Almacene y recupere el historial y el contexto de las conversaciones con la BedrockSessionSaver LangGraph biblioteca

En lugar de utilizar directamente las API de administración de sesiones de Amazon Bedrock, puede almacenar y recuperar el historial y el contexto de las conversaciones en LangGraph la BedrockSessionSaver biblioteca. Se trata de una implementación personalizada de LangGraph CheckpointSaver. Utiliza las API de Amazon Bedrock con una LangGraph-based interfaz. Para obtener más información, consulte langgraph-checkpoint-aws en el repositorio. LangChain GitHub

En el siguiente ejemplo de código, se muestra cómo utilizar la BedrockSessionSaver LangGraph biblioteca para realizar un seguimiento del estado cuando un usuario interactúa con Claude. Cómo usar este ejemplo de código:

import boto3
from typing import Dict, TypedDict, Annotated, Sequence, Union
from langgraph.graph import StateGraph, END
from langgraph_checkpoint_aws.saver import BedrockSessionSaver
from langchain_core.messages import HumanMessage, AIMessage
import json


# Define state structure
class State(TypedDict):
    messages: Sequence[Union[HumanMessage, AIMessage]]
    current_question: str


# Function to get response from Claude
def get_response(messages):
    bedrock = boto3.client('bedrock-runtime', region_name="us-west-2")
    prompt = "\n".join([f"{'Human' if isinstance(m, HumanMessage) else 'Assistant'}: {m.content}"
                        for m in messages])

    response = bedrock.invoke_model(
        modelId="anthropic.claude-3-5-sonnet-20241022-v2:0",
        body=json.dumps({
            "anthropic_version": "bedrock-2023-05-31",
            "max_tokens": 1000,
            "messages": [
                {
                    "role": "user",
                    "content": [
                        {
                            "type": "text",
                            "text": prompt
                        }
                    ]
                }
            ],
            "temperature": 0.7
        })
    )

    response_body = json.loads(response['body'].read())
    return response_body['content'][0]['text']


# Node function to process user question
def process_question(state: State) -> Dict:
    messages = list(state["messages"])
    messages.append(HumanMessage(content=state["current_question"]))

    # Get response from Claude
    response = get_response(messages)
    messages.append(AIMessage(content=response))

    # Print assistant's response
    print("\nAssistant:", response)

    # Get next user input
    next_question = input("\nYou: ").strip()

    return {
        "messages": messages,
        "current_question": next_question
    }


# Node function to check if conversation should continue
def should_continue(state: State) -> bool:
    # Check if the last message was from the user and contains 'quit'
    if state["current_question"].lower() == 'quit':
        return False
    return True


# Create the graph
def create_graph(session_saver):
    # Initialize state graph
    workflow = StateGraph(State)

    # Add nodes
    workflow.add_node("process_question", process_question)

    # Add conditional edges
    workflow.add_conditional_edges(
        "process_question",
        should_continue,
        {
            True: "process_question",
            False: END
        }
    )

    # Set entry point
    workflow.set_entry_point("process_question")

    return workflow.compile(session_saver)


def main():
    # Create a runtime client
    agent_run_time_client = boto3.client("bedrock-agent-runtime",
                                         region_name="REGION")
            
    # Initialize Bedrock session saver. The Region must match the Region used for the agent_run_time_client.
    session_saver = BedrockSessionSaver(region_name="REGION")

    # Create graph
    graph = create_graph(session_saver)

    # Create session
    session_id = agent_run_time_client.create_session()["sessionId"]
    print("Session started. Type 'quit' to end.")

    # Configure graph
    config = {"configurable": {"thread_id": session_id}}

    # Initial state
    state = {
        "messages": [],
        "current_question": "Hello! How can I help you today? (Type 'quit' to end)"
    }

    # Print initial greeting
    print(f"\nAssistant: {state['current_question']}")

    state["current_question"] = input("\nYou: ").strip()

    # Process the question through the graph
    graph.invoke(state, config)
    print("\nSession contents:")
    for i in graph.get_state_history(config, limit=3):
        print(i)


if __name__ == "__main__":
    main()