NL2Repo-Bench: Towards Long-Horizon Repository Generation Evaluation of Coding Agents
Abstract
Recent advances in coding agents suggest rapid progress toward autonomous software development, yet existing benchmarks fail to rigorously evaluate the long-horizon capabilities required to build complete software systems. Most prior evaluations focus on localized code generation, scaffolded completion, or short-term repair tasks, leaving open the question of whether agents can sustain coherent reasoning, planning, and execution over the extended horizons demanded by real-world repository construction. To address this gap, we present NL2Repo Bench, a benchmark explicitly designed to evaluate the long-horizon repository generation ability of coding agents. Given only a single natural-language requirements document and an empty workspace, agents must autonomously design the architecture, manage dependencies, implement multi-module logic, and produce a fully installable Python library. Our experiments across state-of-the-art open- and closed-source models reveal that long-horizon repository generation remains largely unsolved: even the strongest agents achieve below 40% average test pass rates and rarely complete an entire repository correctly. Detailed analysis uncovers fundamental long-horizon failure modes, including premature termination, loss of global coherence, fragile cross-file dependencies, and inadequate planning over hundreds of interaction steps. NL2Repo Bench establishes a rigorous, verifiable testbed for measuring sustained agentic competence and highlights long-horizon reasoning as a central bottleneck for the next generation of autonomous coding agents.
Keywords
Cite
@article{arxiv.2512.12730,
title = {NL2Repo-Bench: Towards Long-Horizon Repository Generation Evaluation of Coding Agents},
author = {Jingzhe Ding and Shengda Long and Changxin Pu and Huan Zhou and Hongwan Gao and Xiang Gao and Chao He and Yue Hou and Fei Hu and Zhaojian Li and Weiran Shi and Zaiyuan Wang and Daoguang Zan and Chenchen Zhang and Xiaoxu Zhang and Qizhi Chen and Xianfu Cheng and Bo Deng and Qingshui Gu and Kai Hua and Juntao Lin and Pai Liu and Mingchen Li and Xuanguang Pan and Zifan Peng and Yujia Qin and Yong Shan and Zhewen Tan and Weihao Xie and Zihan Wang and Yishuo Yuan and Jiayu Zhang and Enduo Zhao and Yunfei Zhao and He Zhu and Liya Zhu and Chenyang Zou and Ming Ding and Jianpeng Jiao and Jiaheng Liu and Minghao Liu and Qian Liu and Chongyang Tao and Jian Yang and Tong Yang and Zhaoxiang Zhang and Xinjie Chen and Wenhao Huang and Ge Zhang},
journal= {arXiv preprint arXiv:2512.12730},
year = {2026}
}