Dettmers releases CliffCompaction: 50% token savings for million-token coding agent sessions
Tim_Dettmers · x · 2026-09-23
Tim Dettmers' team open-sourced CliffCompaction, an autocompaction tool for coding agents that supports million-token sessions and cuts token costs by up to 50% while matching or beating baselines on Terminal-Bench and KernelBench.
- Key principle: only truncate or drop content, never rephrase; never compact a compaction—each pass operates on original content only, preventing context drift.
- Results: under parallel test-time scaling, Kimi K2.6 + CliffCompaction matches Opus 4.7 and beats Opus 4.6 and GPT-5.3 Codex at lower cost; +10pp on Terminal-Bench for less than two full-context runs.
- Continual learning: reaches 2.23x CUDA kernel speedup at 200 steps and 3.58x at 400 steps on KernelBench, surpassing specialized search algorithms and trained agents.
- Integration: works with Claude Code and Codex; the team says it has better vibes than their built-in compaction after months of use. Paper, code, PyPI and blog are all available.
More from coding & agent
- lattedit launches free local-first browser LaTeX editor with MCP support for coding agents — cneuralnetwork · 2026-11-11
- Rivet launches SQLite Forking: 20ms agent-thread forks with zero data copying — samgoodwin89 · 2026-11-11
- YouArt Desktop launches: AI agent edits video in CapCut, DaVinci and Premiere from client feedback — mhdfaran · 2026-11-11
- Boubou: one-command local voice AI that serves your phone and robots over Wi-Fi — LuozhuZhang · 2026-11-11
- Python 3.15 makes AttributeError actionable: suggests .append for .push mix-ups — KhuyenTran16 · 2026-11-11
- sentence-transformers maintainer releases new embedding pooling training method, code & checkpoints — tomaarsen · 2026-11-11