diff --git a/tests/test_tokenizer.py b/tests/test_tokenizer.py
new file mode 100644
index 00000000..4440d737
--- /dev/null
+++ b/tests/test_tokenizer.py
@@ -0,0 +1,23 @@
+import unittest
+from autopr.utils.tokenizer import num_tokens_from_messages
+
+class TestTokenizer(unittest.TestCase):
+
+    def test_num_tokens_from_messages_chat_completions(self):
+        messages = [
+            {"role": "system", "content": "You are a helpful assistant."},
+            {"role": "user", "content": "What is the capital of France?"},
+            {"role": "assistant", "content": "The capital of France is Paris."}
+        ]
+
+        token_count = num_tokens_from_messages(messages)
+        self.assertTrue(token_count > 0, "Token count should be greater than 0")
+
+    def test_num_tokens_from_messages_ordinary_completions(self):
+        completion_text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit."
+
+        token_count = num_tokens_from_messages(completion_text)
+        self.assertTrue(token_count > 0, "Token count should be greater than 0")
+
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file