custom supabase checkpointer

[kaushalendra-pandey]

I wanted a create a checkpointer which uses supabase to store data. How can i do that ?

[hinthornw]

Maybe reference the postgres implmenetation

[Shavvimal]

Try something like this:

import os
from typing import Optional
from dotenv import load_dotenv
from psycopg import AsyncConnection
from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
from api.utils.logger import setup_logger

load_dotenv()


class PGDatabase:
    """
    A singleton class for managing PostgreSQL database connections and LangGraph checkpointing.
    Uses direct connection for Supabase compatibility.
    """

    _instance: Optional["PGDatabase"] = None

    def __new__(cls) -> "PGDatabase":
        if cls._instance is None:
            cls._instance = super(PGDatabase, cls).__new__(cls)
        return cls._instance

    def __init__(self) -> None:
        if not hasattr(self, "initialized"):
            self._db_uri = os.getenv("DATABASE_URI")
            self.conn: Optional[AsyncConnection] = None
            self._checkpointer: Optional[AsyncPostgresSaver] = None
            self.logger = setup_logger()
            self.initialized = True

    async def setup_connection(self) -> None:
        """Initialize the database connection and set up the checkpointer"""
        if self.conn:
            await self.close_connection()

        self.conn = await AsyncConnection.connect(
            self._db_uri,
            autocommit=True,  # Required for concurrent operations
            sslmode="require",  # Enforce SSL
            connect_timeout=10,  # Add timeout
        )

        try:
            self._checkpointer = AsyncPostgresSaver(self.conn)
            await self._checkpointer.setup()
        except Exception as e:
            await self.close_connection()
            raise e

    async def close_connection(self) -> None:
        """Close the database connection and cleanup prepared statements"""
        if self.conn:
            try:
                # Clean up any prepared statements
                async with self.conn.cursor() as cur:
                    await cur.execute("DEALLOCATE ALL")
            except Exception as e:
                self.logger.warning(f"Error cleaning up prepared statements: {e}")
            finally:
                await self.conn.close()
                self.conn = None
                self._checkpointer = None

    @property
    def checkpointer(self) -> Optional[AsyncPostgresSaver]:
        """Access the LangGraph checkpointer"""
        return self._checkpointer

    async def __aenter__(self) -> "PGDatabase":
        """Async context manager entry"""
        await self.setup_connection()
        return self

    async def __aexit__(self, exc_type, exc_val, exc_tb) -> None:
        """Async context manager exit"""
        await self.close_connection()


if __name__ == "__main__":
    import asyncio

    async def test_connection():
        async with PGDatabase() as db:
            print("Database connection established")
            # Your database operations here
        print("Database connection closed")

    asyncio.run(test_connection())

Then use the checkpointer property as in the docs

[SkrOYC]

I will open source the repo once I clean it
https://www.npmjs.com/package/@skroyc/langgraph-supabase-checkpointer

[SkrOYC]

Thanks for the comments! That's the reason I have not open source it yet, I left some documentation neglected (I'm so sorry for the confusion).
I will solve it hopefully this week and also make is so that it is just a single migration without any confusions about v1 or v2.

The reason there is a v2 is that I created the glob storage following some inspiration from the official Postgres checkpointer but it's quite unefficient to save directly in the database instead of using Supabase Storage, which is what V2 does.

I will let you know as soon as I publish the repo!

[UtsavChokshiCNU]

@SkrOYC ... It would be really great, if you can open source repository. You can add me as maintainer. It is now digressing from standard langgraph's BaseCheckpointSaver interface. SupabaseSaver is now missing deleteThread method.

[SkrOYC]

I'm sorry for the delay! My weeks are longer than expected sometimes 😅
I'm reestructuring the repo to a monorepo with two separate packages: SupabaseSaver and SupabaseStore
I'll work on it and come back in short

[SkrOYC]

@SkrOYC ... It would be really great, if you can open source repository. You can add me as maintainer. It is now digressing from standard langgraph's BaseCheckpointSaver interface. SupabaseSaver is now missing deleteThead method.

Could you reference where the method is? I was not able to find it directly in the langgraphjs repo

[UtsavChokshiCNU]

@SkrOYC .. https://langchain-ai.github.io/langgraphjs/reference/classes/checkpoint.BaseCheckpointSaver.html#deleteThread

If you are looking at langgraph repo using your installed packages in IDE then make sure you install version > 0.4.0