create_openai_tools_agent

Example:

from langchain_classic import hub
from langchain_openai import ChatOpenAI
from langchain_classic.agents import (
    AgentExecutor,
    create_openai_tools_agent,
)

prompt = hub.pull("hwchase17/openai-tools-agent")
model = ChatOpenAI()
tools = ...

agent = create_openai_tools_agent(model, tools, prompt)
agent_executor = AgentExecutor(agent=agent, tools=tools)

agent_executor.invoke({"input": "hi"})

# Using with chat history
from langchain_core.messages import AIMessage, HumanMessage

agent_executor.invoke(
    {
        "input": "what's my name?",
        "chat_history": [
            HumanMessage(content="hi! my name is bob"),
            AIMessage(content="Hello Bob! How can I assist you today?"),
        ],
    }
)

Prompt:

The agent prompt must have an agent_scratchpad key that is a MessagesPlaceholder. Intermediate agent actions and tool output messages will be passed in here.

Here's an example:

from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder

prompt = ChatPromptTemplate.from_messages(
    [
        ("system", "You are a helpful assistant"),
        MessagesPlaceholder("chat_history", optional=True),
        ("human", "{input}"),
        MessagesPlaceholder("agent_scratchpad"),
    ]
)