diff --git a/2-Application/src/main/java/category/CategoryIdGenerator.java b/2-Application/src/main/java/category/CategoryIdGenerator.java
new file mode 100644
index 0000000..637fe15
--- /dev/null
+++ b/2-Application/src/main/java/category/CategoryIdGenerator.java
@@ -0,0 +1,6 @@
+package category;
+
+public interface CategoryIdGenerator
+{
+	CategoryId generateId();
+}
diff --git a/2-Application/src/main/java/category/CategoryUseCase.java b/2-Application/src/main/java/category/CategoryUseCase.java
new file mode 100644
index 0000000..2b83312
--- /dev/null
+++ b/2-Application/src/main/java/category/CategoryUseCase.java
@@ -0,0 +1,24 @@
+package category;
+
+import java.util.Set;
+
+public class CategoryUseCase {
+
+	private final CategoryRepository categoryRepository;
+	private final CategoryIdGenerator categoryIdGenerator;
+
+	CategoryUseCase(final CategoryRepository categoryRepository, final CategoryIdGenerator idGenerator) {
+		this.categoryRepository = categoryRepository;
+		this.categoryIdGenerator = idGenerator;
+	}
+
+	public void addCategory(CategoryName name) {
+
+		var id = this.categoryIdGenerator.generateId();
+		this.categoryRepository.add(new Category(name, id));
+	}
+
+	public Set<Category> getCategories() {
+		return categoryRepository.getAll();
+	}
+}