OpenHands/openhands/server/session/agent_session.py

import asyncio
import concurrent.futures
from threading import Thread
from typing import Callable, Optional

from openhands.controller import AgentController
from openhands.controller.agent import Agent
from openhands.controller.state.state import State
from openhands.core.config import AgentConfig, AppConfig, LLMConfig
from openhands.core.logger import openhands_logger as logger
from openhands.core.schema.agent import AgentState
from openhands.events.action.agent import ChangeAgentStateAction
from openhands.events.event import EventSource
from openhands.events.stream import EventStream
from openhands.runtime import get_runtime_cls
from openhands.runtime.runtime import Runtime
from openhands.security import SecurityAnalyzer, options
from openhands.storage.files import FileStore


class AgentSession:
    """Represents a session with an Agent

    Attributes:
        controller: The AgentController instance for controlling the agent.
    """

    sid: str
    event_stream: EventStream
    file_store: FileStore
    controller: AgentController | None = None
    runtime: Runtime | None = None
    security_analyzer: SecurityAnalyzer | None = None
    _closed: bool = False
    loop: asyncio.AbstractEventLoop

    def __init__(self, sid: str, file_store: FileStore):
        """Initializes a new instance of the Session class

        Parameters:
        - sid: The session ID
        - file_store: Instance of the FileStore
        """

        self.sid = sid
        self.event_stream = EventStream(sid, file_store)
        self.file_store = file_store
        self.loop = asyncio.new_event_loop()

    async def start(
        self,
        runtime_name: str,
        config: AppConfig,
        agent: Agent,
        max_iterations: int,
        max_budget_per_task: float | None = None,
        agent_to_llm_config: dict[str, LLMConfig] | None = None,
        agent_configs: dict[str, AgentConfig] | None = None,
        status_message_callback: Optional[Callable] = None,
    ):
        """Starts the Agent session
        Parameters:
        - runtime_name: The name of the runtime associated with the session
        - config:
        - agent:
        - max_iterations:
        - max_budget_per_task:
        - agent_to_llm_config:
        - agent_configs:
        """
        if self.controller or self.runtime:
            raise RuntimeError(
                'Session already started. You need to close this session and start a new one.'
            )

        self.thread = Thread(target=self._run, daemon=True)
        self.thread.start()

        def coro_callback(task):
            fut: concurrent.futures.Future = concurrent.futures.Future()
            try:
                fut.set_result(task.result())
            except Exception as e:
                logger.error(f'Error starting session: {e}')

        coro = self._start(
            runtime_name,
            config,
            agent,
            max_iterations,
            max_budget_per_task,
            agent_to_llm_config,
            agent_configs,
            status_message_callback,
        )
        asyncio.run_coroutine_threadsafe(coro, self.loop).add_done_callback(
            coro_callback
        )  # type: ignore

    async def _start(
        self,
        runtime_name: str,
        config: AppConfig,
        agent: Agent,
        max_iterations: int,
        max_budget_per_task: float | None = None,
        agent_to_llm_config: dict[str, LLMConfig] | None = None,
        agent_configs: dict[str, AgentConfig] | None = None,
        status_message_callback: Optional[Callable] = None,
    ):
        self._create_security_analyzer(config.security.security_analyzer)
        self._create_runtime(runtime_name, config, agent, status_message_callback)
        self._create_controller(
            agent,
            config.security.confirmation_mode,
            max_iterations,
            max_budget_per_task=max_budget_per_task,
            agent_to_llm_config=agent_to_llm_config,
            agent_configs=agent_configs,
        )
        self.event_stream.add_event(
            ChangeAgentStateAction(AgentState.INIT), EventSource.USER
        )
        if self.controller:
            self.controller.agent_task = self.controller.start_step_loop()
            await self.controller.agent_task  # type: ignore

    def _run(self):
        asyncio.set_event_loop(self.loop)
        self.loop.run_forever()

