Step 3.7 Flash API

About Step 3.7 Flash

StepFun multimodal reasoning model with image and video input, tool calling, adjustable reasoning effort, and 256K context.

Use reasoning_effort low, medium, or high to control the reasoning budget. Prompt-cache hits are billed at StepFun cache-hit rates. Linkup web search is available through web_search_linkup and adds $0.013 per call when invoked.

Also known as Step Flash, StepFun Step 3.7 Flash, Step-3.7-Flash, step-3-7-flash

Step 3.7 Flash specs

Model ID

step-3-7-flash

Provider

StepFun

Category

Text Generation

Released

May 28, 2026

Context window

256K tokens

Max output

131,072 tokens

Input

TextImageVideo

Output

Text

Structured output

JSON Mode

Region

International

Endpoints

POST/v1/chat/completionsPOST/v1/responsesPOST/v1/messagesPOST/v1beta/models/step-3-7-flash:generateContent

Alternate model IDs

step-3.7-flashstepfun/step-3-7-flashstepfun/step-3.7-flash

Step 3.7 Flash API pricing

Live pay-as-you-go rates from the EmpirioLabs catalog. You are billed only for what you use, with no monthly minimum.

How to call the Step 3.7 Flash API

Step 3.7 Flash serves the OpenAI-compatible Chat Completions API. Point any OpenAI SDK at https://api.empiriolabs.ai/v1 with your EmpirioLabs API key and use the model id step-3-7-flash. Get an API key from the EmpirioLabs dashboard.

curl https://api.empiriolabs.ai/v1/chat/completions \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "step-3-7-flash",
    "messages": [
      {"role": "user", "content": "Write a haiku about the ocean."}
    ]
  }'

from openai import OpenAI

client = OpenAI(
    base_url="https://api.empiriolabs.ai/v1",
    api_key="YOUR_EMPIRIOLABS_API_KEY",
)

response = client.chat.completions.create(
    model="step-3-7-flash",
    messages=[{"role": "user", "content": "Write a haiku about the ocean."}],
)
print(response.choices[0].message.content)

Step 3.7 Flash API parameters

Request parameters supported by the Step 3.7 Flash API on EmpirioLabs. Defaults apply when a field is omitted.

Good to know

Supports text, image, and video input with 256K context, function tools, JSON object mode, reasoning_effort low, medium, or high, and optional Linkup web search. Video input supports MP4 under 128 MB, with clips under 5 minutes recommended.

Step 3.7 Flash API: common questions

How much does the Step 3.7 Flash API cost?

On EmpirioLabs, Step 3.7 Flash is billed pay as you go: Input $0.20 per 1M prompt tokens; Output $1.15 per 1M generated tokens; Implicit cache read $0.04 per 1M cached input tokens. The live rate card on this page always matches what the API charges.

What is the context window of Step 3.7 Flash?

Step 3.7 Flash supports a 256K-token context window with up to 131,072 output tokens per response.

Is the Step 3.7 Flash API OpenAI-compatible?

Yes. Step 3.7 Flash serves the OpenAI-compatible Chat Completions API, so existing OpenAI SDKs work by pointing base_url at https://api.empiriolabs.ai/v1 and setting the model id to step-3-7-flash.

Can I try Step 3.7 Flash in the browser before integrating?

Yes. The EmpirioLabs playground runs Step 3.7 Flash in the browser with the same parameters the API exposes, so you can test prompts before writing code.

How do I get a Step 3.7 Flash API key?

Create an EmpirioLabs account, then generate a key under API Keys in the dashboard. Billing is pay-as-you-go credits, so you only pay for the requests you make.