A mysterious new AI model is making the rounds among developers — and nobody is saying who built it. Ox Alpha appeared on OpenRouter on Thursday as a "stealth model" from an anonymous third-party provider. OpenRouter describes it as a "reasoning model designed for coding, sustained agentic work, and production workloads. It is suited for long-horizon software engineering, complex reasoning, and workflows that combine text with visual context."
It's also free.
OpenCode, an open-source AI coding agent, said on X that Ox Alpha would be free for a week with "near unlimited usage" and that its provider had capacity for 100 trillion tokens per day, which is roughly 100 times the number of AI tokens Visa said it uses in an entire month.
Ox Alpha has already attracted interest from prominent tech figures. Stripe CEO Patrick Collison tried the model and said in a post on X that "it's very impressive."
Early speculation suggests it may be the product of a Chinese AI lab. Wccftech, an online tech publication, suggested that the Chinese lab behind GLM-5, Z.ai, as one possibility, noting that the company previously tested GLM-5 anonymously under the name "Pony Alpha" and that developers have identified similarities in Ox Alpha's tokenizer behavior and responses.
That speculation comes as Chinese AI labs like Zhipu, DeepSeek, and Moonshot AI increasingly challenge US rivals. Models from those companies have approached the performance of leading American systems at a fraction of the cost and are largely open-source.
Moonshot's Kimi K3, released in July, is a 2.8 trillion-parameter open-weight model built for coding, reasoning, and agentic tasks that quickly drew attention in Silicon Valley for its performance and lower price.
Still, the evidence is far from conclusive.
Wccftech later highlighted a competing analysis suggesting Ox Alpha's tokenizer could instead point toward Microsoft's MAI family.
On Saturday, Andrew Curran, a prominent AI analyst, wrote on X that GLM had been the leading theory on Friday night, but by Saturday morning, "people seem less sure of anything."