apis/src/main/kotlin/org/yapp/apis/util/NicknameGenerator.kt b/apis/src/main/kotlin/org/yapp/apis/auth/util/NicknameGenerator.kt
similarity index 97%
rename from apis/src/main/kotlin/org/yapp/apis/util/NicknameGenerator.kt
rename to apis/src/main/kotlin/org/yapp/apis/auth/util/NicknameGenerator.kt
index 6a5ff6a1..4441d80b 100644
--- a/apis/src/main/kotlin/org/yapp/apis/util/NicknameGenerator.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/auth/util/NicknameGenerator.kt
@@ -1,4 +1,4 @@
-package org.yapp.apis.util
+package org.yapp.apis.auth.util
 
 object NicknameGenerator {
 
@@ -23,4 +23,4 @@ object NicknameGenerator {
         val noun = nouns.random()
         return "$adj $noun"
     }
-}
\ No newline at end of file
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/book/exception/BookErrorCode.kt b/apis/src/main/kotlin/org/yapp/apis/book/exception/BookErrorCode.kt
index 2034b7ff..7e956c57 100644
--- a/apis/src/main/kotlin/org/yapp/apis/book/exception/BookErrorCode.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/book/exception/BookErrorCode.kt
@@ -3,15 +3,15 @@ package org.yapp.apis.book.exception
 import org.springframework.http.HttpStatus
 import org.yapp.globalutils.exception.BaseErrorCode
 
-
 enum class BookErrorCode(
     private val httpStatus: HttpStatus,
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
+
     /* 500 INTERNAL_SERVER_ERROR */
-    ALADIN_API_SEARCH_FAILED(HttpStatus.INTERNAL_SERVER_ERROR, "BOOK_001", "알라딘 도서 검색 API 호출에 실패했습니다."),
-    ALADIN_API_LOOKUP_FAILED(HttpStatus.INTERNAL_SERVER_ERROR, "BOOK_002", "알라딘 도서 상세 조회 API 호출에 실패했습니다.");
+    ALADIN_API_SEARCH_FAILED(HttpStatus.INTERNAL_SERVER_ERROR, "BOOK_500_01", "알라딘 도서 검색 API 호출에 실패했습니다."),
+    ALADIN_API_LOOKUP_FAILED(HttpStatus.INTERNAL_SERVER_ERROR, "BOOK_500_02", "알라딘 도서 상세 조회 API 호출에 실패했습니다.");
 
     override fun getHttpStatus(): HttpStatus = httpStatus
     override fun getCode(): String = code
diff --git a/apis/src/main/kotlin/org/yapp/apis/book/exception/UserBookErrorCode.kt b/apis/src/main/kotlin/org/yapp/apis/book/exception/UserBookErrorCode.kt
index 46e23880..4530c3ef 100644
--- a/apis/src/main/kotlin/org/yapp/apis/book/exception/UserBookErrorCode.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/book/exception/UserBookErrorCode.kt
@@ -4,13 +4,14 @@ import org.springframework.http.HttpStatus
 import org.yapp.globalutils.exception.BaseErrorCode
 
 enum class UserBookErrorCode(
-    private val status: HttpStatus,
+    private val httpStatus: HttpStatus,
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    USER_BOOK_NOT_FOUND(HttpStatus.NOT_FOUND, "USER_BOOK_001", "사용자의 책을 찾을 수 없습니다.");
 
