225 lines
9.2 KiB
Python

import os
from collections import deque
import openhands.agenthub.codeact_agent.function_calling as codeact_function_calling
from openhands.controller.agent import Agent
from openhands.controller.state.state import State
from openhands.core.config import AgentConfig
from openhands.core.logger import openhands_logger as logger
from openhands.core.message import Message, TextContent
from openhands.events.action import (
Action,
AgentFinishAction,
)
from openhands.llm.llm import LLM
from openhands.memory.condenser import Condenser
from openhands.memory.conversation_memory import ConversationMemory
from openhands.runtime.plugins import (
AgentSkillsRequirement,
JupyterRequirement,
PluginRequirement,
)
from openhands.utils.prompt import PromptManager
class CodeActAgent(Agent):
VERSION = '2.2'
"""
The Code Act Agent is a minimalist agent.
The agent works by passing the model a list of action-observation pairs and prompting the model to take the next step.
### Overview
This agent implements the CodeAct idea ([paper](https://arxiv.org/abs/2402.01030), [tweet](https://twitter.com/xingyaow_/status/1754556835703751087)) that consolidates LLM agents' **act**ions into a unified **code** action space for both *simplicity* and *performance* (see paper for more details).
The conceptual idea is illustrated below. At each turn, the agent can:
1. **Converse**: Communicate with humans in natural language to ask for clarification, confirmation, etc.
2. **CodeAct**: Choose to perform the task by executing code
- Execute any valid Linux `bash` command
- Execute any valid `Python` code with [an interactive Python interpreter](https://ipython.org/). This is simulated through `bash` command, see plugin system below for more details.
![image](https://github.com/All-Hands-AI/OpenHands/assets/38853559/92b622e3-72ad-4a61-8f41-8c040b6d5fb3)
"""
sandbox_plugins: list[PluginRequirement] = [
# NOTE: AgentSkillsRequirement need to go before JupyterRequirement, since
# AgentSkillsRequirement provides a lot of Python functions,
# and it needs to be initialized before Jupyter for Jupyter to use those functions.
AgentSkillsRequirement(),
JupyterRequirement(),
]
def __init__(
self,
llm: LLM,
config: AgentConfig,
) -> None:
"""Initializes a new instance of the CodeActAgent class.
Parameters:
- llm (LLM): The llm to be used by this agent
"""
super().__init__(llm, config)
self.pending_actions: deque[Action] = deque()
self.reset()
# Retrieve the enabled tools
self.tools = codeact_function_calling.get_tools(
codeact_enable_browsing=self.config.codeact_enable_browsing,
codeact_enable_jupyter=self.config.codeact_enable_jupyter,
codeact_enable_llm_editor=self.config.codeact_enable_llm_editor,
llm=self.llm,
)
logger.debug(
f'TOOLS loaded for CodeActAgent: {', '.join([tool.get('function').get('name') for tool in self.tools])}'
)
self.prompt_manager = PromptManager(
prompt_dir=os.path.join(os.path.dirname(__file__), 'prompts'),
)
# Create a ConversationMemory instance
self.conversation_memory = ConversationMemory(self.config, self.prompt_manager)
self.condenser = Condenser.from_config(self.config.condenser)
logger.debug(f'Using condenser: {type(self.condenser)}')
def reset(self) -> None:
"""Resets the CodeAct Agent."""
super().reset()
self.pending_actions.clear()
def step(self, state: State) -> Action:
"""Performs one step using the CodeAct Agent.
This includes gathering info on previous steps and prompting the model to make a command to execute.
Parameters:
- state (State): used to get updated info
Returns:
- CmdRunAction(command) - bash command to run
- IPythonRunCellAction(code) - IPython code to run
- AgentDelegateAction(agent, inputs) - delegate action for (sub)task
- MessageAction(content) - Message action to run (e.g. ask for clarification)
- AgentFinishAction() - end the interaction
"""
# Continue with pending actions if any
if self.pending_actions:
return self.pending_actions.popleft()
# if we're done, go back
latest_user_message = state.get_last_user_message()
if latest_user_message and latest_user_message.content.strip() == '/exit':
return AgentFinishAction()
# prepare what we want to send to the LLM
messages = self._get_messages(state)
params: dict = {
'messages': self.llm.format_messages_for_llm(messages),
}
params['tools'] = self.tools
response = self.llm.completion(**params)
actions = codeact_function_calling.response_to_actions(response)
for action in actions:
self.pending_actions.append(action)
return self.pending_actions.popleft()
def _get_messages(self, state: State) -> list[Message]:
"""Constructs the message history for the LLM conversation.
This method builds a structured conversation history by processing events from the state
and formatting them into messages that the LLM can understand. It handles both regular
message flow and function-calling scenarios.
The method performs the following steps:
1. Initializes with system prompt and optional initial user message
2. Processes events (Actions and Observations) into messages
3. Handles tool calls and their responses in function-calling mode
4. Manages message role alternation (user/assistant/tool)
5. Applies caching for specific LLM providers (e.g., Anthropic)
6. Adds environment reminders for non-function-calling mode
Args:
state (State): The current state object containing conversation history and other metadata
Returns:
list[Message]: A list of formatted messages ready for LLM consumption, including:
- System message with prompt
- Initial user message (if configured)
- Action messages (from both user and assistant)
- Observation messages (including tool responses)
- Environment reminders (in non-function-calling mode)
Note:
- In function-calling mode, tool calls and their responses are carefully tracked
to maintain proper conversation flow
- Messages from the same role are combined to prevent consecutive same-role messages
- For Anthropic models, specific messages are cached according to their documentation
"""
if not self.prompt_manager:
raise Exception('Prompt Manager not instantiated.')
# Use ConversationMemory to process initial messages
messages = self.conversation_memory.process_initial_messages(
with_caching=self.llm.is_caching_prompt_active()
)
# Condense the events from the state.
events = self.condenser.condensed_history(state)
logger.debug(
f'Processing {len(events)} events from a total of {len(state.history)} events'
)
# Use ConversationMemory to process events
messages = self.conversation_memory.process_events(
condensed_history=events,
initial_messages=messages,
max_message_chars=self.llm.config.max_message_chars,
vision_is_active=self.llm.vision_is_active(),
)
messages = self._enhance_messages(messages)
if self.llm.is_caching_prompt_active():
self.conversation_memory.apply_prompt_caching(messages)
return messages
def _enhance_messages(self, messages: list[Message]) -> list[Message]:
"""Enhances the user message with additional context based on keywords matched.
Args:
messages (list[Message]): The list of messages to enhance
Returns:
list[Message]: The enhanced list of messages
"""
assert self.prompt_manager, 'Prompt Manager not instantiated.'
results: list[Message] = []
is_first_message_handled = False
prev_role = None
for msg in messages:
if msg.role == 'user' and not is_first_message_handled:
is_first_message_handled = True
# compose the first user message with examples
self.prompt_manager.add_examples_to_initial_message(msg)
elif msg.role == 'user':
# Add double newline between consecutive user messages
if prev_role == 'user' and len(msg.content) > 0:
# Find the first TextContent in the message to add newlines
for content_item in msg.content:
if isinstance(content_item, TextContent):
# If the previous message was also from a user, prepend two newlines to ensure separation
content_item.text = '\n\n' + content_item.text
break
results.append(msg)
prev_role = msg.role
return results