StepFun’s Step 5 Preview is callable, but not downloadable yet
StepFun’s Step 5 Preview is available through an API, but the BF16 model is not yet something you can run yourself. Its Hugging Face repository contains only a .gitattributes file, with no weights, license, model card, or configuration; StepFun’s materials put the open-weights release on October 15, 2026. For now, self-hosting plans have no checkpoint behind them.