Step-3

Reasoning Tool Calling Attachments

StepFun flash model for efficient multimodal reasoning, coding, and tool use

Providers 2

Released Jul 31, 2025

Input Modalities image, text

Output Modalities text

Tarsk Use coding

Available Providers (2)

Provider	Model ID	Input Cost	Output Cost	Context	Max Output	Docs
ZenMux	`stepfun/step-3`	$0.21/MTok	$0.57/MTok	65.5K	64K
NanoGPT	`step-3`	$0.25/MTok	$0.65/MTok	65.5K	8.2K

Reasoning

Tool Calling

Attachments

Open Weights

Structured Output