diff --git a/.github/workflows/code_check.yaml b/.github/workflows/code_check.yaml
index fcb5809..350e3df 100644
--- a/.github/workflows/code_check.yaml
+++ b/.github/workflows/code_check.yaml
@@ -23,24 +23,9 @@ jobs:
       - name: Get dependencies
         run: flutter pub get
 
-      - name: Setup Dart Code Metrics
-        run: dart pub get dart_code_metrics
-
-      - name: Run Dart Code Metrics
-        run: |
-          dirs_to_analyze=""
-          if [ -d lib ]; then dirs_to_analyze+=" lib"; fi
-          if [ -d test ]; then dirs_to_analyze+=" test"; fi
-          if [ -d example ]; then dirs_to_analyze+=" example"; fi
-          if [ dirs_to_analyze != "" ]
-          then
-            dart run dart_code_metrics:metrics \
-              analyze \
-              $dirs_to_analyze \
-              --fatal-warnings \
-              --fatal-performance \
-              --fatal-style
-          fi
+      - name: Custom lint
+        run: dart run custom_lint
+        
       - name: Check formatting
         run: dart format . --set-exit-if-changed
 
diff --git a/example/lib/main.dart b/example/lib/main.dart
index 0f8e3d7..da7d074 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -10,7 +10,7 @@ void main() {
 }
 
 /// Example App main page
-// ignore: prefer-match-file-name
+// ignore: prefer_match_file_name
 class App extends StatefulWidget {
   /// Example app constructor
   const App({super.key});
diff --git a/lib/languagetool_textfield.dart b/lib/languagetool_textfield.dart
index 780083a..6379dc5 100644
--- a/lib/languagetool_textfield.dart
+++ b/lib/languagetool_textfield.dart
@@ -1,20 +1,20 @@
 library languagetool_textfield;
 
-export 'client/language_tool_client.dart';
-export 'core/controllers/language_tool_controller.dart';
-export 'core/enums/delay_type.dart';
-export 'core/model/category.dart';
-export 'core/model/language_tool_raw.dart';
-export 'core/model/match.dart';
-export 'core/model/replacement.dart';
-export 'core/model/rule.dart';
-export 'domain/highlight_style.dart';
-export 'domain/language_check_service.dart';
-export 'domain/mistake.dart';
-export 'domain/writing_mistake.dart';
-export 'implementations/debounce_lang_tool_service.dart';
-export 'implementations/lang_tool_service.dart';
-export 'implementations/throttling_lang_tool_service.dart';
-export 'presentation/language_tool_text_field.dart';
-export 'utils/mistake_popup.dart';
-export 'utils/popup_overlay_renderer.dart';
+export 'src/client/language_tool_client.dart';
+export 'src/core/controllers/language_tool_controller.dart';
+export 'src/core/enums/delay_type.dart';
+export 'src/core/model/category.dart';
+export 'src/core/model/language_tool_raw.dart';
+export 'src/core/model/match.dart';
+export 'src/core/model/replacement.dart';
+export 'src/core/model/rule.dart';
+export 'src/domain/highlight_style.dart';
+export 'src/domain/language_check_service.dart';
+export 'src/domain/mistake.dart';
+export 'src/domain/writing_mistake.dart';
+export 'src/implementations/debounce_lang_tool_service.dart';
+export 'src/implementations/lang_tool_service.dart';
+export 'src/implementations/throttling_lang_tool_service.dart';
+export 'src/presentation/language_tool_text_field.dart';
+export 'src/utils/mistake_popup.dart';
+export 'src/utils/popup_overlay_renderer.dart';
diff --git a/lib/client/language_tool_client.dart b/lib/src/client/language_tool_client.dart
similarity index 92%
rename from lib/client/language_tool_client.dart
rename to lib/src/client/language_tool_client.dart
index 48e70a9..af62e3a 100644
--- a/lib/client/language_tool_client.dart
+++ b/lib/src/client/language_tool_client.dart
@@ -1,8 +1,8 @@
 import 'dart:convert';
 
 import 'package:http/http.dart' as http;
-import 'package:languagetool_textfield/core/model/language_tool_raw.dart';
-import 'package:languagetool_textfield/domain/writing_mistake.dart';
+import 'package:languagetool_textfield/src/core/model/language_tool_raw.dart';
+import 'package:languagetool_textfield/src/domain/writing_mistake.dart';
 
