MemorySaver/Checkpointer is not recalling thread discussion

Product Help LangGraph
,
1

Hello I’m pretty new to LangGraph in general but I’m experiencing some issues with recalling using a checkpointer.

So I do have this setup:

import {
  Annotation,
  StateGraph,
  MessagesAnnotation,
  START,
  END,
  MemorySaver,
} from '@langchain/langgraph';
import { createReactAgent } from '@langchain/langgraph/prebuilt';
import { ChatOpenAI } from '@langchain/openai';
import { tools } from './tools';

// LLm model
const llm = new ChatOpenAI({
  model: 'gpt-4o',
  temperature: 0,
});

// Agent
const agent = createReactAgent({
  llm,
  tools,
});

// State
const StateAnnotation = Annotation.Root({
  ...MessagesAnnotation.spec,
  test: Annotation<string>(),
});

const graph = new StateGraph(StateAnnotation);

// Nodes
const node1 = async (state: typeof StateAnnotation.State) => {
  const { messages, test } = state;

  const lastMessage = messages[messages.length - 1];

  const result = await agent.invoke(
    {
      messages: [lastMessage],
    },
    {
      configurable: { thread_id: '1' },
    },
  );

  return result;
};

// Graph
graph.addNode('node1', node1).addEdge(START, 'node1').addEdge('node1', END);

const checkpointer = new MemorySaver();

export const compiledGraph = graph.compile({
  checkpointer,
});

And working with it mainly from langgraph studio.

Now on my first prompt i’m sending for example:
user: ‘Hello my name is John’
assistant: ‘Hello John how can I help you today?’

On my second input i’m asking:
user: ‘What is my name?’
assistant: ‘I’m sorry, but I don’t have access to personal data…’

I see If i pass here:


  const result = await agent.invoke(
    {
      messages: [lastMessage],
    },
    {
      configurable: { thread_id: '1' },
    },
  );

All of the messages it’s able to recall my name but at the same time I don’t want to use all of the previous conversation as a Input ( at least this is how i’m thinking could be wrong tho )

Also I’m using MessagesAnnotation.spec which I’m aware takes care for the messages inside the state with the reducer and everything but how writing is happening there? I feel like something are happening under the hood and is hard to understand whats going on.

Any advices are much appreciated it!

2

Okay, I understand now. The issue is that when running inside LangGraph Studio, it’s using PostgreSQL to persist state—so the Memory Saver feature seems redundant, lol.

However, when accessing it via Postman, even if we pass all the messages, without a checkpointer there’s no persistent state across requests. That’s where we can actually see the Memory Saver in action. :heart: