diff --git a/src/main/java/com/haru/api/domain/lastOpened/service/UserDocumentLastOpenedServiceImpl.java b/src/main/java/com/haru/api/domain/lastOpened/service/UserDocumentLastOpenedServiceImpl.java
index 55ee2866..68997067 100644
--- a/src/main/java/com/haru/api/domain/lastOpened/service/UserDocumentLastOpenedServiceImpl.java
+++ b/src/main/java/com/haru/api/domain/lastOpened/service/UserDocumentLastOpenedServiceImpl.java
@@ -49,6 +49,7 @@ public void updateLastOpened(UserDocumentId userDocumentId, Long workspaceId, St
     }
 
     @Override
+    @Transactional
     public void createInitialRecordsForWorkspaceUsers(List<User> usersInWorkspace, Documentable document) {
 
         // 저장할 엔티티 리스트 생성
diff --git a/src/main/java/com/haru/api/domain/snsEvent/controller/SnsEventController.java b/src/main/java/com/haru/api/domain/snsEvent/controller/SnsEventController.java
index 6cf6f77f..03ff0436 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/controller/SnsEventController.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/controller/SnsEventController.java
@@ -2,17 +2,20 @@
 
 import com.haru.api.domain.snsEvent.dto.SnsEventRequestDTO;
 import com.haru.api.domain.snsEvent.dto.SnsEventResponseDTO;
+import com.haru.api.domain.snsEvent.entity.SnsEvent;
 import com.haru.api.domain.snsEvent.entity.enums.Format;
 import com.haru.api.domain.snsEvent.entity.enums.ListType;
 import com.haru.api.domain.snsEvent.service.SnsEventCommandService;
 import com.haru.api.domain.snsEvent.service.SnsEventQueryService;
-import com.haru.api.domain.user.security.jwt.SecurityUtil;
+import com.haru.api.domain.user.entity.User;
+import com.haru.api.domain.workspace.entity.Workspace;
+import com.haru.api.global.annotation.AuthSnsEvent;
+import com.haru.api.global.annotation.AuthUser;
+import com.haru.api.global.annotation.AuthWorkspace;
 import com.haru.api.global.apiPayload.ApiResponse;
 import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
 import lombok.RequiredArgsConstructor;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
 @RestController
@@ -31,10 +34,12 @@ public class SnsEventController {
     @PostMapping("/{workspaceId}")
     public ApiResponse<SnsEventResponseDTO.CreateSnsEventResponse> instagramOauthRedirectUri(
             @PathVariable String workspaceId,
-            @RequestBody SnsEventRequestDTO.CreateSnsRequest request
+            @RequestBody SnsEventRequestDTO.CreateSnsRequest request,
+            @Parameter(hidden = true) @AuthUser User user,
+            @Parameter(hidden = true) @AuthWorkspace Workspace workspace
     ) {
         return ApiResponse.onSuccess(
-                snsEventCommandService.createSnsEvent(Long.parseLong(workspaceId), request)
+                snsEventCommandService.createSnsEvent(user, workspace, request)
         );
     }
 
@@ -58,11 +63,12 @@ public ApiResponse<?> instagramRedirectUri(
     @PostMapping("/{workspaceId}/link-instagram")
     public ApiResponse<SnsEventResponseDTO.LinkInstagramAccountResponse> linkInstagramAccount(
             @RequestHeader("code") String code,
-            @PathVariable String workspaceId
+            @PathVariable String workspaceId,
+            @Parameter(hidden = true) @AuthWorkspace Workspace workspace
     ) {
         System.out.println("Received accessToken: " + code);
         return ApiResponse.onSuccess(
-                snsEventCommandService.getInstagramAccessTokenAndAccount(code, Long.parseLong(workspaceId))
+                snsEventCommandService.getInstagramAccessTokenAndAccount(code, workspace)
         );
     }
 
@@ -73,11 +79,13 @@ public ApiResponse<SnsEventResponseDTO.LinkInstagramAccountResponse> linkInstagr
     )
     @GetMapping("/{workspaceId}/list")
     public ApiResponse<SnsEventResponseDTO.GetSnsEventListRequest> getSnsEventList(
-            @PathVariable String workspaceId
+            @PathVariable String workspaceId,
+            @Parameter(hidden = true) @AuthUser User user,
+            @Parameter(hidden = true) @AuthWorkspace Workspace workspace
     ) {
-        Long userId = SecurityUtil.getCurrentUserId();
+
         return ApiResponse.onSuccess(
-                snsEventQueryService.getSnsEventList(userId, Long.parseLong(workspaceId))
+                snsEventQueryService.getSnsEventList(user, workspace)
         );
     }
 
@@ -86,14 +94,18 @@ public ApiResponse<SnsEventResponseDTO.GetSnsEventListRequest> getSnsEventList(
             description = "# [v1.0 (2025-08-05)](https://www.notion.so/2265da7802c580e8b883e3e4481fd61d?v=2265da7802c5816ab095000cc1ddadca&p=22a5da7802c580d3bed7c57de0b88492&pm=s)" +
                     " SNS 이벤트명 수정 API입니다. Header에 access token을 넣고 Path Variable에는 snsEvnetId를 Request Body에 SNS 이벤트 수정 정보(title)를 담아 요청해주세요."
     )
-    @PatchMapping("/{snsEvnetId}")
+    @PatchMapping("/{snsEventId}")
     public ApiResponse<?> updateSnsEventTitle(
-            @PathVariable String snsEvnetId,
-            @RequestBody SnsEventRequestDTO.UpdateSnsEventRequest request
+            @PathVariable String snsEventId,
+            @RequestBody SnsEventRequestDTO.UpdateSnsEventRequest request,
+            @Parameter(hidden = true) @AuthUser User user,
+            @Parameter(hidden = true) @AuthSnsEvent SnsEvent snsEvent
     ) {
-        Long userId = SecurityUtil.getCurrentUserId();
-        snsEventCommandService.updateSnsEventTitle(userId, Long.parseLong(snsEvnetId), request);
+
+        snsEventCommandService.updateSnsEventTitle(user, snsEvent, request);
+
         return ApiResponse.onSuccess("");
+
     }
 