 /// Class to interact with the LanguageTool API.
 ///
diff --git a/lib/core/controllers/language_tool_controller.dart b/lib/src/core/controllers/language_tool_controller.dart
similarity index 93%
rename from lib/core/controllers/language_tool_controller.dart
rename to lib/src/core/controllers/language_tool_controller.dart
index cd1bb8d..1aa9bed 100644
--- a/lib/core/controllers/language_tool_controller.dart
+++ b/lib/src/core/controllers/language_tool_controller.dart
@@ -3,18 +3,18 @@ import 'dart:math';
 import 'package:collection/collection.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
-import 'package:languagetool_textfield/client/language_tool_client.dart';
-import 'package:languagetool_textfield/core/enums/delay_type.dart';
-import 'package:languagetool_textfield/core/enums/mistake_type.dart';
-import 'package:languagetool_textfield/domain/highlight_style.dart';
-import 'package:languagetool_textfield/domain/language_check_service.dart';
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/implementations/debounce_lang_tool_service.dart';
-import 'package:languagetool_textfield/implementations/lang_tool_service.dart';
-import 'package:languagetool_textfield/implementations/throttling_lang_tool_service.dart';
-import 'package:languagetool_textfield/utils/closed_range.dart';
-import 'package:languagetool_textfield/utils/keep_latest_response_service.dart';
-import 'package:languagetool_textfield/utils/mistake_popup.dart';
+import 'package:languagetool_textfield/src/client/language_tool_client.dart';
+import 'package:languagetool_textfield/src/core/enums/delay_type.dart';
+import 'package:languagetool_textfield/src/core/enums/mistake_type.dart';
+import 'package:languagetool_textfield/src/domain/highlight_style.dart';
+import 'package:languagetool_textfield/src/domain/language_check_service.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/implementations/debounce_lang_tool_service.dart';
+import 'package:languagetool_textfield/src/implementations/lang_tool_service.dart';
+import 'package:languagetool_textfield/src/implementations/throttling_lang_tool_service.dart';
+import 'package:languagetool_textfield/src/utils/closed_range.dart';
+import 'package:languagetool_textfield/src/utils/keep_latest_response_service.dart';
+import 'package:languagetool_textfield/src/utils/mistake_popup.dart';
 
 /// A TextEditingController with overrides buildTextSpan for building
 /// marked TextSpans with tap recognizer
diff --git a/lib/core/enums/delay_type.dart b/lib/src/core/enums/delay_type.dart
similarity index 100%
rename from lib/core/enums/delay_type.dart
rename to lib/src/core/enums/delay_type.dart
diff --git a/lib/core/enums/mistake_type.dart b/lib/src/core/enums/mistake_type.dart
similarity index 100%
rename from lib/core/enums/mistake_type.dart
rename to lib/src/core/enums/mistake_type.dart
diff --git a/lib/core/langtool_images.dart b/lib/src/core/langtool_images.dart
similarity index 100%
rename from lib/core/langtool_images.dart
rename to lib/src/core/langtool_images.dart
diff --git a/lib/core/model/category.dart b/lib/src/core/model/category.dart
similarity index 100%
rename from lib/core/model/category.dart
rename to lib/src/core/model/category.dart
diff --git a/lib/core/model/language_tool_raw.dart b/lib/src/core/model/language_tool_raw.dart
similarity index 100%
rename from lib/core/model/language_tool_raw.dart
rename to lib/src/core/model/language_tool_raw.dart
diff --git a/lib/core/model/match.dart b/lib/src/core/model/match.dart
similarity index 92%
rename from lib/core/model/match.dart
rename to lib/src/core/model/match.dart
index 5af21bf..1b905f3 100644
--- a/lib/core/model/match.dart
+++ b/lib/src/core/model/match.dart
@@ -1,5 +1,5 @@
-import 'package:languagetool_textfield/core/model/replacement.dart';
-import 'package:languagetool_textfield/core/model/rule.dart';
+import 'package:languagetool_textfield/src/core/model/replacement.dart';
+import 'package:languagetool_textfield/src/core/model/rule.dart';
 
