Context

Within Langgraph we will want to have a mongodb implementation of document store as well (if and when it becomes part of the open-source package). This is independent of Atlas (as was the checkpointer).

There is a reference implementation in langgraph.store.postgres: BasePostgresStore

Definition of done

Implemented, tested, and reviewed by LangGraph maintainers.

Pitfalls

There may be tests that must be passed for it to be fully pluggable that are in langgraph/tests. This was the case with test_pregel.py in the Checkpointer.