-    override fun getHttpStatus(): HttpStatus = status
+    USER_BOOK_NOT_FOUND(HttpStatus.NOT_FOUND, "USER_BOOK_404_01", "사용자의 책을 찾을 수 없습니다.");
+
+    override fun getHttpStatus(): HttpStatus = httpStatus
     override fun getCode(): String = code
     override fun getMessage(): String = message
 }
diff --git a/apis/src/main/kotlin/org/yapp/apis/config/AppleJwtConfig.kt b/apis/src/main/kotlin/org/yapp/apis/config/AppleJwtConfig.kt
new file mode 100644
index 00000000..0da3bbef
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/config/AppleJwtConfig.kt
@@ -0,0 +1,102 @@
+package org.yapp.apis.config
+
+import com.nimbusds.jose.jwk.Curve
+import com.nimbusds.jose.jwk.ECKey
+import com.nimbusds.jose.jwk.JWKSet
+import com.nimbusds.jose.jwk.source.ImmutableJWKSet
+import com.nimbusds.jose.jwk.source.JWKSource
+import com.nimbusds.jose.proc.SecurityContext
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.security.oauth2.core.*
+import org.springframework.security.oauth2.jwt.*
+import org.yapp.apis.auth.helper.apple.ApplePrivateKeyLoader
+import java.security.interfaces.ECPublicKey
+
+@Configuration
+class AppleJwtConfig(
+    private val applePrivateKeyLoader: ApplePrivateKeyLoader,
+    private val appleProperties: AppleOauthProperties
+) {
+    companion object {
+        private const val APPLE_JWKS_URI = "https://appleid.apple.com/auth/keys"
+    }
+
+    /**
+     * Apple OAuth 인증을 위한 JWKSource를 생성합니다.
+     *
+     * - EC 키 쌍(KeyPair)을 기반으로 JWK(JSON Web Key)를 구성
+     * - Nimbus 라이브러리의 JwtEncoder에서 Apple client_secret 생성 시 사용
+     *
+     * @return Apple 인증용 JWKSource<SecurityContext> (ImmutableJWKSet 형태)
+     */
+    @Bean
+    @Qualifier("appleJwkSource")
+    fun appleJwkSource(): JWKSource<SecurityContext> {
+        val keyPair = applePrivateKeyLoader.keyPair
+        val publicKey = keyPair.public as ECPublicKey
+        val privateKey = keyPair.private
+
+        val ecKey = ECKey.Builder(Curve.P_256, publicKey)
+            .privateKey(privateKey)
+            .keyID(appleProperties.keyId)
+            .build()
+
+        return ImmutableJWKSet(JWKSet(ecKey))
+    }
+
+    /**
+     * Apple 전용 JWK 소스를 사용하여 client_secret 생성에 사용될 JwtEncoder를 생성합니다.
+     *
+     * - NimbusJwtEncoder는 JWKSource 기반으로 JWT 서명을 처리
+     *
+     * @param jwkSource Apple용 JWKSource Bean
+     * @return Apple client_secret 생성용 JwtEncoder 객체
+     */
+    @Bean
+    @Qualifier("appleJwtEncoder")
+    fun appleJwtEncoder(
+        @Qualifier("appleJwkSource") jwkSource: JWKSource<SecurityContext>
+    ): JwtEncoder {
+        return NimbusJwtEncoder(jwkSource)
+    }
+
+    /**
+     * Apple에서 발급한 ID Token을 검증하기 위한 JwtDecoder를 생성합니다.
+     *
+     * - NimbusJwtDecoder를 사용하여 Apple 공개키(JWKS) 기반 검증 수행
+     * - APPLE_JWKS_URI("https://appleid.apple.com/auth/keys")에서 공개키(JWK Set) 가져오기
+     *
+     *  검증 로직
+     *   1. 서명(Signature) 유효성 검증: Apple의 공개키와 토큰 서명이 일치하는지 확인
+     *   2. Issuer 검증: 토큰의 iss 클레임이 예상 값인지 확인
+     *   3. Audience 검증: 토큰의 aud 클레임이 애플리케이션의 clientId와 일치하는지 확인
+     *
+     * @return Apple ID Token 검증용 JwtDecoder
+     */
+    @Bean
+    @Qualifier("appleIdTokenDecoder")
+    fun appleIdTokenDecoder(): JwtDecoder {
+        val decoder = NimbusJwtDecoder.withJwkSetUri(APPLE_JWKS_URI).build()
+
+        val issuerValidator: OAuth2TokenValidator<Jwt> =
+            JwtValidators.createDefaultWithIssuer(appleProperties.audience)
+
+        val audienceValidator = OAuth2TokenValidator<Jwt> { token ->
+            if (token.audience.contains(appleProperties.clientId)) {
+                OAuth2TokenValidatorResult.success()
+            } else {
+                val error = OAuth2Error(
+                    OAuth2ErrorCodes.INVALID_TOKEN, "The required audience is missing", null
+                )
+                OAuth2TokenValidatorResult.failure(error)
+            }
+        }
+
+        val combinedValidator = DelegatingOAuth2TokenValidator(issuerValidator, audienceValidator)
+        decoder.setJwtValidator(combinedValidator)
+
+        return decoder
+    }
+}
diff --git a/apis/src/main/kotlin/org/yapp/apis/config/AppleOauthProperties.kt b/apis/src/main/kotlin/org/yapp/apis/config/AppleOauthProperties.kt
new file mode 100644
index 00000000..d761b860
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/config/AppleOauthProperties.kt
@@ -0,0 +1,12 @@
+package org.yapp.apis.config
+
+import org.springframework.boot.context.properties.ConfigurationProperties
+
+@ConfigurationProperties(prefix = "oauth.apple")
+data class AppleOauthProperties(
+    val clientId: String,
+    val keyId: String,
+    val teamId: String,
+    val keyPath: String,
+    val audience: String
+)
diff --git a/apis/src/main/kotlin/org/yapp/apis/config/AuthConfig.kt b/apis/src/main/kotlin/org/yapp/apis/config/AuthConfig.kt
new file mode 100644
index 00000000..060a5a87
--- /dev/null
+++ b/apis/src/main/kotlin/org/yapp/apis/config/AuthConfig.kt
@@ -0,0 +1,8 @@
+package org.yapp.apis.config
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties
+import org.springframework.context.annotation.Configuration
+
+@Configuration
+@EnableConfigurationProperties(AppleOauthProperties::class)
+class AuthConfig
diff --git a/apis/src/main/kotlin/org/yapp/apis/readingrecord/exception/ReadingRecordErrorCode.kt b/apis/src/main/kotlin/org/yapp/apis/readingrecord/exception/ReadingRecordErrorCode.kt
index c1181e57..117bd431 100644
--- a/apis/src/main/kotlin/org/yapp/apis/readingrecord/exception/ReadingRecordErrorCode.kt
+++ b/apis/src/main/kotlin/org/yapp/apis/readingrecord/exception/ReadingRecordErrorCode.kt
@@ -8,7 +8,7 @@ enum class ReadingRecordErrorCode(
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    READING_RECORD_NOT_FOUND(HttpStatus.NOT_FOUND, "READING_RECORD_001", "독서 기록을 찾을 수 없습니다.");
+    READING_RECORD_NOT_FOUND(HttpStatus.NOT_FOUND, "READING_RECORD_404_01", "독서 기록을 찾을 수 없습니다.");
 
     override fun getHttpStatus(): HttpStatus = status
     override fun getCode(): String = code
diff --git a/apis/src/main/resources/application.yml b/apis/src/main/resources/application.yml
index aaf88d7c..1be2c434 100644
--- a/apis/src/main/resources/application.yml
+++ b/apis/src/main/resources/application.yml
@@ -73,3 +73,16 @@ springdoc:
     enabled: false
   api-docs:
     enabled: false
+
+aladin:
+  api:
+    ttb-key: dummy-aladin-key
+
+oauth:
+  apple:
+    client-id: dummy.client.id
+    key-id: DUMMYKEYID
+    team-id: DUMMYTEAMID
+    key-path: "path-ignored-by-mock"
+    audience: https://appleid.apple.com
+
diff --git a/apis/src/main/resources/static/kakao-login.html b/apis/src/main/resources/static/kakao-login.html
index b3edd49b..1c63c4d9 100644
--- a/apis/src/main/resources/static/kakao-login.html
+++ b/apis/src/main/resources/static/kakao-login.html
@@ -121,7 +121,10 @@ <h1 style="text-align:center">소셜 로그인 테스트</h1>
                 fetch(`${API_SERVER}/api/v1/auth/signin`, {
                     method: 'POST',
                     headers: {'Content-Type': 'application/json'},
-                    body: JSON.stringify({providerType: "KAKAO", oauthToken: accessToken})
+                    body: JSON.stringify({
+                        providerType: "KAKAO",
+                        oauthToken: accessToken
+                    })
                 })
                     .then(res => res.json())
                     .then(data => {
@@ -137,36 +140,104 @@ <h1 style="text-align:center">소셜 로그인 테스트</h1>
         });
     });
 
