266 lines
11 KiB
Python

import copy
import os
from collections import deque
from litellm import ChatCompletionToolParam
import openhands.agenthub.codeact_agent.function_calling as codeact_function_calling
from openhands.agenthub.codeact_agent.tools.bash import create_cmd_run_tool
from openhands.agenthub.codeact_agent.tools.browser import BrowserTool
from openhands.agenthub.codeact_agent.tools.finish import FinishTool
from openhands.agenthub.codeact_agent.tools.ipython import IPythonTool
from openhands.agenthub.codeact_agent.tools.llm_based_edit import LLMBasedFileEditTool
from openhands.agenthub.codeact_agent.tools.str_replace_editor import (
create_str_replace_editor_tool,
)
from openhands.agenthub.codeact_agent.tools.think import ThinkTool
from openhands.agenthub.codeact_agent.tools.web_read import WebReadTool
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
from openhands.events.action import (
Action,
AgentFinishAction,
)
from openhands.events.event import Event
from openhands.llm.llm import LLM
from openhands.memory.condenser import Condenser
from openhands.memory.condenser.condenser import Condensation, View
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
- config (AgentConfig): The configuration for this agent
"""
super().__init__(llm, config)
self.pending_actions: deque[Action] = deque()
self.reset()
self.tools = self._get_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)}')
self.response_to_actions_fn = codeact_function_calling.response_to_actions
def _get_tools(self) -> list[ChatCompletionToolParam]:
# For these models, we use short tool descriptions ( < 1024 tokens)
# to avoid hitting the OpenAI token limit for tool descriptions.
SHORT_TOOL_DESCRIPTION_LLM_SUBSTRS = ['gpt-', 'o3', 'o1', 'o4']
use_short_tool_desc = False
if self.llm is not None:
use_short_tool_desc = any(
model_substr in self.llm.config.model
for model_substr in SHORT_TOOL_DESCRIPTION_LLM_SUBSTRS
)
tools = []
if self.config.enable_cmd:
tools.append(
create_cmd_run_tool(use_short_description=use_short_tool_desc)
)
if self.config.enable_think:
tools.append(ThinkTool)
if self.config.enable_finish:
tools.append(FinishTool)
if self.config.enable_browsing:
tools.append(WebReadTool)
tools.append(BrowserTool)
if self.config.enable_jupyter:
tools.append(IPythonTool)
if self.config.enable_llm_editor:
tools.append(LLMBasedFileEditTool)
elif self.config.enable_editor:
tools.append(
create_str_replace_editor_tool(
use_short_description=use_short_tool_desc
)
)
return tools
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()
# Condense the events from the state. If we get a view we'll pass those
# to the conversation manager for processing, but if we get a condensation
# event we'll just return that instead of an action. The controller will
# immediately ask the agent to step again with the new view.
condensed_history: list[Event] = []
match self.condenser.condensed_history(state):
case View(events=events):
condensed_history = events
case Condensation(action=condensation_action):
return condensation_action
logger.debug(
f'Processing {len(condensed_history)} events from a total of {len(state.history)} events'
)
messages = self._get_messages(condensed_history)
params: dict = {
'messages': self.llm.format_messages_for_llm(messages),
}
params['tools'] = self.tools
if self.mcp_tools:
# Only add tools with unique names
existing_names = {tool['function']['name'] for tool in params['tools']}
unique_mcp_tools = [
tool
for tool in self.mcp_tools
if tool['function']['name'] not in existing_names
]
if self.llm.config.model == 'gemini-2.5-pro-preview-03-25':
logger.info(
f'Removing the default fields from the MCP tools for {self.llm.config.model} '
"since it doesn't support them and the request would crash."
)
# prevent mutation of input tools
unique_mcp_tools = copy.deepcopy(unique_mcp_tools)
# Strip off default fields that cause errors with gemini-preview
for tool in unique_mcp_tools:
if 'function' in tool and 'parameters' in tool['function']:
if 'properties' in tool['function']['parameters']:
for prop_name, prop in tool['function']['parameters'][
'properties'
].items():
if 'default' in prop:
del prop['default']
params['tools'] += unique_mcp_tools
# log to litellm proxy if possible
params['extra_body'] = {'metadata': state.to_llm_metadata(agent_name=self.name)}
response = self.llm.completion(**params)
logger.debug(f'Response from LLM: {response}')
actions = self.response_to_actions_fn(response)
logger.debug(f'Actions after response_to_actions: {actions}')
for action in actions:
self.pending_actions.append(action)
return self.pending_actions.popleft()
def _get_messages(self, events: list[Event]) -> 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. Checks for SystemMessageAction in events, adds one if missing (legacy support)
2. Processes events (Actions and Observations) into messages, including SystemMessageAction
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:
events: The list of events to convert to messages
Returns:
list[Message]: A list of formatted messages ready for LLM consumption, including:
- System message with prompt (from SystemMessageAction)
- 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 events (including SystemMessageAction)
messages = self.conversation_memory.process_events(
condensed_history=events,
max_message_chars=self.llm.config.max_message_chars,
vision_is_active=self.llm.vision_is_active(),
)
if self.llm.is_caching_prompt_active():
self.conversation_memory.apply_prompt_caching(messages)
return messages