Ox Alpha emerges as new stealth AI model with 1M context window

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 i...