-    // Apple 로그인
+    // Apple 로그인 - popup 모드
     document.getElementById('apple-login-btn').addEventListener('click', () => {
         AppleID.auth.init({
             clientId: '',
             scope: 'name email',
-            redirectURI: 'http://localhost:8080/kakao-login.html',
+            redirectURI: `${window.location.origin}/kakao-login.html`,
+            state: 'apple-login-' + Date.now(),
+            responseType: 'code', // authorization code만 요청 (popup 모드에서 안정적)
+            responseMode: 'query', // URL query parameter로 응답 받기
             usePopup: true
         });
 
+        // Apple Sign In 실행
         AppleID.auth.signIn()
             .then(response => {
-                // id_token을 서버로 전송
-                const id_token = response.authorization.id_token;
-                fetch(`${API_SERVER}/api/v1/auth/signin`, {
+                console.log('Apple 로그인 성공:', response);
+                
+                const authorizationCode = response.authorization?.code;
+                
+                if (!authorizationCode) {
+                    throw new Error('Authorization code not received from Apple');
+                }
+
+                const idToken = response.authorization?.id_token || 'popup-mode-token';
+
+                const requestData = {
+                    providerType: "APPLE",
+                    oauthToken: idToken,
+                    authorizationCode: authorizationCode
+                };
+
+                console.log('서버로 전송할 데이터:', requestData);
+
+                return fetch(`${API_SERVER}/api/v1/auth/signin`, {
                     method: 'POST',
                     headers: {'Content-Type': 'application/json'},
-                    body: JSON.stringify({providerType: "APPLE", idToken: id_token})
-                })
-                    .then(res => res.json())
-                    .then(data => {
-                        document.getElementById('result').textContent = 'Apple 로그인 성공\n\nJWT: ' + data.accessToken;
-                    })
-                    .catch(err => {
-                        document.getElementById('result').textContent = 'Apple 로그인 실패: ' + err.message;
-                    });
+                    body: JSON.stringify(requestData)
+                });
+            })
+            .then(async response => {
+                const data = await response.json();
+                if (!response.ok) {
+                    throw new Error(`서버 에러 (${response.status}): ${data.message || 'Unknown error'}`);
+                }
+                return data;
+            })
+            .then(data => {
+                document.getElementById('result').textContent = 
+                    'Apple 로그인 성공!\n\n' +
+                    'JWT: ' + data.accessToken + '\n\n' +
+                    '사용자 정보: ' + JSON.stringify(data.user || {}, null, 2);
             })
             .catch(error => {
-                document.getElementById('result').textContent = 'Apple 로그인 실패: ' + JSON.stringify(error);
+                console.error('Apple 로그인 에러:', error);
+                document.getElementById('result').textContent = 'Apple 로그인 실패: ' + error.message;
             });
     });
+
+    // Apple 콜백 처리 (페이지 로드 시 URL 파라미터 확인)
+    window.addEventListener('load', () => {
+        const urlParams = new URLSearchParams(window.location.search);
+        const code = urlParams.get('code');
+        const state = urlParams.get('state');
+        
+        if (code && state && state.startsWith('apple-login-')) {
+            console.log('Apple 콜백 감지됨:', { code, state });
+            
+            const requestData = {
+                providerType: "APPLE",
+                oauthToken: 'callback-id-token',
+                authorizationCode: code
+            };
+
+            fetch(`${API_SERVER}/api/v1/auth/signin`, {
+                method: 'POST',
+                headers: {'Content-Type': 'application/json'},
+                body: JSON.stringify(requestData)
+            })
+                .then(async response => {
+                    const data = await response.json();
+                    if (!response.ok) {
+                        throw new Error(`서버 에러 (${response.status}): ${data.message || 'Unknown error'}`);
+                    }
+                    return data;
+                })
+                .then(data => {
+                    document.getElementById('result').textContent = 
+                        'Apple 로그인 성공 (콜백)!\n\n' +
+                        'JWT: ' + data.accessToken;
+                        
+                    history.replaceState({}, document.title, window.location.pathname);
+                })
+                .catch(error => {
+                    console.error('Apple 콜백 처리 에러:', error);
+                    document.getElementById('result').textContent = 'Apple 로그인 실패 (콜백): ' + error.message;
+                });
+        }
+    });
 </script>
 
 </body>
diff --git a/apis/src/test/kotlin/org/yapp/apis/ApisApplicationTests.kt b/apis/src/test/kotlin/org/yapp/apis/ApisApplicationTests.kt
index e4ed9bb7..1501662c 100644
--- a/apis/src/test/kotlin/org/yapp/apis/ApisApplicationTests.kt
+++ b/apis/src/test/kotlin/org/yapp/apis/ApisApplicationTests.kt
@@ -6,7 +6,7 @@ import org.springframework.test.context.ActiveProfiles
 
 @SpringBootTest
 @ActiveProfiles("test")
-class ApisApplicationTests {
+class ApisApplicationTests : BaseIntegrationTest() {
 