     @Operation(
@@ -101,13 +113,18 @@ public ApiResponse<?> updateSnsEventTitle(
             description = "# [v1.0 (2025-08-05)](https://www.notion.so/2265da7802c580e8b883e3e4481fd61d?v=2265da7802c5816ab095000cc1ddadca&p=2265da7802c5809b84d3d8c09f95c36b&pm=s)" +
                     " SNS 이벤트 삭제 API입니다. Header에 access token을 넣고 Path Variable에는 삭제할 SNS Event의 snsEvnetId를 담아 요청해주세요."
     )
-    @DeleteMapping("/{snsEvnetId}")
+    @DeleteMapping("/{snsEventId}")
     public ApiResponse<?> deleteSnsEvent(
-            @PathVariable String snsEvnetId
+            @PathVariable String snsEventId,
+            @Parameter(hidden = true) @AuthUser User user,
+            @Parameter(hidden = true) @AuthSnsEvent SnsEvent snsEvent
+
     ) {
-        Long userId = SecurityUtil.getCurrentUserId();
-        snsEventCommandService.deleteSnsEvent(userId, Long.parseLong(snsEvnetId));
+
+        snsEventCommandService.deleteSnsEvent(user, snsEvent);
+
         return ApiResponse.onSuccess("");
+
     }
 
     @Operation(
@@ -117,11 +134,12 @@ public ApiResponse<?> deleteSnsEvent(
     )
     @GetMapping("/{snsEventId}")
     public ApiResponse<SnsEventResponseDTO.GetSnsEventRequest> getSnsEvent(
-            @PathVariable String snsEventId
+            @PathVariable String snsEventId,
+            @Parameter(hidden = true) @AuthUser User user,
+            @Parameter(hidden = true) @AuthSnsEvent SnsEvent snsEvent
     ) {
-        Long userId = SecurityUtil.getCurrentUserId();
         return ApiResponse.onSuccess(
-                snsEventQueryService.getSnsEvent(userId, Long.parseLong(snsEventId))
+                snsEventQueryService.getSnsEvent(user, snsEvent)
         );
     }
 
@@ -134,27 +152,18 @@ public ApiResponse<SnsEventResponseDTO.GetSnsEventRequest> getSnsEvent(
     public ApiResponse<SnsEventResponseDTO.ListDownLoadLinkResponse> downloadList(
             @PathVariable String snsEventId,
             @RequestParam ListType listType,
-            @RequestParam Format format
+            @RequestParam Format format,
+            @Parameter(hidden = true) @AuthUser User user,
+            @Parameter(hidden = true) @AuthSnsEvent SnsEvent snsEvent
     ) {
-        Long userId = SecurityUtil.getCurrentUserId();
         return ApiResponse.onSuccess(
                 snsEventCommandService.downloadList(
-                        userId,
-                        Long.parseLong(snsEventId),
+                        user,
+                        snsEvent,
                         listType,
                         format
                 )
         );
-
-//        String listTypefileName = listType == ListType.PARTICIPANT ? "참여자" : "당첨자";
-//        String filename = format == Format.PDF ? listTypefileName + ".pdf" : listTypefileName + ".docx";
-//        String contentType = format == Format.PDF
-//                ? MediaType.APPLICATION_PDF_VALUE
-//                : "application/vnd.openxmlformats-officedocument.wordprocessingml.document";
-//
-//        return ResponseEntity.ok()
-//                .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"")
-//                .contentType(MediaType.parseMediaType(contentType))
-//                .body(fileBytes);
     }
+
 }
diff --git a/src/main/java/com/haru/api/domain/snsEvent/dto/SnsEventRequestDTO.java b/src/main/java/com/haru/api/domain/snsEvent/dto/SnsEventRequestDTO.java
index 127bced6..11ffc926 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/dto/SnsEventRequestDTO.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/dto/SnsEventRequestDTO.java
@@ -1,5 +1,6 @@
 package com.haru.api.domain.snsEvent.dto;
 
+import com.haru.api.global.common.entity.TitleHolder;
 import lombok.*;
 
 import java.time.LocalDateTime;
@@ -33,7 +34,7 @@ public static class SnsCondition {
     @Builder
     @NoArgsConstructor
     @AllArgsConstructor
-    public static class UpdateSnsEventRequest {
+    public static class UpdateSnsEventRequest implements TitleHolder {
         private String title;
     }
 }
diff --git a/src/main/java/com/haru/api/domain/snsEvent/entity/SnsEvent.java b/src/main/java/com/haru/api/domain/snsEvent/entity/SnsEvent.java
index 69406f33..9fa17e19 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/entity/SnsEvent.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/entity/SnsEvent.java
@@ -30,13 +30,12 @@ public class SnsEvent extends BaseEntity implements Documentable {
     @Column(nullable = false, length = 100)
     private String title;
 
-    @Column(length = 255)
     private String snsLink;
 
     @Column(length = 200)
     private String snsLinkTitle;
 
-    @ManyToOne(fetch = FetchType.LAZY)
+    @ManyToOne(fetch = FetchType.EAGER)
     @JoinColumn(name = "user_id")
     private User creator;
 
diff --git a/src/main/java/com/haru/api/domain/snsEvent/repository/SnsEventRepository.java b/src/main/java/com/haru/api/domain/snsEvent/repository/SnsEventRepository.java
index 54984d8c..1b6b827e 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/repository/SnsEventRepository.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/repository/SnsEventRepository.java
@@ -8,6 +8,7 @@
 
 import java.time.LocalDateTime;
 import java.util.List;
+import java.util.Optional;
 
