Add user proxy docs. Make user proxy's default impl cancellable

python/packages/autogen-agentchat/src/autogen_agentchat/agents/_user_proxy_agent.py

@@ -2,6 +2,7 @@
 from inspect import iscoroutinefunction
 from typing import Awaitable, Callable, List, Optional, Sequence, Union, cast
 
+from aioconsole import ainput  # type: ignore
 from autogen_core import CancellationToken
 
 from ..base import Response
@@ -14,6 +15,15 @@
 InputFuncType = Union[SyncInputFunc, AsyncInputFunc]
 
 
+# TODO: ainput doesn't seem to play nicely with jupyter.
+#       No input window appears in this case.
+async def cancellable_input(prompt: str, cancellation_token: Optional[CancellationToken]) -> str:
+    task = asyncio.Task[str](asyncio.create_task(ainput(prompt)))  # type: ignore
+    if cancellation_token is not None:
+        cancellation_token.link_future(task)
+    return await task
+
+
 class UserProxyAgent(BaseChatAgent):
     """An agent that can represent a human user through an input function.
 
@@ -40,6 +50,63 @@ class UserProxyAgent(BaseChatAgent):
 
         See `Pause for User Input <https://microsoft.github.io/autogen/dev/user-guide/agentchat-user-guide/tutorial/teams.html#pause-for-user-input>`_ for more information.
 
+    Example:
+        Simple usage case::
+
+            import asyncio
+            from autogen_core import CancellationToken
+            from autogen_agentchat.agents import UserProxyAgent
+            from autogen_agentchat.messages import TextMessage
+
+
+            async def simple_user_agent():
+                agent = UserProxyAgent("user_proxy")
+                response = await asyncio.create_task(
+                    agent.on_messages(
+                        [TextMessage(content="What is your name? ", source="user")],
+                        cancellation_token=CancellationToken(),
+                    )
+                )
+                print(f"Your name is {response.chat_message.content}")
+
+    Example:
+        Cancellable usage case::
+
+            import asyncio
+            from typing import Any
+            from autogen_core import CancellationToken
+            from autogen_agentchat.agents import UserProxyAgent
+            from autogen_agentchat.messages import TextMessage
+
+
+            token = CancellationToken()
+            agent = UserProxyAgent("user_proxy")
+
+
+            async def timeout(delay: float):
+                await asyncio.sleep(delay)
+
+
+            def cancellation_callback(task: asyncio.Task[Any]):
+                token.cancel()
+
+
+            async def cancellable_user_agent():
+                try:
+                    timeout_task = asyncio.create_task(timeout(3))
+                    timeout_task.add_done_callback(cancellation_callback)
+                    agent_task = asyncio.create_task(
+                        agent.on_messages(
+                            [TextMessage(content="What is your name? ", source="user")],
+                            cancellation_token=CancellationToken(),
+                        )
+                    )
+                    response = await agent_task
+                    print(f"Your name is {response.chat_message.content}")
+                except Exception as e:
+                    print(f"Exception: {e}")
+                except BaseException as e:
+                    print(f"BaseException: {e}")
     """
 
     def __init__(
@@ -51,7 +118,7 @@ def __init__(
     ) -> None:
         """Initialize the UserProxyAgent."""
         super().__init__(name=name, description=description)
-        self.input_func = input_func or input
+        self.input_func = input_func or cancellable_input
         self._is_async = iscoroutinefunction(self.input_func)
 
     @property

python/packages/autogen-core/docs/src/user-guide/agentchat-user-guide/tutorial/agents.ipynb

@@ -26,7 +26,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -101,6 +101,39 @@
     "as well as a list of inner messages in the {py:attr}`~autogen_agentchat.base.Response.inner_messages` attribute,\n",
     "which stores the agent's \"thought process\" that led to the final response.\n",
     "\n",
+    "## User Proxy Agent\n",
+    "\n",
+    "{py:class}`~autogen_agentchat.agents.UserProxyAgent` is a built-in agent that\n",
+    provides one way for a user to intervene in the process. This agent will put the team in a temporary blocking state, and thus any exceptions or runtime failures while in the blocked state will result in a deadlock. It is strongly advised that this agent be coupled with a timeout mechanic and that all errors and exceptions emanating from it are handled.
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from autogen_agentchat.agents import UserProxyAgent\n",
+    "\n",
+    "\n",
+    "async def user_proxy_run() -> None:\n",
+    "    user_proxy_agent = UserProxyAgent(\"user_proxy\")\n",
+    "    response = await user_proxy_agent.on_messages(\n",
+    "        [TextMessage(content=\"What is your name? \", source=\"user\")], cancellation_token=CancellationToken()\n",
+    "    )\n",
+    "    print(f\"Your name is {response.chat_message.content}\")\n",
+    "\n",
+    "\n",
+    "# Use asyncio.run(user_proxy_run()) when running in a script.\n",
+    "await user_proxy_run()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The User Proxy agent is ideally used for on-demand human-in-the-loop interactions for scenarios such as Just In Time approvals, human feedback, alerts, etc. For slower user interactions, consider terminating the session using a termination condition and start another one from run or run_stream with another message.\n",
+    "\n",
     "### Stream Messages\n",
     "\n",
     "We can also stream each message as it is generated by the agent by using the\n",

python/packages/autogen-core/pyproject.toml

@@ -17,6 +17,7 @@ classifiers = [
 dependencies = [
     "openai>=1.3",
     "pillow",
+    "aioconsole",
     "aiohttp",
     "typing-extensions",
     "pydantic<3.0.0,>=2.0.0",