diff --git a/src/main/java/com/teamEWSN/gitdeun/codereference/controller/CodeReferenceController.java b/src/main/java/com/teamEWSN/gitdeun/codereference/controller/CodeReferenceController.java
index 904cce0..35d093f 100644
--- a/src/main/java/com/teamEWSN/gitdeun/codereference/controller/CodeReferenceController.java
+++ b/src/main/java/com/teamEWSN/gitdeun/codereference/controller/CodeReferenceController.java
@@ -1,5 +1,4 @@
 package com.teamEWSN.gitdeun.codereference.controller;
 
 public class CodeReferenceController {
-    
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/codereference/entity/CodeReference.java b/src/main/java/com/teamEWSN/gitdeun/codereference/entity/CodeReference.java
index e71e410..7eae685 100644
--- a/src/main/java/com/teamEWSN/gitdeun/codereference/entity/CodeReference.java
+++ b/src/main/java/com/teamEWSN/gitdeun/codereference/entity/CodeReference.java
@@ -1,5 +1,31 @@
 package com.teamEWSN.gitdeun.codereference.entity;
 
+import com.teamEWSN.gitdeun.mindmapnode.entity.MindmapNode;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "code_reference")
 public class CodeReference {
-    
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "node_id", nullable = false)
+    private MindmapNode node;
+
+    @Column(name = "file_path", columnDefinition = "TEXT", nullable = false)
+    private String filePath;
+
+    @Column(name = "start_line", length = 255)
+    private String startLine;
+
+    @Column(name = "end_line", length = 255)
+    private String endLine;
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReview.java b/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReview.java
index f36f8e8..84b1779 100644
--- a/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReview.java
+++ b/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReview.java
@@ -1,5 +1,46 @@
 package com.teamEWSN.gitdeun.codereview.entity;
 
-public class CodeReview {
-    
+import com.teamEWSN.gitdeun.common.util.AuditedEntity;
+import com.teamEWSN.gitdeun.mindmapnode.entity.MindmapNode;
+import com.teamEWSN.gitdeun.user.entity.User;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Code_Review")
+public class CodeReview extends AuditedEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "author_id", nullable = false)
+    private User author;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "node_id", nullable = false)
+    private MindmapNode node;
+
+    @Column(name = "ref_id")
+    private Long refId;
+
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false)
+    @ColumnDefault("'PENDING'")
+    private CodeReviewStatus status;
+
+    @Column(name = "comment_cnt")
+    @ColumnDefault("0")
+    private Integer commentCount;
+
+    @Column(name = "unresolved_thread_cnt")
+    @ColumnDefault("0")
+    private Integer unresolvedThreadCount;
+
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReviewStatus.java b/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReviewStatus.java
new file mode 100644
index 0000000..99a0912
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/codereview/entity/CodeReviewStatus.java
@@ -0,0 +1,6 @@
+package com.teamEWSN.gitdeun.codereview.entity;
+
+public enum CodeReviewStatus {
+    PENDING,
+    RESOLVED
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/controller/CommentController.java b/src/main/java/com/teamEWSN/gitdeun/comment/controller/CommentController.java
new file mode 100644
index 0000000..154605b
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/controller/CommentController.java
@@ -0,0 +1,4 @@
+package com.teamEWSN.gitdeun.comment.controller;
+
+public class CommentController {
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/dto/CommentResponseDto.java b/src/main/java/com/teamEWSN/gitdeun/comment/dto/CommentResponseDto.java
new file mode 100644
index 0000000..e306b6e
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/dto/CommentResponseDto.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.comment.dto;
+
+public class CommentResponseDto {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/entity/AttachmentType.java b/src/main/java/com/teamEWSN/gitdeun/comment/entity/AttachmentType.java
new file mode 100644
index 0000000..7433cc5
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/entity/AttachmentType.java
@@ -0,0 +1,6 @@
+package com.teamEWSN.gitdeun.comment.entity;
+
+public enum AttachmentType {
+    IMAGE,
+    FILE
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/entity/Comment.java b/src/main/java/com/teamEWSN/gitdeun/comment/entity/Comment.java
new file mode 100644
index 0000000..72e028c
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/entity/Comment.java
@@ -0,0 +1,44 @@
+package com.teamEWSN.gitdeun.comment.entity;
+
+import com.teamEWSN.gitdeun.codereview.entity.CodeReview;
+import com.teamEWSN.gitdeun.common.util.AuditedEntity;
+import com.teamEWSN.gitdeun.user.entity.User;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Comment")
+public class Comment extends AuditedEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "code_review_id", nullable = false)
+    private CodeReview codeReview;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "parent_comment_id")
+    private Comment parentComment;
+
+    @Column(columnDefinition = "TEXT", nullable = false)
+    private String content;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "emoji_type")
+    private EmojiType emojiType;
+
+    @Column(name = "resolved_at")
+    private LocalDateTime resolvedAt;
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/entity/CommentAttachment.java b/src/main/java/com/teamEWSN/gitdeun/comment/entity/CommentAttachment.java
new file mode 100644
index 0000000..42c380a
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/entity/CommentAttachment.java
@@ -0,0 +1,37 @@
+package com.teamEWSN.gitdeun.comment.entity;
+
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Comment_Attachment")
+public class CommentAttachment {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "comment_id", nullable = false)
+    private Comment comment;
+
+    @Column(length = 255, nullable = false)
+    private String url;
+
+    @Column(name = "file_name", length = 200, nullable = false)
+    private String fileName;
+
+    @Column(name = "mime_type", length = 100, nullable = false)
+    private String mimeType;
+
+    @Column(nullable = false)
+    private Long size;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "attachment_type", nullable = false)
+    private AttachmentType attachmentType;
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/entity/EmojiType.java b/src/main/java/com/teamEWSN/gitdeun/comment/entity/EmojiType.java
new file mode 100644
index 0000000..96c76fc
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/entity/EmojiType.java
@@ -0,0 +1,9 @@
+package com.teamEWSN.gitdeun.comment.entity;
+
+public enum EmojiType {
+    QUESTION,
+    IDEA,
+    BUG,
+    IMPORTANT,
+    LOVE
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/repository/CommentRepository.java b/src/main/java/com/teamEWSN/gitdeun/comment/repository/CommentRepository.java
new file mode 100644
index 0000000..e9ce416
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/repository/CommentRepository.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.comment.repository;
+
+public class CommentRepository {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/comment/service/CommentService.java b/src/main/java/com/teamEWSN/gitdeun/comment/service/CommentService.java
new file mode 100644
index 0000000..1bbffe9
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/comment/service/CommentService.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.comment.service;
+
+public class CommentService {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/config/FastApiConfig.java b/src/main/java/com/teamEWSN/gitdeun/common/config/FastApiConfig.java
new file mode 100644
index 0000000..430d07a
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/common/config/FastApiConfig.java
@@ -0,0 +1,21 @@
+package com.teamEWSN.gitdeun.common.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+public class FastApiConfig {
+
+    @Value("${fastapi.base-url}")
+    private String baseUrl;
+
+    // FastAPI 서버와 통신하기 위한 전용 WebClient Bean
+    @Bean("fastApiWebClient")
+    public WebClient webClient() {
+        return WebClient.builder()
+            .baseUrl(baseUrl)
+            .build();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/config/WebClientConfig.java b/src/main/java/com/teamEWSN/gitdeun/common/config/WebClientConfig.java
index f9e78f8..6022d60 100644
--- a/src/main/java/com/teamEWSN/gitdeun/common/config/WebClientConfig.java
+++ b/src/main/java/com/teamEWSN/gitdeun/common/config/WebClientConfig.java
@@ -7,7 +7,8 @@
 @Configuration
 public class WebClientConfig {
 
