diff --git a/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationApiMapper.java b/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationApiMapper.java
index 53be488..2603ee2 100644
--- a/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationApiMapper.java
+++ b/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationApiMapper.java
@@ -17,7 +17,7 @@ public interface ConversationApiMapper {
 
     @Mapping(target = "title", source = "title", defaultValue = "Untitled")
     @Mapping(target = "discussions", source = "discussions")
-    ConversationResponseCompact mapList(Conversation conversation);
+    ConversationResponseCompact mapCompact(Conversation conversation);
 
     default List<Discussion> defaultDiscussions() {
         return new ArrayList<>();
diff --git a/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationController.java b/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationController.java
index 9163e78..6a7da75 100644
--- a/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationController.java
+++ b/backend/src/main/java/com/llm_service/llm_service/controller/conversation/ConversationController.java
@@ -2,6 +2,7 @@
 
 import com.llm_service.llm_service.dto.Conversation;
 import com.llm_service.llm_service.dto.Discussion;
+import com.llm_service.llm_service.exception.UnAuthorizedException;
 import com.llm_service.llm_service.exception.conversation.ConversationNotFoundException;
 import com.llm_service.llm_service.service.ConversationService;
 import io.swagger.v3.oas.annotations.Operation;
@@ -34,9 +35,9 @@ public class ConversationController {
             })
     @Operation(summary = "Get all conversations")
     @GetMapping
-    public ResponseEntity<List<ConversationResponseCompact>> getAllConversations() {
+    public ResponseEntity<List<ConversationResponseCompact>> getAllConversations() throws UnAuthorizedException {
         return ResponseEntity.ok(conversationService.getAll().stream()
-                .map(conversationApiMapper::mapList)
+                .map(conversationApiMapper::mapCompact)
                 .toList());
     }
 
@@ -50,7 +51,7 @@ public ResponseEntity<List<ConversationResponseCompact>> getAllConversations() {
     @Operation(summary = "Get conversation by ID")
     @GetMapping("/{id}")
     public ResponseEntity<ConversationResponse> getConversationById(@PathVariable UUID id)
-            throws ConversationNotFoundException {
+            throws ConversationNotFoundException, UnAuthorizedException {
         Conversation conversation =
                 conversationService.getByID(id).orElseThrow(() -> new ConversationNotFoundException(id));
 
@@ -66,7 +67,7 @@ public ResponseEntity<ConversationResponse> getConversationById(@PathVariable UU
             })
     @Operation(summary = "Create new conversation")
     @PostMapping
-    public ResponseEntity<ConversationResponse> createConversation() {
+    public ResponseEntity<ConversationResponse> createConversation() throws Exception {
         Conversation conversation = conversationService.start();
 
         return ResponseEntity.status(HttpStatus.OK).body(conversationApiMapper.map(conversation));
@@ -83,7 +84,7 @@ public ResponseEntity<ConversationResponse> createConversation() {
     @PutMapping("/{id}/continue")
     public ResponseEntity<List<DiscussionResponse>> continueConversation(
             @PathVariable UUID id, @RequestBody ConversationRequest conversationRequest)
-            throws ConversationNotFoundException {
+            throws ConversationNotFoundException, UnAuthorizedException {
         Conversation conversation =
                 conversationService.getByID(id).orElseThrow(() -> new ConversationNotFoundException(id));
         List<Discussion> discussions = conversationService.askLlmQuestion(conversation, conversationRequest.getText());
@@ -100,14 +101,13 @@ public ResponseEntity<List<DiscussionResponse>> continueConversation(
             })
     @Operation(summary = "update conversation title")
     @PutMapping("/{id}")
-    public ResponseEntity<ConversationResponse> editConversation(
-            @PathVariable UUID id, @RequestBody ConversationTitleRequest conversationTitleRequest)
-            throws ConversationNotFoundException {
+    public ResponseEntity<ConversationResponseCompact> editConversation(
+            @PathVariable UUID id, @RequestBody ConversationTitleRequest conversationTitleRequest) throws Exception {
         Conversation conversation =
                 conversationService.getByID(id).orElseThrow(() -> new ConversationNotFoundException(id));
         conversationService.editTitle(conversation, conversationTitleRequest.getTitle());
 
