Step 5 Preview is StepFun's open-weight MoE for coding, financial research and long-running agents. It has 600B total parameters, 27B active per token and a 1M-token context, with deployment support for vLLM, SGLang and Transformers.

An Apache 2.0 open-weight Flash model for real-world agents. Step 3.7 Flash combines vision, coding, search, tool use, 256K context, ~11B active params, and up to 400 TPS.

Step 3.5 Flash is StepFun’s 196B sparse MoE model that activates only 11B parameters per token. It delivers frontier reasoning and strong agentic performance with high efficiency. Seamless native OpenClaw integration makes it one of the best open models for running serious agents right now.