China’s Z.AI Co., also known as Zhipu, said it created Ox Alpha, an AI model that has reached the top of online usage charts while offering high performance at no cost. The company confirmed on Wednesday that Ox Alpha is a new iteration of its GLM model series. Z.AI said it will release Ox Alpha’s model weights tonight. The confirmation followed speculation over the model’s origin and development.

Ox Alpha is a free stealth reasoning model on OpenRouter for coding, sustained agentic work, production workloads, long-horizon software engineering, and complex reasoning. It accepts text, images, and video as input and returns text, supporting workflows that combine written and visual context. The model was released on August 20, 2026. An anonymous third-party provider develops and operates Ox Alpha during its preview period. OpenRouter routes requests directly to the model but is not its developer, owner, or provider. The provider retains prompts and completions, although it does not use them for training; other handling is governed by OpenRouter’s Stealth Model Terms. Ox Alpha is hosted by one provider, so OpenRouter has no alternative provider routing choices for requests. The model has a 1,048,576-token context window and can generate up to 131,072 completion tokens. It supports function calling through tools and tool_choice, plus JSON output through response_format without JSON Schema enforcement. OpenRouter lists prompt and completion token pricing at zero. Its reported median latency is 2.02 seconds and median throughput is 50 tokens per second. OpenRouter reports 99.99% uptime and 96.79% availability over the measured period.