-        return ResponseEntity.status(HttpStatus.OK).body(conversationApiMapper.map(conversation));
+        return ResponseEntity.status(HttpStatus.OK).body(conversationApiMapper.mapCompact(conversation));
     }
 
     @ApiResponses(
@@ -119,7 +119,8 @@ public ResponseEntity<ConversationResponse> editConversation(
             })
     @Operation(summary = "deletes a conversation")
     @DeleteMapping("/{id}")
-    public ResponseEntity<Void> deleteConversation(@PathVariable UUID id) throws ConversationNotFoundException {
+    public ResponseEntity<Void> deleteConversation(@PathVariable UUID id)
+            throws ConversationNotFoundException, UnAuthorizedException {
         conversationService.getByID(id).orElseThrow(() -> new ConversationNotFoundException(id));
         conversationService.delete(id);
         return ResponseEntity.status(HttpStatus.OK).body(null);
@@ -144,4 +145,9 @@ public ResponseEntity<String> handleConversationNotFoundException(
             ConversationNotFoundException conversationNotFoundException) {
         return ResponseEntity.status(HttpStatus.NOT_FOUND).body(conversationNotFoundException.getMessage());
     }
+
+    @ExceptionHandler(UnAuthorizedException.class)
+    public ResponseEntity<String> handleUnAuthorized(UnAuthorizedException unAuthorizedException) {
+        return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(unAuthorizedException.getMessage());
+    }
 }
diff --git a/backend/src/main/java/com/llm_service/llm_service/exception/UnAuthorizedException.java b/backend/src/main/java/com/llm_service/llm_service/exception/UnAuthorizedException.java
new file mode 100644
index 0000000..8fa08b4
--- /dev/null
+++ b/backend/src/main/java/com/llm_service/llm_service/exception/UnAuthorizedException.java
@@ -0,0 +1,7 @@
+package com.llm_service.llm_service.exception;
+
+public class UnAuthorizedException extends Exception {
+    public UnAuthorizedException() {
+        super("UnAuthorized");
+    }
+}
diff --git a/backend/src/main/java/com/llm_service/llm_service/exception/conversation/ConversationNotFoundException.java b/backend/src/main/java/com/llm_service/llm_service/exception/conversation/ConversationNotFoundException.java
index a052d4d..95609c1 100644
--- a/backend/src/main/java/com/llm_service/llm_service/exception/conversation/ConversationNotFoundException.java
+++ b/backend/src/main/java/com/llm_service/llm_service/exception/conversation/ConversationNotFoundException.java
@@ -6,4 +6,8 @@ public class ConversationNotFoundException extends Exception {
     public ConversationNotFoundException(UUID id) {
         super("Conversation with id " + id + " is not found");
     }
+
+    public ConversationNotFoundException() {
+        super("Conversation with is not found");
+    }
 }
diff --git a/backend/src/main/java/com/llm_service/llm_service/persistance/entities/ConversationEntity.java b/backend/src/main/java/com/llm_service/llm_service/persistance/entities/ConversationEntity.java
index 06c20da..7d5cf5d 100644
--- a/backend/src/main/java/com/llm_service/llm_service/persistance/entities/ConversationEntity.java
+++ b/backend/src/main/java/com/llm_service/llm_service/persistance/entities/ConversationEntity.java
@@ -15,6 +15,10 @@ public class ConversationEntity extends BaseEntity {
     @OneToMany(mappedBy = "conversation", orphanRemoval = true)
     private List<DiscussionEntity> discussions;
 
+    @ManyToOne
+    @JoinColumn(name = "user_id")
+    private UserEntity user;
+
     @Column(name = "title")
     private String title;
 
diff --git a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationEntityMapper.java b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationEntityMapper.java
index 5b27232..e754c0d 100644
--- a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationEntityMapper.java
+++ b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationEntityMapper.java
@@ -1,13 +1,16 @@
 package com.llm_service.llm_service.persistance.repositories.conversation;
 
 import com.llm_service.llm_service.dto.Conversation;
+import com.llm_service.llm_service.dto.User;
 import com.llm_service.llm_service.persistance.entities.ConversationEntity;
 import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
 
