Z.

ai, the Chinese AI lab behind the GLM model series, has been confirmed as the creator of Ox Alpha, a mysterious open-weight model that appeared on OpenRouter over the weekend and quickly topped benchmarks.

Bloomberg reported the connection, and Z.ai confirmed that Ox Alpha is the newest iteration of its GLM family.

The company says Ox Alpha is a reasoning model designed for coding, sustained agentic work, and production workloads, with strengths in long-horizon software engineering, complex reasoning, and text-plus-visual workflows.

Weights will be released on Wednesday, allowing developers to build on it.

The release adds to a growing wave of low-cost, high-capability Chinese models that threaten the market share of expensive frontier labs like OpenAI and Anthropic. Earlier this month, Z.

ai also released GLM-5.3, which rivals Anthropic’s Fable 5 on certain benchmarks. TechCrunch has reached out to Z.ai for further comment.