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....

Input

$0.13 / 1M tokens

Output

$0.39 / 1M tokens

Context

262K tokens

Capabilities

✓ Streaming✓ Tool / function calling○ JSON / structured output○ Vision (image input)

Call this model

Pass stepfun/step-3.5-flash as the model. Change only the base URL from your existing OpenAI SDK setup.

quickstart.sh

curl https://modeldatabase.com/v1/chat/completions \
  -H "Authorization: Bearer $MDB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "stepfun/step-3.5-flash",
    "messages": [{"role":"user","content":"Hello!"}]
  }'

Prices are final — the routing margin is already included. See the full pricing table or the API docs.