 @Repository
 public interface SnsEventRepository extends JpaRepository<SnsEvent, Long> {
@@ -22,4 +23,11 @@ public interface SnsEventRepository extends JpaRepository<SnsEvent, Long> {
             "WHERE mt.workspace.id = :workspaceId " +
             "AND mt.createdAt BETWEEN :startDate AND :endDate")
     List<SnsEvent> findAllDocumentForCalendars(Long workspaceId, LocalDateTime startDate, LocalDateTime endDate);
+
+    @Query("SELECT se FROM SnsEvent se " +
+            "WHERE se.id = :snsEventId AND EXISTS (" +
+            "  SELECT 1 FROM UserWorkspace uw " +
+            "  WHERE uw.user.id = :userId AND uw.workspace.id = se.workspace.id" +
+            ")")
+    Optional<SnsEvent> findSnsEventByIdIfUserHasAccess(Long userId, Long snsEventId);
 }
diff --git a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandService.java b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandService.java
index c7ab30ad..cda950e2 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandService.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandService.java
@@ -2,17 +2,20 @@
 
 import com.haru.api.domain.snsEvent.dto.SnsEventRequestDTO;
 import com.haru.api.domain.snsEvent.dto.SnsEventResponseDTO;
+import com.haru.api.domain.snsEvent.entity.SnsEvent;
 import com.haru.api.domain.snsEvent.entity.enums.Format;
 import com.haru.api.domain.snsEvent.entity.enums.ListType;
+import com.haru.api.domain.user.entity.User;
+import com.haru.api.domain.workspace.entity.Workspace;
 
 public interface SnsEventCommandService {
-    SnsEventResponseDTO.CreateSnsEventResponse createSnsEvent(Long workspaceId, SnsEventRequestDTO.CreateSnsRequest request);
+    SnsEventResponseDTO.CreateSnsEventResponse createSnsEvent(User user, Workspace workspace, SnsEventRequestDTO.CreateSnsRequest request);
 
-    SnsEventResponseDTO.LinkInstagramAccountResponse getInstagramAccessTokenAndAccount(String code, Long workspaceId);
+    SnsEventResponseDTO.LinkInstagramAccountResponse getInstagramAccessTokenAndAccount(String code, Workspace workspace);
 
-    void updateSnsEventTitle(Long userId, Long snsEventId, SnsEventRequestDTO.UpdateSnsEventRequest request);
+    void updateSnsEventTitle(User user, SnsEvent snsEvent, SnsEventRequestDTO.UpdateSnsEventRequest request);
 
-    void deleteSnsEvent(Long userId, Long snsEventId);
+    void deleteSnsEvent(User user, SnsEvent snsEvent);
 
-    SnsEventResponseDTO.ListDownLoadLinkResponse downloadList(Long userId, Long snsEventId, ListType listType, Format format);
+    SnsEventResponseDTO.ListDownLoadLinkResponse downloadList(User user, SnsEvent snsEvent, ListType listType, Format format);
 }
diff --git a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandServiceImpl.java b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandServiceImpl.java
index 5b08770e..0496e02c 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandServiceImpl.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventCommandServiceImpl.java
@@ -1,6 +1,5 @@
 package com.haru.api.domain.snsEvent.service;
 
-import com.haru.api.domain.lastOpened.repository.UserDocumentLastOpenedRepository;
 import com.haru.api.domain.lastOpened.service.UserDocumentLastOpenedService;
 import com.haru.api.domain.snsEvent.converter.SnsEventConverter;
 import com.haru.api.domain.snsEvent.dto.SnsEventRequestDTO;
@@ -14,13 +13,13 @@
 import com.haru.api.domain.snsEvent.repository.SnsEventRepository;
 import com.haru.api.domain.snsEvent.repository.WinnerRepository;
 import com.haru.api.domain.user.entity.User;
-import com.haru.api.domain.user.repository.UserRepository;
-import com.haru.api.domain.user.security.jwt.SecurityUtil;
 import com.haru.api.domain.userWorkspace.entity.UserWorkspace;
 import com.haru.api.domain.userWorkspace.entity.enums.Auth;
 import com.haru.api.domain.userWorkspace.repository.UserWorkspaceRepository;
 import com.haru.api.domain.workspace.entity.Workspace;
 import com.haru.api.domain.workspace.repository.WorkspaceRepository;
+import com.haru.api.global.annotation.DeleteDocument;
+import com.haru.api.global.annotation.UpdateDocumentTitle;
 import com.haru.api.global.apiPayload.exception.handler.MemberHandler;
 import com.haru.api.global.apiPayload.exception.handler.SnsEventHandler;
 import com.haru.api.global.apiPayload.exception.handler.WorkspaceHandler;
@@ -34,7 +33,6 @@
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.poi.xwpf.usermodel.*;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.RestClientException;
@@ -56,20 +54,13 @@
 public class SnsEventCommandServiceImpl implements SnsEventCommandService{
 
