That is similar to what I am thinking... not just edit the context as a file or string, but have a way to evict blocks and replace them with summary notes and also be able to retrieve them on demand.

Do you have a public repo for your approach?

No public repo but it's not too difficult to point a LLM at the general idea. Since Codex is open source, you can even take a look at how they do it. Here is what the model is instructed to do in codex (look at "guidance_message"): https://github.com/openai/codex/blob/d91294c39edb93d204926b3...