diff --git a/trustgraph-base/trustgraph/api/flow.py b/trustgraph-base/trustgraph/api/flow.py
index 681696c3..74b7a117 100644
--- a/trustgraph-base/trustgraph/api/flow.py
+++ b/trustgraph-base/trustgraph/api/flow.py
@@ -132,16 +132,24 @@ class FlowInstance:
             input
         )["response"]
 
-    def agent(self, question, user="trustgraph", state="", group=None, history=None):
+    def agent(self, question, user="trustgraph", state=None, group=None, history=None):
 
         # The input consists of a question and optional context
         input = {
             "question": question,
             "user": user,
-            "state": state,
-            "group": group or [],
-            "history": history or []
         }
+        
+        # Only include state if it has a value
+        if state is not None:
+            input["state"] = state
+            
+        # Only include group if it has a value
+        if group is not None:
+            input["group"] = group
+            
+        # Always include history (empty list if None)
+        input["history"] = history or []
 
         return self.request(
             "service/agent",
diff --git a/trustgraph-base/trustgraph/messaging/translators/agent.py b/trustgraph-base/trustgraph/messaging/translators/agent.py
index 4408fea3..d6ce8bbb 100644
--- a/trustgraph-base/trustgraph/messaging/translators/agent.py
+++ b/trustgraph-base/trustgraph/messaging/translators/agent.py
@@ -9,8 +9,8 @@ class AgentRequestTranslator(MessageTranslator):
     def to_pulsar(self, data: Dict[str, Any]) -> AgentRequest:
         return AgentRequest(
             question=data["question"],
-            state=data.get("state", ""),
-            group=data.get("group", []),
+            state=data.get("state", None),
+            group=data.get("group", None),
             history=data.get("history", []),
             user=data.get("user", "trustgraph")
         )
diff --git a/trustgraph-cli/trustgraph/cli/invoke_agent.py b/trustgraph-cli/trustgraph/cli/invoke_agent.py
index c5ca93e4..4c853dee 100644
--- a/trustgraph-cli/trustgraph/cli/invoke_agent.py
+++ b/trustgraph-cli/trustgraph/cli/invoke_agent.py
@@ -29,7 +29,7 @@ def output(text, prefix="> ", width=78):
 
 async def question(
         url, question, flow_id, user, collection,
-        plan=None, state=None, verbose=False
+        plan=None, state=None, group=None, verbose=False
 ):
 
     if not url.endswith("/"):
@@ -55,19 +55,24 @@ async def question(
 
     async with connect(url) as ws:
 
-        req = json.dumps({
+        req = {
             "id": mid,
             "service": "agent",
             "flow": flow_id,
             "request": {
                 "question": question,
                 "user": user,
-                "state": state or "",
-                "group": [],
                 "history": []
             }
+        }
+        
+        # Only add optional fields if they have values
+        if state is not None:
+            req["request"]["state"] = state
+        if group is not None:
+            req["request"]["group"] = group
             
-        })
+        req = json.dumps(req)
 
         await ws.send(req)
 
@@ -144,6 +149,12 @@ def main():
         help=f'Agent initial state (default: unspecified)'
     )
 
+    parser.add_argument(
+        '-g', '--group',
+        nargs='+',
+        help='Agent tool groups (can specify multiple)'
+    )
+
     parser.add_argument(
         '-v', '--verbose',
         action="store_true",
@@ -163,6 +174,7 @@ def main():
                 collection = args.collection,
                 plan = args.plan,
                 state = args.state,
+                group = args.group,
                 verbose = args.verbose,
             )
         )