Step 3.5 Flash 2603

stepfun-ai/step-3.5-flash-2603

Step 3.5 Flash 2603 is optimized for high-frequency agentic and coding workflows with improved token efficiency and faster reasoning. NOTE: This model runs via StepFun, which may log and train on your prompts.

Reasoning

Chat with this model Create an API key

Pricing

Includes our margin. Charged per request from your balance.

Input: $0.11 per 1M tokens
Output: $0.33 per 1M tokens
Typical message: $0.00099

Details

Provider: StepFun
Context: 262K tokens
Max output: 66K tokens
Added: Apr 14, 2026

Use it from the API

Replace $HIDE_API_KEY with a key from the Developers page. Base URL https://hide.st/api/v1.

curl https://hide.st/api/v1/chat/completions \
  -H "Authorization: Bearer $HIDE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "stepfun-ai/step-3.5-flash-2603",
    "messages": [
      {"role": "user", "content": "Hello!"}
    ]
  }'

Pricing

Details

Use it from the API

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