     private final SpringTemplateEngine templateEngine;
-    @Value("${instagram.client.id}")
-    private String instagramClientId;
-    @Value("${instagram.client.secret}")
-    private String instagramClientSecret;
-    @Value("${instagram.redirect.uri}")
-    private String instagramRedirectUri;
+
     private final SnsEventRepository snsEventRepository;
-    private final UserRepository userRepository;
     private final WorkspaceRepository workspaceRepository;
     private final UserWorkspaceRepository userWorkspaceRepository;
     private final ParticipantRepository participantRepository;
     private final WinnerRepository winnerRepository;
     private final RestTemplate restTemplate;
-    private final UserDocumentLastOpenedRepository userDocumentLastOpenedRepository;
     private final UserDocumentLastOpenedService userDocumentLastOpenedService;
     private final InstagramOauth2RestTemplate instagramOauth2RestTemplate;
     private final int WORD_TABLE_SIZE = 40; // 페이지당 총 아이디 수
@@ -81,22 +72,16 @@ public class SnsEventCommandServiceImpl implements SnsEventCommandService{
     @Override
     @Transactional
     public SnsEventResponseDTO.CreateSnsEventResponse createSnsEvent(
-            Long workspaceId,
+            User user,
+            Workspace workspace,
             SnsEventRequestDTO.CreateSnsRequest request
     ) {
         // SNS 이벤트 생성 및 저장
-        Long userId = SecurityUtil.getCurrentUserId();
-        User foundUser = userRepository.findById(userId)
-                .orElseThrow(() -> new MemberHandler(MEMBER_NOT_FOUND));
-        Workspace foundWorkspace = workspaceRepository.findById(workspaceId)
-                .orElseThrow(() -> new WorkspaceHandler(WORKSPACE_NOT_FOUND));
-        UserWorkspace foundUserWorkSapce = userWorkspaceRepository.findByUserAndWorkspace(foundUser, foundWorkspace)
-                .orElseThrow(() -> new MemberHandler(NOT_BELONG_TO_WORKSPACE));
-        SnsEvent createdSnsEvent = SnsEventConverter.toSnsEvent(request, foundUser);
-        createdSnsEvent.setWorkspace(foundWorkspace);
+        SnsEvent createdSnsEvent = SnsEventConverter.toSnsEvent(request, user);
+        createdSnsEvent.setWorkspace(workspace);
 
-        // Instagarm API 호출 후 참여라 리스트, 당첨자 리스트 생성 및 저장
-        String accessToken = foundWorkspace.getInstagramAccessToken();
+        // Instagram API 호출 후 참여자 리스트, 당첨자 리스트 생성 및 저장
+        String accessToken = workspace.getInstagramAccessToken();
         if (accessToken == null || accessToken.isEmpty()) {
             throw new SnsEventHandler(SNS_EVENT_NO_ACCESS_TOKEN);
         }
@@ -171,7 +156,7 @@ public SnsEventResponseDTO.CreateSnsEventResponse createSnsEvent(
 
         // sns event 생성 시 워크스페이스에 속해있는 모든 유저에 대해
         // last opened 테이블에 마지막으로 연 시간은 null로하여 추가
-        List<User> usersInWorkspace = userWorkspaceRepository.findUsersByWorkspaceId(savedSnsEvent.getId());
+        List<User> usersInWorkspace = userWorkspaceRepository.findUsersByWorkspaceId(workspace.getId());
         userDocumentLastOpenedService.createInitialRecordsForWorkspaceUsers(usersInWorkspace, savedSnsEvent);
 
         return SnsEventResponseDTO.CreateSnsEventResponse.builder()
@@ -179,6 +164,131 @@ public SnsEventResponseDTO.CreateSnsEventResponse createSnsEvent(
                 .build();
     }
 
+
+    @Override
+    @Transactional
+    public SnsEventResponseDTO.LinkInstagramAccountResponse getInstagramAccessTokenAndAccount(
+            String code,
+            Workspace workspace
+    ) {
+        String shortLivedAccessToken;
+        String longLivedAccessToken;
+        Map<String, Object> userInfo;
+        try {
+            // 1. Access Token 요청
+            shortLivedAccessToken = instagramOauth2RestTemplate.getShortLivedAccessTokenUrl(code);
+            // 2. 단기 토큰을 장기(Long-Lived) 토큰으로 교환
+            longLivedAccessToken = instagramOauth2RestTemplate.getLongLivedAccessToken(shortLivedAccessToken);
+            // 3. 장기 토큰으로 사용자 계정 정보 요청
+            userInfo = instagramOauth2RestTemplate.getInstagramAccountInfo(longLivedAccessToken);
+        } catch (Exception e) {
+            log.error("Instagram OAuth2 처리 중 오류 발생: {}", e.getMessage());
+            throw new SnsEventHandler(SNS_EVENT_INSTAGRAM_API_ERROR);
+        }
+        // 4. 워크스페이스에 인스타그램 계정 정보 저장
+        String instagramId = (String) userInfo.get("user_id");
+        Workspace foundWorkspace = workspaceRepository.findById(workspace.getId())
+                .orElseThrow(() -> new WorkspaceHandler(WORKSPACE_NOT_FOUND));
