diff --git a/clearml_agent/backend_api/session/session.py b/clearml_agent/backend_api/session/session.py
index 27fc877..dbf8cf4 100644
--- a/clearml_agent/backend_api/session/session.py
+++ b/clearml_agent/backend_api/session/session.py
@@ -111,7 +111,8 @@ class Session(TokenManager):
         self._logger = logger
 
         self.__access_key = api_key or ENV_ACCESS_KEY.get(
-            default=(self.config.get("api.credentials.access_key", None) or self.default_key)
+            default=(self.config.get("api.credentials.access_key", None) or self.default_key),
+            value_cb=lambda key, value: logger.info("Using environment access key {}={}".format(key, value))
         )
         if not self.access_key:
             raise ValueError(
@@ -119,7 +120,8 @@ class Session(TokenManager):
             )
 
         self.__secret_key = secret_key or ENV_SECRET_KEY.get(
-            default=(self.config.get("api.credentials.secret_key", None) or self.default_secret)
+            default=(self.config.get("api.credentials.secret_key", None) or self.default_secret),
+            value_cb=lambda key, value: logger.info("Using environment secret key {}=********".format(key))
         )
         if not self.secret_key:
             raise ValueError(
diff --git a/clearml_agent/backend_config/entry.py b/clearml_agent/backend_config/entry.py
index 1107563..489d326 100644
--- a/clearml_agent/backend_config/entry.py
+++ b/clearml_agent/backend_config/entry.py
@@ -64,8 +64,8 @@ class Entry(object):
             converter = self.default_conversions().get(self.type, self.type)
         return converter(value)
 
-    def get_pair(self, default=NotSet, converter=None):
-        # type: (Any, Converter) -> Optional[Tuple[Text, Any]]
+    def get_pair(self, default=NotSet, converter=None, value_cb=None):
+        # type: (Any, Converter, Callable[[str, Any], None]) -> Optional[Tuple[Text, Any]]
         for key in self.keys:
             value = self._get(key)
             if value is NotSet:
@@ -75,13 +75,20 @@ class Entry(object):
             except Exception as ex:
                 self.error("invalid value {key}={value}: {ex}".format(**locals()))
                 break
+            # noinspection PyBroadException
+            try:
+                if value_cb:
+                    value_cb(key, value)
+            except Exception:
+                pass
             return key, value
+
         result = self.default if default is NotSet else default
         return self.key, result
 
-    def get(self, default=NotSet, converter=None):
-        # type: (Any, Converter) -> Optional[Any]
-        return self.get_pair(default=default, converter=converter)[1]
+    def get(self, default=NotSet, converter=None, value_cb=None):
+        # type: (Any, Converter, Callable[[str, Any], None]) -> Optional[Any]
+        return self.get_pair(default=default, converter=converter, value_cb=value_cb)[1]
 
     def set(self, value):
         # type: (Any, Any) -> (Text, Any)