-    @Bean
+    // OAuth 및 기타 외부 API 통신을 위한 범용 WebClient Bean
+    @Bean("oauthWebClient")
     public WebClient webClient() {
         return WebClient.builder().build();
     }
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/exception/ErrorCode.java b/src/main/java/com/teamEWSN/gitdeun/common/exception/ErrorCode.java
index a0cd2ed..05d382d 100644
--- a/src/main/java/com/teamEWSN/gitdeun/common/exception/ErrorCode.java
+++ b/src/main/java/com/teamEWSN/gitdeun/common/exception/ErrorCode.java
@@ -34,6 +34,10 @@ public enum ErrorCode {
     SOCIAL_ACCOUNT_CONNECT_FAILED(HttpStatus.INTERNAL_SERVER_ERROR, "OAUTH-006", "소셜 계정 연동에 실패했습니다."),
     SOCIAL_TOKEN_REFRESH_NOT_SUPPORTED(HttpStatus.BAD_REQUEST, "OAUTH-007", "리프레시 토큰 갱신은 지원하지 않습니다. 재인증이 필요합니다."),
 
+    // 리포지토리 관련
+    REPO_NOT_FOUND_BY_ID(HttpStatus.NOT_FOUND, "REPO-001", "해당 ID로 요청한 리포지토리를 찾을 수 없습니다."),
+    REPO_NOT_FOUND_BY_URL(HttpStatus.NOT_FOUND, "REPO-002", "해당 URL로 요청한 리포지토리를 찾을 수 없습니다."),
+
     // S3 파일 관련
     // Client Errors (4xx)
     FILE_NOT_FOUND(HttpStatus.NOT_FOUND, "FILE-001", "요청한 파일을 찾을 수 없습니다."),
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/fastapi/FastApiClient.java b/src/main/java/com/teamEWSN/gitdeun/common/fastapi/FastApiClient.java
new file mode 100644
index 0000000..894e902
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/common/fastapi/FastApiClient.java
@@ -0,0 +1,44 @@
+package com.teamEWSN.gitdeun.common.fastapi;
+
+import com.teamEWSN.gitdeun.common.fastapi.dto.FastApiCommitTimeResponse;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import java.time.LocalDateTime;
+
+@Component
+public class FastApiClient {
+
+    private final WebClient webClient; // FastApiConfig에서 생성한 Bean을 주입받음
+
+    public FastApiClient(@Qualifier("fastApiWebClient") WebClient webClient) {
+        this.webClient = webClient;
+    }
+
+    /**
+     * FastAPI 서버에 특정 GitHub 리포지토리의 최신 커밋 시간을 요청합니다.
+     * @param githubRepoUrl 조회할 리포지토리의 URL
+     * @return 최신 커밋 시간
+     */
+    public LocalDateTime fetchLatestCommitTime(String githubRepoUrl) {
+        // FastAPI의 가벼운 엔드포인트(예: /check-commit-time)를 호출합니다.
+        FastApiCommitTimeResponse response = webClient.get()
+            .uri(uriBuilder -> uriBuilder
+                .path("/check-commit-time") // FastAPI에 정의된 엔드포인트 경로
+                .queryParam("url", githubRepoUrl) // 쿼리 파라미터로 URL 전달
+                .build())
+            .retrieve() // 응답을 받아옴
+            .bodyToMono(FastApiCommitTimeResponse.class) // 응답 본문을 DTO로 변환
+            .block(); // 비동기 응답을 동기적으로 기다림
+
+        // null 체크 후 날짜 반환
+        if (response == null) {
+            throw new RuntimeException("FastAPI 서버로부터 최신 커밋 시간 정보를 받아오지 못했습니다.");
+        }
+        return response.getLatestCommitAt();
+    }
+
+    // TODO: requestAnalysis 등 다른 FastAPI 호출 메서드들도 여기에 구현
+
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/fastapi/dto/AnalysisResultDto.java b/src/main/java/com/teamEWSN/gitdeun/common/fastapi/dto/AnalysisResultDto.java
new file mode 100644
index 0000000..ff5d85f
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/common/fastapi/dto/AnalysisResultDto.java
@@ -0,0 +1,21 @@
+package com.teamEWSN.gitdeun.common.fastapi.dto;
+
+import com.teamEWSN.gitdeun.mindmap.entity.MindmapType;
+import lombok.Getter;
+
+import java.time.LocalDateTime;
+
+@Getter
+public class AnalysisResultDto {
+    // FastAPI가 반환하는 Repo 관련 정보
+    private String defaultBranch;
+    private String language;
+    private String description;
+    private LocalDateTime githubLastUpdatedAt;
+
+    // FastAPI가 반환하는 Mindmap 관련 정보
+    private String mapData;
+    private MindmapType type;
+    private String prompt;
+    // TODO: FastAPI 응답에 맞춰 필드 정의
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/fastapi/dto/FastApiCommitTimeResponse.java b/src/main/java/com/teamEWSN/gitdeun/common/fastapi/dto/FastApiCommitTimeResponse.java
new file mode 100644
index 0000000..40f202e
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/common/fastapi/dto/FastApiCommitTimeResponse.java
@@ -0,0 +1,12 @@
+package com.teamEWSN.gitdeun.common.fastapi.dto;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Setter // JSON 역직렬화를 위해 필요
+public class FastApiCommitTimeResponse {
+    private LocalDateTime latestCommitAt;
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/oauth/entity/OauthProvider.java b/src/main/java/com/teamEWSN/gitdeun/common/oauth/entity/OauthProvider.java
index f573228..52054d9 100644
--- a/src/main/java/com/teamEWSN/gitdeun/common/oauth/entity/OauthProvider.java
+++ b/src/main/java/com/teamEWSN/gitdeun/common/oauth/entity/OauthProvider.java
@@ -2,5 +2,5 @@
 
