diff --git a/w12/.DS_Store b/w12/.DS_Store
new file mode 100644
index 0000000..97af285
Binary files /dev/null and b/w12/.DS_Store differ
diff --git a/w12/App.java b/w12/App.java
new file mode 100644
index 0000000..a7b17d4
--- /dev/null
+++ b/w12/App.java
@@ -0,0 +1,63 @@
+package com.crawler;
+
+import com.crawler.command.*;
+import com.crawler.controller.CrawlerController;
+import com.crawler.repository.ArticleRepository;
+import com.crawler.repository.InMemoryArticleRepository;
+import com.crawler.view.ConsoleView;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class App {
+    private final Map<String, Command> commands = new HashMap<>();
+    private final ConsoleView view;
+    private final AtomicBoolean running = new AtomicBoolean(true);
+
+    public App() {
+        view = new ConsoleView();
+        ArticleRepository repository = new InMemoryArticleRepository();
+        CrawlerController controller = new CrawlerController(repository, view);
+
+        commands.put("crawl", new CrawlCommand(controller, view));
+        commands.put("list", new ListCommand(controller));
+        commands.put("save", new SaveCommand(controller));
+        commands.put("load", new LoadCommand(controller));
+        commands.put("help", new HelpCommand(view));
+        commands.put("exit", new ExitCommand(view, () -> running.set(false)));
+    }
+
+    public void run() {
+        view.displayWelcome();
+        view.displayHelp();
+
+        while (running.get()) {
+            try {
+                String input = view.readInput();
+                if (input.isEmpty()) {
+                    continue;
+                }
+
+                String[] parts = input.split("\\s+", 3);
+                String commandName = parts[0].toLowerCase();
+                String[] args = parts.length > 1 ? java.util.Arrays.copyOfRange(parts, 1, parts.length) : new String[0];
+
+                Command command = commands.get(commandName);
+                if (command != null) {
+                    command.execute(args);
+                } else {
+                    view.displayError("Unknown command: " + commandName);
+                    view.displayInfo("Type 'help' for available commands");
+                }
+            } catch (Exception e) {
+                view.displayError("Error: " + e.getMessage());
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        App app = new App();
+        app.run();
+    }
+}
diff --git a/w12/repository/ArticleRepository.java b/w12/repository/ArticleRepository.java
new file mode 100644
index 0000000..0feb516
--- /dev/null
+++ b/w12/repository/ArticleRepository.java
@@ -0,0 +1,18 @@
+package com.crawler.repository;
+
+import com.crawler.model.Article;
+import java.util.List;
+import java.util.Optional;
+
+public interface ArticleRepository {
+    void save(Article article);
+    void saveAll(List<Article> articles);
+    Optional<Article> findById(String id);
+    Optional<Article> findByUrl(String url);
+    List<Article> findAll();
+    List<Article> findBySource(String source);
+    void deleteById(String id);
+    void deleteAll();
+    int count();
+    boolean existsByUrl(String url);
+}
diff --git a/w12/repository/InMemoryArticleRepository.java b/w12/repository/InMemoryArticleRepository.java
new file mode 100644
index 0000000..31c5578
--- /dev/null
+++ b/w12/repository/InMemoryArticleRepository.java
@@ -0,0 +1,78 @@
+package com.crawler.repository;
+
+import com.crawler.model.Article;
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collectors;
+
+public class InMemoryArticleRepository implements ArticleRepository {
+    private final Map<String, Article> articles = new ConcurrentHashMap<>();
+    private final Map<String, String> urlToIdMap = new ConcurrentHashMap<>();
+    private final AtomicInteger idGenerator = new AtomicInteger(1);
+
+    @Override
+    public void save(Article article) {
+        if (article.getId() == null) {
+            article.setId(String.valueOf(idGenerator.getAndIncrement()));
+        }
+        articles.put(article.getId(), article);
+        if (article.getUrl() != null) {
+            urlToIdMap.put(article.getUrl(), article.getId());
+        }
+    }
+
+    @Override
+    public void saveAll(List<Article> articleList) {
+        for (Article article : articleList) {
+            save(article);
+        }
+    }
+
+    @Override
+    public Optional<Article> findById(String id) {
+        return Optional.ofNullable(articles.get(id));
+    }
+
+    @Override
+    public Optional<Article> findByUrl(String url) {
+        String id = urlToIdMap.get(url);
+        return id != null ? Optional.ofNullable(articles.get(id)) : Optional.empty();
+    }
+
+    @Override
+    public List<Article> findAll() {
+        return new ArrayList<>(articles.values());
+    }
+
+    @Override
+    public List<Article> findBySource(String source) {
+        return articles.values().stream()
+                .filter(a -> source.equals(a.getSource()))
+                .collect(Collectors.toList());
+    }
+
+    @Override
+    public void deleteById(String id) {
+        Article article = articles.remove(id);
+        if (article != null && article.getUrl() != null) {
+            urlToIdMap.remove(article.getUrl());
+        }
+    }
+
+    @Override
+    public void deleteAll() {
+        articles.clear();
+        urlToIdMap.clear();
+    }
+
+    @Override
+    public int count() {
+        return articles.size();
+    }
+
+    @Override
+    public boolean existsByUrl(String url) {
+        return urlToIdMap.containsKey(url);
+    }
+}