    async def close(self):
        """Closes the Agent session"""

        if self._closed:
            return
        if self.controller is not None:
            end_state = self.controller.get_state()
            end_state.save_to_session(self.sid, self.file_store)
            await self.controller.close()
        if self.runtime is not None:
            self.runtime.close()
        if self.security_analyzer is not None:
            await self.security_analyzer.close()

        self.loop.call_soon_threadsafe(self.loop.stop)
        if self.thread:
            # We may be closing an agent_session that was never actually started
            self.thread.join()

        self._closed = True

    def _create_security_analyzer(self, security_analyzer: str | None):
        """Creates a SecurityAnalyzer instance that will be used to analyze the agent actions

        Parameters:
        - security_analyzer: The name of the security analyzer to use
        """

        if security_analyzer:
            logger.debug(f'Using security analyzer: {security_analyzer}')
            self.security_analyzer = options.SecurityAnalyzers.get(
                security_analyzer, SecurityAnalyzer
            )(self.event_stream)

    def _create_runtime(
        self,
        runtime_name: str,
        config: AppConfig,
        agent: Agent,
        status_message_callback: Optional[Callable] = None,
    ):
        """Creates a runtime instance

        Parameters:
        - runtime_name: The name of the runtime associated with the session
        - config:
        - agent:
        """

        if self.runtime is not None:
            raise RuntimeError('Runtime already created')

        logger.info(f'Initializing runtime `{runtime_name}` now...')
        runtime_cls = get_runtime_cls(runtime_name)

        try:
            self.runtime = runtime_cls(
                config=config,
                event_stream=self.event_stream,
                sid=self.sid,
                plugins=agent.sandbox_plugins,
                status_message_callback=status_message_callback,
            )
        except Exception as e:
            logger.error(f'Runtime initialization failed: {e}')
            raise

        if self.runtime is not None:
            logger.debug(
                f'Runtime initialized with plugins: {[plugin.name for plugin in self.runtime.plugins]}'
            )
        else:
            logger.warning('Runtime initialization failed')

    def _create_controller(
        self,
        agent: Agent,
        confirmation_mode: bool,
        max_iterations: int,
        max_budget_per_task: float | None = None,
        agent_to_llm_config: dict[str, LLMConfig] | None = None,
        agent_configs: dict[str, AgentConfig] | None = None,
    ):
        """Creates an AgentController instance

        Parameters:
        - agent:
        - confirmation_mode: Whether to use confirmation mode
        - max_iterations:
        - max_budget_per_task:
        - agent_to_llm_config:
        - agent_configs:
        """

        if self.controller is not None:
            raise RuntimeError('Controller already created')
        if self.runtime is None:
            raise RuntimeError(
                'Runtime must be initialized before the agent controller'
            )

        logger.info(
            '\n--------------------------------- OpenHands Configuration ---------------------------------\n'
            f'LLM: {agent.llm.config.model}\n'
            f'Base URL: {agent.llm.config.base_url}\n'
            f'Agent: {agent.name}\n'
            '-------------------------------------------------------------------------------------------'
        )

        self.controller = AgentController(
            sid=self.sid,
            event_stream=self.event_stream,
            agent=agent,
            max_iterations=int(max_iterations),
            max_budget_per_task=max_budget_per_task,
            agent_to_llm_config=agent_to_llm_config,
            agent_configs=agent_configs,
            confirmation_mode=confirmation_mode,
            # AgentSession is designed to communicate with the frontend, so we don't want to
            # run the agent in headless mode.
            headless_mode=False,
        )
        try:
            agent_state = State.restore_from_session(self.sid, self.file_store)
            self.controller.set_initial_state(
                agent_state, max_iterations, confirmation_mode
            )
            logger.info(f'Restored agent state from session, sid: {self.sid}')
        except Exception as e:
            logger.info(f'State could not be restored: {e}')
        logger.info('Agent controller initialized.')