diff --git a/autogpt/token_counter.py b/autogpt/token_counter.py
index c1239722..a85a54be 100644
--- a/autogpt/token_counter.py
+++ b/autogpt/token_counter.py
@@ -27,7 +27,7 @@ def count_message_tokens(
         logger.warn("Warning: model not found. Using cl100k_base encoding.")
         encoding = tiktoken.get_encoding("cl100k_base")
     if model == "gpt-3.5-turbo":
-        # !Node: gpt-3.5-turbo may change over time.
+        # !Note: gpt-3.5-turbo may change over time.
         # Returning num tokens assuming gpt-3.5-turbo-0301.")
         return count_message_tokens(messages, model="gpt-3.5-turbo-0301")
     elif model == "gpt-4":
diff --git a/tests/test_token_counter.py b/tests/test_token_counter.py
new file mode 100644
index 00000000..d13f2ae0
--- /dev/null
+++ b/tests/test_token_counter.py
@@ -0,0 +1,61 @@
+import unittest
+import tests.context
+
+from scripts.token_counter import count_message_tokens, count_string_tokens
+
+class TestTokenCounter(unittest.TestCase):
+
+    def test_count_message_tokens(self):
+        messages = [
+            {"role": "user", "content": "Hello"},
+            {"role": "assistant", "content": "Hi there!"}
+        ]
+        self.assertEqual(count_message_tokens(messages), 17)
+
+    def test_count_message_tokens_with_name(self):
+        messages = [
+            {"role": "user", "content": "Hello", "name": "John"},
+            {"role": "assistant", "content": "Hi there!"}
+        ]
+        self.assertEqual(count_message_tokens(messages), 17)
+
+    def test_count_message_tokens_empty_input(self):
+        self.assertEqual(count_message_tokens([]), 3)
+
+    def test_count_message_tokens_invalid_model(self):
+        messages = [
+            {"role": "user", "content": "Hello"},
+            {"role": "assistant", "content": "Hi there!"}
+        ]
+        with self.assertRaises(KeyError):
+            count_message_tokens(messages, model="invalid_model")
+
+    def test_count_message_tokens_gpt_4(self):
+        messages = [
+            {"role": "user", "content": "Hello"},
+            {"role": "assistant", "content": "Hi there!"}
+        ]
+        self.assertEqual(count_message_tokens(messages, model="gpt-4-0314"), 15)
+
+    def test_count_string_tokens(self):
+        string = "Hello, world!"
+        self.assertEqual(count_string_tokens(string, model_name="gpt-3.5-turbo-0301"), 4)
+
+    def test_count_string_tokens_empty_input(self):
+        self.assertEqual(count_string_tokens("", model_name="gpt-3.5-turbo-0301"), 0)
+
+    def test_count_message_tokens_invalid_model(self):
+        messages = [
+            {"role": "user", "content": "Hello"},
+            {"role": "assistant", "content": "Hi there!"}
+        ]
+        with self.assertRaises(NotImplementedError):
+            count_message_tokens(messages, model="invalid_model")
+
+    def test_count_string_tokens_gpt_4(self):
+        string = "Hello, world!"
+        self.assertEqual(count_string_tokens(string, model_name="gpt-4-0314"), 4)
+
+
+if __name__ == '__main__':
+    unittest.main()