     @Test
     fun contextLoads() {
diff --git a/apis/src/test/kotlin/org/yapp/apis/BaseIntegrationTest.kt b/apis/src/test/kotlin/org/yapp/apis/BaseIntegrationTest.kt
new file mode 100644
index 00000000..debb32a8
--- /dev/null
+++ b/apis/src/test/kotlin/org/yapp/apis/BaseIntegrationTest.kt
@@ -0,0 +1,9 @@
+package org.yapp.apis
+
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.context.annotation.Import
+import org.yapp.apis.config.MockTestConfiguration
+
+@SpringBootTest
+@Import(MockTestConfiguration::class)
+abstract class BaseIntegrationTest
diff --git a/apis/src/test/kotlin/org/yapp/apis/config/MockTestConfiguration.kt b/apis/src/test/kotlin/org/yapp/apis/config/MockTestConfiguration.kt
new file mode 100644
index 00000000..07927f1b
--- /dev/null
+++ b/apis/src/test/kotlin/org/yapp/apis/config/MockTestConfiguration.kt
@@ -0,0 +1,25 @@
+package org.yapp.apis.config
+
+import org.mockito.Mockito
+import org.springframework.boot.test.context.TestConfiguration
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Primary
+import org.yapp.apis.auth.helper.apple.ApplePrivateKeyLoader
+import java.security.KeyPairGenerator
+
+@TestConfiguration
+class MockTestConfiguration {
+
+    @Bean
+    @Primary
+    fun mockApplePrivateKeyLoader(): ApplePrivateKeyLoader {
+        val mockLoader = Mockito.mock(ApplePrivateKeyLoader::class.java)
+
+        val keyPairGenerator = KeyPairGenerator.getInstance("EC")
+        keyPairGenerator.initialize(256)
+        val keyPair = keyPairGenerator.generateKeyPair()
+        Mockito.`when`(mockLoader.keyPair).thenReturn(keyPair)
+
+        return mockLoader
+    }
+}
diff --git a/buildSrc/src/main/kotlin/Dependencies.kt b/buildSrc/src/main/kotlin/Dependencies.kt
index ad06fb0e..b4d5270f 100644
--- a/buildSrc/src/main/kotlin/Dependencies.kt
+++ b/buildSrc/src/main/kotlin/Dependencies.kt
@@ -8,9 +8,10 @@ object Dependencies {
         const val BOOT_STARTER_ACTUATOR = "org.springframework.boot:spring-boot-starter-actuator"
         const val BOOT_STARTER_TEST = "org.springframework.boot:spring-boot-starter-test"
         const val BOOT_STARTER_DATA_REDIS = "org.springframework.boot:spring-boot-starter-data-redis"
-        const val BOOT_STARTER_OAUTH2_RESOURCE_SERVER =
-            "org.springframework.boot:spring-boot-starter-oauth2-resource-server"
+        const val BOOT_STARTER_OAUTH2_RESOURCE_SERVER = "org.springframework.boot:spring-boot-starter-oauth2-resource-server"
+        const val BOOT_STARTER_OAUTH2_CLIENT = "org.springframework.boot:spring-boot-starter-oauth2-client"
         const val KOTLIN_REFLECT = "org.jetbrains.kotlin:kotlin-reflect"
+        const val CONFIGURATION_PROCESSOR = "org.springframework.boot:spring-boot-configuration-processor"
     }
 
     object Database {
@@ -57,4 +58,9 @@ object Dependencies {
         const val JPA = "com.querydsl:querydsl-jpa:5.0.0:jakarta"
         const val APT = "com.querydsl:querydsl-apt:5.0.0:jakarta"
     }
+
+    object BouncyCastle {
+        const val BC_PROV = "org.bouncycastle:bcprov-jdk18on:1.78.1"
+        const val BC_PKIX = "org.bouncycastle:bcpkix-jdk18on:1.78.1"
+    }
 }
diff --git a/domain/src/main/kotlin/org/yapp/domain/book/exception/BookErrorCode.kt b/domain/src/main/kotlin/org/yapp/domain/book/exception/BookErrorCode.kt
index b5302256..912b52e6 100644
--- a/domain/src/main/kotlin/org/yapp/domain/book/exception/BookErrorCode.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/book/exception/BookErrorCode.kt
@@ -4,14 +4,15 @@ import org.springframework.http.HttpStatus
 import org.yapp.globalutils.exception.BaseErrorCode
 
 enum class BookErrorCode(
-    private val status: HttpStatus,
+    private val httpStatus: HttpStatus,
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    BOOK_NOT_FOUND(HttpStatus.NOT_FOUND, "BOOK_001", "도서 정보를 찾을 수 없습니다."),
-    BOOK_ALREADY_EXISTS(HttpStatus.CONFLICT, "BOOK_002", "이미 존재하는 도서입니다.");
 
-    override fun getHttpStatus(): HttpStatus = status
+    BOOK_NOT_FOUND(HttpStatus.NOT_FOUND, "BOOK_404_01", "도서 정보를 찾을 수 없습니다."),
+    BOOK_ALREADY_EXISTS(HttpStatus.CONFLICT, "BOOK_409_01", "이미 존재하는 도서입니다.");
+
+    override fun getHttpStatus(): HttpStatus = httpStatus
     override fun getCode(): String = code
     override fun getMessage(): String = message
 }
diff --git a/domain/src/main/kotlin/org/yapp/domain/readingrecord/exception/ReadingRecordErrorCode.kt b/domain/src/main/kotlin/org/yapp/domain/readingrecord/exception/ReadingRecordErrorCode.kt
index 9ec94af4..8170d8f2 100644
--- a/domain/src/main/kotlin/org/yapp/domain/readingrecord/exception/ReadingRecordErrorCode.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/readingrecord/exception/ReadingRecordErrorCode.kt
@@ -8,7 +8,7 @@ enum class ReadingRecordErrorCode(
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    READING_RECORD_NOT_FOUND(HttpStatus.NOT_FOUND, "READING_RECORD_001", "독서 기록을 찾을 수 없습니다.");
+    READING_RECORD_NOT_FOUND(HttpStatus.NOT_FOUND, "READING_RECORD_404_01", "독서 기록을 찾을 수 없습니다.");
 
     override fun getHttpStatus(): HttpStatus = status
     override fun getCode(): String = code
diff --git a/domain/src/main/kotlin/org/yapp/domain/token/exception/TokenErrorCode.kt b/domain/src/main/kotlin/org/yapp/domain/token/exception/TokenErrorCode.kt
index 934ec4d0..cbdd7524 100644
--- a/domain/src/main/kotlin/org/yapp/domain/token/exception/TokenErrorCode.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/token/exception/TokenErrorCode.kt
@@ -4,15 +4,16 @@ import org.springframework.http.HttpStatus
 import org.yapp.globalutils.exception.BaseErrorCode
 
 enum class TokenErrorCode(
-    private val status: HttpStatus,
+    private val httpStatus: HttpStatus,
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    TOKEN_NOT_FOUND(HttpStatus.NOT_FOUND, "TOKEN_001", "토큰 정보를 찾을 수 없습니다."),
-    INVALID_REFRESH_TOKEN(HttpStatus.UNAUTHORIZED, "TOKEN_002", "유효하지 않은 리프레시 토큰입니다."),
-    EXPIRED_REFRESH_TOKEN(HttpStatus.UNAUTHORIZED, "TOKEN_003", "리프레시 토큰이 만료되었습니다.");
 
