Step-3.5-Flash

High-traffic StepFun flash model tuned for cheap fast inference and agent loops.

BatchIn ExclusivePublic model detailMoE Transformer

Params

196B / 11B active

Context

128K

Max Output

32K

License

Apache 2.0

TTFT

160ms

Throughput

120 tok/s

Why pick it

OpenRouter traffic leader
Exclusive positioning vs SiliconFlow

Pricing

TierStandardCachedSiliconFlowSavings

Realtime$0.01 / $0.04$0.004N/AN/A

Batch$0.01 / $0.02$0.004N/AN/A

Quick start

OpenAI-compatible surface. Swap the base URL and ship.

Try in Playground Open pricing

Python

from openai import OpenAI

client = OpenAI(
    base_url="https://api.luminapath.tech/v1",
    api_key="BATCHIN_API_KEY"
)

resp = client.chat.completions.create(
    model="step-3.5-flash",
    messages=[{"role": "user", "content": "Summarize why this model is a fit for my workload."}]
)

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

JavaScript

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.luminapath.tech/v1",
  apiKey: process.env.BATCHIN_API_KEY,
});

const resp = await client.chat.completions.create({
  model: "step-3.5-flash",
  messages: [{ role: "user", content: "Summarize why this model is a fit for my workload." }],
});

console.log(resp.choices[0]?.message?.content);

cURL

curl https://api.luminapath.tech/v1/chat/completions \
  -H "Authorization: Bearer $BATCHIN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "step-3.5-flash",
    "messages": [{"role":"user","content":"Summarize why this model is a fit for my workload."}]
  }'

Specs

Architecture

MoE Transformer

Vendor group

BatchIn Exclusive

Context window

128K

Max output

32K

Best for

exclusive

fast