 public enum OauthProvider {
     GOOGLE,
-    GITHUB,
+    GITHUB
 }
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GitHubApiHelper.java b/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GitHubApiHelper.java
index c87661b..12a779d 100644
--- a/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GitHubApiHelper.java
+++ b/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GitHubApiHelper.java
@@ -3,8 +3,8 @@
 import com.teamEWSN.gitdeun.common.exception.ErrorCode;
 import com.teamEWSN.gitdeun.common.exception.GlobalException;
 import com.teamEWSN.gitdeun.common.oauth.dto.GitHubEmailDto;
-import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.HttpHeaders;
@@ -20,11 +20,14 @@
 
 @Slf4j
 @Component
-@RequiredArgsConstructor
 public class GitHubApiHelper {
 
     private final WebClient webClient;
 
+    public GitHubApiHelper(@Qualifier("oauthWebClient") WebClient webClient) {
+        this.webClient = webClient;
+    }
+
     @Value("${spring.security.oauth2.client.registration.github.client-id}")
     private String clientId;
 
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GoogleApiHelper.java b/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GoogleApiHelper.java
index 7a0d3c8..dadc42b 100644
--- a/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GoogleApiHelper.java
+++ b/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/GoogleApiHelper.java
@@ -3,8 +3,8 @@
 import com.teamEWSN.gitdeun.common.exception.ErrorCode;
 import com.teamEWSN.gitdeun.common.exception.GlobalException;
 import com.teamEWSN.gitdeun.common.oauth.record.GoogleTokenResponse;
-import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Component;
@@ -18,11 +18,14 @@
 
 @Slf4j
 @Component
-@RequiredArgsConstructor
 public class GoogleApiHelper {
 
     private final WebClient webClient;
 
+    public GoogleApiHelper(@Qualifier("oauthWebClient") WebClient webClient) {
+        this.webClient = webClient;
+    }
+
     @Value("${spring.security.oauth2.client.registration.google.client-id}")
     private String googleClientId;
 
diff --git a/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/SocialTokenRefreshService.java b/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/SocialTokenRefreshService.java
index 2d2a0f5..41c22d0 100644
--- a/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/SocialTokenRefreshService.java
+++ b/src/main/java/com/teamEWSN/gitdeun/common/oauth/service/SocialTokenRefreshService.java
@@ -1,6 +1,5 @@
 package com.teamEWSN.gitdeun.common.oauth.service;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import com.teamEWSN.gitdeun.common.exception.GlobalException;
 import com.teamEWSN.gitdeun.common.exception.ErrorCode;
 import com.teamEWSN.gitdeun.common.oauth.entity.OauthProvider;
@@ -10,11 +9,11 @@
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import java.util.Optional;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.http.HttpHeaders;
+
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
-import org.springframework.web.reactive.function.client.WebClient;
+
+import static com.teamEWSN.gitdeun.common.exception.ErrorCode.*;
 
 
 // 레포 및 마인드맵 호출 시 소셜로그인 토큰 갱신 호출
@@ -25,22 +24,14 @@
 public class SocialTokenRefreshService {
 
     private final SocialConnectionRepository socialConnectionRepository;
-    private final WebClient webClient;
-    private final ObjectMapper objectMapper = new ObjectMapper(); // JSON 파싱을 위한 ObjectMapper'
     private final GitHubApiHelper gitHubApiHelper;
     private final GoogleApiHelper googleApiHelper;
 
-    @Value("${spring.security.oauth2.client.registration.google.client-id}")
-    private String googleClientId;
-
-    @Value("${spring.security.oauth2.client.registration.google.client-secret}")
-    private String googleClientSecret;
-
 
