Kimi K2.6: Moonshot AI's Open-Source Model Leads HLE — Developer Guide 2026

On April 21, 2026, Moonshot AI released Kimi K2.6 — and quietly handed developers the most capable open-source AI agent ever built. The new model scores 54.0 on Humanity’s Last Exam (HLE-Full) using tools, outperforming GPT-5.4, Gemini 3.1 Pro, and C...