Step 3.5 Flash 2603 API
StepFun's Step 3.5 Flash 2603, through an OpenAI-compatible API. Providers quote it on an open exchange, and each request goes to the offer with the lowest estimated charge that meets your rules.
- Providers compete for each request. The exchange ranks the offers that meet your rules by estimated charge. It fixes your maximum charge before the first token, and you pay for the tokens that the model uses.
- The OpenAI and Anthropic APIs. Use the OpenAI or Anthropic SDK that you have. Set the base URL and your key, and send step-3.5-flash-2603 as the model.
- Your data rules. Send x-liquid-retention: none and only offers whose provider does not keep your content compete for the request.
Facts
- Model name
- step-3.5-flash-2603
- Maker
- StepFun
- Context window
- 262.1K tokens
- Input price
- $0.100 per million tokens
- Output price
- $0.301 per million tokens
- Providers
- 1 independent provider
- Regions
- us
Providers
- Architect: us, $0.100 input and $0.301 output per million tokens, $0.100 cache read per million tokens, 262.1K tokens of context
Request
curl https://router.inference.ai.exchange/v1/chat/completions \
-H "Authorization: Bearer $LIQUID_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "step-3.5-flash-2603",
"messages": [{"role":"user","content":"Say hello."}]
}'Questions
- What is Step 3.5 Flash 2603?
- Step 3.5 Flash 2603 is a model from StepFun.
- How much does Step 3.5 Flash 2603 cost?
- Offers now ask $0.100 per million input tokens and $0.301 per million output tokens. A job pays for the tokens it uses. The exchange picks the cheapest eligible offer.
- What is the context length of Step 3.5 Flash 2603?
- The largest offer takes 262,144 input tokens. A smaller offer can take less. The exchange skips an offer that cannot take your message.
- What can Step 3.5 Flash 2603 do?
- Its providers list Reasoning effort, JSON object, JSON schema, Frequency penalty, Logit bias, Log probabilities, Min-p sampling, Presence penalty, Repetition penalty, Seed, Stop sequences, Top-k sampling, Top-p sampling, Text, Tools.
- What inputs and outputs does Step 3.5 Flash 2603 support?
- Text → Text.
- Which providers serve Step 3.5 Flash 2603?
- 1 independent provider quote it now, with 1 offer. The table above ranks them by the cost of a typical job.
- How do I call Step 3.5 Flash 2603?
- Send "step-3.5-flash-2603" as the model in an OpenAI or Anthropic request. The API section links to setup steps for each client.
- When was Step 3.5 Flash 2603 listed?
- The exchange first listed it on 10/10/2026. This is not its release date.