     // 기존 refreshToken 기반 갱신(주기적/자동 갱신)
     public void refreshSocialToken(Long userId, OauthProvider provider) {
         SocialConnection connection = socialConnectionRepository.findByUserIdAndProvider(userId, provider)
-            .orElseThrow(() -> new GlobalException(ErrorCode.SOCIAL_CONNECTION_NOT_FOUND));
+            .orElseThrow(() -> new GlobalException(SOCIAL_CONNECTION_NOT_FOUND));
 
         switch (provider) {
             case GOOGLE -> refreshGoogle(connection, Optional.empty(), Optional.empty());
@@ -81,7 +72,7 @@ private void refreshGoogle(SocialConnection conn,
         // 2. refreshToken 기반 재발급 (latestRefresh가 있으면 그것 사용, 없으면 기존)
         String refreshToUse = latestRefreshOpt.orElse(conn.getRefreshToken());
         if (refreshToUse == null) {
-            throw new GlobalException(ErrorCode.INVALID_REFRESH_TOKEN);
+            throw new GlobalException(INVALID_REFRESH_TOKEN);
         }
 
         GoogleTokenResponse res = googleApiHelper.refreshToken(refreshToUse);
diff --git a/src/main/java/com/teamEWSN/gitdeun/invitation/entity/Invitation.java b/src/main/java/com/teamEWSN/gitdeun/invitation/entity/Invitation.java
index 720d849..9879940 100644
--- a/src/main/java/com/teamEWSN/gitdeun/invitation/entity/Invitation.java
+++ b/src/main/java/com/teamEWSN/gitdeun/invitation/entity/Invitation.java
@@ -1,5 +1,47 @@
 package com.teamEWSN.gitdeun.invitation.entity;
 
+import com.teamEWSN.gitdeun.mindmap.entity.Mindmap;
+import com.teamEWSN.gitdeun.user.entity.User;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+import org.hibernate.annotations.CreationTimestamp;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Invitation")
 public class Invitation {
-    
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "mindmap_id", nullable = false)
+    private Mindmap mindmap;
+
+    @Column(length = 36, nullable = false, unique = true)
+    private String token;
+
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false)
+    @ColumnDefault("'READ_ONLY'")
+    private InvitationStatus status;
+
+    @CreationTimestamp
+    @Column(name = "invited_at", updatable = false)
+    private LocalDateTime invitedAt;
+
+    @Column(name = "is_accept", nullable = false)
+    @ColumnDefault("false")
+    private boolean isAccept;
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/invitation/entity/InvitationStatus.java b/src/main/java/com/teamEWSN/gitdeun/invitation/entity/InvitationStatus.java
new file mode 100644
index 0000000..09101f3
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/invitation/entity/InvitationStatus.java
@@ -0,0 +1,6 @@
+package com.teamEWSN.gitdeun.invitation.entity;
+
+public enum InvitationStatus {
+    READ_ONLY,
+    EDIT_ALLOWED
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/controller/MeetingController.java b/src/main/java/com/teamEWSN/gitdeun/meeting/controller/MeetingController.java
new file mode 100644
index 0000000..9241da3
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/controller/MeetingController.java
@@ -0,0 +1,4 @@
+package com.teamEWSN.gitdeun.meeting.controller;
+
+public class MeetingController {
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/dto/MeetingResponseDto.java b/src/main/java/com/teamEWSN/gitdeun/meeting/dto/MeetingResponseDto.java
new file mode 100644
index 0000000..0e4edf7
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/dto/MeetingResponseDto.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.meeting.dto;
+
+public class MeetingResponseDto {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/entity/Meeting.java b/src/main/java/com/teamEWSN/gitdeun/meeting/entity/Meeting.java
new file mode 100644
index 0000000..1f1676c
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/entity/Meeting.java
@@ -0,0 +1,46 @@
+package com.teamEWSN.gitdeun.meeting.entity;
+
+import com.teamEWSN.gitdeun.common.util.CreatedEntity;
+import com.teamEWSN.gitdeun.mindmapnode.entity.MindmapNode;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Meeting")
+public class Meeting extends CreatedEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @OneToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "node_id", nullable = false)
+    private MindmapNode node;
+
+    @Column(name = "room_name", length = 255, nullable = false)
+    private String roomName;
+
+    @Column(length = 255)
+    private String title;
+
+    @Column(columnDefinition = "TEXT")
+    private String summary;
+
+    @Column(name = "shared_to_ai", nullable = false)
+    @ColumnDefault("false")
+    private boolean sharedToAI;
+
+    @Column(name = "started_at", nullable = false)
+    private LocalDateTime startedAt;
+
+    @Column(name = "ended_at")
+    private LocalDateTime endedAt;
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/entity/Participant.java b/src/main/java/com/teamEWSN/gitdeun/meeting/entity/Participant.java
new file mode 100644
index 0000000..65ccea3
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/entity/Participant.java
@@ -0,0 +1,36 @@
+package com.teamEWSN.gitdeun.meeting.entity;
+
+import com.teamEWSN.gitdeun.user.entity.User;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.CreationTimestamp;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Participant")
+@IdClass(ParticipantId.class)
+public class Participant {
+
+    @Id
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @Id
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "meeting_id", nullable = false)
+    private Meeting meeting;
+
+    @CreationTimestamp
+    @Column(name = "joined_at", nullable = false, updatable = false)
+    private LocalDateTime joinedAt;
+
+    @Column(name = "left_at")
+    private LocalDateTime leftAt;
+
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/entity/ParticipantId.java b/src/main/java/com/teamEWSN/gitdeun/meeting/entity/ParticipantId.java
new file mode 100644
index 0000000..673a00f
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/entity/ParticipantId.java
@@ -0,0 +1,13 @@
+package com.teamEWSN.gitdeun.meeting.entity;
+
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+
+import java.io.Serializable;
+
+@NoArgsConstructor
+@EqualsAndHashCode
+public class ParticipantId implements Serializable {
+    private Long user;
+    private Long meeting;
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/repository/MeetingRepository.java b/src/main/java/com/teamEWSN/gitdeun/meeting/repository/MeetingRepository.java
new file mode 100644
index 0000000..c38249a
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/repository/MeetingRepository.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.meeting.repository;
+
+public class MeetingRepository {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/meeting/service/MeetingService.java b/src/main/java/com/teamEWSN/gitdeun/meeting/service/MeetingService.java
new file mode 100644
index 0000000..4f11b95
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/meeting/service/MeetingService.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.meeting.service;
+
+public class MeetingService {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmap/controller/MindmapController.java b/src/main/java/com/teamEWSN/gitdeun/mindmap/controller/MindmapController.java
index 10fedef..dc7cfd5 100644
--- a/src/main/java/com/teamEWSN/gitdeun/mindmap/controller/MindmapController.java
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmap/controller/MindmapController.java
@@ -1,5 +1,8 @@
 package com.teamEWSN.gitdeun.mindmap.controller;
 
