Kimi K2: Open Agentic Intelligence

著者: Kimi Team, Bai, Yifan, Bao, Yiping, Charles, Y., Chen, Cheng, Chen, Guanduo, Chen, Haiting, Chen, Huarong, Chen, Jiahao, Chen, Ningxin, Chen, Ruijue, Chen, Yanru, Chen, Yuankun, Chen, Yutian, Chen, Zhuofu, Cui, Jialei, Ding, Hao, Dong, Mengnan, Du, Angang, Du, Chenzhuang, Du, Dikang, Du, Yulun, Fan, Yu, Feng, Yichen, Fu, Kelin, Gao, Bofei, Gao, Chenxiao, Gao, Hongcheng, Gao, Peizhong, Gao, Tong ほか 170 名 - arXiv 2025 被引用: 1,047

We introduce Kimi K2, a Mixture-of-Experts (MoE) large language model with 32 billion activated parameters and 1 trillion total parameters. We propose the MuonClip optimizer, which improves upon Muon with a novel QK-clip technique to address training instability while enjoying the advanced token efficiency of Muon. Based on MuonClip, K2 was pre-trained on 15.5 trillion tokens with zero loss spike. During post-training, K2 undergoes a multi-stage post-training process, highlighted by a large-scale agentic data synthesis pipeline and a joint reinforcement learning (RL) stage, where the model improves its capabilities through interactions with real and synthetic environments. Kimi K2 achieves state-of-the-art performance among open-source non-thinking models, with strengths in agentic capabilities. Notably, K2 obtains 66.1 on Tau2-Bench, 76.5 on ACEBench (En), 65.8 on SWE-Bench Verified, and 47.3 on SWE-Bench Multilingual -- surpassing most open and closed-sourced baselines in non-thinking settings. It also exhibits strong capabilities in coding, mathematics, and reasoning tasks, with a score of 53.7 on LiveCodeBench v6, 49.5 on AIME 2025, 75.1 on GPQA-Diamond, and 27.1 on OJBench, all without extended thinking. These results position Kimi K2 as one of the most capable open-source large language models to date, particularly in software engineering and agentic tasks. We release our base and post-trained model checkpoints to facilitate future research and applications of agentic intelligence.