Upload agent.py

agent.py

@@ -0,0 +1,154 @@
+import os
+import time
+from typing import TypedDict, Annotated, Sequence
+import operator
+from langgraph.graph import StateGraph, END
+from langgraph.prebuilt import ToolNode
+from langchain_google_genai import ChatGoogleGenerativeAI
+from langchain_community.tools import DuckDuckGoSearchRun
+from langchain_community.document_loaders import WikipediaLoader
+from langchain_core.messages import BaseMessage, SystemMessage, AIMessage
+from langchain.agents import Tool
+from langchain_core.tools import tool
+
+# Load environment variables
+google_api_key = os.getenv("GOOGLE_API_KEY") or os.environ.get("GOOGLE_API_KEY")
+if not google_api_key:
+    raise ValueError("Missing GOOGLE_API_KEY environment variable")
+
+# Load system prompt
+with open("System_Prompt.txt", "r", encoding="utf-8") as f:
+    system_prompt = f.read()
+sys_msg = SystemMessage(content=system_prompt)
+
+# Tool Definitions
+@tool
+def multiply(a: int, b: int) -> int:
+    """Multiply two integers together."""
+    return a * b
+
+@tool
+def add(a: int, b: int) -> int:
+    """Add two integers together."""
+    return a + b
+
+@tool
+def subtract(a: int, b: int) -> int:
+    """Subtract b from a."""
+    return a - b
+
+@tool
+def divide(a: int, b: int) -> float:
+    """Divide a by b. Returns float. Raises error if b is zero."""
+    if b == 0:
+        raise ValueError("Cannot divide by zero.")
+    return a / b
+
+@tool
+def wiki_search(query: str) -> str:
+    """Search Wikipedia and return up to 2 relevant documents."""
+    docs = WikipediaLoader(query=query, load_max_docs=2).load()
+    if not docs:
+        return "No Wikipedia results found."
+    return "\n\n".join([d.page_content[:1000] for d in docs])
+
+# Tool inventory with valid names
+tools = [
+    Tool(name="Math_Multiply", func=multiply, description="Multiplies two integers"),
+    Tool(name="Math_Add", func=add, description="Adds two integers"),
+    Tool(name="Math_Subtract", func=subtract, description="Subtracts two integers"),
+    Tool(name="Math_Divide", func=divide, description="Divides two numbers"),
+    Tool(name="Search_Wikipedia", func=wiki_search, description="Searches Wikipedia"),
+    Tool(
+        name="Search_Web", 
+        func=DuckDuckGoSearchRun().run,
+        description="Searches the web using DuckDuckGo"
+    )
+]
+
+# Graph Definition
+class AgentState(TypedDict):
+    """State definition for the agent workflow"""
+    messages: Annotated[Sequence[BaseMessage], operator.add]
+
+def build_graph():
+    """Constructs and compiles the LangGraph workflow"""
+    
+    # Initialize LLM with Gemini 2.0 Flash and rate limiting
+    llm = ChatGoogleGenerativeAI(
+        model="gemini-2.0-flash-exp",
+        temperature=0.3,
+        google_api_key=google_api_key,
+        max_retries=3,  # 添加内置重试
+        request_timeout=30  # 设置超时
+    )
+    llm_with_tools = llm.bind_tools(tools)
+
+    # Custom tool condition to avoid '__end__' issues
+    def custom_tools_condition(state: AgentState):
+        """Determines whether to use tools or end the workflow"""
+        last_message = state["messages"][-1]
+        
+        # Check if it's an AI message with tool calls
+        if hasattr(last_message, "tool_calls") and last_message.tool_calls:
+            return "use_tools"
+        
+        # Check if it's an error message
+        if isinstance(last_message, AIMessage) and "ERROR" in last_message.content:
+            return "end"
+            
+        # Check if it's a final answer
+        if "FINAL ANSWER" in last_message.content:
+            return "end"
+            
+        return "use_tools"
+
+    # Node definitions with error handling
+    def agent_node(state: AgentState):
+        """Main agent node that processes messages with retry logic"""
+        try:
+            # Add rate limiting
+            time.sleep(1)  # 1 second delay between requests
+            
+            response = llm_with_tools.invoke(state["messages"])
+            return {"messages": [response]}
+        
+        except Exception as e:
+            # Handle specific errors
+            error_type = "UNKNOWN"
+            if "429" in str(e):
+                error_type = "QUOTA_EXCEEDED"
+            elif "400" in str(e):
+                error_type = "INVALID_REQUEST"
+                
+            error_msg = f"AGENT ERROR ({error_type}): {str(e)[:200]}"
+            return {"messages": [AIMessage(content=error_msg)]}
+
+    # Graph construction
+    workflow = StateGraph(AgentState)
+    
+    # Add nodes to the workflow
+    workflow.add_node("agent", agent_node)
+    workflow.add_node("tools", ToolNode(tools))
+    
+    # Configure graph flow with clear endpoints
+    workflow.set_entry_point("agent")
+    
+    # Add conditional edges with custom condition
+    workflow.add_conditional_edges(
+        "agent",
+        custom_tools_condition,
+        {
+            "use_tools": "tools",
+            "end": END  # Directly to END
+        }
+    )
+    
+    # Add edge from tools back to agent
+    workflow.add_edge("tools", "agent")
+    
+    # Ensure END has no incoming edges except through condition
+    return workflow.compile()
+
+# Initialize the agent graph
+agent_graph = build_graph()