Kimi K3.1 Pro closes the gap with closed models through post-training, not parameters

On October 23, 2026, Moonshot AI released Kimi K3.1 Pro, a 3T-class open-weight model built from heavy post-training of K3: it beats GPT-6 Astra on Terminal-Bench 4.0 and cuts its hallucination rate by nearly three times, without adding a single parameter. Full weights land on November 4 — a window to plan around for anyone who self-hosts.