 public class MindmapController {
-    
+
+
+    // TODO: 마인드맵 로딩 시 자동 확인 + 새로고침 시 재동기화
+
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/Mindmap.java b/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/Mindmap.java
index fa5027d..d26a8a3 100644
--- a/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/Mindmap.java
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/Mindmap.java
@@ -1,5 +1,51 @@
 package com.teamEWSN.gitdeun.mindmap.entity;
 
-public class Mindmap {
-    
+import com.teamEWSN.gitdeun.common.util.AuditedEntity;
+import com.teamEWSN.gitdeun.repo.entity.Repo;
+import com.teamEWSN.gitdeun.user.entity.User;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+import org.hibernate.annotations.JdbcTypeCode;
+import org.hibernate.type.SqlTypes;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Mindmap")
+public class Mindmap extends AuditedEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "repo_id", nullable = false)
+    private Repo repo;
+
+    // owner
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @Column(columnDefinition = "TEXT")
+    private String prompt;
+
+    @Column(length = 100, nullable = false)
+    private String branch;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "type", nullable = false)
+    private MindmapType type;
+
+    @Column(name = "Field", length = 255, nullable = false)
+    @ColumnDefault("'확인용 (n)'")
+    private String field;
+
+    @JdbcTypeCode(SqlTypes.JSON)
+    @Column(name = "map_data", columnDefinition = "json", nullable = false)
+    private String mapData;
+
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/MindmapType.java b/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/MindmapType.java
new file mode 100644
index 0000000..dfeefec
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmap/entity/MindmapType.java
@@ -0,0 +1,6 @@
+package com.teamEWSN.gitdeun.mindmap.entity;
+
+public enum MindmapType {
+    DEV,
+    CHECK
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmap/mapper/MindmapMapper.java b/src/main/java/com/teamEWSN/gitdeun/mindmap/mapper/MindmapMapper.java
new file mode 100644
index 0000000..3b027ba
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmap/mapper/MindmapMapper.java
@@ -0,0 +1,8 @@
+package com.teamEWSN.gitdeun.mindmap.mapper;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.ReportingPolicy;
+
+@Mapper(componentModel = "spring", unmappedTargetPolicy = ReportingPolicy.IGNORE)
+public interface MindmapMapper {
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmap/repository/MindmapRepository.java b/src/main/java/com/teamEWSN/gitdeun/mindmap/repository/MindmapRepository.java
index d866bea..4e26d5f 100644
--- a/src/main/java/com/teamEWSN/gitdeun/mindmap/repository/MindmapRepository.java
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmap/repository/MindmapRepository.java
@@ -1,5 +1,10 @@
 package com.teamEWSN.gitdeun.mindmap.repository;
 
-public class MindmapRepository {
+import com.teamEWSN.gitdeun.mindmap.entity.Mindmap;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface MindmapRepository extends JpaRepository<Mindmap, Integer> {
     
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapedge/controller/MindmapEdgeController.java b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/controller/MindmapEdgeController.java
new file mode 100644
index 0000000..f9cc934
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/controller/MindmapEdgeController.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.mindmapedge.controller;
+
+public class MindmapEdgeController {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapedge/dto/MindmapEdgeDto.java b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/dto/MindmapEdgeDto.java
new file mode 100644
index 0000000..f7b9ab7
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/dto/MindmapEdgeDto.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.mindmapedge.dto;
+
+public class MindmapEdgeDto {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapedge/entity/EdgeType.java b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/entity/EdgeType.java
new file mode 100644
index 0000000..0807276
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/entity/EdgeType.java
@@ -0,0 +1,7 @@
+package com.teamEWSN.gitdeun.mindmapedge.entity;
+
+public enum EdgeType {
+    CROSS,
+    PARENT,
+    CHILD
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapedge/entity/MindmapEdge.java b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/entity/MindmapEdge.java
new file mode 100644
index 0000000..17a8409
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/entity/MindmapEdge.java
@@ -0,0 +1,42 @@
+package com.teamEWSN.gitdeun.mindmapedge.entity;
+
+import com.teamEWSN.gitdeun.common.util.AuditedEntity;
+import com.teamEWSN.gitdeun.mindmapnode.entity.MindmapNode;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+
+import java.math.BigDecimal;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Mindmap_Edge")
+public class MindmapEdge extends AuditedEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "from_node_id", nullable = false)
+    private MindmapNode fromNode;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "to_node_id", nullable = false)
+    private MindmapNode toNode;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "type", nullable = false)
+    private EdgeType type;
+
+    @Column(nullable = false)
+    @ColumnDefault("0")
+    private BigDecimal strength;
+
+    @Column(name = "arango_key")
+    private Long arangoKey;
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapedge/repository/MindmapEdgeRepository.java b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/repository/MindmapEdgeRepository.java
new file mode 100644
index 0000000..73abaf4
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/repository/MindmapEdgeRepository.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.mindmapedge.repository;
+
+public class MindmapEdgeRepository {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapedge/service/MindmapEdgeService.java b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/service/MindmapEdgeService.java
new file mode 100644
index 0000000..ab345d5
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapedge/service/MindmapEdgeService.java
@@ -0,0 +1,5 @@
+package com.teamEWSN.gitdeun.mindmapedge.service;
+
+public class MindmapEdgeService {
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmapnode/entity/MindmapNode.java b/src/main/java/com/teamEWSN/gitdeun/mindmapnode/entity/MindmapNode.java
index 40ae180..59b15c3 100644
--- a/src/main/java/com/teamEWSN/gitdeun/mindmapnode/entity/MindmapNode.java
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmapnode/entity/MindmapNode.java
@@ -1,5 +1,41 @@
 package com.teamEWSN.gitdeun.mindmapnode.entity;
 
