StepFun Step 5 Preview lands on OpenRouter with 600B parameters and 1M context

StepFun Step 5 Preview has been added to OpenRouter: a sparse Mixture-of-Experts model with 27B active and 600B total parameters, a 1M-token context and pricing of $1 in / $2.70 out per 1M tokens. It targets agentic work and software engineering tasks.

• Sparse MoE: 27B active parameters out of 600B total
• 1M-token context at $1/$2.70 per 1M tokens
• Focused on agentic work and software engineering
• Claude Haiku 5.5 listed as the next release