-    override fun getHttpStatus(): HttpStatus = status
+    TOKEN_NOT_FOUND(HttpStatus.NOT_FOUND, "TOKEN_404_01", "토큰 정보를 찾을 수 없습니다."),
+    INVALID_REFRESH_TOKEN(HttpStatus.UNAUTHORIZED, "TOKEN_401_01", "유효하지 않은 리프레시 토큰입니다."),
+    EXPIRED_REFRESH_TOKEN(HttpStatus.UNAUTHORIZED, "TOKEN_401_02", "리프레시 토큰이 만료되었습니다.");
+
+    override fun getHttpStatus(): HttpStatus = httpStatus
     override fun getCode(): String = code
     override fun getMessage(): String = message
 }
diff --git a/domain/src/main/kotlin/org/yapp/domain/user/User.kt b/domain/src/main/kotlin/org/yapp/domain/user/User.kt
index 6b342a74..47c67e58 100644
--- a/domain/src/main/kotlin/org/yapp/domain/user/User.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/user/User.kt
@@ -6,20 +6,6 @@ import org.yapp.globalutils.validator.EmailValidator
 import java.time.LocalDateTime
 import java.util.*
 
-/**
- * User domain model.
- *
- * @property id The unique identifier of the user.
- * @property email The email of the user.
- * @property nickname The nickname of the user.
- * @property profileImageUrl The URL of the user's profile image.
- * @property providerType The type of authentication provider.
- * @property providerId The ID from the authentication provider.
- * @property role The roles of the user (e.g., USER, ADMIN).
- * @property createdAt The timestamp when the user was created.
- * @property updatedAt The timestamp when the user was last updated.
- * @property deletedAt The timestamp when the user was soft-deleted, or null if the user is not deleted.
- */
 data class User private constructor(
     val id: Id,
     val email: Email,
@@ -29,6 +15,7 @@ data class User private constructor(
     val providerId: ProviderId,
     val role: Role,
     val termsAgreed: Boolean = false,
+    val appleRefreshToken: String? = null,
     val createdAt: LocalDateTime? = null,
     val updatedAt: LocalDateTime? = null,
     val deletedAt: LocalDateTime? = null
@@ -47,6 +34,12 @@ data class User private constructor(
         )
     }
 
+    fun updateAppleRefreshToken(token: String): User {
+        return this.copy(
+            appleRefreshToken = token
+        )
+    }
+
     companion object {
         fun create(
             email: String,
@@ -64,7 +57,8 @@ data class User private constructor(
                 providerType = providerType,
                 providerId = ProviderId.newInstance(providerId),
                 role = Role.USER,
-                termsAgreed = termsAgreed
+                termsAgreed = termsAgreed,
+                appleRefreshToken = null
             )
         }
 
@@ -86,7 +80,8 @@ data class User private constructor(
                 providerType = providerType,
                 providerId = ProviderId.newInstance(providerId),
                 role = role,
-                termsAgreed = termsAgreed
+                termsAgreed = termsAgreed,
+                appleRefreshToken = null
             )
         }
 
@@ -99,6 +94,7 @@ data class User private constructor(
             providerId: ProviderId,
             role: Role,
             termsAgreed: Boolean = false,
+            appleRefreshToken: String? = null,
             createdAt: LocalDateTime? = null,
             updatedAt: LocalDateTime? = null,
             deletedAt: LocalDateTime? = null
@@ -112,6 +108,7 @@ data class User private constructor(
                 providerId = providerId,
                 role = role,
                 termsAgreed = termsAgreed,
+                appleRefreshToken = appleRefreshToken,
                 createdAt = createdAt,
                 updatedAt = updatedAt,
                 deletedAt = deletedAt
diff --git a/domain/src/main/kotlin/org/yapp/domain/user/UserDomainService.kt b/domain/src/main/kotlin/org/yapp/domain/user/UserDomainService.kt
index 34a66c48..e0fe64f3 100644
--- a/domain/src/main/kotlin/org/yapp/domain/user/UserDomainService.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/user/UserDomainService.kt
@@ -2,16 +2,16 @@ package org.yapp.domain.user
 
 import org.yapp.domain.user.exception.UserErrorCode
 import org.yapp.domain.user.exception.UserNotFoundException
+import org.yapp.domain.user.vo.UserAuthVO
 import org.yapp.domain.user.vo.UserIdentityVO
 import org.yapp.domain.user.vo.UserProfileVO
 import org.yapp.globalutils.annotation.DomainService
-import org.yapp.globalutils.util.TimeProvider
-import java.util.UUID
+
+import java.util.*
 
 @DomainService
 class UserDomainService(
     private val userRepository: UserRepository,
-    private val timeProvider: TimeProvider
 ) {
     fun findUserProfileById(id: UUID): UserProfileVO {
         val user = userRepository.findById(id) ?: throw UserNotFoundException(UserErrorCode.USER_NOT_FOUND)
@@ -23,17 +23,17 @@ class UserDomainService(
         return UserIdentityVO.newInstance(user)
     }
 
-    fun findUserByProviderTypeAndProviderId(providerType: ProviderType, providerId: String): UserIdentityVO? {
+    fun findUserByProviderTypeAndProviderId(providerType: ProviderType, providerId: String): UserAuthVO? {
         return userRepository.findByProviderTypeAndProviderId(providerType, providerId)
-            ?.let { UserIdentityVO.newInstance(it) }
+            ?.let { UserAuthVO.newInstance(it) }
     }
 
     fun findUserByProviderTypeAndProviderIdIncludingDeleted(
         providerType: ProviderType,
         providerId: String
-    ): UserIdentityVO? {
+    ): UserAuthVO? {
         return userRepository.findByProviderTypeAndProviderIdIncludingDeleted(providerType, providerId)
-            ?.let { UserIdentityVO.newInstance(it) }
+            ?.let { UserAuthVO.newInstance(it) }
     }
 
     fun existsActiveUserByIdAndDeletedAtIsNull(id: UUID): Boolean {
@@ -44,13 +44,13 @@ class UserDomainService(
         return userRepository.existsByEmail(email)
     }
 
-    fun createNewUser(
+    fun createUser(
         email: String,
         nickname: String,
         profileImageUrl: String?,
         providerType: ProviderType,
         providerId: String
-    ): UserIdentityVO {
+    ): UserAuthVO {
         val user = User.create(
             email = email,
             nickname = nickname,
@@ -59,15 +59,15 @@ class UserDomainService(
             providerId = providerId
         )
         val savedUser = userRepository.save(user)
-        return UserIdentityVO.newInstance(savedUser)
+        return UserAuthVO.newInstance(savedUser)
     }
 
