StepFun (阶跃星辰) scheduled its flagship Step 5 Preview model’s open-source release for October 15.

StepFun (阶跃星辰) scheduled the open-source release of its latest flagship foundation model, Step 5 Preview, for October 15, according to the supplied report citing official information. As of the digest date, this is an announced release schedule rather than a completed open-source release.

The same message says Step 5 Preview reached first place on OpenRouter’s Trending list and second place globally on its daily list. The report does not specify the daily ranking’s underlying metric or provide associated usage totals.

These are platform-ranking statements, not disclosed model-quality benchmark results. The source provides no parameter count, license terms, release-artifact details, context-window specification, or hardware requirements.