Reasoning Tools JSON Open weights

Newer StepFun flash model for faster agents, coding, and multimodal prompts

stepfun/step-3.7-flash 2026-05-29 256K context $0.202/M input $1.211/M output
21 providers
Reasoning Open weights

StepFun flash lane for quick multimodal reasoning and coding assistance

stepfun/step-3.5-flash 2026-01-29 256K context $0.105/M input $0.314/M output
15 providers