Step 5 Preview, a 1M-context MoE from StepFun, shows up on OpenRouter
StepFun has released 'Step 5 Preview,' a 600B parameter Mixture-of-Experts model, now available on OpenRouter. The model is optimized for agentic workflows, software engineering, and professional finance tasks.
Why it matters
The release represents a significant advancement in large-scale, agentic AI models capable of handling complex, multi-step reasoning tasks.
Search ⌘ K Dashboard Models Benchmarks Chat Chat Rankings Apps Ori Pricing Docs Models Rankings Ori Benchmarks Chat Chat Pricing Docs Sign Up Sign Up © 2026 OpenRouter, Inc Product Chat Rankings Benchmarks Apps Discover Models Ori Collections Providers Tools Pricing Business Enterprise Labs Company About Blog Careers Hiring Privacy Terms of Service Trust Center Support Works With OR Data Brand Developer Documentation API Reference Developer Platform Status AI Site Map Connect Discord GitHub LinkedIn X YouTube Sign Up Sign Up StepFun: Step 5 Preview stepfun / step-5-preview Compare API Try this model Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional knowledge work, with particular strength in finance.
It is designed for extended tasks that span large codebases and documents, using tools and refining results over multiple steps.
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