Langgraph

https://www.langchain.com/langgraph 

from typing import Annotated

from typing_extensions import TypedDict

from langgraph.graph import StateGraph, START, END

from langgraph.graph.message import add_messages

class State(TypedDict):

    # Messages have the type "list". The `add_messages` function

    # in the annotation defines how this state key should be updated

    # (in this case, it appends messages to the list, rather than overwriting them)

    messages: Annotated[list, add_messages]

graph_builder = StateGraph(State)

def stream_graph_updates(user_input: str):

    for event in graph.stream({"messages": [("user", user_input)]}):

        for value in event.values():

            print("Assistant:", value["messages"][-1].content)

while True:

    try:

        user_input = input("User: ")

        if user_input.lower() in ["quit", "exit", "q"]:

            print("Goodbye!")

            break

        stream_graph_updates(user_input)

    except:

        # fallback if input() is not available

        user_input = "What do you know about LangGraph?"

        print("User: " + user_input)

        stream_graph_updates(user_input)

        break

from langchain_community.tools.tavily_search import TavilySearchResults

tool = TavilySearchResults(max_results=2)

tools = [tool]

tool.invoke("What's a 'node' in LangGraph?")

from typing import Annotated

from langchain_anthropic import ChatAnthropic

from typing_extensions import TypedDict

from langgraph.graph import StateGraph, START, END

from langgraph.graph.message import add_messages

class State(TypedDict):

    messages: Annotated[list, add_messages]

graph_builder = StateGraph(State)

llm = ChatAnthropic(model="claude-3-5-sonnet-20240620")

# Modification: tell the LLM which tools it can call

llm_with_tools = llm.bind_tools(tools)

def chatbot(state: State):

    return {"messages": [llm_with_tools.invoke(state["messages"])]}

graph_builder.add_node("chatbot", chatbot)