Undefined table 'checkpoints' when using Postgres

[vignesh-spericorn]

Checked other resources

• I added a very descriptive title to this issue.
• I searched the LangGraph/LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangGraph/LangChain rather than my code.
• I am sure this is better as an issue rather than a GitHub discussion, since this is a LangGraph bug and not a design question.

Example Code

from langgraph.checkpoint.postgres import PostgresSaver
from psycopg import Connection

DB_URI = "postgresql://postgres:postgres@localhost:5432/llama_db?sslmode=disable"
connection_kwargs = {
    "autocommit": True,
    "prepare_threshold": 0,
}

with Connection.connect(DB_URI, **connection_kwargs) as conn:
    checkpointer = PostgresSaver(conn)
    # NOTE: you need to call .setup() the first time you're using your checkpointer
    checkpointer.setup()
    # Finally, we compile it!
    app = workflow.compile(checkpointer=checkpointer)

    config = {"configurable": {"thread_id": "1"}}

    while True:
        user_input=input("User: ")
        if user_input.lower() in ["quit","q"]:
            print("Good Bye")
            break

        for event in app.stream({'messages': user_input}, config, stream_mode='updates'):
            for value in event.values():
                pass

            print_update(event)
            
        print("Assistant:",value["messages"][0].content)

Error Message and Stack Trace (if applicable)

psycopg.errors.UndefinedTable: relation "checkpoints" does not exist
LINE 34: from checkpoints WHERE thread_id = $1 AND checkpoint_ns = $2...

Description

I was trying this example to create a custom chatbot with memory that is managed according to my logic instead of 6 messages. When i try to use Postgres instead of MemorySaver() I get the above error message that 'checkpoints' table doesn't exist.

System Info

Ubuntu 20.04
Python 3.11.10
langgraph==0.2.34
langgraph-checkpoint==2.0.1
langgraph-checkpoint-postgres==2.0.1

[vbarda]

@vignesh-spericorn were there any errors from running checkpointer.setup()? the error you're seeing seems to indicate that .setup() didn't properly run

[vignesh-spericorn]

@vbarda i didn't get any errors i checked the Postgres DB it had the following tables
checkpoint_blobs
checkpoint_writes
checkpoint_migrations

but checkpoints table is not present

[vbarda]

@vignesh-spericorn hmm, could you try deleting all checkpoint-related tables you mentioned and then re-running .setup()?