StepFun: Step 3.5 Flash

stepfun/step-3.5-flash

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....

Context window: 262,144 tokens
Input: text
Output: text
Relay support: Text & documents

Open in workspace →OpenRouter model page

Reference prices & points

Our global markup: 15% · 1 USD = 10,000 points · Price version 0

Billing unit	OpenRouter / USD	Our reference / USD	Points
Input / 1M tokens	$0.1	$0.115	1,150
Output / 1M tokens	$0.3	$0.345	3,450

Actual charge = the OpenRouter request cost × the markup locked for that request. Catalogue rates may be routing references; caching, long context, images and audio are charged when used. Listed prices do not mean every capability is available through this relay.

Catalogue time: 2026-11-11T23:05:25.472Z · Live catalogue

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{
  "prompt": "0.0000001",
  "completion": "0.0000003"
}

Integration & availability

Use /v1/chat/completions for non-streaming, multi-turn conversations. Models marked for vision accept images; documents can be extracted to text in the workspace. Create a site API key and ensure you have enough points and the service is enabled. Provider availability, context and budget limits apply.

Read the API guide → · Back to model directory