StepFun: Step 3.5 Flash
Stepfun
stepfun/step-3.5-flashAbout this model
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....
Make a request
OpenAI-compatible: set the base URL and your Promptix API key, keep your existing SDK.
curl https://promptix.tn/api/v1/chat/completions \ -H "Authorization: Bearer $PROMPTIX_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "stepfun/step-3.5-flash", "messages": [ {"role": "user", "content": "Hello! What can you do?"} ] }'Pricing
In TND per 1M tokens. VAT and the platform fee are added at top-up.
Input tokens
0.332 TNDper 1M tokens
Output tokens
0.997 TNDper 1M tokens
1,000 requests with 1K input and 500 output tokens cost about 0.831 TND.
Specifications
- Provider
- Stepfun
- Context window
- 262,144 tokens
- Input modality
- Text
- Added
- Jan 29, 2026
- Supported parameters
frequency_penaltyinclude_reasoningmax_tokensreasoningtemperaturetool_choicetoolstop_k