The anonymous model Ox Alpha that appeared on OpenRouter in stealth mode this weekend has been revealed as a new GLM model from Zai (Zhipu AI). It immediately took the top usage spot—more than doubling DeepSeek—and OpenRouter calls it the largest launch in the platform’s history.

The community identified Zai as the author before the company confirmed it, through characteristic API errors and tokenizer architecture. Bloomberg confirmed the model is optimized for coding and complex agentic tasks and is multimodal—a shift from Zai’s previous lineup, which kept text GLM and visual GLM-V models separate.

Ox Alpha is free on OpenRouter for one more week, after which Zai will announce commercial pricing. The weights are promised to be released today.

Related: Zhipu AI Releases GLM-5.2 with 1M Token Context Window, ZAI releases GLM-4.7 Flash

Bloomberg: China’s Z-AI Made Ox Alpha, Stealth Model That Rivals DeepSeek