---
title: 'CliffCompaction: Cost-Efficient Compaction for Long-Horizon Coding Agents'
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
license_note: 'paper is CC BY 4.0 (verified on arXiv abs page 2026-11-11; icon by-4.0.png, http://creativecommons.org/licenses/by/4.0/); note is our own summary'
source: https://iinventedlight.com/library/notes/2609-26779-cliffcompaction.md
source_license: 'CC BY 4.0'
attribution: 'Summary by iinventedlight (AI-assisted). Source: Trang Nguyen, Eulrang Cho, Bingqing Chen, Tim Dettmers, CliffCompaction: Cost-Efficient Compaction for Long-Horizon Coding Agents (CC BY 4.0).'
author: 'iinventedlight (AI-assisted)'
date: 2026-11-11
status: published
approved_by: "Cole Withington, 2026-11-11 20:07 PT, Librarian chat widget t1715u: \"okay you can publish the ones you're comfortable with\""
checked_on: 2026-11-11
as_of: 2026-11-11
confidence: medium
untested: 'Not reproduced. Abs page and HTML key sections read 2026-11-11. Named code URLs checked for HTTP 200; code not run.'
category: arxiv
topic_area: 'ai-research: agent memory and context compaction'
tags: agents, memory, compaction, arxiv
arxiv_id: 2609.26779
alias: 2609.26779-cliffcompaction
sources:
  - id: S1
    title: 'CliffCompaction: Cost-Efficient Compaction for Long-Horizon Coding Agents'
    publisher: arXiv
    authors: 'Trang Nguyen, Eulrang Cho, Bingqing Chen, Tim Dettmers'
    url: https://arxiv.org/abs/2609.26779
    version_read: 'v1 (22 Sep 2026)'
    accessed: 2026-11-11
    license: 'CC BY 4.0'
---
# CliffCompaction: Cost-Efficient Compaction for Long-Horizon Coding Agents

## Summary
We develop CliffCompaction, an autocompaction technique for coding agents. On Terminal-Bench 2.0, it achieves higher success rates while reducing cost by 50%. On KernelBench, CliffCompaction reaches CUDA kernel speedups of 2.23 times after 200 steps and 3.58 times after 400 steps. [S1]

## Claims
- id: C1
  claim: 'The method is an autocompaction technique for coding agents.'
  source: S1
  evidence: "We develop CliffCompaction , an autocompaction technique for coding agents."
- id: C2
  claim: 'They report a 50% cost reduction on Terminal-Bench 2.0 with higher success rates.'
  source: S1
  evidence: "On Terminal-Bench 2.0, it achieves higher success rates while reducing cost by 50%."
- id: C3
  claim: 'A public GitHub repository is linked from the paper HTML.'
  source: S1
  evidence: "https://github.com/nguyenvuthientrang/cliffcompaction"

## Verification
- Code available: HTML points to https://github.com/nguyenvuthientrang/cliffcompaction (HTTP 200 on 2026-11-11). Not run.
- Reproduced: not reproduced (2026-11-11). Code not run.
- Related work: Live notes ao-compaction and ao-cost-compression-accounting. AutoCompact in this batch learns when to compact instead.
- Limits: Author-reported on their scaffolds and models, including GLM-5.1 and Kimi K2.6 at 32K and 16K thresholds on SWE-bench Verified.
- License: CC BY 4.0 on the abs page (2026-11-11; icon by-4.0.png; http://creativecommons.org/licenses/by/4.0/). Submitted 22 Sep 2026 (v1). Sources: [S1] https://arxiv.org/abs/2609.26779, v1 (22 Sep 2026). checked_on: 2026-11-11.

## When to apply
Use when asking whether a cheaper compaction method can hold coding-agent success under a bounded context, including long continual-learning runs.

## Facts
- id: F1
  claim: 'CliffCompaction is presented as an autocompaction method for coding agents that aims to cut cost under a bounded context.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0
- id: F2
  claim: 'The authors report higher success on Terminal-Bench 2.0 while reducing cost by 50%.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0
- id: F3
  claim: 'On KernelBench, they report CUDA kernel speedups of 2.23 times after 200 steps and 3.58 times after 400 steps.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0

## Sources
- [S1] arXiv 2609.26779, https://arxiv.org/abs/2609.26779. License: CC BY 4.0. v1 (22 Sep 2026). Accessed 2026-11-11.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted). Paper is CC BY 4.0.

---

Agents: [/agents.md](/agents.md) | [/.well-known/agent-library.json](/.well-known/agent-library.json).