fix: empty a2a message (#2163)

* fix: build NewTask manually to allow empty messages

* lint: fix ruff warn

* refactor: add explicit AG2 prefix

Author: Lancetnik

autogen/a2a/agent_executor.py

@@ -3,11 +3,11 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from datetime import datetime, timezone
+from uuid import uuid4
 
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
-from a2a.types import TaskArtifactUpdateEvent, TaskState, TaskStatus, TaskStatusUpdateEvent
-from a2a.utils import new_task
+from a2a.types import Task, TaskArtifactUpdateEvent, TaskState, TaskStatus, TaskStatusUpdateEvent
 from a2a.utils.message import new_agent_text_message
 
 from autogen import ConversableAgent
@@ -33,8 +33,17 @@ async def execute(self, context: RequestContext, event_queue: EventQueue) -> Non
 
         task = context.current_task
         if not task:
-            task = new_task(context.message)
-            task.status.timestamp = datetime.now(timezone.utc).isoformat()
+            request = context.message
+            # build task object manually to allow empty messages
+            task = Task(
+                status=TaskStatus(
+                    state=TaskState.submitted,
+                    timestamp=datetime.now(timezone.utc).isoformat(),
+                ),
+                id=request.task_id or str(uuid4()),
+                context_id=request.context_id or str(uuid4()),
+                history=[request],
+            )
             # publish the task status submitted event
             await event_queue.enqueue_event(task)
 

autogen/a2a/utils.py

@@ -10,8 +10,9 @@
 
 from autogen.remote.protocol import RequestMessage, ResponseMessage
 
-CLIENT_TOOLS_KEY = "ag2_client_tools"
-CONTEXT_KEY = "ag2_context_update"
+AG2_METADATA_KEY_PREFIX = "ag2_"
+CLIENT_TOOLS_KEY = f"{AG2_METADATA_KEY_PREFIX}client_tools"
+CONTEXT_KEY = f"{AG2_METADATA_KEY_PREFIX}context_update"
 
 
 def request_message_to_a2a(

autogen/oai/client_utils.py

@@ -129,13 +129,10 @@ def merge_config_with_tools(config: dict[str, Any], client_config: dict[str, Any
     full_config = {**config, **client_config}
 
     # Add tools if tools contains something AND are not using deprecated functions
-    config_tools = config.get("tools", [])
-    client_tools = client_config.get("tools", [])
-
-    if config_tools or client_tools:
+    tools = config.get("tools", []) + client_config.get("tools", [])
+    if tools and "functions" not in full_config:
         # Don't add tools if functions parameter is present (deprecated API)
-        if "functions" not in full_config:
-            full_config["tools"] = config_tools + client_tools
+        full_config["tools"] = tools
 
     return full_config
 

test/a2a/chats/test_chat.py

@@ -44,6 +44,25 @@ async def test_simple_messaging(remote_agent: ConversableAgent, a2a_client: Http
     }
 
 
+@pytest.mark.asyncio()
+async def test_empty_message_send(remote_agent: ConversableAgent, a2a_client: HttpxClientFactory) -> None:
+    # arrange
+    remote_agent_mirror = A2aRemoteAgent(url="http://memory", name="remote-mirror", client=a2a_client)
+
+    with TestAgent(remote_agent, ["Hi, I am remote agent!"]):
+        # act
+        _, message = await remote_agent_mirror.a_generate_remote_reply([
+            {"content": ""},
+        ])
+
+    # assert
+    assert message == {
+        "content": "Hi, I am remote agent!",
+        "name": "remote",
+        "role": "assistant",
+    }
+
+
 @pytest.mark.asyncio()
 async def test_conversation(remote_agent: ConversableAgent, a2a_client: HttpxClientFactory) -> None:
     # arrange