Someone just dropped a powerful new AI model onto OpenRouter’s API platform and walked away without leaving a business card. Ox Alpha, listed under the provider name “Stealth,” launched on August 20 with a 1,048,576-token context window, multimodal reasoning across text, image, and video inputs, and a price tag of exactly zero dollars for its one-week preview period.
The model’s anonymous debut has sent the developer community into full detective mode, with tokenizer fingerprinting and API signature matching pointing strongly toward a familiar suspect: China’s Zhipu AI, now known as Z.ai.
What Ox Alpha actually does
A million-token context window is the headline feature, and it’s worth understanding what that means in practice. Most large language models can process somewhere between 8,000 and 128,000 tokens at once. A million tokens is roughly equivalent to feeding the model an entire codebase, or several full-length novels, in a single prompt.
That kind of capacity makes Ox Alpha particularly suited for long-horizon software engineering tasks, where an AI agent needs to understand vast amounts of existing code before making changes. Early testers have already noted its seamless integration into coding agents and editors.
