Mystery AI model Ox Alpha appears on OpenRouter, free with 1M context

Ox Alpha, a free stealth model with a 1M context window and multimodal capabilities, appeared on OpenRouter on Aug 20, 2026. It scored 96% on SWE-bench Verified Mini (48/50) and over 80% on DeepSWE tasks, outperforming GPT-5.6 Sol and Fable 5 Max. Its origin is unknown, with speculation ranging from a Chinese lab to Gemini 3.5 Pro.