-    fun restoreDeletedUser(userId: UUID): UserIdentityVO {
+    fun restoreDeletedUser(userId: UUID): UserAuthVO {
         val deletedUser = userRepository.findById(userId)
             ?: throw UserNotFoundException(UserErrorCode.USER_NOT_FOUND)
 
         val restoredUser = userRepository.save(deletedUser.restore())
-        return UserIdentityVO.newInstance(restoredUser)
+        return UserAuthVO.newInstance(restoredUser)
     }
 
     fun updateTermsAgreement(userId: UUID, termsAgreed: Boolean): UserProfileVO {
@@ -77,4 +77,13 @@ class UserDomainService(
         val updatedUser = userRepository.save(user.updateTermsAgreement(termsAgreed))
         return UserProfileVO.newInstance(updatedUser)
     }
+
+    fun updateAppleRefreshToken(userId: UUID, refreshToken: String): UserIdentityVO {
+        val user = userRepository.findById(userId)
+            ?: throw UserNotFoundException(UserErrorCode.USER_NOT_FOUND)
+
+        val updatedUser = userRepository.save(user.updateAppleRefreshToken(refreshToken))
+
+        return UserIdentityVO.newInstance(updatedUser)
+    }
 }
diff --git a/domain/src/main/kotlin/org/yapp/domain/user/exception/UserErrorCode.kt b/domain/src/main/kotlin/org/yapp/domain/user/exception/UserErrorCode.kt
index 3ee966e6..424b6967 100644
--- a/domain/src/main/kotlin/org/yapp/domain/user/exception/UserErrorCode.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/user/exception/UserErrorCode.kt
@@ -4,13 +4,14 @@ import org.springframework.http.HttpStatus
 import org.yapp.globalutils.exception.BaseErrorCode
 
 enum class UserErrorCode(
-    private val status: HttpStatus,
+    private val httpStatus: HttpStatus,
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    USER_NOT_FOUND(HttpStatus.NOT_FOUND, "USER_001", "유저 정보를 찾을 수 없습니다.");
 
-    override fun getHttpStatus(): HttpStatus = status
+    USER_NOT_FOUND(HttpStatus.NOT_FOUND, "USER_404_01", "유저 정보를 찾을 수 없습니다.");
+
+    override fun getHttpStatus(): HttpStatus = httpStatus
     override fun getCode(): String = code
     override fun getMessage(): String = message
 }
diff --git a/domain/src/main/kotlin/org/yapp/domain/user/vo/UserAuthVO.kt b/domain/src/main/kotlin/org/yapp/domain/user/vo/UserAuthVO.kt
new file mode 100644
index 00000000..9d8c6675
--- /dev/null
+++ b/domain/src/main/kotlin/org/yapp/domain/user/vo/UserAuthVO.kt
@@ -0,0 +1,20 @@
+package org.yapp.domain.user.vo
+
+import org.yapp.domain.user.User
+import org.yapp.globalutils.auth.Role
+
+data class UserAuthVO(
+    val id: User.Id,
+    val role: Role,
+    val appleRefreshToken: String?
+) {
+    companion object {
+        fun newInstance(user: User): UserAuthVO {
+            return UserAuthVO(
+                id = user.id,
+                role = user.role,
+                appleRefreshToken = user.appleRefreshToken
+            )
+        }
+    }
+}
diff --git a/domain/src/main/kotlin/org/yapp/domain/userbook/exception/UserBookErrorCode.kt b/domain/src/main/kotlin/org/yapp/domain/userbook/exception/UserBookErrorCode.kt
index bfadebdd..72af880d 100644
--- a/domain/src/main/kotlin/org/yapp/domain/userbook/exception/UserBookErrorCode.kt
+++ b/domain/src/main/kotlin/org/yapp/domain/userbook/exception/UserBookErrorCode.kt
@@ -8,7 +8,7 @@ enum class UserBookErrorCode(
     private val code: String,
     private val message: String
 ) : BaseErrorCode {
-    USER_BOOK_NOT_FOUND(HttpStatus.NOT_FOUND, "USER_BOOK_001", "유저의 책 정보를 찾을 수 없습니다.");
+    USER_BOOK_NOT_FOUND(HttpStatus.NOT_FOUND, "USER_BOOK_404_01", "유저의 책 정보를 찾을 수 없습니다.");
 
     override fun getHttpStatus(): HttpStatus = status
     override fun getCode(): String = code
diff --git a/gateway/src/main/kotlin/org/yapp/gateway/config/JwtConfig.kt b/gateway/src/main/kotlin/org/yapp/gateway/config/JwtConfig.kt
index 769e01d0..863d7ebd 100644
--- a/gateway/src/main/kotlin/org/yapp/gateway/config/JwtConfig.kt
+++ b/gateway/src/main/kotlin/org/yapp/gateway/config/JwtConfig.kt
@@ -8,6 +8,7 @@ import com.nimbusds.jose.proc.SecurityContext
 import org.springframework.beans.factory.annotation.Value
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
+import org.springframework.context.annotation.Primary
 import org.springframework.core.convert.converter.Converter
 import org.springframework.security.authentication.AbstractAuthenticationToken
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken
@@ -49,6 +50,7 @@ class JwtConfig(
      * @return 생성된 `JwtEncoder` 객체
      */
     @Bean
+    @Primary
     fun jwtEncoder(jwkSource: JWKSource<SecurityContext>): JwtEncoder {
         return NimbusJwtEncoder(jwkSource)
     }
@@ -60,6 +62,7 @@ class JwtConfig(
      * @return 생성된 `JwtDecoder` 객체
      */
     @Bean
+    @Primary
     fun jwtDecoder(): JwtDecoder {
         val secretKeySpec = SecretKeySpec(secretKey.toByteArray(), SIGNATURE_ALGORITHM.name)
         val decoder = NimbusJwtDecoder.withSecretKey(secretKeySpec).build()
diff --git a/gateway/src/main/kotlin/org/yapp/gateway/security/SecurityConfig.kt b/gateway/src/main/kotlin/org/yapp/gateway/security/SecurityConfig.kt
index 69be2a5e..eb140e68 100644
--- a/gateway/src/main/kotlin/org/yapp/gateway/security/SecurityConfig.kt
+++ b/gateway/src/main/kotlin/org/yapp/gateway/security/SecurityConfig.kt
@@ -10,9 +10,6 @@ import org.springframework.security.authentication.AbstractAuthenticationToken
 import org.springframework.security.oauth2.jwt.Jwt
 import org.springframework.security.web.SecurityFilterChain
 
