fix: add current user message to input_list and fix langgraph model in sync tutorials

- 010_multiturn/acp.py: append current user message to input_list before Runner.run();
  without this, Runner.run() was called with an empty list (history excludes current
  turn), causing an OpenAI API error for missing input
- 020_streaming/acp.py: same fix for Runner.run_streamed(); also add `return` after
  yielding the no-API-key error message so the generator does not fall through
- 030_langgraph/graph.py: change MODEL_NAME from "gpt-5" (invalid) to "gpt-4o";
  remove unsupported `reasoning` kwarg from ChatOpenAI constructor

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: scale-ballen

examples/tutorials/00_sync/010_multiturn/project/acp.py

@@ -88,6 +88,9 @@ async def handle_message_send(
     # Convert task messages to OpenAI Agents SDK format
     input_list = convert_task_messages_to_oai_agents_inputs(task_messages)
 
+    # Append the current user message (not yet persisted in task history)
+    input_list.append({"role": "user", "content": params.content.content})
+
     # Run the agent
     result = await Runner.run(test_agent, input_list, run_config=run_config)
 

examples/tutorials/00_sync/020_streaming/project/acp.py

@@ -56,6 +56,7 @@ async def handle_message_send(
                 content="Hey, sorry I'm unable to respond to your message because you're running this example without an OpenAI API key. Please set the OPENAI_API_KEY environment variable to run this example. Do this by either by adding a .env file to the project/ directory or by setting the environment variable in your terminal.",
             ),
         )
+        return
 
     # Try to retrieve the state. If it doesn't exist, create it.
     task_state = await adk.state.get_by_task_and_agent(task_id=params.task.id, agent_id=params.agent.id)
@@ -86,6 +87,9 @@ async def handle_message_send(
     # Convert task messages to OpenAI Agents SDK format
     input_list = convert_task_messages_to_oai_agents_inputs(task_messages)
 
+    # Append the current user message (not yet persisted in task history)
+    input_list.append({"role": "user", "content": params.content.content})
+
     # Run the agent and stream the events
     result = Runner.run_streamed(test_agent, input_list, run_config=run_config)
 

examples/tutorials/00_sync/030_langgraph/project/graph.py

@@ -20,7 +20,7 @@
 from project.tools import TOOLS
 from agentex.lib.adk import create_checkpointer
 
-MODEL_NAME = "gpt-5"
+MODEL_NAME = "gpt-4o"
 SYSTEM_PROMPT = """You are a helpful AI assistant with access to tools.
 
 Current date and time: {timestamp}
@@ -46,7 +46,6 @@ async def create_graph():
     """
     llm = ChatOpenAI(
         model=MODEL_NAME,
-        reasoning={"effort": "high", "summary": "auto"},
     )
     llm_with_tools = llm.bind_tools(TOOLS)