Stepfun-ai News

StepFun: Step 3.5 Flash (free) (stepfun/step-3.5-flash)

Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token. It is a reasoning model that is incredibly speed efficient even at long contexts.