ConnectOnion

1from langchain.agents import Tool, AgentExecutor
2from langchain.agents import create_react_agent
3from langchain.llms import OpenAI
4from langchain.prompts import PromptTemplate
5from langchain.memory import ConversationBufferMemory
6from langchain.schema import SystemMessage
7import json
8
9# Define the calculation tool
10def calculate_tool(expression: str) -> str:
11    try:
12        result = eval(expression)
13        return json.dumps({"result": result})
14    except Exception as e:
15        return json.dumps({"error": str(e)})
16
17# Create tool wrapper
18tools = [
19    Tool(
20        name="Calculator",
21        func=calculate_tool,
22        description="Useful for mathematical calculations"
23    )
24]
25
26# Setup prompt template
27template = """You are a helpful assistant.
28
29{history}
30Human: {input}
31{agent_scratchpad}
32"""
33
34prompt = PromptTemplate(
35    input_variables=["history", "input", "agent_scratchpad"],
36    template=template
37)
38
39# Initialize LLM
40llm = OpenAI(temperature=0)
41
42# Setup memory
43memory = ConversationBufferMemory(
44    memory_key="history",
45    return_messages=True
46)
47
48# Create agent
49agent = create_react_agent(
50    llm=llm,
51    tools=tools,
52    prompt=prompt
53)
54
55# Create executor
56agent_executor = AgentExecutor(
57    agent=agent,
58    tools=tools,
59    memory=memory,
60    verbose=True,
61    handle_parsing_errors=True
62)
63
64# Finally use it
65result = agent_executor.invoke({"input": "What's 42 * 17?"})
66print(result["output"])