16337
6087066a91
涉及三处 LLM 调用： - LangGraph Agent 对话（graph.py） - VLM 图片分析（agent_dispatcher.py） - VLM 告警复核（vlm_service.py）
72 lines
2.1 KiB
Python
72 lines
2.1 KiB
Python
"""
|
||
LangGraph StateGraph 构建
|
||
|
||
构建 assistant + ToolNode 的 ReAct 图，接入 Dashscope Qwen。
|
||
"""
|
||
|
||
from typing import Optional
|
||
|
||
from langgraph.graph import StateGraph, START, END
|
||
from langgraph.prebuilt import ToolNode, tools_condition
|
||
from langgraph.checkpoint.memory import MemorySaver
|
||
from langchain_openai import ChatOpenAI
|
||
|
||
from app.config import settings
|
||
from app.utils.logger import logger
|
||
from .state import AgentState
|
||
from .tools import all_tools
|
||
from .prompts import SYSTEM_PROMPT
|
||
|
||
|
||
def _create_llm():
|
||
"""创建 LLM 客户端（通过 Dashscope OpenAI 兼容接口对接 Qwen）"""
|
||
return ChatOpenAI(
|
||
model=settings.agent.model,
|
||
base_url=settings.agent.vlm_base_url,
|
||
api_key=settings.agent.vlm_api_key,
|
||
timeout=settings.agent.timeout,
|
||
temperature=0.1,
|
||
)
|
||
|
||
|
||
def build_agent_graph(checkpointer=None):
|
||
"""构建并编译 Agent 图
|
||
|
||
Args:
|
||
checkpointer: LangGraph checkpointer 实例（None=不持久化）
|
||
|
||
Returns:
|
||
编译后的 CompiledGraph
|
||
"""
|
||
llm = _create_llm()
|
||
llm_with_tools = llm.bind_tools(all_tools)
|
||
|
||
def assistant(state: AgentState):
|
||
"""LLM 推理节点：接收消息 + 系统提示，返回回复或工具调用"""
|
||
system_msg = {"role": "system", "content": SYSTEM_PROMPT}
|
||
response = llm_with_tools.invoke([system_msg] + state["messages"])
|
||
return {"messages": [response]}
|
||
|
||
# 构建图
|
||
builder = StateGraph(AgentState)
|
||
|
||
# 两个核心节点
|
||
builder.add_node("assistant", assistant)
|
||
builder.add_node("tools", ToolNode(all_tools))
|
||
|
||
# 边：START → assistant → (条件) → tools 或 END
|
||
builder.add_edge(START, "assistant")
|
||
builder.add_conditional_edges("assistant", tools_condition)
|
||
builder.add_edge("tools", "assistant")
|
||
|
||
# 编译
|
||
graph = builder.compile(checkpointer=checkpointer)
|
||
logger.info("LangGraph Agent 图已编译")
|
||
return graph
|
||
|
||
|
||
def create_default_graph():
|
||
"""创建带内存 checkpoint 的默认图（开发用）"""
|
||
checkpointer = MemorySaver()
|
||
return build_agent_graph(checkpointer=checkpointer)
|