Files

161 lines
4.6 KiB
Python

import os
import asyncio
import json
from typing import TypedDict, Annotated, List
from langchain_openai import ChatOpenAI
from langchain_core.messages import HumanMessage, AIMessage
from langchain.tools import tool
from deepagents import create_deep_agent
from deepagents.backends import FilesystemBackend, LocalShellBackend, CompositeBackend
from langgraph.graph import StateGraph, START, END
from langgraph.graph.message import add_messages
# ---------- LLM ----------
llm = ChatOpenAI(
model="openai/gpt-oss-20b:free",
base_url="https://openrouter.ai/api/v1",
api_key=os.getenv("OPENAI_API_KEY"),
temperature=0.0,
)
# ---------- Backend ----------
backend = CompositeBackend(
[
LocalShellBackend(workspace_dir="./workspace"),
FilesystemBackend(),
]
)
# ---------- Tools (optional example) ----------
@tool
def echo_tool(text: str) -> str:
"""Return the given text unchanged."""
return text
# ---------- Deep Agent ----------
deep_agent = create_deep_agent(
model=llm,
tools=[echo_tool],
backend=backend,
system_prompt="You are a helpful planning agent.",
)
# ---------- State ----------
class PlanningState(TypedDict):
messages: Annotated[List[AIMessage | HumanMessage], add_messages]
task: str
plan: List[str] | None
current_step: int
results: List[str]
# ---------- Planner Node ----------
def planner_node(state: PlanningState) -> PlanningState:
prompt = f"""You are given a task. Break it into 3-6 concrete steps.
Return the plan as a JSON array of strings, e.g. ["step 1", "step 2", ...].
Task: {state['task']}"""
response = deep_agent.invoke(
{"messages": [HumanMessage(content=prompt)]},
{"configurable": {"thread_id": "planner"}},
)
content = response["messages"][-1].content
try:
plan = json.loads(content)
if not isinstance(plan, list):
raise ValueError
except Exception:
# Fallback: try to extract lines starting with numbers
lines = [line.strip() for line in content.splitlines() if line.strip()]
plan = [line.split(".", 1)[-1].strip() for line in lines if line[0].isdigit()]
state["plan"] = plan
state["current_step"] = 0
state["results"] = []
return state
# ---------- Execution Node ----------
def execution_node(state: PlanningState) -> PlanningState:
step_idx = state["current_step"]
step_instruction = state["plan"][step_idx]
prompt = f"""You are executing step {step_idx + 1} of a plan.
Task: {state['task']}
Step: {step_instruction}
Provide a concise answer for this step."""
response = deep_agent.invoke(
{"messages": [HumanMessage(content=prompt)]},
{"configurable": {"thread_id": f"exec-{step_idx}"}},
)
result = response["messages"][-1].content
state["results"].append(f"[Step {step_idx + 1}] {result}")
state["current_step"] += 1
return state
# ---------- Conditional Edge ----------
def should_continue(state: PlanningState) -> str:
if state["current_step"] >= len(state["plan"]):
return "finish"
return "execute"
# ---------- Build Graph ----------
graph = StateGraph(PlanningState)
graph.add_node("planning", planner_node)
graph.add_node("execution", execution_node)
graph.add_edge(START, "planning")
graph.add_edge("planning", "execution")
graph.add_conditional_edges(
"execution",
should_continue,
{"execute": "execution", "finish": END},
)
graph.set_entry_point("planning")
graph = graph.compile()
# ---------- Runner ----------
async def run_planning_agent(task: str) -> str:
# Initialise state
state: PlanningState = {
"messages": [],
"task": task,
"plan": None,
"current_step": 0,
"results": [],
}
# Run graph
async for event in graph.astream(state):
# We only need final state
pass
final_state = event
# Build final answer
plan_text = "\n".join(f"{i+1}. {step}" for i, step in enumerate(final_state["plan"]))
steps_text = "\n".join(final_state["results"])
summary_prompt = f"""You have completed all steps of the following task.
Task: {task}
Plan:
{plan_text}
Steps results:
{steps_text}
Provide a concise final summary."""
summary_resp = deep_agent.invoke(
{"messages": [HumanMessage(content=summary_prompt)]},
{"configurable": {"thread_id": "summary"}},
)
summary = summary_resp["messages"][-1].content
output = f"""Задача: {task}
План:
{plan_text}
{steps_text}
Итог: {summary}
"""
return output
# ---------- Main ----------
if __name__ == "__main__":
example_task = "Сравни Python и JavaScript"
result = asyncio.run(run_planning_agent(example_task))
print(result)