+        if (foundWorkspace.getInstagramId() != null && foundWorkspace.getInstagramId().equals(instagramId)) {
+            throw new SnsEventHandler(SNS_EVENT_INSTAGRAM_ALREADY_LINKED);
+        }
+        foundWorkspace.saveInstagramId(instagramId);
+        foundWorkspace.saveInstagramAccessToken(longLivedAccessToken);
+        foundWorkspace.saveInstagramAccountName((String) userInfo.get("username"));
+        return SnsEventConverter.toLinkInstagramAccountResponse((String) userInfo.get("username"));
+    }
+  
+    @Override
+    @Transactional
+    @UpdateDocumentTitle
+    public void updateSnsEventTitle(
+            User user,
+            SnsEvent snsEvent,
+            SnsEventRequestDTO.UpdateSnsEventRequest request
+    ) {
+
+        UserWorkspace foundUserWorkspace = userWorkspaceRepository.findByWorkspaceAndAuth(snsEvent.getWorkspace(), Auth.ADMIN)
+                .orElseThrow(() -> new MemberHandler(WORKSPACE_CREATOR_NOT_FOUND));
+
+        // 수정 권한 확인 (워크스페이스 생성자 혹은 SNS 이벤트의 생성자만 수정 가능)
+        if (!foundUserWorkspace.getUser().getId().equals(user.getId()) || !snsEvent.getCreator().getId().equals(user.getId())) {
+            throw new SnsEventHandler(SNS_EVENT_NO_AUTHORITY);
+        }
+
+        snsEvent.updateTitle(request.getTitle());
+        snsEventRepository.save(snsEvent);
+
+    }
+
+    @Override
+    @Transactional
+    @DeleteDocument
+    public void deleteSnsEvent(
+            User user,
+            SnsEvent snsEvent
+    ) {
+
+        UserWorkspace foundUserWorkspace = userWorkspaceRepository.findByWorkspaceAndAuth(snsEvent.getWorkspace(), Auth.ADMIN)
+                .orElseThrow(() -> new MemberHandler(WORKSPACE_CREATOR_NOT_FOUND));
+
+        // 수정 권한 확인 (워크스페이스 생성자 혹은 SNS 이벤트의 생성자만 삭제 가능)
+        if (!foundUserWorkspace.getUser().getId().equals(user.getId()) || !snsEvent.getCreator().getId().equals(user.getId())) {
+            throw new SnsEventHandler(SNS_EVENT_NO_AUTHORITY);
+        }
+        snsEventRepository.delete(snsEvent);
+
+    }
+
+    @Override
+    public SnsEventResponseDTO.ListDownLoadLinkResponse downloadList(
+            User user,
+            SnsEvent snsEvent,
+            ListType listType,
+            Format format
+    ) {
+        String downloadLink = "";
+
+        String snsEventTitle = snsEvent.getTitle();
+        if (listType == ListType.PARTICIPANT) {
+            if (format == Format.PDF) {
+                String keyName = snsEvent.getKeyNameParticipantPdf();
+                if (keyName == null || keyName.isEmpty()) {
+                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
+                }
+                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_participnat_list.pdf");
+            } else if (format == Format.DOCX) {
+                String keyName = snsEvent.getKeyNameParticipantWord();
+                if (keyName == null || keyName.isEmpty()) {
+                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
+                }
+                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_participnat_list.docx");
+            } else {
+                throw new SnsEventHandler(SNS_EVENT_WRONG_FORMAT);
+            }
+        } else if (listType == ListType.WINNER) {
+            if (format == Format.PDF) {
+                String keyName = snsEvent.getKeyNameWinnerPdf();
+                if (keyName == null || keyName.isEmpty()) {
+                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
+                }
+                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_winner_list.pdf");
+            } else if (format == Format.DOCX) {
+                String keyName = snsEvent.getKeyNameWinnerWord();
+                if (keyName == null || keyName.isEmpty()) {
+                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
+                }
+                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_winner_list.docx");
+            } else {
+                throw new SnsEventHandler(SNS_EVENT_WRONG_FORMAT);
+            }
+        } else {
+            throw new SnsEventHandler(SNS_EVENT_WRONG_LIST_TYPE);
+        }
+        return SnsEventResponseDTO.ListDownLoadLinkResponse.builder()
+                .downloadLink(downloadLink)
+                .build();
+    }
+
     private String createListHtml(
             SnsEvent snsEvent,
             ListType listType
@@ -305,7 +415,7 @@ private SnsEventResponseDTO.InstagramMediaResponse fetchInstagramMedia(
     }
 