 @Mapper(componentModel = "spring")
 public interface ConversationEntityMapper {
 
     Conversation map(ConversationEntity conversationEntity);
 
-    ConversationEntity map(Conversation conversation);
+    @Mapping(source = "conversation.id", target = "id")
+    ConversationEntity map(Conversation conversation, User user);
 }
diff --git a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationJpaPersistenceManager.java b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationJpaPersistenceManager.java
index f1916f3..2cd09ec 100644
--- a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationJpaPersistenceManager.java
+++ b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationJpaPersistenceManager.java
@@ -1,6 +1,7 @@
 package com.llm_service.llm_service.persistance.repositories.conversation;
 
 import com.llm_service.llm_service.dto.Conversation;
+import com.llm_service.llm_service.dto.User;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
@@ -14,20 +15,25 @@ public class ConversationJpaPersistenceManager implements ConversationPersistenc
     private final ConversationEntityMapper conversationEntityMapper;
 
     @Override
-    public List<Conversation> findAll() {
+    public List<Conversation> findAll(UUID userId) {
         return conversationRepository.findAll().stream()
+                .filter(conversationEntity -> conversationEntity.getUser().getId() == userId)
                 .map(conversationEntityMapper::map)
                 .toList();
     }
 
     @Override
-    public Optional<Conversation> findById(UUID id) {
-        return conversationRepository.findById(id).map(conversationEntityMapper::map);
+    public Optional<Conversation> findById(UUID id, UUID userId) {
+        return conversationRepository
+                .findById(id)
+                .filter(conversationEntity -> conversationEntity.getUser().getId() == userId)
+                .map(conversationEntityMapper::map);
     }
 
     @Override
-    public Conversation save(Conversation conversation) {
-        return conversationEntityMapper.map(conversationRepository.save(conversationEntityMapper.map(conversation)));
+    public Conversation save(Conversation conversation, User user) {
+        return conversationEntityMapper.map(
+                conversationRepository.save(conversationEntityMapper.map(conversation, user)));
     }
 
     @Override
diff --git a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationPersistenceManager.java b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationPersistenceManager.java
index 89e992d..547d5cb 100644
--- a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationPersistenceManager.java
+++ b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/conversation/ConversationPersistenceManager.java
@@ -1,16 +1,17 @@
 package com.llm_service.llm_service.persistance.repositories.conversation;
 
 import com.llm_service.llm_service.dto.Conversation;
+import com.llm_service.llm_service.dto.User;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 
 public interface ConversationPersistenceManager {
-    List<Conversation> findAll();
+    List<Conversation> findAll(UUID userId);
 
-    Optional<Conversation> findById(UUID id);
+    Optional<Conversation> findById(UUID id, UUID userId);
 
-    Conversation save(Conversation conversation);
+    Conversation save(Conversation conversation, User user);
 
     void delete(UUID id);
 
diff --git a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionJpaPersistenceManager.java b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionJpaPersistenceManager.java
index 27fadce..342094a 100644
--- a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionJpaPersistenceManager.java
+++ b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionJpaPersistenceManager.java
@@ -2,6 +2,7 @@
 
 import com.llm_service.llm_service.dto.Conversation;
 import com.llm_service.llm_service.dto.Discussion;
+import com.llm_service.llm_service.dto.User;
 import com.llm_service.llm_service.persistance.entities.DiscussionEntity;
 import com.llm_service.llm_service.persistance.repositories.conversation.ConversationEntityMapper;
 import java.util.List;
@@ -30,11 +31,11 @@ public Optional<Discussion> findById(UUID id) {
     }
 
