Files
pepperplus-cb/src/control_backend/core/agent_system.py
Twirre Meulenbelt aa5b386f65 feat: semantically determine goal completion
ref: N25B-432
2026-01-07 17:08:23 +01:00

208 lines
7.2 KiB
Python

import asyncio
import logging
from abc import ABC, abstractmethod
from asyncio import Task
from collections.abc import Coroutine
import zmq
import zmq.asyncio as azmq
from control_backend.core.config import settings
from control_backend.schemas.internal_message import InternalMessage
# Central directory to resolve agent names to instances
_agent_directory: dict[str, "BaseAgent"] = {}
class AgentDirectory:
"""
Helper class to keep track of which agents are registered.
Used for handling message routing.
"""
@staticmethod
def register(name: str, agent: "BaseAgent"):
_agent_directory[name] = agent
@staticmethod
def get(name: str) -> "BaseAgent | None":
return _agent_directory.get(name)
class BaseAgent(ABC):
"""
Abstract base class for all agents in the system.
This class provides the foundational infrastructure for agent lifecycle management, messaging
(both intra-process and inter-process via ZMQ), and asynchronous behavior execution.
.. warning::
Do not inherit from this class directly for creating new agents. Instead, inherit from
:class:`control_backend.agents.base.BaseAgent`, which ensures proper logger configuration.
:ivar name: The unique name of the agent.
:ivar inbox: The queue for receiving internal messages.
:ivar _tasks: A set of currently running asynchronous tasks/behaviors.
:ivar _running: A boolean flag indicating if the agent is currently running.
:ivar logger: The logger instance for the agent.
"""
logger: logging.Logger
def __init__(self, name: str):
"""
Initialize the BaseAgent.
:param name: The unique identifier for this agent.
"""
self.name = name
self.inbox: asyncio.Queue[InternalMessage] = asyncio.Queue()
self._tasks: set[asyncio.Task] = set()
self._running = False
# Register immediately
AgentDirectory.register(name, self)
@abstractmethod
async def setup(self):
"""
Initialize agent-specific resources.
This method must be overridden by subclasses. It is called after the agent has started
and the ZMQ sockets have been initialized. Use this method to:
* Initialize connections (databases, APIs, etc.)
* Add initial behaviors using :meth:`add_behavior`
"""
pass
async def start(self):
"""
Start the agent and its internal loops.
This method:
1. Sets the running state to True.
2. Initializes ZeroMQ PUB/SUB sockets for inter-process communication.
3. Calls the user-defined :meth:`setup` method.
4. Starts the inbox processing loop and the ZMQ receiver loop.
"""
self.logger.info(f"Starting agent {self.name}")
self._running = True
context = azmq.Context.instance()
# Setup the internal publishing socket
self._internal_pub_socket = context.socket(zmq.PUB)
self._internal_pub_socket.connect(settings.zmq_settings.internal_pub_address)
# Setup the internal receiving socket
self._internal_sub_socket = context.socket(zmq.SUB)
self._internal_sub_socket.connect(settings.zmq_settings.internal_sub_address)
self._internal_sub_socket.subscribe(f"internal/{self.name}")
await self.setup()
# Start processing inbox and ZMQ messages
self.add_behavior(self._process_inbox())
self.add_behavior(self._receive_internal_zmq_loop())
async def stop(self):
"""
Stop the agent.
Sets the running state to False and cancels all running background tasks.
"""
self._running = False
for task in self._tasks:
task.cancel()
self.logger.info(f"Agent {self.name} stopped")
async def send(self, message: InternalMessage):
"""
Send a message to another agent.
This method intelligently routes the message:
* If the target agent is in the same process (found in :class:`AgentDirectory`),
the message is put directly into its inbox.
* If the target agent is not found locally, the message is serialized and sent
via ZeroMQ to the internal publication address.
:param message: The message to send.
"""
target = AgentDirectory.get(message.to)
if target:
await target.inbox.put(message)
self.logger.debug(f"Sent message {message.body} to {message.to} via regular inbox.")
else:
# Apparently target agent is on a different process, send via ZMQ
topic = f"internal/{message.to}".encode()
body = message.model_dump_json().encode()
await self._internal_pub_socket.send_multipart([topic, body])
self.logger.debug(f"Sent message {message.body} to {message.to} via ZMQ.")
async def _process_inbox(self):
"""
Internal loop that processes messages from the inbox.
Reads messages from ``self.inbox`` and passes them to :meth:`handle_message`.
"""
while self._running:
msg = await self.inbox.get()
self.logger.debug(f"Received message from {msg.sender}.")
await self.handle_message(msg)
async def _receive_internal_zmq_loop(self):
"""
Internal loop that listens for ZMQ messages.
Subscribes to ``internal/<agent_name>`` topics. When a message is received,
it is deserialized into an :class:`InternalMessage` and put into the local inbox.
This bridges the gap between inter-process ZMQ communication and the intra-process inbox.
"""
while self._running:
try:
_, body = await self._internal_sub_socket.recv_multipart()
msg = InternalMessage.model_validate_json(body)
await self.inbox.put(msg)
except asyncio.CancelledError:
break
except Exception:
self.logger.exception("Could not process ZMQ message.")
async def handle_message(self, msg: InternalMessage):
"""
Handle an incoming message.
This method must be overridden by subclasses to define how the agent reacts to messages.
:param msg: The received message.
:raises NotImplementedError: If not overridden by the subclass.
"""
raise NotImplementedError
def add_behavior(self, coro: Coroutine) -> Task:
"""
Add a background behavior (task) to the agent.
This is the preferred way to run continuous loops or long-running tasks within an agent.
The task is tracked and will be automatically cancelled when :meth:`stop` is called.
:param coro: The coroutine to execute as a task.
"""
async def try_coro(coro_: Coroutine):
try:
await coro_
except asyncio.CancelledError:
self.logger.debug("A behavior was canceled successfully: %s", coro_)
except Exception:
self.logger.warning("An exception occurred in a behavior.", exc_info=True)
task = asyncio.create_task(try_coro(coro))
self._tasks.add(task)
task.add_done_callback(self._tasks.discard)
return task