ranxianglei/billion-context is a TypeScript plugin that hierarchically compresses the long conversation history of a coding agent so it can be carried on in a small context window. The latest release identifiable from the provided material is v0.1.208. What specifically changed in that version is not stated in the provided material.
The plugin is described as a structure that summarizes the conversation accumulating during long tasks step by step and holds it in the context window, and that passes the compressed content between multiple coding tools and models. Hierarchical compression is a way of keeping the needed context by stacking summaries stage by stage instead of shrinking the whole conversation in one pass. The goal is to keep working on a single session with a small context window even as the record grows long. The README cites long-running sessions on the scale of hundreds of millions of tokens and a 100K context window as its goals, and it explains integration with Claude Code, Codex, OpenCode and pi, along with how to check installation and cache state. The repository also contains a paper draft and English and Chinese documentation.
The README also claims a 5x reduction in tokens, but that is a figure written in the read material, and no independent evidence of reproduction has been confirmed. The design aimed at long-running sessions and a small context window is therefore confirmed, but expectations about the size of the reduction or the actual scale are hard to judge from the published description alone.