OpenRouter’s official account introduced Ox Alpha as a “new stealth model,” positioned for efficient coding, sustained agentic work, and real-world production use. The post gives two key specifications: a one-million-token context window and text, image, and video input, then directs users to the Ox Alpha page for testing and feedback.
This official post directly supports the “native multimodal” narrative, but it does not identify the developer. X search results connect the model to Z.ai/GLM-5.3 Flash through community fingerprints. The safe wording is that the community is uncovering the identity—not that OpenRouter has confirmed Z.ai ownership.
This is a product announcement, not a benchmark report. It gives no visual-understanding accuracy, video-length limit, stable pricing commitment, or API model ID.
GLM-5.3-Flash
