StepFun: Step 3.5 Flash

stepfun/step-3.5-flash

262KContext Window

66KMax Output

Supported Protocols:reasoninginclude_reasoningtemperaturetop_ptop_kfrequency_penaltytoolstool_choice

Normal

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. It is a reasoning model that is incredibly speed efficient even at long contexts.

Capabilities

🧠 Reasoning🔧 Function CallingText GenerationCode GenerationAnalysis & ReasoningReasoning

Technical Specs

Input Modality

Text

Output Modality

Text

Arch

—

Default Temperature

0.7

Default Top_P

Pricing

Pay per use, no monthly fees

Billing Type	Unit	Price
Text Input	—	$0.1000/M tokens
Text Output	—	$0.3000/M tokens

Quick Start

from openai import OpenAI

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

response = client.chat.completions.create(
    model="stepfun/step-3.5-flash",
    messages=[
        {"role": "user", "content": "Hello!"}
    ],
)

print(response.choices[0].message.content)

FAQ

StepFun: Step 3.5 Flash

stepfun/step-3.5-flash

In< ¥0.001/1K

Out< ¥0.001/1K

Context Window262K

Max Output66K

Start Using →View Integration Docs

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