     @Override
-    public Discussion save(Discussion discussion, Conversation conversation) {
+    public Discussion save(Discussion discussion, Conversation conversation, User user) {
         DiscussionEntity discussionEntity = DiscussionEntity.builder()
                 .text(discussion.getText())
                 .promptRole(discussion.getPromptRole())
-                .conversation(conversationEntityMapper.map(conversation))
+                .conversation(conversationEntityMapper.map(conversation, user))
                 .build();
         return discussionEntityMapper.map(discussionRepository.save(discussionEntity));
     }
diff --git a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionPersistenceManager.java b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionPersistenceManager.java
index 500427b..7702aa6 100644
--- a/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionPersistenceManager.java
+++ b/backend/src/main/java/com/llm_service/llm_service/persistance/repositories/discussion/DiscussionPersistenceManager.java
@@ -2,6 +2,7 @@
 
 import com.llm_service.llm_service.dto.Conversation;
 import com.llm_service.llm_service.dto.Discussion;
+import com.llm_service.llm_service.dto.User;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
@@ -11,7 +12,7 @@ public interface DiscussionPersistenceManager {
 
     Optional<Discussion> findById(UUID id);
 
-    Discussion save(Discussion discussion, Conversation conversation);
+    Discussion save(Discussion discussion, Conversation conversation, User user);
 
     void delete(UUID id);
 }
diff --git a/backend/src/main/java/com/llm_service/llm_service/service/ConversationService.java b/backend/src/main/java/com/llm_service/llm_service/service/ConversationService.java
index fd10205..294b9f7 100644
--- a/backend/src/main/java/com/llm_service/llm_service/service/ConversationService.java
+++ b/backend/src/main/java/com/llm_service/llm_service/service/ConversationService.java
@@ -2,9 +2,12 @@
 
 import com.llm_service.llm_service.dto.Conversation;
 import com.llm_service.llm_service.dto.Discussion;
+import com.llm_service.llm_service.dto.User;
+import com.llm_service.llm_service.exception.UnAuthorizedException;
 import com.llm_service.llm_service.persistance.entities.DiscussionRole;
 import com.llm_service.llm_service.persistance.repositories.conversation.ConversationPersistenceManager;
 import com.llm_service.llm_service.persistance.repositories.discussion.DiscussionPersistenceManager;
+import com.llm_service.llm_service.service.user.UserContext;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
@@ -18,33 +21,60 @@ public class ConversationService {
     private final LLMService llmService;
     private final ConversationPersistenceManager conversationPersistenceManager;
     private final DiscussionPersistenceManager discussionPersistenceManager;
+    private final UserContext userContext;
+
+    public Conversation start() throws Exception {
+        Optional<User> user = userContext.getUserFromContext();
+
+        if (user.isEmpty()) {
+            // TODO fix it later
+            throw new Exception("");
+        }
 
-    public Conversation start() {
         Conversation conversation = Conversation.builder().discussions(null).build();
-        return conversationPersistenceManager.save(conversation);
+        return conversationPersistenceManager.save(conversation, user.get());
     }
 
-    public List<Conversation> getAll() {
-        return conversationPersistenceManager.findAll();
+    public List<Conversation> getAll() throws UnAuthorizedException {
+        Optional<User> user = userContext.getUserFromContext();
+
+        if (user.isEmpty()) {
+            throw new UnAuthorizedException();
+        }
+
+        return conversationPersistenceManager.findAll(user.get().getId());
     }
 
-    public Optional<Conversation> getByID(UUID id) {
-        return conversationPersistenceManager.findById(id);
+    public Optional<Conversation> getByID(UUID id) throws UnAuthorizedException {
+        Optional<User> user = userContext.getUserFromContext();
+        if (user.isEmpty()) {
+            throw new UnAuthorizedException();
+        }
+
+        return conversationPersistenceManager.findById(id, user.get().getId());
     }
 
     // TODO optimize this fetching mechanism
-    public List<Discussion> askLlmQuestion(Conversation conversation, String text) {
+    public List<Discussion> askLlmQuestion(Conversation conversation, String text) throws UnAuthorizedException {
+
+        Optional<User> user = userContext.getUserFromContext();
+
+        if (user.isEmpty()) {
+            throw new UnAuthorizedException();
+        }
+
         Discussion discussionFromUserParam =
                 Discussion.builder().promptRole(DiscussionRole.USER).text(text).build();
 
