Step 5 Preview, a 1M-context MoE from StepFun, shows up on OpenRouter

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). $1 per million input tokens, $2.70 per million output tokens. 1,000,000 token context window, maximum output of 64,000 tokens.