scrapeRL / backend /app /agents /planner.py
NeerajCodz's picture
feat: implement multi-agent system with coordinator
3bfb250
"""Planner agent for goal decomposition and task planning."""
from typing import Any
from app.core.action import Action, ActionType
from app.core.observation import Observation
from .base import BaseAgent
class PlannerAgent(BaseAgent):
"""
Agent responsible for high-level planning and goal decomposition.
The PlannerAgent analyzes the task requirements and creates
structured plans that other agents can execute. It handles:
- Breaking down complex tasks into subtasks
- Determining the optimal sequence of actions
- Adapting plans based on execution results
- Coordinating multi-step extraction workflows
"""
def __init__(
self,
agent_id: str = "planner",
config: dict[str, Any] | None = None,
):
"""
Initialize the PlannerAgent.
Args:
agent_id: Unique identifier for this agent.
config: Optional configuration with keys:
- max_plan_depth: Maximum depth of nested plans (default: 5)
- replan_threshold: Error count before replanning (default: 2)
- planning_model: LLM model to use for planning
"""
super().__init__(agent_id, config)
self.max_plan_depth = self.config.get("max_plan_depth", 5)
self.replan_threshold = self.config.get("replan_threshold", 2)
self._current_plan: list[Action] | None = None
self._plan_step: int = 0
async def act(self, observation: Observation) -> Action:
"""
Select the next action based on the current plan or create a new one.
If no plan exists or the current plan has failed, creates a new plan.
Otherwise, returns the next action in the current plan.
Args:
observation: The current state observation.
Returns:
The next action to execute.
"""
try:
# Check if we need to replan due to errors
if observation.consecutive_errors >= self.replan_threshold:
self._current_plan = None
self._plan_step = 0
# Create plan if none exists
if self._current_plan is None or self._plan_step >= len(self._current_plan):
self._current_plan = await self.plan(observation)
self._plan_step = 0
if not self._current_plan:
return self._create_done_action("No actions planned")
# Get next action from plan
action = self._current_plan[self._plan_step]
action.plan_step = self._plan_step
action.agent_id = self.agent_id
self._plan_step += 1
return action
except Exception as e:
return self._create_error_action(f"Planning error: {e}")
async def plan(self, observation: Observation) -> list[Action]:
"""
Create a plan of actions to achieve the task goals.
Analyzes the observation to determine:
- What fields still need to be extracted
- What navigation may be required
- What verification steps are needed
Args:
observation: The current state observation.
Returns:
A list of planned actions in execution order.
"""
try:
actions: list[Action] = []
task_context = observation.task_context
if not task_context:
return [self._create_done_action("No task context provided")]
# Determine remaining fields to extract
remaining_fields = observation.fields_remaining
extracted_fields = [f.field_name for f in observation.extracted_so_far]
# If no URL loaded, plan navigation first
if not observation.current_url:
search_action = self._plan_initial_navigation(task_context)
if search_action:
actions.append(search_action)
# Plan extraction for remaining fields
for field in remaining_fields:
extraction_action = self._plan_field_extraction(
field,
observation,
)
actions.append(extraction_action)
# Plan verification if fields have been extracted
if extracted_fields:
verify_action = self._plan_verification(extracted_fields)
actions.append(verify_action)
# Add completion action
actions.append(
Action(
action_type=ActionType.DONE,
parameters={"success": True, "message": "Plan completed"},
reasoning="All planned steps completed",
confidence=0.9,
agent_id=self.agent_id,
)
)
return actions
except Exception as e:
return [self._create_error_action(f"Plan creation failed: {e}")]
def _plan_initial_navigation(self, task_context: Any) -> Action | None:
"""Plan initial navigation based on task context."""
if task_context.hints:
# Use hints for navigation
for hint in task_context.hints:
if hint.startswith("http"):
return Action(
action_type=ActionType.NAVIGATE,
parameters={"url": hint},
reasoning=f"Navigating to hinted URL: {hint}",
confidence=0.85,
agent_id=self.agent_id,
)
# Default to search
search_query = f"{task_context.task_name} site information"
return Action(
action_type=ActionType.SEARCH_ENGINE,
parameters={"query": search_query, "engine": "google"},
reasoning=f"Searching for: {search_query}",
confidence=0.7,
agent_id=self.agent_id,
)
def _plan_field_extraction(
self,
field_name: str,
observation: Observation,
) -> Action:
"""Plan extraction for a specific field."""
# Check if we have page elements that might contain the field
selector = None
confidence = 0.6
for element in observation.page_elements:
element_text = (element.text or "").lower()
if field_name.lower() in element_text:
selector = element.selector
confidence = 0.8
break
return Action(
action_type=ActionType.EXTRACT_FIELD,
parameters={
"field_name": field_name,
"selector": selector,
"extraction_method": "text",
},
reasoning=f"Extracting field: {field_name}",
confidence=confidence,
agent_id=self.agent_id,
)
def _plan_verification(self, fields: list[str]) -> Action:
"""Plan verification for extracted fields."""
return Action(
action_type=ActionType.VERIFY_FIELD,
parameters={
"field_name": fields[0] if fields else "unknown",
"validation_rules": ["not_empty", "format_check"],
},
reasoning=f"Verifying extracted fields: {fields}",
confidence=0.75,
agent_id=self.agent_id,
)
def _create_done_action(self, message: str) -> Action:
"""Create a done action."""
return Action(
action_type=ActionType.DONE,
parameters={"success": True, "message": message},
reasoning=message,
confidence=1.0,
agent_id=self.agent_id,
)
def _create_error_action(self, error: str) -> Action:
"""Create a fail action for errors."""
return Action(
action_type=ActionType.FAIL,
parameters={"success": False, "message": error},
reasoning=error,
confidence=1.0,
agent_id=self.agent_id,
)
def get_current_plan(self) -> list[Action] | None:
"""Get the current plan."""
return self._current_plan
def get_plan_progress(self) -> tuple[int, int]:
"""Get current plan progress as (current_step, total_steps)."""
total = len(self._current_plan) if self._current_plan else 0
return (self._plan_step, total)
def reset(self) -> None:
"""Reset the planner state."""
super().reset()
self._current_plan = None
self._plan_step = 0