diff --git a/tests/unit/test_client.py b/tests/unit/test_client.py
index 27da2ab..36e25ad 100644
--- a/tests/unit/test_client.py
+++ b/tests/unit/test_client.py
@@ -183,7 +183,7 @@ def test_check_and_refresh_token_invalid_format(self, mock_get_tr_env, mock_auth
 
     @patch("kis_agent.core.client.auth")
     @patch("kis_agent.core.client.getTREnv")
-    @patch("requests.request")
+    @patch("httpx.request")
     def test_make_request_success(self, mock_request, mock_get_tr_env, mock_auth):
         """API 요청 성공"""
         mock_auth.return_value = {
@@ -221,7 +221,7 @@ def test_make_request_success(self, mock_request, mock_get_tr_env, mock_auth):
 
     @patch("kis_agent.core.client.auth")
     @patch("kis_agent.core.client.getTREnv")
-    @patch("requests.request")
+    @patch("httpx.request")
     def test_make_request_json_decode_error(
         self, mock_request, mock_get_tr_env, mock_auth
     ):
@@ -259,7 +259,7 @@ def test_make_request_json_decode_error(
 
     @patch("kis_agent.core.client.auth")
     @patch("kis_agent.core.client.getTREnv")
-    @patch("requests.request")
+    @patch("httpx.request")
     def test_make_request_no_rt_cd(self, mock_request, mock_get_tr_env, mock_auth):
         """rt_cd 없는 응답 처리"""
         mock_auth.return_value = {
@@ -289,7 +289,7 @@ def test_make_request_no_rt_cd(self, mock_request, mock_get_tr_env, mock_auth):
 
     @patch("kis_agent.core.client.auth")
     @patch("kis_agent.core.client.getTREnv")
-    @patch("requests.request")
+    @patch("httpx.request")
     def test_make_request_api_error(self, mock_request, mock_get_tr_env, mock_auth):
         """API 오류 응답 처리"""
         mock_auth.return_value = {
@@ -323,7 +323,7 @@ def test_make_request_api_error(self, mock_request, mock_get_tr_env, mock_auth):
 
     @patch("kis_agent.core.client.auth")
     @patch("kis_agent.core.client.getTREnv")
-    @patch("requests.request")
+    @patch("httpx.request")
     def test_make_request_http_error_with_retry(
         self, mock_request, mock_get_tr_env, mock_auth
     ):
@@ -363,7 +363,7 @@ def test_make_request_http_error_with_retry(
 
     @patch("kis_agent.core.client.auth")
     @patch("kis_agent.core.client.getTREnv")
-    @patch("requests.request")
+    @patch("httpx.request")
     def test_make_request_exception_handling(
         self, mock_request, mock_get_tr_env, mock_auth
     ):
diff --git a/tests/unit/test_client_comprehensive.py b/tests/unit/test_client_comprehensive.py
index cee2909..88f8714 100644
--- a/tests/unit/test_client_comprehensive.py
+++ b/tests/unit/test_client_comprehensive.py
@@ -354,7 +354,7 @@ def test_make_request_success(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {
@@ -392,7 +392,7 @@ def test_make_request_json_decode_error(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     # json.JSONDecodeError를 발생시켜야 함
@@ -426,7 +426,7 @@ def test_make_request_no_rt_cd(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {"data": "no_rt_cd"}
@@ -456,7 +456,7 @@ def test_make_request_api_error(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {
@@ -508,7 +508,7 @@ def side_effect(*args, **kwargs):
                         }
                     return mock_response
 
-                with patch("requests.request", side_effect=side_effect):
+                with patch("httpx.request", side_effect=side_effect):
                     client = client_module.KISClient(
                         enable_rate_limiter=False, verbose=False
                     )
@@ -552,7 +552,7 @@ def side_effect(*args, **kwargs):
                         }
                     return mock_response
 
-                with patch("requests.request", side_effect=side_effect), patch(
+                with patch("httpx.request", side_effect=side_effect), patch(
                     "time.sleep"
                 ):  # 대기 시간 건너뛰기
                     client = client_module.KISClient(
@@ -578,7 +578,7 @@ def test_make_request_http_error(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 500
                     mock_response.json.return_value = {
@@ -612,7 +612,7 @@ def test_make_request_request_exception(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_request.side_effect = requests.exceptions.ConnectionError(
                         "Connection failed"
                     )
@@ -640,7 +640,7 @@ def test_make_request_post_method(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {"rt_cd": "0"}
@@ -672,7 +672,7 @@ def test_make_request_verbose_logging(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {"rt_cd": "0", "output": {}}
@@ -809,7 +809,7 @@ def test_get_kospi200_index(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {
@@ -982,7 +982,7 @@ def test_rate_limiter_report_success(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {"rt_cd": "0"}
@@ -1016,7 +1016,7 @@ def test_rate_limiter_report_error(self):
                 mock_tr_env.my_token = "Bearer token"
                 mock_get_tr_env.return_value = mock_tr_env
 
-                with patch("requests.request") as mock_request:
+                with patch("httpx.request") as mock_request:
                     mock_response = MagicMock()
                     mock_response.status_code = 200
                     mock_response.json.return_value = {