 /// Object that stores information about matched mistakes.
 class Match {
diff --git a/lib/core/model/replacement.dart b/lib/src/core/model/replacement.dart
similarity index 100%
rename from lib/core/model/replacement.dart
rename to lib/src/core/model/replacement.dart
diff --git a/lib/core/model/rule.dart b/lib/src/core/model/rule.dart
similarity index 88%
rename from lib/core/model/rule.dart
rename to lib/src/core/model/rule.dart
index 7a4bdd5..785b5d9 100644
--- a/lib/core/model/rule.dart
+++ b/lib/src/core/model/rule.dart
@@ -1,5 +1,5 @@
-import 'package:languagetool_textfield/core/enums/mistake_type.dart';
-import 'package:languagetool_textfield/core/model/category.dart';
+import 'package:languagetool_textfield/src/core/enums/mistake_type.dart';
+import 'package:languagetool_textfield/src/core/model/category.dart';
 
 /// Object that stores information about the rule (description, type, etc).
 class Rule {
diff --git a/lib/domain/highlight_style.dart b/lib/src/domain/highlight_style.dart
similarity index 100%
rename from lib/domain/highlight_style.dart
rename to lib/src/domain/highlight_style.dart
diff --git a/lib/domain/language_check_service.dart b/lib/src/domain/language_check_service.dart
similarity index 78%
rename from lib/domain/language_check_service.dart
rename to lib/src/domain/language_check_service.dart
index 2cac080..6bb796c 100644
--- a/lib/domain/language_check_service.dart
+++ b/lib/src/domain/language_check_service.dart
@@ -1,5 +1,5 @@
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/utils/result.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/utils/result.dart';
 
 /// A base language check service.
 abstract class LanguageCheckService {
diff --git a/lib/domain/mistake.dart b/lib/src/domain/mistake.dart
similarity index 94%
rename from lib/domain/mistake.dart
rename to lib/src/domain/mistake.dart
index 7719e03..d54746f 100644
--- a/lib/domain/mistake.dart
+++ b/lib/src/domain/mistake.dart
@@ -1,4 +1,4 @@
-import 'package:languagetool_textfield/core/enums/mistake_type.dart';
+import 'package:languagetool_textfield/src/core/enums/mistake_type.dart';
 
 /// A data model class that stores information about a single writing mistake.
 class Mistake {
diff --git a/lib/domain/typedefs.dart b/lib/src/domain/typedefs.dart
similarity index 67%
rename from lib/domain/typedefs.dart
rename to lib/src/domain/typedefs.dart
index 598bbdd..de210f9 100644
--- a/lib/domain/typedefs.dart
+++ b/lib/src/domain/typedefs.dart
@@ -1,7 +1,7 @@
 import 'package:flutter/widgets.dart';
-import 'package:languagetool_textfield/core/controllers/language_tool_controller.dart';
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/utils/popup_overlay_renderer.dart';
+import 'package:languagetool_textfield/src/core/controllers/language_tool_controller.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/utils/popup_overlay_renderer.dart';
 
