diff --git a/pom.xml b/pom.xml
index 5e0cab1..7f860a7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -65,6 +65,25 @@
             <artifactId>picocli</artifactId>
             <version>4.7.6</version>
         </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>2.18.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.18.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+            <version>2.18.1</version>
+        </dependency>
+
     </dependencies>
 
     <build>
diff --git a/src/main/java/ua/com/javarush/gnew/m2/cli/PhoneBookCLI.java b/src/main/java/ua/com/javarush/gnew/m2/cli/PhoneBookCLI.java
index 3830973..edf788a 100644
--- a/src/main/java/ua/com/javarush/gnew/m2/cli/PhoneBookCLI.java
+++ b/src/main/java/ua/com/javarush/gnew/m2/cli/PhoneBookCLI.java
@@ -8,33 +8,51 @@
 import ua.com.javarush.gnew.m2.cli.commands.ListContacts;
 import ua.com.javarush.gnew.m2.cli.commands.SearchContact;
 import ua.com.javarush.gnew.m2.cli.commands.SetUser;
+import ua.com.javarush.gnew.m2.repository.ForSettingsRepository;
 import ua.com.javarush.gnew.m2.service.PhoneBookInterface;
+import ua.com.javarush.gnew.m2.service.SettingsService;
+import ua.com.javarush.gnew.m2.service.SettingsServiceInterface;
 import ua.com.javarush.gnew.m2.service.SimplePhoneBook;
 
+import java.util.concurrent.Callable;
+
 @Command(
-    name = "phonebook",
-    mixinStandardHelpOptions = true,
-    version = "PhoneBook CLI 1.0",
-    description = "CLI для управління контактами в телефонній книзі")
+        name = "phonebook",
+        mixinStandardHelpOptions = true,
+        version = "PhoneBook CLI 1.0",
+        description = "CLI для управління контактами в телефонній книзі"
+)
 public class PhoneBookCLI implements CliCommand {
 
+  private final SettingsServiceInterface settingsService;
+
+  public PhoneBookCLI(SettingsServiceInterface settingsService) {
+    this.settingsService = settingsService;
+  }
+
   @Override
   public Integer call() {
-    System.out.println("Використовуйте одну з команд: user, add, search, edit, delete, list");
+    System.out.println("Використовуйте одну з команд: user, add, search, edit, delete, list, locale");
     return 0;
   }
 
   public static int init(String[] args) {
 
     PhoneBookInterface phoneBook = new SimplePhoneBook();
+      SettingsServiceInterface settingsService = new SettingsService(new ForSettingsRepository());
 
-    return new CommandLine(new PhoneBookCLI())
-        .addSubcommand("add", new AddContact(phoneBook))
-        .addSubcommand("search", new SearchContact(phoneBook))
-        .addSubcommand("edit", new EditContact(phoneBook))
-        .addSubcommand("delete", new DeleteContact(phoneBook))
-        .addSubcommand("list", new ListContacts(phoneBook))
-        .addSubcommand("user", new SetUser())
-        .execute(args);
+    return new CommandLine(new PhoneBookCLI(settingsService))
+            .addSubcommand("add", new AddContact(phoneBook))
+            .addSubcommand("search", new SearchContact(phoneBook))
+            .addSubcommand("edit", new EditContact(phoneBook))
+            .addSubcommand("delete", new DeleteContact(phoneBook))
+            .addSubcommand("list", new ListContacts(phoneBook))
+            .addSubcommand("user", new SetUser())
+            .addSubcommand("locale", (Callable<Integer>) () -> {
+              settingsService.setLocale("uk");
+              System.out.println("Locale set to Ukrainian.");
+              return 0;
+            })
+            .execute(args);
   }
 }
diff --git a/src/main/java/ua/com/javarush/gnew/m2/repository/ContactDtoRepository.java b/src/main/java/ua/com/javarush/gnew/m2/repository/ContactDtoRepository.java
index 0381963..5d53195 100644
--- a/src/main/java/ua/com/javarush/gnew/m2/repository/ContactDtoRepository.java
+++ b/src/main/java/ua/com/javarush/gnew/m2/repository/ContactDtoRepository.java
@@ -1,17 +1,57 @@
 package ua.com.javarush.gnew.m2.repository;
 
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Collectors;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
 import ua.com.javarush.gnew.m2.dto.ContactDto;
 
 public interface ContactDtoRepository {
-  List<ContactDto> findAll();
+  ObjectMapper objectMapper = new ObjectMapper().enable(SerializationFeature.INDENT_OUTPUT);
+  default List<ContactDto> findAll() throws IOException {
+    File file = new File("demo.st");
+    if (!file.exists()) {
+      return new ArrayList<>();
+    }
+    return objectMapper.readValue(file, objectMapper.getTypeFactory().constructCollectionType(List.class, ContactDto.class));
+  }
+
 
-  Optional<ContactDto> findById(long id);
+  default Optional<ContactDto> findById(long id) throws IOException {
+    return findAll().stream().filter(contact -> contact.getId() == id).findFirst();
+  }
 
-  void deleteById(long id);
+  default void deleteById(long id) throws IOException {
+    Optional<ContactDto> contactToDelete = findById(id);
+    if (contactToDelete.isPresent()) {
+      List<ContactDto> contacts = findAll();
+      contacts.remove(contactToDelete.get());
+      saveAll(contacts);
+    } else {
+      System.out.println("Контакт с id " + id + " не найден.");
+    }
+  }
 
-  void saveAll(List<ContactDto> contacts);
+  default void saveAll(List<ContactDto> contacts) throws IOException {
+    objectMapper.writeValue(new File("demo.st"),contacts);
+  }
 
-  void save(ContactDto contactDto);
+  default void save(ContactDto contactDto) throws IOException {
+    List<ContactDto> contacts = findAll();
+    contacts.add(contactDto);
+    saveAll(contacts);
+  }
+  default List<ContactDto> findByKeyword(String keyword) throws IOException {
+    List<ContactDto> contacts = findAll();
+    return contacts.stream()
+            .filter(contact -> contact.getFullName().contains(keyword) ||
+                    contact.getPhones().stream().anyMatch(phones -> phones.contains(keyword)) ||
+                    contact.getEmails().stream().anyMatch(emails -> emails.contains(keyword)))
+            .collect(Collectors.toList());
+  }
 }
diff --git a/src/main/java/ua/com/javarush/gnew/m2/repository/ForSettingsRepository.java b/src/main/java/ua/com/javarush/gnew/m2/repository/ForSettingsRepository.java
new file mode 100644
index 0000000..1265045
--- /dev/null
+++ b/src/main/java/ua/com/javarush/gnew/m2/repository/ForSettingsRepository.java
@@ -0,0 +1,26 @@
+package ua.com.javarush.gnew.m2.repository;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ForSettingsRepository implements SettingsRepository {
+
+    @Override
+    public void save(Map<String, String> settings) throws IOException {
+    }
+
+    @Override
+    public Map<String, String> load() throws IOException {
+        return new HashMap<>();
+    }
+
+    @Override
+    public void saveSingleSetting(String key, String value) throws IOException {
+    }
+
+    @Override
+    public String loadSingleSetting(String key) throws IOException {
+        return "";
+    }
+}