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....

262K context·$0.10 in·$0.30 out·Jan 2026 release·Reasoning, Tools / functions, Web search

Available on

OpenRouter

Providers

Where StepFun: Step 3.5 Flash runs in Big-AGI, with each service's own model ID and USD-per-1M-token rates. The summary above prefers the creator's claim; rates below are each service's own.

ServiceModel IDContextInputOutput

OpenRouter

stepfun/step-3.5-flash

262K

$0.10

$0.30

Usage mix in Big-AGI: OpenRouter 100%Specs as reported by each service · usage over the last 2 days · refreshed hourly

Run StepFun: Step 3.5 Flash in Big-AGI.

Connect your own key on any of the services above, at their rates, no markup - and run it side by side with every other model.

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