diff --git a/backend/src/main/java/online/wesal/wesal/dto/ApiResponse.java b/backend/src/main/java/online/wesal/wesal/dto/ApiResponse.java
new file mode 100644
index 0000000..a2cf922
--- /dev/null
+++ b/backend/src/main/java/online/wesal/wesal/dto/ApiResponse.java
@@ -0,0 +1,62 @@
+package online.wesal.wesal.dto;
+
+public class ApiResponse<T> {
+    
+    private boolean status;
+    private String message;
+    private T data;
+    
+    public ApiResponse() {}
+    
+    public ApiResponse(boolean status) {
+        this.status = status;
+    }
+    
+    public ApiResponse(boolean status, String message) {
+        this.status = status;
+        this.message = message;
+    }
+    
+    public ApiResponse(boolean status, T data) {
+        this.status = status;
+        this.data = data;
+    }
+    
+    public ApiResponse(boolean status, String message, T data) {
+        this.status = status;
+        this.message = message;
+        this.data = data;
+    }
+    
+    public static <T> ApiResponse<T> success(T data) {
+        return new ApiResponse<>(true, data);
+    }
+    
+    public static <T> ApiResponse<T> error(String message) {
+        return new ApiResponse<>(false, message);
+    }
+    
+    public boolean isStatus() {
+        return status;
+    }
+    
+    public void setStatus(boolean status) {
+        this.status = status;
+    }
+    
+    public String getMessage() {
+        return message;
+    }
+    
+    public void setMessage(String message) {
+        this.message = message;
+    }
+    
+    public T getData() {
+        return data;
+    }
+    
+    public void setData(T data) {
+        this.data = data;
+    }
+}
\ No newline at end of file
diff --git a/backend/src/main/java/online/wesal/wesal/dto/CreateInvitationRequest.java b/backend/src/main/java/online/wesal/wesal/dto/CreateInvitationRequest.java
new file mode 100644
index 0000000..7ace87e
--- /dev/null
+++ b/backend/src/main/java/online/wesal/wesal/dto/CreateInvitationRequest.java
@@ -0,0 +1,76 @@
+package online.wesal.wesal.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Positive;
+import java.time.LocalDateTime;
+
+public class CreateInvitationRequest {
+    
+    @NotBlank
+    private String title;
+    
+    @NotBlank
+    private String description;
+    
+    private LocalDateTime dateTime;
+    
+    private String location;
+    
+    @NotNull
+    @Positive
+    private Integer maxParticipants;
+    
+    @NotNull
+    private Long tagId;
+    
+    public CreateInvitationRequest() {}
+    
+    public String getTitle() {
+        return title;
+    }
+    
+    public void setTitle(String title) {
+        this.title = title;
+    }
+    
+    public String getDescription() {
+        return description;
+    }
+    
+    public void setDescription(String description) {
+        this.description = description;
+    }
+    
+    public LocalDateTime getDateTime() {
+        return dateTime;
+    }
+    
+    public void setDateTime(LocalDateTime dateTime) {
+        this.dateTime = dateTime;
+    }
+    
+    public String getLocation() {
+        return location;
+    }
+    
+    public void setLocation(String location) {
+        this.location = location;
+    }
+    
+    public Integer getMaxParticipants() {
+        return maxParticipants;
+    }
+    
+    public void setMaxParticipants(Integer maxParticipants) {
+        this.maxParticipants = maxParticipants;
+    }
+    
+    public Long getTagId() {
+        return tagId;
+    }
+    
+    public void setTagId(Long tagId) {
+        this.tagId = tagId;
+    }
+}
\ No newline at end of file
diff --git a/backend/src/main/java/online/wesal/wesal/dto/InvitationResponse.java b/backend/src/main/java/online/wesal/wesal/dto/InvitationResponse.java
new file mode 100644
index 0000000..f729d39
--- /dev/null
+++ b/backend/src/main/java/online/wesal/wesal/dto/InvitationResponse.java
@@ -0,0 +1,172 @@
+package online.wesal.wesal.dto;
+
+import java.time.LocalDateTime;
+
+public class InvitationResponse {
+    
+    private Long id;
+    private String title;
+    private String description;
+    private LocalDateTime dateTime;
+    private String location;
+    private Integer maxParticipants;
+    private Integer currentAttendees;
+    private TagDto tag;
+    private UserDto creator;
+    private LocalDateTime createdAt;
+    
+    public InvitationResponse() {}
+    
+    public Long getId() {
+        return id;
+    }
+    
+    public void setId(Long id) {
+        this.id = id;
+    }
+    
+    public String getTitle() {
+        return title;
+    }
+    
+    public void setTitle(String title) {
+        this.title = title;
+    }
+    
+    public String getDescription() {
+        return description;
+    }
+    
+    public void setDescription(String description) {
+        this.description = description;
+    }
+    
+    public LocalDateTime getDateTime() {
+        return dateTime;
+    }
+    
+    public void setDateTime(LocalDateTime dateTime) {
+        this.dateTime = dateTime;
+    }
+    
+    public String getLocation() {
+        return location;
+    }
+    
+    public void setLocation(String location) {
+        this.location = location;
+    }
+    
+    public Integer getMaxParticipants() {
+        return maxParticipants;
+    }
+    
+    public void setMaxParticipants(Integer maxParticipants) {
+        this.maxParticipants = maxParticipants;
+    }
+    
+    public Integer getCurrentAttendees() {
+        return currentAttendees;
+    }
+    
+    public void setCurrentAttendees(Integer currentAttendees) {
+        this.currentAttendees = currentAttendees;
+    }
+    
+    public TagDto getTag() {
+        return tag;
+    }
+    
+    public void setTag(TagDto tag) {
+        this.tag = tag;
+    }
+    
+    public UserDto getCreator() {
+        return creator;
+    }
+    
+    public void setCreator(UserDto creator) {
+        this.creator = creator;
+    }
+    
+    public LocalDateTime getCreatedAt() {
+        return createdAt;
+    }
+    
+    public void setCreatedAt(LocalDateTime createdAt) {
+        this.createdAt = createdAt;
+    }
+    
+    public static class TagDto {
+        private Long id;
+        private String name;
+        private String colorHex;
+        private String iconName;
+        
+        public TagDto() {}
+        
+        public Long getId() {
+            return id;
+        }
+        
+        public void setId(Long id) {
+            this.id = id;
+        }
+        
+        public String getName() {
+            return name;
+        }
+        
+        public void setName(String name) {
+            this.name = name;
+        }
+        
+        public String getColorHex() {
+            return colorHex;
+        }
+        
+        public void setColorHex(String colorHex) {
+            this.colorHex = colorHex;
+        }
+        
+        public String getIconName() {
+            return iconName;
+        }
+        
+        public void setIconName(String iconName) {
+            this.iconName = iconName;
+        }
+    }
+    
+    public static class UserDto {
+        private Long id;
+        private String displayName;
+        private String avatar;
+        
+        public UserDto() {}
+        
+        public Long getId() {
+            return id;
+        }
+        
+        public void setId(Long id) {
+            this.id = id;
+        }
+        
+        public String getDisplayName() {
+            return displayName;
+        }
+        
+        public void setDisplayName(String displayName) {
+            this.displayName = displayName;
+        }
+        
+        public String getAvatar() {
+            return avatar;
+        }
+        
+        public void setAvatar(String avatar) {
+            this.avatar = avatar;
+        }
+    }
+}
\ No newline at end of file