For days, Ox Alpha drew heavy interest from developers who praised its coding skills and tried to identify who built it. The popular model was free to test and anonymous, which fueled speculation about whether a major lab was behind it. The company Z.ai has now said Ox Alpha was its work.
Z.ai grew out of a top Chinese university
Z.ai, known domestically as Zhipu AI, says it was founded in 2019 using technology originating at Tsinghua University in Beijing. The firm developed the GLM, or General Language Model, family of large language models, and introduced its ChatGLM chatbot in 2023.
It went public just this year
The company listed in Hong Kong in January under the corporate name Knowledge Atlas Technology, later changing its English name to Z.ai in July. Its shares were priced at 116.20 Hong Kong dollars and began trading on January 8. Z.ai’s stock now trades around HK$1,100, roughly nine times the IPO price.
In 2024, it reported revenue of 724.3 million Chinese yuan, about 108 million dollars, more than double its 2023 total, according to its disclosures. The company said it spent about 3.2 billion yuan on research and development and recorded a net loss of about 4.7 billion yuan. Z.ai is scheduled to report first-half results on Monday.
What does Z.ai actually do?
The firm delivers services through two main segments. It offers cloud-based access as well as customized deployments installed on customers’ own infrastructure. Its product lines include APIs, enterprise AI agents, general-purpose models, and technical services.
Ox Alpha was really GLM-5.3-Flash
Z.ai said it tested GLM-5.3-Flash anonymously under the Ox Alpha label on OpenRouter and OpenCode. The move set off a guessing game among developers, with some pointing to a Chinese lab and others wondering if Microsoft was involved. The discussion spread on Chinese social platforms, where users dubbed it the “Niu Lai Model,” a nod to a low-budget animated film about a calf that became a meme this month.
On Wednesday, Z.ai confirmed that Ox Alpha was GLM-5.3-Flash. The model is multimodal, handling text, images, and video. Its weights are available on Hugging Face, allowing developers to download and run it locally.
Ox Alpha runs on Chinese chips
The company said all traffic from the Ox Alpha test was served using Chinese AI chips. The statement comes as Washington has restricted China’s access to advanced semiconductors used to train and run AI systems. Z.ai said the domestic chips had limits in memory capacity and bandwidth.
Engineers sought to offset those constraints through software optimization and workload distribution across the hardware. For investors watching the broader semiconductor and AI hardware space, recent moves in names like AMD and Intel have drawn attention.
Z.ai has tested models anonymously before
Ox Alpha was not Z.ai’s first hidden release. The company previously evaluated GLM-5 under the alias Pony Alpha. Z.ai said the purpose of running GLM-5.3-Flash as Ox Alpha was to collect user feedback ahead of a formal launch.