 
-    public List<SnsEventResponseDTO.Comment> getComments(
+    private List<SnsEventResponseDTO.Comment> getComments(
             String mediaId,
             String accessToken
     ) {
@@ -347,7 +457,7 @@ private int countOccurrences(
         return count;
     }
 
-    public List<String> pickWinners(Set<String> participants, int n) {
+    private List<String> pickWinners(Set<String> participants, int n) {
         List<String> list = new ArrayList<>(participants); // Set → List로 변환
         Collections.shuffle(list); // 무작위 섞기
 
@@ -358,157 +468,6 @@ public List<String> pickWinners(Set<String> participants, int n) {
         return list.subList(0, n); // 앞에서 n개만 추출
     }
 
-    @Override
-    @Transactional
-    public SnsEventResponseDTO.LinkInstagramAccountResponse getInstagramAccessTokenAndAccount(
-            String code,
-            Long workspaceId
-    ) {
-        String shortLivedAccessToken;
-        String longLivedAccessToken;
-        Map<String, Object> userInfo;
-        try {
-            // 1. Access Token 요청
-            shortLivedAccessToken = instagramOauth2RestTemplate.getShortLivedAccessTokenUrl(code);
-            // 2. 단기 토큰을 장기(Long-Lived) 토큰으로 교환
-            longLivedAccessToken = instagramOauth2RestTemplate.getLongLivedAccessToken(shortLivedAccessToken);
-            // 3. 장기 토큰으로 사용자 계정 정보 요청
-            userInfo = instagramOauth2RestTemplate.getInstagramAccountInfo(longLivedAccessToken);
-        } catch (Exception e) {
-            log.error("Instagram OAuth2 처리 중 오류 발생: {}", e.getMessage());
-            throw new SnsEventHandler(SNS_EVENT_INSTAGRAM_API_ERROR);
-        }
-        // 4. 워크스페이스에 인스타그램 계정 정보 저장
-        String instagramId = (String) userInfo.get("user_id");
-        Workspace foundWorkspace = workspaceRepository.findById(workspaceId)
-                .orElseThrow(() -> new WorkspaceHandler(WORKSPACE_NOT_FOUND));
-        if (foundWorkspace.getInstagramId() != null && foundWorkspace.getInstagramId().equals(instagramId)) {
-            throw new SnsEventHandler(SNS_EVENT_INSTAGRAM_ALREADY_LINKED);
-        }
-        foundWorkspace.saveInstagramId(instagramId);
-        foundWorkspace.saveInstagramAccessToken(longLivedAccessToken);
-        foundWorkspace.saveInstagramAccountName((String) userInfo.get("username"));
-        return SnsEventConverter.toLinkInstagramAccountResponse((String) userInfo.get("username"));
-    }
-  
-    @Override
-    @Transactional
-    public void updateSnsEventTitle(
-            Long userId,
-            Long snsEventId,
-            SnsEventRequestDTO.UpdateSnsEventRequest request
-    ) {
-        User foundUser = userRepository.findById(userId)
-                .orElseThrow(() -> new MemberHandler(MEMBER_NOT_FOUND));
-        SnsEvent foundSnsEvent = snsEventRepository.findById(snsEventId)
-                .orElseThrow(() -> new SnsEventHandler(SNS_EVENT_NOT_FOUND));
-        UserWorkspace foundUserWorkspace = userWorkspaceRepository.findByWorkspaceAndAuth(foundSnsEvent.getWorkspace(), Auth.ADMIN)
-                .orElseThrow(() -> new MemberHandler(WORKSPACE_CREATOR_NOT_FOUND));
-        // 수정 권한 확인 (워크스페이스 생성자 혹은 SNS 이벤트의 생성자만 수정 가능)
-        if (!foundUserWorkspace.getUser().getId().equals(foundUser.getId()) || !foundSnsEvent.getCreator().getId().equals(foundUser.getId())) {
-            throw new SnsEventHandler(SNS_EVENT_NO_AUTHORITY);
-        }
-        foundSnsEvent.updateTitle(request.getTitle());
-        snsEventRepository.save(foundSnsEvent);
-
-        // sns event 수정 시 워크스페이스에 속해있는 모든 유저에 대해
-        // last opened 테이블에서 해당 문서 정보 업데이트
-        userDocumentLastOpenedService.updateRecordsForWorkspaceUsers(foundSnsEvent);
-    }
-
-    @Override
-    @Transactional
-    public void deleteSnsEvent(
-            Long userId,
-            Long snsEventId
-    ) {
-        User foundUser = userRepository.findById(userId)
-                .orElseThrow(() -> new MemberHandler(MEMBER_NOT_FOUND));
-        SnsEvent foundSnsEvent = snsEventRepository.findById(snsEventId)
-                .orElseThrow(() -> new SnsEventHandler(SNS_EVENT_NOT_FOUND));
-        UserWorkspace foundUserWorkspace = userWorkspaceRepository.findByWorkspaceAndAuth(foundSnsEvent.getWorkspace(), Auth.ADMIN)
-                .orElseThrow(() -> new MemberHandler(WORKSPACE_CREATOR_NOT_FOUND));
-        // 수정 권한 확인 (워크스페이스 생성자 혹은 SNS 이벤트의 생성자만 삭제 가능)
-        if (!foundUserWorkspace.getUser().getId().equals(foundUser.getId()) || !foundSnsEvent.getCreator().getId().equals(foundUser.getId())) {
-            throw new SnsEventHandler(SNS_EVENT_NO_AUTHORITY);
-        }
-        snsEventRepository.delete(foundSnsEvent);
-
-        // sns event 삭제 시 워크스페이스에 속해있는 모든 유저에 대해
-        // last opened 테이블에서 해당 문서 id를 가지고 있는 튜플 모두 삭제
-        userDocumentLastOpenedService.deleteRecordsForWorkspaceUsers(foundSnsEvent);
-    }
-
-    @Override
-    public SnsEventResponseDTO.ListDownLoadLinkResponse downloadList(
-            Long userId,
-            Long snsEventId,
-            ListType listType,
-            Format format
-    ) {
-        String downloadLink = "";
-        User foundUser = userRepository.findById(userId)
-                .orElseThrow(() -> new MemberHandler(MEMBER_NOT_FOUND));
-        SnsEvent foundSnsEvent = snsEventRepository.findById(snsEventId)
-                .orElseThrow(() -> new SnsEventHandler(SNS_EVENT_NOT_FOUND));
-        String snsEventTitle = foundSnsEvent.getTitle();
-        if (listType == ListType.PARTICIPANT) {
-            if (format == Format.PDF) {
-                String keyName = foundSnsEvent.getKeyNameParticipantPdf();
-                if (keyName == null || keyName.isEmpty()) {
-                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
-                }
-                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_participnat_list.pdf");
-            } else if (format == Format.DOCX) {
-                String keyName = foundSnsEvent.getKeyNameParticipantWord();
-                if (keyName == null || keyName.isEmpty()) {
-                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
-                }
-                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_participnat_list.docx");
-            } else {
-                throw new SnsEventHandler(SNS_EVENT_WRONG_FORMAT);
-            }
-        } else if (listType == ListType.WINNER) {
-            if (format == Format.PDF) {
-                String keyName = foundSnsEvent.getKeyNameWinnerPdf();
-                if (keyName == null || keyName.isEmpty()) {
-                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
-                }
-                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_winner_list.pdf");
-            } else if (format == Format.DOCX) {
-                String keyName = foundSnsEvent.getKeyNameWinnerWord();
-                if (keyName == null || keyName.isEmpty()) {
-                    throw new SnsEventHandler(SNS_EVENT_LIST_KEYNAME_NOT_FOUND);
-                }
-                downloadLink = amazonS3Manager.generatePresignedUrlForDownloadPdfAndWord(keyName, snsEventTitle + "_winner_list.docx");
-            } else {
-                throw new SnsEventHandler(SNS_EVENT_WRONG_FORMAT);
-            }
-        } else {
-            throw new SnsEventHandler(SNS_EVENT_WRONG_LIST_TYPE);
-        }
-        return SnsEventResponseDTO.ListDownLoadLinkResponse.builder()
-                .downloadLink(downloadLink)
-                .build();
-    }
-
-    private String injectHead(String html) {
-        String fontCss = """
-        <style>
-            body {
-                font-family: 'NotoSansKR', sans-serif;
-            }
-        </style>
-        """;
-        if (html.toLowerCase().contains("<head>")) {
-            // <head> 바로 뒤에 스타일 삽입
-            return html.replaceFirst("(?i)<head>", "<head>" + fontCss);
-        } else {
-            // head가 없으면 생성
-            return html.replaceFirst("(?i)<html>", "<html><head>" + fontCss + "</head>");
-        }
-    }
-
     private byte[] addPdfTitle(byte[] pdfBytes, String text, byte[] fontBytes) throws Exception {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         PdfReader reader = new PdfReader(new ByteArrayInputStream(pdfBytes));
diff --git a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryService.java b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryService.java
index e73ef735..3c1f0427 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryService.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryService.java
@@ -1,10 +1,13 @@
 package com.haru.api.domain.snsEvent.service;
 