-/**
- * Security configuration for the gateway.
- */
 @Configuration
 @EnableWebSecurity
 class SecurityConfig(
diff --git a/global-utils/src/main/kotlin/org/yapp/globalutils/exception/CommonErrorCode.kt b/global-utils/src/main/kotlin/org/yapp/globalutils/exception/CommonErrorCode.kt
index cd684b3f..0a5ec36b 100644
--- a/global-utils/src/main/kotlin/org/yapp/globalutils/exception/CommonErrorCode.kt
+++ b/global-utils/src/main/kotlin/org/yapp/globalutils/exception/CommonErrorCode.kt
@@ -11,16 +11,16 @@ enum class CommonErrorCode(
     private val message: String
 ) : BaseErrorCode {
 
-    CONFLICT(HttpStatus.CONFLICT, "COMMON_001", "Duplicated Value"),
-    REQUEST_PARAMETER_BIND_FAILED(HttpStatus.BAD_REQUEST, "COMMON_002", "PARAMETER_BIND_FAILED"),
-    BAD_REQUEST(HttpStatus.BAD_REQUEST, "COMMON_003", "BAD REQUEST"),
-    INVALID_REQUEST(HttpStatus.BAD_REQUEST, "COMMON_004", "INVALID REQUEST"),
-    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "COMMON_005", "INTERNAL SERVER ERROR"),
-    MALFORMED_JSON(HttpStatus.BAD_REQUEST, "COMMON_006", "MALFORMED JSON"),
-    METHOD_NOT_ALLOWED(HttpStatus.METHOD_NOT_ALLOWED, "COMMON_007", "METHOD NOT ALLOWED"),
-    UNAUTHORIZED(HttpStatus.UNAUTHORIZED, "COMMON_008", "UNAUTHORIZED"),
-    FORBIDDEN(HttpStatus.FORBIDDEN, "COMMON_009", "FORBIDDEN"),
-    NOT_FOUND(HttpStatus.NOT_FOUND, "COMMON_010", "NOT FOUND"),
+    CONFLICT(HttpStatus.CONFLICT, "COMMON_409_01", "Duplicated Value"),
+    REQUEST_PARAMETER_BIND_FAILED(HttpStatus.BAD_REQUEST, "COMMON_400_01", "PARAMETER_BIND_FAILED"),
+    BAD_REQUEST(HttpStatus.BAD_REQUEST, "COMMON_400_02", "BAD REQUEST"),
+    INVALID_REQUEST(HttpStatus.BAD_REQUEST, "COMMON_400_03", "INVALID REQUEST"),
+    MALFORMED_JSON(HttpStatus.BAD_REQUEST, "COMMON_400_04", "MALFORMED JSON"),
+    UNAUTHORIZED(HttpStatus.UNAUTHORIZED, "COMMON_401_01", "UNAUTHORIZED"),
+    FORBIDDEN(HttpStatus.FORBIDDEN, "COMMON_403_01", "FORBIDDEN"),
+    NOT_FOUND(HttpStatus.NOT_FOUND, "COMMON_404_01", "NOT FOUND"),
+    METHOD_NOT_ALLOWED(HttpStatus.METHOD_NOT_ALLOWED, "COMMON_405_01", "METHOD NOT ALLOWED"),
+    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "COMMON_500_01", "INTERNAL SERVER ERROR"),
     ;
 
 
diff --git a/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinApi.kt b/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinApi.kt
index f58fe191..1d8eca40 100644
--- a/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinApi.kt
+++ b/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinApi.kt
@@ -10,8 +10,8 @@ import org.yapp.infra.external.aladin.response.AladinSearchResponse
 @Component
 class AladinApi(
     private val aladinRestClient: AladinRestClient,
-    @Value("\${aladin.api.ttbkey:#{null}}")
-    private var ttbKey: String? = null
+    @Value("\${aladin.api.ttb-key}")
+    private var ttbKey: String
 ) {
     fun searchBooks(request: AladinBookSearchRequest): Result<AladinSearchResponse> {
         return runCatching {
diff --git a/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinRestClient.kt b/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinRestClient.kt
index ffb93338..0b1d7b1c 100644
--- a/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinRestClient.kt
+++ b/infra/src/main/kotlin/org/yapp/infra/external/aladin/AladinRestClient.kt
@@ -16,7 +16,7 @@ class AladinRestClient(
     private val DEFAULT_OUTPUT_FORMAT = "JS"
 
     fun itemSearch(
-        ttbKey: String?,
+        ttbKey: String,
         params: Map<String, Any>
     ): AladinSearchResponse {
         val uriBuilder = UriComponentsBuilder.fromUriString("/ItemSearch.aspx")
@@ -32,7 +32,7 @@ class AladinRestClient(
     }
 