-public class MindmapNode {
-    
+import com.teamEWSN.gitdeun.common.util.AuditedEntity;
+import com.teamEWSN.gitdeun.mindmap.entity.Mindmap;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Mindmap_Node")
+public class MindmapNode extends AuditedEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "mindmap_id", nullable = false)
+    private Mindmap mindmap;
+
+    @Column(length = 100, nullable = false)
+    private String label;
+
+    @Column(columnDefinition = "TEXT", nullable = false)
+    private String path;
+
+    @Column(nullable = false)
+    @ColumnDefault("1")
+    private Integer depth;
+
+    @Column(name = "arango_key", length = 64)
+    private String arangoKey;
+
+    @Column(name = "Importance", nullable = false)
+    @ColumnDefault("0")
+    private Double importance;
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/controller/RepoController.java b/src/main/java/com/teamEWSN/gitdeun/repo/controller/RepoController.java
index b903ef3..6eb6968 100644
--- a/src/main/java/com/teamEWSN/gitdeun/repo/controller/RepoController.java
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/controller/RepoController.java
@@ -1,5 +1,42 @@
 package com.teamEWSN.gitdeun.repo.controller;
 
+import com.teamEWSN.gitdeun.repo.dto.RepoResponseDto;
+import com.teamEWSN.gitdeun.repo.dto.RepoUpdateCheckResponseDto;
+import com.teamEWSN.gitdeun.repo.service.RepoService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/repos")
 public class RepoController {
-    
+
+    private final RepoService repoService;
+
+    // 리포지토리 URL을 통한 등록 확인
+    @GetMapping("/check")
+    public ResponseEntity<RepoResponseDto> checkRepoExists(@RequestParam String url) {
+        RepoResponseDto response = repoService.findRepoByUrl(url);
+        return ResponseEntity.ok(response);
+    }
+
+    // 리포지토리 정보 조회
+    @GetMapping("/{repoId}")
+    public ResponseEntity<RepoResponseDto> getRepoInfo(@PathVariable Long repoId) {
+        RepoResponseDto response = repoService.findRepoById(repoId);
+        return ResponseEntity.ok(response);
+    }
+
+    /**
+     * 특정 리포지토리에 대한 업데이트 필요 여부 확인
+     */
+    @GetMapping("/{repoId}/status")
+    public ResponseEntity<RepoUpdateCheckResponseDto> getRepoUpdateStatus(@PathVariable Long repoId) {
+        RepoUpdateCheckResponseDto response = repoService.checkUpdateNeeded(repoId);
+        return ResponseEntity.ok(response);
+    }
+
+
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoDto.java b/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoDto.java
deleted file mode 100644
index 9c8714f..0000000
--- a/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoDto.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package com.teamEWSN.gitdeun.repo.dto;
-
-public class RepoDto {
-    
-}
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoResponseDto.java b/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoResponseDto.java
new file mode 100644
index 0000000..218143c
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoResponseDto.java
@@ -0,0 +1,23 @@
+package com.teamEWSN.gitdeun.repo.dto;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Builder
+public class RepoResponseDto {
+
+    private final Long repoId;
+    private final String githubRepoUrl;
+    private final String defaultBranch;
+    private final String language;
+    private final String description;
+    private final LocalDateTime githubLastUpdatedAt;
+    private final LocalDateTime lastSyncedAt;
+
+    @Setter // Mapper의 @AfterMapping에서 이 값을 설정
+    private boolean updateNeeded; // 재동기화 필요 여부 플래그
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoUpdateCheckResponseDto.java b/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoUpdateCheckResponseDto.java
new file mode 100644
index 0000000..199cdd7
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/dto/RepoUpdateCheckResponseDto.java
@@ -0,0 +1,11 @@
+package com.teamEWSN.gitdeun.repo.dto;
+
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public class RepoUpdateCheckResponseDto {
+    private final boolean updateNeeded;
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/entity/Repo.java b/src/main/java/com/teamEWSN/gitdeun/repo/entity/Repo.java
index c527d3f..8f0be06 100644
--- a/src/main/java/com/teamEWSN/gitdeun/repo/entity/Repo.java
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/entity/Repo.java
@@ -1,5 +1,51 @@
 package com.teamEWSN.gitdeun.repo.entity;
 
