tl;dr: Moonshot's Kimi K3.1 Pro is a new 3T-class open-weight model with a 1M-token context, posting competitive results against Claude Opus 5.5 and GPT-6 Astra on coding (65.7% on Terminal-Bench 4.0), 3D/CAD generation, and financial reasoning benchmarks. A "Highspeed" variant runs 2-3× faster, and the team deliberately stripped cyber-related data from training to cap offensive security capabilities before release. Available now via Kimi.ai and API, with full weights to be released by Nov 4, 2026.