 /// Callback used to build popup body
 typedef MistakeBuilderCallback = Widget Function({
diff --git a/lib/domain/writing_mistake.dart b/lib/src/domain/writing_mistake.dart
similarity index 92%
rename from lib/domain/writing_mistake.dart
rename to lib/src/domain/writing_mistake.dart
index fd55829..e9aaf67 100644
--- a/lib/domain/writing_mistake.dart
+++ b/lib/src/domain/writing_mistake.dart
@@ -1,4 +1,4 @@
-import 'package:languagetool_textfield/core/enums/mistake_type.dart';
+import 'package:languagetool_textfield/src/core/enums/mistake_type.dart';
 
 /// Object that stores information about a single writing mistake.
 class WritingMistake {
diff --git a/lib/implementations/debounce_lang_tool_service.dart b/lib/src/implementations/debounce_lang_tool_service.dart
similarity index 77%
rename from lib/implementations/debounce_lang_tool_service.dart
rename to lib/src/implementations/debounce_lang_tool_service.dart
index ec03d37..e7fc013 100644
--- a/lib/implementations/debounce_lang_tool_service.dart
+++ b/lib/src/implementations/debounce_lang_tool_service.dart
@@ -1,6 +1,6 @@
-import 'package:languagetool_textfield/domain/language_check_service.dart';
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/utils/result.dart';
+import 'package:languagetool_textfield/src/domain/language_check_service.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/utils/result.dart';
 import 'package:throttling/throttling.dart';
 
 /// A language check service with debouncing.
@@ -21,6 +21,7 @@ class DebounceLangToolService extends LanguageCheckService {
   Future<Result<List<Mistake>>?> findMistakes(String text) async =>
       await debouncing.debounce(() => baseService.findMistakes(text));
 
+  // ignore: proper_super_calls
   @override
   Future<void> dispose() async {
     debouncing.close();
diff --git a/lib/implementations/lang_tool_service.dart b/lib/src/implementations/lang_tool_service.dart
similarity index 74%
rename from lib/implementations/lang_tool_service.dart
rename to lib/src/implementations/lang_tool_service.dart
index c71ce6a..9cd9e9c 100644
--- a/lib/implementations/lang_tool_service.dart
+++ b/lib/src/implementations/lang_tool_service.dart
@@ -1,8 +1,8 @@
-import 'package:languagetool_textfield/client/language_tool_client.dart';
-import 'package:languagetool_textfield/domain/language_check_service.dart';
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/domain/writing_mistake.dart';
-import 'package:languagetool_textfield/utils/result.dart';
+import 'package:languagetool_textfield/src/client/language_tool_client.dart';
+import 'package:languagetool_textfield/src/domain/language_check_service.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/domain/writing_mistake.dart';
+import 'package:languagetool_textfield/src/utils/result.dart';
 
 /// An implementation of language check service with language tool service.
 class LangToolService extends LanguageCheckService {
diff --git a/lib/implementations/throttling_lang_tool_service.dart b/lib/src/implementations/throttling_lang_tool_service.dart
similarity index 78%
rename from lib/implementations/throttling_lang_tool_service.dart
rename to lib/src/implementations/throttling_lang_tool_service.dart
index 5b851d0..dfa6868 100644
--- a/lib/implementations/throttling_lang_tool_service.dart
+++ b/lib/src/implementations/throttling_lang_tool_service.dart
@@ -1,6 +1,6 @@
-import 'package:languagetool_textfield/domain/language_check_service.dart';
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/utils/result.dart';
+import 'package:languagetool_textfield/src/domain/language_check_service.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/utils/result.dart';
 import 'package:throttling/throttling.dart';
 
 /// A language check service with debouncing.
@@ -22,6 +22,7 @@ class ThrottlingLangToolService extends LanguageCheckService {
   Future<Result<List<Mistake>>?> findMistakes(String text) async =>
       throttling.throttle(() => baseService.findMistakes(text));
 
