StepFun

first_party

Getting credentials

api_key via header (header Authorization: Bearer)

Environment: STEPFUN_API_KEY

Create a key on the StepFun platform console (EN platform stepfun.ai, CN stepfun.com).

ID	URL	Protocol	Auth
chat-completions	`https://api.stepfun.ai/v1/chat/completions`	openai-chat	any

textstreaming

EN platform stepfun.ai, CN stepfun.com; step-3 (321B/38B VLM, Jul 2025) is the prior generation. (docs)
Parallel Thinking (PaCoRe) reasoning on 3.5-flash; 3.7-flash has three reasoning levels + Advisor Mode. (docs)

Model	Wire ID	Endpoint	Status	Reasoning
stepfun/step-3-5-flash	`step-3.5-flash`	chat-completions	ga	adaptive · default on · returns reasoning_content
stepfun/step-3-7-flash	`step-3.7-flash`	chat-completions	ga	effort · default on · returns reasoning_content