Disclosure: I work on MemorySync (I'm Mohammed, the founder). I drafted this page with AI assistance and checked it against the source thread and the official docs listed under Sources on Oct 28, 2026. I read the thread and the LangChain docs; I didn't run this agent for this page.

The question

In the LangChain forum thread "LangGraph + PostgreSQL: Chat history and summarization best practice" (Apr 20, 2026), a developer building a ChatGPT-style chatbot on LangGraph, with PostgreSQL as the checkpointer, described the bind:

When I summarize older messages and delete them from the database, the UI breaks because full chat history is lost

If I don't delete messages, context becomes too large for the model

They wanted the UI to show the full conversation while the model sees "summarized older messages" plus "recent messages".

Status (checked Oct 28, 2026): the thread is open, with one reply from a community member and no accepted answer.…