 import com.haru.api.domain.snsEvent.dto.SnsEventResponseDTO;
+import com.haru.api.domain.snsEvent.entity.SnsEvent;
+import com.haru.api.domain.user.entity.User;
+import com.haru.api.domain.workspace.entity.Workspace;
 
 public interface SnsEventQueryService {
 
-    SnsEventResponseDTO.GetSnsEventListRequest getSnsEventList(Long userId, Long workspaceId);
+    SnsEventResponseDTO.GetSnsEventListRequest getSnsEventList(User user, Workspace workspace);
 
-    SnsEventResponseDTO.GetSnsEventRequest getSnsEvent(Long userId, Long snsEventId);
+    SnsEventResponseDTO.GetSnsEventRequest getSnsEvent(User user, SnsEvent snsEvent);
 }
diff --git a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryServiceImpl.java b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryServiceImpl.java
index a4d817b1..cbe8128a 100644
--- a/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryServiceImpl.java
+++ b/src/main/java/com/haru/api/domain/snsEvent/service/SnsEventQueryServiceImpl.java
@@ -10,58 +10,43 @@
 import com.haru.api.domain.snsEvent.repository.SnsEventRepository;
 import com.haru.api.domain.snsEvent.repository.WinnerRepository;
 import com.haru.api.domain.user.entity.User;
-import com.haru.api.domain.user.repository.UserRepository;
-import com.haru.api.domain.userWorkspace.entity.UserWorkspace;
-import com.haru.api.domain.userWorkspace.repository.UserWorkspaceRepository;
 import com.haru.api.domain.workspace.entity.Workspace;
-import com.haru.api.domain.workspace.repository.WorkspaceRepository;
 import com.haru.api.global.annotation.TrackLastOpened;
-import com.haru.api.global.apiPayload.exception.handler.MemberHandler;
-import com.haru.api.global.apiPayload.exception.handler.SnsEventHandler;
-import com.haru.api.global.apiPayload.exception.handler.WorkspaceHandler;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
 
-import static com.haru.api.global.apiPayload.code.status.ErrorStatus.*;
-
 @Service
 @RequiredArgsConstructor
 public class SnsEventQueryServiceImpl implements SnsEventQueryService {
 
-    private final UserRepository userRepository;
-    private final WorkspaceRepository workspaceRepository;
-    private final UserWorkspaceRepository userWorkspaceRepository;
     private final SnsEventRepository snsEventRepository;
     private final ParticipantRepository participantRepository;
     private final WinnerRepository winnerRepository;
 
     @Override
-    public SnsEventResponseDTO.GetSnsEventListRequest getSnsEventList(Long userId, Long workspaceId) {
-        User foundUser = userRepository.findById(userId)
-                .orElseThrow(() -> new MemberHandler(MEMBER_NOT_FOUND));
-        Workspace foundWorkspace = workspaceRepository.findById(workspaceId)
-                .orElseThrow(() -> new WorkspaceHandler(WORKSPACE_NOT_FOUND));
-        UserWorkspace foundUserWorkSpace = userWorkspaceRepository.findByUserAndWorkspace(foundUser, foundWorkspace)
-                .orElseThrow(() -> new MemberHandler(NOT_BELONG_TO_WORKSPACE));
-        List<SnsEvent> snsEventList = snsEventRepository.findAllByWorkspace(foundWorkspace);
+    public SnsEventResponseDTO.GetSnsEventListRequest getSnsEventList(User user, Workspace workspace) {
+
+        List<SnsEvent> snsEventList = snsEventRepository.findAllByWorkspace(workspace);
+
         return SnsEventConverter.toGetSnsEventListRequest(snsEventList);
+
     }
 
     @Override
     @TrackLastOpened(type = DocumentType.SNS_EVENT_ASSISTANT)
-    public SnsEventResponseDTO.GetSnsEventRequest getSnsEvent(Long userId, Long snsEventId) {
-        User foundUser = userRepository.findById(userId)
-                .orElseThrow(() -> new MemberHandler(MEMBER_NOT_FOUND));
-        SnsEvent foundSnsEvent = snsEventRepository.findById(snsEventId)
-                .orElseThrow(() -> new SnsEventHandler(SNS_EVENT_NOT_FOUND));
-        List<Participant> participantList = participantRepository.findAllBySnsEvent(foundSnsEvent);
-        List<Winner> winnerList = winnerRepository.findAllBySnsEvent(foundSnsEvent);
+    public SnsEventResponseDTO.GetSnsEventRequest getSnsEvent(User user, SnsEvent snsEvent) {
+
+        List<Participant> participantList = participantRepository.findAllBySnsEvent(snsEvent);
+
+        List<Winner> winnerList = winnerRepository.findAllBySnsEvent(snsEvent);
+
         return SnsEventConverter.toGetSnsEventRequest(
-                foundSnsEvent,
+                snsEvent,
                 participantList,
                 winnerList
         );
+
     }
 }
diff --git a/src/main/java/com/haru/api/domain/workspace/entity/Workspace.java b/src/main/java/com/haru/api/domain/workspace/entity/Workspace.java
index eb0f9416..04ff62cf 100644
--- a/src/main/java/com/haru/api/domain/workspace/entity/Workspace.java
+++ b/src/main/java/com/haru/api/domain/workspace/entity/Workspace.java
@@ -34,7 +34,7 @@ public class Workspace extends BaseEntity {
 
     private String instagramId;
 