-        Discussion discussionFromUser = discussionPersistenceManager.save(discussionFromUserParam, conversation);
+        Discussion discussionFromUser =
+                discussionPersistenceManager.save(discussionFromUserParam, conversation, user.get());
 
         if (conversation.getDiscussions().isEmpty()) {
             String conversationTitle = discussionFromUser
                     .getText()
                     .substring(0, Math.min(20, discussionFromUser.getText().length()));
             conversationPersistenceManager.save(
-                    conversation.toBuilder().title(conversationTitle).build());
+                    conversation.toBuilder().title(conversationTitle).build(), user.get());
         }
 
         String prompt = initializeModel();
@@ -58,7 +88,7 @@ public List<Discussion> askLlmQuestion(Conversation conversation, String text) {
                 .build();
 
         Discussion discussionFromAssistance =
-                discussionPersistenceManager.save(discussionFromAssistanceParam, conversation);
+                discussionPersistenceManager.save(discussionFromAssistanceParam, conversation, user.get());
 
         List<Discussion> newDiscussions = new ArrayList<>();
 
@@ -76,9 +106,16 @@ public void deleteAll() {
         conversationPersistenceManager.deleteAll();
     }
 
-    public void editTitle(Conversation conversation, String title) {
+    public void editTitle(Conversation conversation, String title) throws Exception {
+        Optional<User> user = userContext.getUserFromContext();
+
+        if (user.isEmpty()) {
+            // TODO fix it later
+            throw new Exception("");
+        }
+
         conversationPersistenceManager.save(
-                conversation.toBuilder().title(title).build());
+                conversation.toBuilder().title(title).build(), user.get());
     }
 
     private String getPrediction(String text) {
diff --git a/backend/src/main/java/com/llm_service/llm_service/service/jwt/filter/JwtAuthenticationFilter.java b/backend/src/main/java/com/llm_service/llm_service/service/jwt/filter/JwtAuthenticationFilter.java
index ebfdc97..c0030f2 100644
--- a/backend/src/main/java/com/llm_service/llm_service/service/jwt/filter/JwtAuthenticationFilter.java
+++ b/backend/src/main/java/com/llm_service/llm_service/service/jwt/filter/JwtAuthenticationFilter.java
@@ -6,6 +6,7 @@
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import lombok.RequiredArgsConstructor;
 import org.springframework.lang.NonNull;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.context.SecurityContextHolder;
@@ -16,16 +17,12 @@
 import org.springframework.web.filter.OncePerRequestFilter;
 
 @Component
+@RequiredArgsConstructor
 public class JwtAuthenticationFilter extends OncePerRequestFilter {
 
     private final JwtService jwtService;
     private final UserDetailsService userDetailsService;
 
-    public JwtAuthenticationFilter(JwtService jwtService, UserDetailsService userDetailsService) {
-        this.jwtService = jwtService;
-        this.userDetailsService = userDetailsService;
-    }
-
     @Override
     protected void doFilterInternal(
             @NonNull HttpServletRequest request,
diff --git a/backend/src/main/java/com/llm_service/llm_service/service/user/UserContext.java b/backend/src/main/java/com/llm_service/llm_service/service/user/UserContext.java
new file mode 100644
index 0000000..f664e68
--- /dev/null
+++ b/backend/src/main/java/com/llm_service/llm_service/service/user/UserContext.java
@@ -0,0 +1,33 @@
+package com.llm_service.llm_service.service.user;
+
+import com.llm_service.llm_service.dto.User;
+import com.llm_service.llm_service.persistance.repositories.user.UserPersistenceManager;
+import java.util.Optional;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class UserContext {
+    private final UserPersistenceManager userPersistenceManager;
+
+    public Optional<User> getUserFromContext() {
+        // Get the authentication object from SecurityContextHolder
+        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+
+        if (authentication != null && authentication.getPrincipal() instanceof UserDetails) {
+            UserDetails userDetails = (UserDetails) authentication.getPrincipal();
+
+            // Access user information from UserDetails
+            String username = userDetails.getUsername();
+            // You can access other user details as well, like authorities: userDetails.getAuthorities()
+
+            return userPersistenceManager.findByUsername(username);
+        }
+
+        return Optional.empty();
+    }
+}