Z.ai has confirmed it is the lab behind Ox Alpha, the mysterious open-weight AI model that appeared anonymously on OpenRouter and has been topping benchmarks against leading models.
According to Bloomberg, Z.ai said Ox Alpha is the newest iteration of its GLM series. The company describes it as “a reasoning model designed for coding, sustained agentic work, and production workloads,” suited for long-horizon software engineering, complex reasoning, and workflows combining text with visual context.
The company said it will release the weights for Ox Alpha on Wednesday, allowing developers to build on top of it. The release adds to the growing presence of cheap, capable Chinese AI models that could challenge expensive frontier offerings from companies like OpenAI and Anthropic.