diff --git a/src/py/mat3ra/api_client/utils/http.py b/src/py/mat3ra/api_client/utils/http.py
index 73b80de..c91de1e 100644
--- a/src/py/mat3ra/api_client/utils/http.py
+++ b/src/py/mat3ra/api_client/utils/http.py
@@ -2,6 +2,15 @@
 import urllib.parse
 
 
+def _extract_server_message(response: requests.Response) -> str:
+    """Extract human-readable message from a JSEND-formatted error response body."""
+    try:
+        body = response.json()
+        return body.get("data", {}).get("message") or body.get("message") or ""
+    except Exception:
+        return ""
+
+
 class BaseConnection(object):
     """
     Base connection class to inherit from. This class should not be instantiated directly.
@@ -32,7 +41,14 @@ def request(self, method, url, params=None, data=None, headers=None):
             params (dict): URL parameters to append to the URL.
         """
         self.response = self.session.request(method=method.lower(), url=url, params=params, data=data, headers=headers)
-        self.response.raise_for_status()
+        try:
+            self.response.raise_for_status()
+        except requests.HTTPError:
+            status_code = self.response.status_code
+            server_message = _extract_server_message(self.response)
+            detail = server_message or "HTTP Error"
+            message = f"Error {status_code}: {detail}."
+            raise requests.HTTPError(message, response=self.response) from None
 
     def get_response(self):
         """
diff --git a/tests/py/unit/test_httpBase.py b/tests/py/unit/test_httpBase.py
index be3a8dc..82c92ed 100644
--- a/tests/py/unit/test_httpBase.py
+++ b/tests/py/unit/test_httpBase.py
@@ -1,3 +1,4 @@
+import json
 from unittest import mock
 
 from mat3ra.api_client.utils.http import Connection
@@ -7,11 +8,10 @@
 API_VERSION_1 = "2018-10-1"
 API_VERSION_2 = "2018-10-2"
 HTTP_STATUS_UNAUTHORIZED = 401
-HTTP_REASON_UNAUTHORIZED = "Unauthorized"
+HTTP_STATUS_UNKNOWN = 418
 EMPTY_CONTENT = ""
-TEST_ENTITY_ID = "28FMvD5knJZZx452H"
-EMPTY_USERNAME = ""
-EMPTY_PASSWORD = ""
+SERVER_MESSAGE = "Custom server error message"
+SERVER_ERROR_RESPONSE = json.dumps({"message": SERVER_MESSAGE})
 
 
 class HTTPBaseUnitTest(EndpointBaseUnitTest):
@@ -36,8 +36,26 @@ def test_preamble_version(self):
 
     @mock.patch("requests.sessions.Session.request")
     def test_raise_http_error(self, mock_request):
-        mock_request.return_value = self.mock_response(EMPTY_CONTENT, HTTP_STATUS_UNAUTHORIZED,
-                                                       reason=HTTP_REASON_UNAUTHORIZED)
+        mock_request.return_value = self.mock_response(EMPTY_CONTENT, HTTP_STATUS_UNAUTHORIZED)
         with self.assertRaises(HTTPError):
             conn = Connection(self.host, self.port, version=API_VERSION_1, secure=True)
-            conn.request("POST", "login", data={"username": EMPTY_USERNAME, "password": EMPTY_PASSWORD})
+            conn.request("POST", "login")
+
+    @mock.patch("requests.sessions.Session.request")
+    def test_http_error_message_with_server_message(self, mock_request):
+        mock_request.return_value = self.mock_response(SERVER_ERROR_RESPONSE, HTTP_STATUS_UNAUTHORIZED)
+        with self.assertRaises(HTTPError) as ctx:
+            conn = Connection(self.host, self.port, version=API_VERSION_1, secure=True)
+            conn.request("POST", "login")
+        self.assertIn("Error 401", str(ctx.exception))
+        self.assertIn(SERVER_MESSAGE, str(ctx.exception))
+
+    @mock.patch("requests.sessions.Session.request")
+    def test_http_error_message_without_server_message(self, mock_request):
+        mock_request.return_value = self.mock_response(EMPTY_CONTENT, HTTP_STATUS_UNKNOWN)
+        with self.assertRaises(HTTPError) as ctx:
+            conn = Connection(self.host, self.port, version=API_VERSION_1, secure=True)
+            conn.request("GET", "materials")
+        self.assertIn("Error 418", str(ctx.exception))
+        self.assertIn("HTTP Error", str(ctx.exception))
+