LangGraph Integration

Persist LangGraph graph state across invocations using Mnemora as the checkpoint backend.

Prerequisites

A Mnemora API key
LangGraph 0.2+ installed

Install

pip install "mnemora[langgraph]"

How it works

MnemoraCheckpointSaver implements LangGraph's BaseCheckpointSaver interface. It maps each LangGraph thread_id to a Mnemora agent_id, and the checkpoint namespace to a Mnemora session_id.

LangGraph concept	Mnemora concept
`thread_id`	`agent_id` (prefixed with `"langgraph:"`)
`checkpoint_ns`	`session_id`
Checkpoint payload	Working memory `data` field
Version counter	DynamoDB optimistic lock `version`

Basic usage

import asyncio
from mnemora import MnemoraClient
from mnemora.integrations.langgraph import MnemoraCheckpointSaver
from langgraph.graph import StateGraph, MessagesState, START, END

async def main():
    async with MnemoraClient(api_key="mnm_...") as client:
        saver = MnemoraCheckpointSaver(client=client)

        graph = StateGraph(MessagesState)
        graph.add_node("echo", lambda state: {"messages": state["messages"]})
        graph.add_edge(START, "echo")
        graph.add_edge("echo", END)

        app = graph.compile(checkpointer=saver)
        config = {"configurable": {"thread_id": "user-123"}}

        result = await app.ainvoke(
            {"messages": [{"role": "user", "content": "Hello"}]},
            config=config,
        )
        print(result["messages"][-1]["content"])

asyncio.run(main())

Custom namespace

saver = MnemoraCheckpointSaver(client=client, namespace="prod-chatbot")

Error handling

from mnemora import MnemoraConflictError, MnemoraAuthError

try:
    result = await app.ainvoke({"messages": [...]}, config=config)
except MnemoraConflictError:
    # Version mismatch — re-read and retry
    pass
except MnemoraAuthError:
    # API key is invalid or revoked
    pass

Troubleshooting

Symptom	Cause	Fix
`ImportError`	Package not installed	Run `pip install "mnemora[langgraph]"`
`ValueError: config must contain thread_id`	Missing thread config	Pass `config={"configurable": {"thread_id": "..."}}`
`MnemoraConflictError`	Concurrent writers	Re-read state and retry