+import com.teamEWSN.gitdeun.common.fastapi.dto.AnalysisResultDto;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Repo")
 public class Repo {
-    
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "github_repo_url", length = 512, nullable = false, unique = true)
+    private String githubRepoUrl;
+
+    @Column(name = "default_branch", length = 100)
+    private String defaultBranch;   // 기본 브랜치
+
+    @Column(length = 50)
+    private String language; // 주요 언어
+
+    @Column(columnDefinition = "TEXT")
+    private String description; // 설명
+
+    @Column(name = "github_last_updated_at")
+    private LocalDateTime githubLastUpdatedAt; // GitHub 브랜치 최신 커밋 시간 (commit.committer.date)
+
+
+    @Builder
+    public Repo(String githubRepoUrl, String defaultBranch, String language, String description, LocalDateTime githubLastUpdatedAt) {
+        this.githubRepoUrl = githubRepoUrl;
+        this.defaultBranch = defaultBranch;
+        this.language = language;
+        this.description = description;
+        this.githubLastUpdatedAt = githubLastUpdatedAt;
+    }
+
+    public void updateWithAnalysis(AnalysisResultDto result) {
+        this.language = result.getLanguage();
+        this.description = result.getDescription();
+        this.githubLastUpdatedAt = result.getGithubLastUpdatedAt();
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/mapper/RepoMapper.java b/src/main/java/com/teamEWSN/gitdeun/repo/mapper/RepoMapper.java
new file mode 100644
index 0000000..fe6db82
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/mapper/RepoMapper.java
@@ -0,0 +1,13 @@
+package com.teamEWSN.gitdeun.repo.mapper;
+
+import com.teamEWSN.gitdeun.repo.dto.RepoResponseDto;
+import com.teamEWSN.gitdeun.repo.entity.Repo;
+import org.mapstruct.Mapper;
+import org.mapstruct.ReportingPolicy;
+
+@Mapper(componentModel = "spring", unmappedTargetPolicy = ReportingPolicy.IGNORE)
+public interface RepoMapper {
+
+    RepoResponseDto toResponseDto(Repo repo);
+
+}
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/repository/RepoRepository.java b/src/main/java/com/teamEWSN/gitdeun/repo/repository/RepoRepository.java
index 7d3b49b..2d7ec47 100644
--- a/src/main/java/com/teamEWSN/gitdeun/repo/repository/RepoRepository.java
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/repository/RepoRepository.java
@@ -1,5 +1,13 @@
 package com.teamEWSN.gitdeun.repo.repository;
 
-public class RepoRepository {
-    
+import com.teamEWSN.gitdeun.repo.entity.Repo;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.Optional;
+
+@Repository
+public interface RepoRepository extends JpaRepository<Repo, Long> {
+
+    Optional<Repo> findByGithubRepoUrl(String githubRepoUrl);
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/repo/service/RepoService.java b/src/main/java/com/teamEWSN/gitdeun/repo/service/RepoService.java
index 9eaf262..544add6 100644
--- a/src/main/java/com/teamEWSN/gitdeun/repo/service/RepoService.java
+++ b/src/main/java/com/teamEWSN/gitdeun/repo/service/RepoService.java
@@ -1,5 +1,64 @@
 package com.teamEWSN.gitdeun.repo.service;
 
+import com.teamEWSN.gitdeun.common.fastapi.FastApiClient;
+import com.teamEWSN.gitdeun.common.exception.ErrorCode;
+import com.teamEWSN.gitdeun.common.exception.GlobalException;
+import com.teamEWSN.gitdeun.repo.dto.RepoResponseDto;
+import com.teamEWSN.gitdeun.repo.dto.RepoUpdateCheckResponseDto;
+import com.teamEWSN.gitdeun.repo.entity.Repo;
+import com.teamEWSN.gitdeun.repo.mapper.RepoMapper;
+import com.teamEWSN.gitdeun.repo.repository.RepoRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDateTime;
+
+@Service
+@RequiredArgsConstructor
+@Transactional(readOnly = true) // 기본적으로는 읽기 전용, 데이터 변경 메서드에 @Transactional을 별도 추가
 public class RepoService {
-    
+
+    private final RepoRepository repoRepository;
+    private final RepoMapper repoMapper;
+    private final FastApiClient fastApiClient;
+
+    /**
+     * Mapper를 통해 'updateNeeded' 플래그가 포함된 DTO를 반환합니다.
+     */
+    public RepoResponseDto findRepoById(Long repoId) {
+        Repo repo = repoRepository.findById(repoId)
+            .orElseThrow(() -> new GlobalException(ErrorCode.REPO_NOT_FOUND_BY_ID));
+        return repoMapper.toResponseDto(repo);
+    }
+
+    /**
+     * 리포지토리 URL로 정보를 조회
+     */
+    public RepoResponseDto findRepoByUrl(String url) {
+        Repo repo = repoRepository.findByGithubRepoUrl(url)
+            .orElseThrow(() -> new GlobalException(ErrorCode.REPO_NOT_FOUND_BY_URL));
+        return repoMapper.toResponseDto(repo);
+    }
+
+    /**
+     * 리포지토리의 최신 업데이트 상태를 실시간으로 확인
+     * @param repoId 확인할 리포지토리의 ID
+     * @return 업데이트 필요 여부를 담은 DTO
+     */
+    public RepoUpdateCheckResponseDto checkUpdateNeeded(Long repoId) {
+        // 시스템의 마지막 동기화 시간 조회
+        Repo repo = repoRepository.findById(repoId)
+            .orElseThrow(() -> new GlobalException(ErrorCode.REPO_NOT_FOUND_BY_ID));
+        LocalDateTime lastSyncedAt = repo.getGithubLastUpdatedAt();
+
+        // FastAPI의 가벼운 API를 호출하여 GitHub의 최신 커밋 시간 조회
+        LocalDateTime latestCommitAt = fastApiClient.fetchLatestCommitTime(repo.getGithubRepoUrl());
+
+        // 두 시간을 비교하여 업데이트 필요 여부 결정
+        boolean isNeeded = latestCommitAt.isAfter(lastSyncedAt);
+
+        return new RepoUpdateCheckResponseDto(isNeeded);
+    }
+
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/user/controller/AuthController.java b/src/main/java/com/teamEWSN/gitdeun/user/controller/AuthController.java
index acc86dd..2f8954a 100644
--- a/src/main/java/com/teamEWSN/gitdeun/user/controller/AuthController.java
+++ b/src/main/java/com/teamEWSN/gitdeun/user/controller/AuthController.java
@@ -3,7 +3,9 @@
 import com.teamEWSN.gitdeun.common.cookie.CookieUtil;
 import com.teamEWSN.gitdeun.common.jwt.CustomUserDetails;
 import com.teamEWSN.gitdeun.common.jwt.JwtToken;
+import com.teamEWSN.gitdeun.common.oauth.entity.OauthProvider;
 import com.teamEWSN.gitdeun.common.oauth.service.OAuthStateService;
+import com.teamEWSN.gitdeun.common.oauth.service.SocialTokenRefreshService;
 import com.teamEWSN.gitdeun.user.dto.UserTokenResponseDto;
 import com.teamEWSN.gitdeun.user.service.AuthService;
 import jakarta.servlet.http.HttpServletResponse;
@@ -26,6 +28,7 @@ public class AuthController {
     private Long refreshTokenExpired;
 
     private final OAuthStateService oAuthStateService;
+    private final SocialTokenRefreshService socialTokenRefreshService;
     private final AuthService authService;
     private final CookieUtil cookieUtil;
 
@@ -66,30 +69,13 @@ public ResponseEntity<UserTokenResponseDto> refreshAccessToken(
         return ResponseEntity.ok(new UserTokenResponseDto(newJwtToken.getAccessToken()));
     }
 
-//    /**
-//     * GitHub의 모든 OAuth 콜백을 처리하는 단일 엔드포인트
-//     * @param code GitHub에서 제공하는 Authorization Code
-//     * @param userDetails 현재 로그인된 사용자 정보. 비로그인 상태면 null.
-//     * @return 로그인 또는 계정 연동 흐름에 따라 적절한 경로로 포워딩 또는 리디렉션
-//     */
-//    @GetMapping("/github/callback")
-//    public ResponseEntity<?> githubCallback(
-//        @RequestParam("code") String code,
-//        @AuthenticationPrincipal CustomUserDetails userDetails,
-//        HttpServletResponse response // 쿠키 설정을 위해 필요
-//    ) {
-//
-//        if (userDetails != null) {
-//            // "계정 연동" 흐름
-//            authService.connectGithubAccount(userDetails.getId(), code);
-//            // 성공했다는 응답 전달
-//            return ResponseEntity.ok().body(Map.of("status", "success", "message", "계정 연동 성공!"));
-//
-//        } else {
-//            // "최초 로그인" 흐름
-//            GithubLoginResponseDto loginResponse = authService.loginWithGithub(code, response);
-//            return ResponseEntity.ok(loginResponse);
-//        }
-//    }
+    // 외부 OAuth 재발급 (Access 만료 → provider 선택)
+    @PostMapping("/oauth/refresh/{provider}")
+    public ResponseEntity<Void> refreshSocial(
+        @AuthenticationPrincipal CustomUserDetails user,
+        @PathVariable OauthProvider provider) {
 
+        socialTokenRefreshService.refreshSocialToken(user.getId(), provider);
+        return ResponseEntity.noContent().build();
+    }
 }
diff --git a/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistory.java b/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistory.java
index 68b7c40..3292b63 100644
--- a/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistory.java
+++ b/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistory.java
@@ -1,5 +1,36 @@
 package com.teamEWSN.gitdeun.visithistory.entity;
 
+import com.teamEWSN.gitdeun.mindmap.entity.Mindmap;
+import com.teamEWSN.gitdeun.user.entity.User;
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.ColumnDefault;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "Visit_History")
+@IdClass(VisitHistoryId.class)
 public class VisitHistory {
-    
+
+    @Id
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @Id
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "mindmap_id", nullable = false)
+    private Mindmap mindmap;
+
+    @Column(name = "last_visited_at", nullable = false)
+    private LocalDateTime lastVisitedAt;
+
+    @Column(nullable = false)
+    @ColumnDefault("false")
+    private boolean pinned;
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistoryId.java b/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistoryId.java
new file mode 100644
index 0000000..40b0755
--- /dev/null
+++ b/src/main/java/com/teamEWSN/gitdeun/visithistory/entity/VisitHistoryId.java
@@ -0,0 +1,13 @@
+package com.teamEWSN.gitdeun.visithistory.entity;
+
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+
+import java.io.Serializable;
+
+@NoArgsConstructor
+@EqualsAndHashCode
+public class VisitHistoryId implements Serializable {
+    private Long user;
+    private Long mindmap;
+}
diff --git a/src/main/resources/application-dev.yml b/src/main/resources/application-dev.yml
index 5f65fb5..8fa6f61 100644
--- a/src/main/resources/application-dev.yml
+++ b/src/main/resources/application-dev.yml
@@ -30,4 +30,7 @@ app:
   front-url: http://localhost:3000
   cookie:
     secure: false
-    same-site: Lax
\ No newline at end of file
+    same-site: Lax
+
+fastapi:
+  base-url: http://localhost:8000  # 내 PC에서 개발할 때의 주소
\ No newline at end of file
diff --git a/src/main/resources/application-prod.yml b/src/main/resources/application-prod.yml
index fbd1c5f..07c7b4e 100644
--- a/src/main/resources/application-prod.yml
+++ b/src/main/resources/application-prod.yml
@@ -28,4 +28,7 @@ app:
   front-url: https://gitdeun.site
   cookie:
     secure: true
-    same-site: None
\ No newline at end of file
+    same-site: None
+
+fastapi:
+  base-url: http://fastapi-server:8000 # Docker 네트워크 내부에서 사용할 주소
\ No newline at end of file