-    @Column(length = 200)
+    @Column(columnDefinition="TEXT")
     private String instagramAccessToken;
 
     @Column(length = 50)
diff --git a/src/main/java/com/haru/api/global/annotation/AuthSnsEvent.java b/src/main/java/com/haru/api/global/annotation/AuthSnsEvent.java
new file mode 100644
index 00000000..ca8fca63
--- /dev/null
+++ b/src/main/java/com/haru/api/global/annotation/AuthSnsEvent.java
@@ -0,0 +1,14 @@
+package com.haru.api.global.annotation;
+
+import com.haru.api.domain.lastOpened.entity.enums.DocumentType;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+@AuthDocument(documentType = DocumentType.SNS_EVENT_ASSISTANT, pathVariableName = "snsEventId")
+public @interface AuthSnsEvent {
+}
diff --git a/src/main/java/com/haru/api/global/argumentResolver/AuthDocumentArgumentResolver.java b/src/main/java/com/haru/api/global/argumentResolver/AuthDocumentArgumentResolver.java
index a5b4bf67..b6a40caf 100644
--- a/src/main/java/com/haru/api/global/argumentResolver/AuthDocumentArgumentResolver.java
+++ b/src/main/java/com/haru/api/global/argumentResolver/AuthDocumentArgumentResolver.java
@@ -86,6 +86,6 @@ private AuthDocument findAuthDocumentAnnotation(MethodParameter parameter) {
                 return annotation.annotationType().getAnnotation(AuthDocument.class);
             }
         }
-        throw new IllegalStateException("AuthDocument 어노테이션을 찾을 수 없습니다.");
+        return null;
     }
 }
diff --git a/src/main/java/com/haru/api/global/documentFinder/SnsEventFinder.java b/src/main/java/com/haru/api/global/documentFinder/SnsEventFinder.java
new file mode 100644
index 00000000..c02f8df3
--- /dev/null
+++ b/src/main/java/com/haru/api/global/documentFinder/SnsEventFinder.java
@@ -0,0 +1,26 @@
+package com.haru.api.global.documentFinder;
+
+import com.haru.api.domain.lastOpened.entity.enums.DocumentType;
+import com.haru.api.domain.snsEvent.repository.SnsEventRepository;
+import com.haru.api.global.apiPayload.code.status.ErrorStatus;
+import com.haru.api.global.apiPayload.exception.handler.SnsEventHandler;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class SnsEventFinder implements DocumentFinder {
+
+    private final SnsEventRepository snsEventRepository;
+
+    @Override
+    public DocumentType getSupportType() {
+        return DocumentType.SNS_EVENT_ASSISTANT;
+    }
+
+    @Override
+    public Object findById(Object id) {
+        return snsEventRepository.findById((Long) id)
+                .orElseThrow(() -> new SnsEventHandler(ErrorStatus.SNS_EVENT_NOT_FOUND));
+    }
+}
diff --git a/src/main/java/com/haru/api/global/interceptor/DocumentMemberAuthInterceptor.java b/src/main/java/com/haru/api/global/interceptor/DocumentMemberAuthInterceptor.java
index 0d386243..1bbea75e 100644
--- a/src/main/java/com/haru/api/global/interceptor/DocumentMemberAuthInterceptor.java
+++ b/src/main/java/com/haru/api/global/interceptor/DocumentMemberAuthInterceptor.java
@@ -2,6 +2,7 @@
 
 import com.haru.api.domain.lastOpened.entity.enums.DocumentType;
 import com.haru.api.domain.meeting.repository.MeetingRepository;
+import com.haru.api.domain.snsEvent.repository.SnsEventRepository;
 import com.haru.api.domain.user.entity.User;
 import com.haru.api.domain.user.repository.UserRepository;
 import com.haru.api.domain.user.security.jwt.SecurityUtil;
@@ -9,6 +10,7 @@
 import com.haru.api.global.annotation.AuthUser;
 import com.haru.api.global.apiPayload.code.status.ErrorStatus;
 import com.haru.api.global.apiPayload.exception.handler.MemberHandler;
+import com.haru.api.global.apiPayload.exception.handler.SnsEventHandler;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import lombok.RequiredArgsConstructor;
@@ -28,6 +30,7 @@ public class DocumentMemberAuthInterceptor implements HandlerInterceptor {
     private final UserRepository userRepository;
 
     private final MeetingRepository meetingRepository;
+    private final SnsEventRepository snsEventRepository;
 
     @Override
     public boolean preHandle(final HttpServletRequest request, final HttpServletResponse response, final Object handler) throws Exception {
@@ -59,6 +62,7 @@ public boolean preHandle(final HttpServletRequest request, final HttpServletResp
             }
         }
 
+        // AuthUser, AuthDocument가 모두 존재하는 경우
         if (hasAuthUserParam && authDocumentInfo != null) {
 
             // AuthDocument에서 DocumentType, pathVariableName 추출
@@ -80,11 +84,17 @@ public boolean preHandle(final HttpServletRequest request, final HttpServletResp
 
             Object foundDocument = null;
 
+            // 유저가 해당 문서가 속한 워크스페이스에 속해있는지 확인하고, 해당 객체를 반환함
             switch (documentType) {
                 case AI_MEETING_MANAGER:
                     foundDocument = meetingRepository.findMeetingByIdIfUserHasAccess(userId, documentId)
                             .orElseThrow(() -> new MemberHandler(ErrorStatus.MEMBER_HAS_NO_ACCESS_TO_MEETING));
                     break;
+
+                case SNS_EVENT_ASSISTANT:
+                    foundDocument = snsEventRepository.findSnsEventByIdIfUserHasAccess(userId, documentId)
+                            .orElseThrow(() -> new SnsEventHandler(ErrorStatus.SNS_EVENT_NOT_FOUND));
+                    break;
             }
 
             // 유저 조회