Step 3.7 Flash API

stepfun/step-3.7-flash
Step 3.7 Flash is StepFun's multimodal MoE model with text, image and video understanding, a 256K context window, and selectable reasoning depth — optimized for fast inference, agentic workflows, and visual analysis.
Context
256K tokens
Input
$0.27508 / 1M tokens
Output
$1.58171 / 1M tokens
Released
Jun 1, 2026

How to use Step 3.7 Flash API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to stepfun/step-3.7-flash.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "stepfun/step-3.7-flash",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "stepfun/step-3.7-flash",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"stepfun/step-3.7-flash","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

Step 3.7 Flash API Pricing

TypePrice
Input
$0.27508 / 1M tokens
Output
$1.58171 / 1M tokens
Cached input
$0.055016 / 1M tokens

Step 3.7 Flash Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
Intelligence
19.5
Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026
Coding
39.6
Composite score across standardised coding evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026

Step 3.7 Flash vs other models

ModelInputOutputContextBest for
$0.27508 / 1M tokens
$1.58171 / 1M tokens
256K tokens
Coding + agents
$6.5 / 1M tokens
$39 / 1M tokens
1.05M tokens
Reasoning + agents
$2.6 / 1M tokens
$13 / 1M tokens
1M tokens
Balanced coding + agents
$3.9 / 1M tokens
$19.5 / 1M tokens
1M tokens
Long-context, multimodal & agentic workflows
$0.65 / 1M tokens
$3.9 / 1M tokens
1.05M tokens
Reasoning + agents

Frequently asked questions

Step 3.7 Flash has a 256,000 tokens context window and can return up to 256,000 tokens.

Step 3.7 Flash takes image, text, video as input and returns text.

Use stepfun/step-3.7-flash as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

Step 3.7 Flash became available on June 1, 2026.

Step 3.7 Flash is priced at input $0.27508 / 1M tokens, output $1.58171 / 1M tokens, cached input $0.055016 / 1M tokens.

Yes, Step 3.7 Flash can stream responses as they are generated.

Yes, Step 3.7 Flash accepts image input alongside text.

Step 3.7 Flash was built by StepFun.

Yes, its capabilities include reasoning alongside function calling and structured outputs.

Yes, it supports function calling, tool use, and parallel tool calls.

Start building with Step 3.7 Flash

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