Step 5 Preview API
About
Build advanced reasoning agents with Step 5 Preview, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers available completely free of charge, native tool calling support. Access Step 5 Preview via the StepFun Step Plan (China) API with up to 66K output tokens.
Capabilities
Input Modalities
textimagevideo
Output Modalities
text
Limits
Context Window
1.0M
Tokens
Input Limit
1.0M
Tokens
Max Output
66K
Tokens
Pricing
Standard (per 1M tokens)
Input
Free
Output
Free
Frequently Asked Questions
Step 5 Preview by StepFun Step Plan (China) costs Free per 1M input tokens and Free per 1M output tokens.
Model Details
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
STEPFUN_API_KEY
API Base URL
https://api.stepfun.com/step_plan/v1