     fun itemLookUp(
-        ttbKey: String?,
+        ttbKey: String,
         params: Map<String, Any> = emptyMap()
     ): AladinBookDetailResponse {
         val uriBuilder = UriComponentsBuilder.fromUriString("/ItemLookUp.aspx")
diff --git a/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/AppleApi.kt b/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/AppleApi.kt
new file mode 100644
index 00000000..7a8dfc40
--- /dev/null
+++ b/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/AppleApi.kt
@@ -0,0 +1,56 @@
+package org.yapp.infra.external.oauth.apple
+
+import org.springframework.stereotype.Component
+import org.springframework.util.LinkedMultiValueMap
+import org.yapp.infra.external.oauth.apple.response.AppleTokenResponse
+
+@Component
+class AppleApi(
+    private val appleRestClient: AppleRestClient
+) {
+    companion object {
+        private const val CLIENT_ID = "client_id"
+        private const val CLIENT_SECRET = "client_secret"
+        private const val CODE = "code"
+        private const val GRANT_TYPE = "grant_type"
+        private const val TOKEN = "token"
+        private const val TOKEN_TYPE_HINT = "token_type_hint"
+        private const val GRANT_TYPE_AUTHORIZATION_CODE = "authorization_code"
+    }
+
+    fun getOauthTokens(
+        clientId: String,
+        clientSecret: String,
+        code: String,
+        grantType: String = GRANT_TYPE_AUTHORIZATION_CODE
+    ): Result<AppleTokenResponse> {
+        val requestBody = LinkedMultiValueMap<String, String>().apply {
+            add(CLIENT_ID, clientId)
+            add(CLIENT_SECRET, clientSecret)
+            add(CODE, code)
+            add(GRANT_TYPE, grantType)
+        }
+
+        return runCatching {
+            appleRestClient.getTokens(requestBody)
+        }
+    }
+    
+    fun revokeToken(
+        clientId: String,
+        clientSecret: String,
+        token: String,
+        tokenTypeHint: String
+    ): Result<Unit> {
+        val requestBody = LinkedMultiValueMap<String, String>().apply {
+            add(CLIENT_ID, clientId)
+            add(CLIENT_SECRET, clientSecret)
+            add(TOKEN, token)
+            add(TOKEN_TYPE_HINT, tokenTypeHint)
+        }
+
+        return runCatching {
+            appleRestClient.revoke(requestBody)
+        }
+    }
+}
diff --git a/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/AppleRestClient.kt b/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/AppleRestClient.kt
new file mode 100644
index 00000000..ea5ad735
--- /dev/null
+++ b/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/AppleRestClient.kt
@@ -0,0 +1,40 @@
+package org.yapp.infra.external.oauth.apple
+
+import org.springframework.http.MediaType
+import org.springframework.stereotype.Component
+import org.springframework.util.MultiValueMap
+import org.springframework.web.client.RestClient
+import org.yapp.infra.external.oauth.apple.response.AppleTokenResponse
+
+@Component
+class AppleRestClient(
+    builder: RestClient.Builder
+) {
+    companion object {
+        private const val BASE_URL = "https://appleid.apple.com/auth"
+        private const val CONTENT_TYPE = "application/x-www-form-urlencoded"
+    }
+
+    private val client = builder
+        .baseUrl(BASE_URL)
+        .build()
+
+    fun getTokens(requestBody: MultiValueMap<String, String>): AppleTokenResponse {
+        return client.post()
+            .uri("/token")
+            .contentType(MediaType.valueOf(CONTENT_TYPE))
+            .body(requestBody)
+            .retrieve()
+            .body(AppleTokenResponse::class.java)
+            ?: throw IllegalStateException("Apple token response body is null")
+    }
+
+    fun revoke(requestBody: MultiValueMap<String, String>) {
+        client.post()
+            .uri("/revoke")
+            .contentType(MediaType.valueOf(CONTENT_TYPE))
+            .body(requestBody)
+            .retrieve()
+            .toBodilessEntity()
+    }
+}
diff --git a/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/response/AppleTokenResponse.kt b/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/response/AppleTokenResponse.kt
new file mode 100644
index 00000000..0de3714f
--- /dev/null
+++ b/infra/src/main/kotlin/org/yapp/infra/external/oauth/apple/response/AppleTokenResponse.kt
@@ -0,0 +1,13 @@
+package org.yapp.infra.external.oauth.apple.response
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies
+import com.fasterxml.jackson.databind.annotation.JsonNaming
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy::class)
+data class AppleTokenResponse(
+    val accessToken: String,
+    val expiresIn: Int,
+    val idToken: String,
+    val refreshToken: String?,
+    val tokenType: String
+)
diff --git a/infra/src/main/kotlin/org/yapp/infra/user/entity/UserEntity.kt b/infra/src/main/kotlin/org/yapp/infra/user/entity/UserEntity.kt
index 64546072..34f86f90 100644
--- a/infra/src/main/kotlin/org/yapp/infra/user/entity/UserEntity.kt
+++ b/infra/src/main/kotlin/org/yapp/infra/user/entity/UserEntity.kt
@@ -4,10 +4,10 @@ import jakarta.persistence.*
 import org.hibernate.annotations.JdbcTypeCode
 import org.hibernate.annotations.SQLDelete
 import org.hibernate.annotations.SQLRestriction
-import org.yapp.infra.common.BaseTimeEntity
 import org.yapp.domain.user.ProviderType
 import org.yapp.domain.user.User
 import org.yapp.globalutils.auth.Role
+import org.yapp.infra.common.BaseTimeEntity
 import java.sql.Types
 import java.util.*
 
@@ -37,7 +37,9 @@ class UserEntity private constructor(
 
     role: Role,
 
-    termsAgreed: Boolean = false
+    termsAgreed: Boolean = false,
+
+    appleRefreshToken: String? = null
 ) : BaseTimeEntity() {
 
     @Column(nullable = false, length = 100)
@@ -57,6 +59,10 @@ class UserEntity private constructor(
     var termsAgreed: Boolean = termsAgreed
         protected set
 
+    @Column(name = "apple_refresh_token", length = 1024)
+    var appleRefreshToken: String? = appleRefreshToken
+        protected set
+
     fun toDomain(): User = User.reconstruct(
         id = User.Id.newInstance(this.id),
         email = User.Email.newInstance(this.email),
@@ -66,6 +72,7 @@ class UserEntity private constructor(
         providerId = User.ProviderId.newInstance(this.providerId),
         role = role,
         termsAgreed = termsAgreed,
+        appleRefreshToken = appleRefreshToken,
         createdAt = createdAt,
         updatedAt = updatedAt,
         deletedAt = deletedAt
@@ -80,7 +87,8 @@ class UserEntity private constructor(
             providerType = user.providerType,
             providerId = user.providerId.value,
             role = user.role,
-            termsAgreed = user.termsAgreed
+            termsAgreed = user.termsAgreed,
+            appleRefreshToken = user.appleRefreshToken
         )
     }
 
diff --git a/infra/src/main/resources/application-external.yml b/infra/src/main/resources/application-external.yml
index 63c84a30..91ac5a41 100644
--- a/infra/src/main/resources/application-external.yml
+++ b/infra/src/main/resources/application-external.yml
@@ -1,3 +1,13 @@
 aladin:
   api:
-    ttbkey: ${ALADIN_API_KEY}
+    ttb-key: ${ALADIN_API_KEY}
+
+oauth:
+  kakao:
+    admin-key: ${KAKAO_ADMIN_KEY}
+  apple:
+    client-id: ${APPLE_CLIENT_ID}
+    key-id: ${APPLE_KEY_ID}
+    team-id: ${APPLE_TEAM_ID}
+    key-path: ${APPLE_KEY_PATH}
+    audience: https://appleid.apple.com