diff --git a/bin/jadb.dart b/bin/jadb.dart
index 8b041d7..3e17cb0 100644
--- a/bin/jadb.dart
+++ b/bin/jadb.dart
@@ -15,7 +15,7 @@ ArgParser argParser() {
     help:
         'Path to the SQLite library. This is used to load the SQLite library dynamically.',
     valueHelp: 'PATH',
-    mandatory: true,
+    defaultsTo: Platform.environment['LIBSQLITE_PATH'],
   );
   return parser;
 }
@@ -24,7 +24,7 @@ Future<void> main(List<String> arguments) async {
   final parser = argParser();
   final ArgResults args = parser.parse(arguments);
 
-  if (!args.wasParsed('libsqlite')) {
+  if (args.option('libsqlite') == null) {
     print(parser.usage);
     exit(64);
   }
diff --git a/bin/test_tool.dart b/bin/test_tool.dart
new file mode 100644
index 0000000..b3fcb5c
--- /dev/null
+++ b/bin/test_tool.dart
@@ -0,0 +1,50 @@
+import 'dart:ffi';
+import 'dart:io';
+
+import 'package:args/args.dart';
+import 'package:jadb/search.dart';
+import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+import 'package:sqlite3/open.dart';
+
+ArgParser argParser() {
+  final parser = ArgParser();
+
+  parser.addOption(
+    'libsqlite',
+    help:
+        'Path to the SQLite library. This is used to load the SQLite library dynamically.',
+    valueHelp: 'PATH',
+    defaultsTo: Platform.environment['LIBSQLITE_PATH'],
+  );
+
+  parser.addOption(
+    'jadb',
+    help: 'Path to the SQLite database file.',
+    valueHelp: 'PATH',
+    mandatory: true,
+  );
+
+  return parser;
+}
+
+Future<void> main(List<String> arguments) async {
+  final parser = argParser();
+  final ArgResults args = parser.parse(arguments);
+
+  if (args.option('libsqlite') == null || !args.wasParsed('jadb')) {
+    print(parser.usage);
+    exit(64);
+  }
+
+  final db = await createDatabaseFactoryFfi(ffiInit: () {
+    open.overrideForAll(() => DynamicLibrary.open(args.option('libsqlite')!));
+  }).openDatabase(Directory.current.uri.resolve(args.option('jadb')!).path);
+
+  final result = await JaDBConnection(db).searchKanji('漢');
+
+  if (result == null) {
+    print("No such kanji");
+  } else {
+    print(result.toJson().toString());
+  }
+}
diff --git a/flake.nix b/flake.nix
index 07eea49..97e33dc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -65,6 +65,9 @@
           sqlint
           sqlfluff
         ];
+        env = {
+          LIBSQLITE_PATH = "${pkgs.sqlite.out}/lib/libsqlite3.so";
+        };
       };
     });
 
diff --git a/pubspec.yaml b/pubspec.yaml
index c031263..f74e069 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -19,6 +19,7 @@ dev_dependencies:
 
 executables:
   jadb: jadb
+  test: test_tool
 
 topics:
   - database