Who’s behind the new ‘stealth model’ Ox Alpha?

Ox Alpha, a free “reasoning model designed for coding, sustained agentic work, and production workload,” was released on OpenRouter, where it is listed as a “stealth model” operated by an anonymous third-party provider. Stripe CEO Patrick Collison praised the model as “very impressive.” Analysts have debated its origin, with some linking it to Chinese GLM models from Z.ai and others suggesting it may be an unreleased Microsoft MAI version.