+  // ignore: proper_super_calls
   @override
   Future<void> dispose() async {
     throttling.close();
diff --git a/lib/presentation/language_tool_text_field.dart b/lib/src/presentation/language_tool_text_field.dart
similarity index 93%
rename from lib/presentation/language_tool_text_field.dart
rename to lib/src/presentation/language_tool_text_field.dart
index 78c7b27..9fce27b 100644
--- a/lib/presentation/language_tool_text_field.dart
+++ b/lib/src/presentation/language_tool_text_field.dart
@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
-import 'package:languagetool_textfield/core/controllers/language_tool_controller.dart';
-import 'package:languagetool_textfield/utils/mistake_popup.dart';
-import 'package:languagetool_textfield/utils/popup_overlay_renderer.dart';
+import 'package:languagetool_textfield/src/core/controllers/language_tool_controller.dart';
+import 'package:languagetool_textfield/src/utils/mistake_popup.dart';
+import 'package:languagetool_textfield/src/utils/popup_overlay_renderer.dart';
 
 /// A TextField widget that checks the grammar using the given
 /// [LanguageToolController]
diff --git a/lib/utils/closed_range.dart b/lib/src/utils/closed_range.dart
similarity index 100%
rename from lib/utils/closed_range.dart
rename to lib/src/utils/closed_range.dart
diff --git a/lib/utils/extensions/string_extension.dart b/lib/src/utils/extensions/string_extension.dart
similarity index 100%
rename from lib/utils/extensions/string_extension.dart
rename to lib/src/utils/extensions/string_extension.dart
diff --git a/lib/utils/keep_latest_response_service.dart b/lib/src/utils/keep_latest_response_service.dart
similarity index 100%
rename from lib/utils/keep_latest_response_service.dart
rename to lib/src/utils/keep_latest_response_service.dart
diff --git a/lib/utils/mistake_popup.dart b/lib/src/utils/mistake_popup.dart
similarity index 95%
rename from lib/utils/mistake_popup.dart
rename to lib/src/utils/mistake_popup.dart
index f36a074..fff7e3c 100644
--- a/lib/utils/mistake_popup.dart
+++ b/lib/src/utils/mistake_popup.dart
@@ -2,12 +2,12 @@ import 'dart:math';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:languagetool_textfield/core/controllers/language_tool_controller.dart';
-import 'package:languagetool_textfield/core/langtool_images.dart';
-import 'package:languagetool_textfield/domain/mistake.dart';
-import 'package:languagetool_textfield/domain/typedefs.dart';
-import 'package:languagetool_textfield/utils/extensions/string_extension.dart';
-import 'package:languagetool_textfield/utils/popup_overlay_renderer.dart';
+import 'package:languagetool_textfield/src/core/controllers/language_tool_controller.dart';
+import 'package:languagetool_textfield/src/core/langtool_images.dart';
+import 'package:languagetool_textfield/src/domain/mistake.dart';
+import 'package:languagetool_textfield/src/domain/typedefs.dart';
+import 'package:languagetool_textfield/src/utils/extensions/string_extension.dart';
+import 'package:languagetool_textfield/src/utils/popup_overlay_renderer.dart';
 
 /// Builder class that uses specified [popupRenderer] and [mistakeBuilder]
 /// to create mistake popup
diff --git a/lib/utils/popup_overlay_renderer.dart b/lib/src/utils/popup_overlay_renderer.dart
similarity index 100%
rename from lib/utils/popup_overlay_renderer.dart
rename to lib/src/utils/popup_overlay_renderer.dart
diff --git a/lib/utils/result.dart b/lib/src/utils/result.dart
similarity index 100%
rename from lib/utils/result.dart
rename to lib/src/utils/result.dart
diff --git a/pubspec.yaml b/pubspec.yaml
index ed96e8a..d42d62d 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -19,7 +19,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  solid_lints: ^0.0.14
+  solid_lints: ^0.1.2
 
 flutter:
   uses-material-design: true