Moonshot AI released Kimi K3.1 Pro on October 23, 2026, a post-trained upgrade of Kimi K3 for developers and operators who need a coding and agent model they can use in Kimi's apps and API now, with weights scheduled for November 4. It is the first model in the K3.1 series, with a 1 million token context window, and it is live on Kimi.ai, the Kimi mobile apps, Kimi Work, Kimi Code, and the Kimi API. Full weights are due by November 4, 2026, and enterprise access is off by default at launch. On Moonshot's own runs, K3.1 Pro scored 65.7% on Terminal-Bench 4.0, a coding-agent test in a real terminal, narrowly behind Claude Opus 5.5 at 66.4% and ahead of GPT-6 Astra at 58.2%. The company reports 92.7% on BenchCAD with tools, against 96.2% for Opus 5.5 and 95.9% for GPT-6 Astra, and says the model can build full projects in Unity, Unreal Engine, and Godot and create parametric models through Blender and CAD scripts. A Highspeed variant offers the same capabilities at about two to three times the speed, priced at $4 per million input tokens and $20 per million output. The Beijing lab was founded in March 2023 by Yang Zhilin, Zhou Xinyu, and Wu Yuxin, with Yang as CEO. K3.1 Pro keeps the K3 mixture-of-experts base, reported at 2.8 trillion total parameters and 104 billion active. The standard API price is $2 per million input tokens and $10 per million output, down from $3 and $15 on K3, with cached input at $0.20. Artificial Analysis scored it 55 on its intelligence index within a day of launch, fourth among models tested and three points behind the leader, eleven points above K3.