Long conversations
A long thread does not have to end. When it comes up against the model's context limit, the older turns are compacted into a summary and the conversation carries on instead of failing.
Fold
Older turns
Compacted
Summary
Marker
The seam stays visible
Compaction is not silent. It is shown in the thread, so you can see where it happened and which part of the history has been folded up.
Cost
Written by a cheap model, on purpose
The summary itself has to be written by a model, and that one is deliberately cheap: a long conversation does not get expensive just by existing.
Container
Nothing in your container moves
Compaction touches the conversation and only the conversation. Files are not part of the context in the first place, so everything in the container is left exactly as it was.