diff --git a/tests/DevApps/SidecarAdapter/python/MicrosoftIdentityWebSidecarClient.py b/tests/DevApps/SidecarAdapter/python/MicrosoftIdentityWebSidecarClient.py
index 9a6acd188..83da2a94e 100644
--- a/tests/DevApps/SidecarAdapter/python/MicrosoftIdentityWebSidecarClient.py
+++ b/tests/DevApps/SidecarAdapter/python/MicrosoftIdentityWebSidecarClient.py
@@ -145,9 +145,10 @@ def get_authorization_header(
         *,
         agent_identity: Optional[str] = None,
         agent_username: Optional[str] = None,
+        agent_user_id: Optional[str] = None,
         options: Optional[SidecarCallOptions] = None,
     ) -> AuthorizationHeaderResult:
-        params = self._build_query_parameters(agent_identity, agent_username, options)
+        params = self._build_query_parameters(agent_identity, agent_username, agent_user_id, options)
         response_data = self._send_json(
             method="GET",
             path=f"AuthorizationHeader/{api_name}",
@@ -162,9 +163,10 @@ def get_authorization_header_unauthenticated(
         *,
         agent_identity: Optional[str] = None,
         agent_username: Optional[str] = None,
+        agent_user_id: Optional[str] = None,
         options: Optional[SidecarCallOptions] = None,
     ) -> AuthorizationHeaderResult:
-        params = self._build_query_parameters(agent_identity, agent_username, options)
+        params = self._build_query_parameters(agent_identity, agent_username, agent_user_id, options)
         response_data = self._send_json(
             method="GET",
             path=f"AuthorizationHeaderUnauthenticated/{api_name}",
@@ -179,10 +181,11 @@ def invoke_downstream_api(
         *,
         agent_identity: Optional[str] = None,
         agent_username: Optional[str] = None,
+        agent_user_id: Optional[str] = None,
         options: Optional[SidecarCallOptions] = None,
         json_body: Any = None,
     ) -> DownstreamApiResult:
-        params = self._build_query_parameters(agent_identity, agent_username, options)
+        params = self._build_query_parameters(agent_identity, agent_username, agent_user_id, options)
         response_data = self._send_json(
             method="POST",
             path=f"DownstreamApi/{api_name}",
@@ -198,10 +201,11 @@ def invoke_downstream_api_unauthenticated(
         *,
         agent_identity: Optional[str] = None,
         agent_username: Optional[str] = None,
+        agent_user_id: Optional[str] = None,
         options: Optional[SidecarCallOptions] = None,
         json_body: Any = None,
     ) -> DownstreamApiResult:
-        params = self._build_query_parameters(agent_identity, agent_username, options)
+        params = self._build_query_parameters(agent_identity, agent_username, agent_user_id, options)
         response_data = self._send_json(
             method="POST",
             path=f"DownstreamApiUnauthenticated/{api_name}",
@@ -226,6 +230,7 @@ def _build_query_parameters(
         self,
         agent_identity: Optional[str],
         agent_username: Optional[str],
+        agent_user_id: Optional[str],
         options: Optional[SidecarCallOptions],
     ) -> Dict[str, Any]:
         params: Dict[str, Any] = {}
@@ -233,6 +238,8 @@ def _build_query_parameters(
             params["AgentIdentity"] = agent_identity
         if agent_username:
             params["AgentUsername"] = agent_username
+        if agent_user_id:
+            params["AgentUserId"] = agent_user_id
 
         if options:
             if options.scopes:
diff --git a/tests/DevApps/SidecarAdapter/python/main.py b/tests/DevApps/SidecarAdapter/python/main.py
index eb6aaa6c8..786610f46 100644
--- a/tests/DevApps/SidecarAdapter/python/main.py
+++ b/tests/DevApps/SidecarAdapter/python/main.py
@@ -32,6 +32,10 @@ def parse_args() -> argparse.Namespace:
         "--agent-username",
         help="Optional AgentUsername query parameter for the sidecar call.",
     )
+    parser.add_argument(
+        "--agent-user-id",
+        help="Optional AgentUserId query parameter for the sidecar call.",
+    )
 
     subparsers = parser.add_subparsers(dest="command", required=True)
 
@@ -270,6 +274,7 @@ def main() -> None:
                     authorization_header,
                     agent_identity=args.agent_identity,
                     agent_username=args.agent_username,
+                    agent_user_id=args.agent_user_id,
                     options=options,
                 )
                 _print_json({"authorizationHeader": result.authorization_header})
@@ -278,6 +283,7 @@ def main() -> None:
                     args.api_name,
                     agent_identity=args.agent_identity,
                     agent_username=args.agent_username,
+                    agent_user_id=args.agent_user_id,
                     options=options,
                 )
                 _print_json({"authorizationHeader": result.authorization_header})
@@ -289,6 +295,7 @@ def main() -> None:
                     authorization_header,
                     agent_identity=args.agent_identity,
                     agent_username=args.agent_username,
+                    agent_user_id=args.agent_user_id,
                     options=options,
                     json_body=body,
                 )
@@ -303,6 +310,7 @@ def main() -> None:
                     args.api_name,
                     agent_identity=args.agent_identity,
                     agent_username=args.agent_username,
+                    agent_user_id=args.agent_user_id,
                     options=options,
                     json_body=body,
                 )