diff --git a/frontend/src/network/models.ts b/frontend/src/network/models.ts
index 75486af..78a6d1f 100644
--- a/frontend/src/network/models.ts
+++ b/frontend/src/network/models.ts
@@ -197,5 +197,6 @@ export interface Collection {
   title: string;
   article: string;
   user: User;
+  resources_count: number;
   images: Image[];
-}
\ No newline at end of file
+}
diff --git a/server/dao/collection.go b/server/dao/collection.go
index 087c50c..d88ef29 100644
--- a/server/dao/collection.go
+++ b/server/dao/collection.go
@@ -80,7 +80,11 @@ func AddResourceToCollection(collectionID uint, resourceID uint) error {
 		collection := &model.Collection{}
 
 		if err := tx.Where("id = ?", collectionID).First(collection).Error; err != nil {
-			return err
+			return model.NewRequestError("Invalid collection ID")
+		}
+
+		if err := tx.Model(&model.Resource{}).Where("id = ?", resourceID).First(&model.Resource{}).Error; err != nil {
+			return model.NewRequestError("Invalid resource ID")
 		}
 
 		if err := tx.Model(collection).Association("Resources").Append(&model.Resource{
@@ -91,6 +95,10 @@ func AddResourceToCollection(collectionID uint, resourceID uint) error {
 			return err
 		}
 
+		if err := tx.Model(collection).UpdateColumn("resources_count", gorm.Expr("resources_count + ?", 1)).Error; err != nil {
+			return err
+		}
+
 		return nil
 	})
 }
@@ -100,7 +108,11 @@ func RemoveResourceFromCollection(collectionID uint, resourceID uint) error {
 		collection := &model.Collection{}
 
 		if err := tx.Where("id = ?", collectionID).First(collection).Error; err != nil {
-			return err
+			return model.NewRequestError("Invalid collection ID")
+		}
+
+		if err := tx.Model(&model.Resource{}).Where("id = ?", resourceID).First(&model.Resource{}).Error; err != nil {
+			return model.NewRequestError("Invalid resource ID")
 		}
 
 		if err := tx.Model(collection).Association("Resources").Delete(&model.Resource{
@@ -111,6 +123,10 @@ func RemoveResourceFromCollection(collectionID uint, resourceID uint) error {
 			return err
 		}
 
+		if err := tx.Model(collection).UpdateColumn("resources_count", gorm.Expr("resources_count - ?", 1)).Error; err != nil {
+			return err
+		}
+
 		return nil
 	})
 }
diff --git a/server/model/collection.go b/server/model/collection.go
index 549c5c6..f962500 100644
--- a/server/model/collection.go
+++ b/server/model/collection.go
@@ -4,28 +4,31 @@ import "gorm.io/gorm"
 
 type Collection struct {
 	gorm.Model
-	Title     string     `gorm:"not null"`
-	Article   string     `gorm:"not null"`
-	UserID    uint       `gorm:"not null"`
-	User      User       `gorm:"foreignKey:UserID;references:ID"`
-	Images    []Image    `gorm:"many2many:collection_images;"`
-	Resources []Resource `gorm:"many2many:collection_resources;"`
+	Title          string     `gorm:"not null"`
+	Article        string     `gorm:"not null"`
+	UserID         uint       `gorm:"not null"`
+	User           User       `gorm:"foreignKey:UserID;references:ID"`
+	ResourcesCount int        `gorm:"default:0"`
+	Images         []Image    `gorm:"many2many:collection_images;"`
+	Resources      []Resource `gorm:"many2many:collection_resources;"`
 }
 
 type CollectionView struct {
-	ID      uint     `json:"id"`
-	Title   string   `json:"title"`
-	Article string   `json:"article"`
-	User    UserView `json:"user"`
-	Images  []Image  `json:"images"`
+	ID             uint     `json:"id"`
+	Title          string   `json:"title"`
+	Article        string   `json:"article"`
+	User           UserView `json:"user"`
+	ResourcesCount int      `json:"resources_count"`
+	Images         []Image  `json:"images"`
 }
 
 func (c Collection) ToView() *CollectionView {
 	return &CollectionView{
-		ID:      c.ID,
-		Title:   c.Title,
-		Article: c.Article,
-		User:    c.User.ToView(),
-		Images:  c.Images,
+		ID:             c.ID,
+		Title:          c.Title,
+		Article:        c.Article,
+		User:           c.User.ToView(),
+		ResourcesCount: c.ResourcesCount,
+		Images:         c.Images,
 	}
 }