Step 3.7 Flash

StepFun (China)MCP Tool CallReasoning
stepfun/step-3.7-flashOpen Weights

Newer StepFun flash model for faster agents, coding, and multimodal prompts

Benchmark Pricing$0.20 / 1M in$1.21 / 1M out$0.04 cache read
Context: 256,000 tokens•Max Output: 256,000 tokens•Knowledge: 2026-03-01•Released: 2026-05-29

TECHNICAL SPECIFICATIONS

Context Window256,000256K tokens
Max Output256,000256K tokens
LicenseOpen SourceSelf-hostable
Input Modalities
TextVisionVideo
Function / Tool CallingSupported (MCP Ready)
Structured OutputsGuaranteed Schema

MODEL CONTEXT PROTOCOL (MCP) READINESS

✓ Step 3.7 Flash natively supports OpenAI / Anthropic format tool calling and is fully compatible with MCP servers and agent loops.

MCP Context Window Recommendations

With a context capacity of 256,000 tokens, this model can handle moderately large MCP tool definitions and multi-turn conversation logs comfortably.

STANDARDIZED BENCHMARKS & EVALS

SWE-Bench Proresolve rate
56.3
SWE-Bench Verifiedresolved
76.5
Terminal-Benchsuccess rate
59.6
Humanity's Last Examaccuracy
47.2
BrowseCompaccuracy
75.8
Toolathlonsuccess rate
49.5
GDPvalwins or ties
45.8
ClawEvalpass^3
67.1
Artificial Analysis Coding Indexindex
37.1
SciCodepercent correct
40
Terminal-Bench Hardsuccess rate
35.6

API CALL INVOCATION EXAMPLE

// Example: Calling Step 3.7 Flash via OpenAI SDK
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.STEPFUN_API_KEY,
});

const response = await client.chat.completions.create({
  model: "stepfun/step-3.7-flash",
  messages: [{ role: "user", content: "Hello! Can you inspect MCP tools?" }],
});

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

PRICING BY PROVIDER

15 providers
StepFun (China)step-3.7-flash
$0.20 / $1.21$0.04 cache
NanoGPTstepfun/step-3.7-flash:thinking
$0.20 / $1.15$0.04 cache
Novita AIstepfun/step-3.7-flash
$0.20 / $1.15$0.04 cache
LLM Gatewaynovita/step-3.7-flash
$0.20 / $1.15$0.04 cache
AIHubMixstep-3.7-flash
$0.22 / $1.32$0.04 cache
Vercel AI Gatewaystepfun/step-3.7-flash
$0.20 / $1.15$0.04 cache
UnoRouterstep-3.7-flash:free
$0.00 / $0.00
StepFun (Global)step-3.7-flash
$0.20 / $1.15$0.04 cache
Hugging Facestepfun-ai/Step-3.7-Flash
$0.20 / $1.15
Kilo Gatewaystepfun/step-3.7-flash
$0.20 / $1.15$0.04 cache
ZenMuxstepfun/step-3.7-flash-free
$0.00 / $0.00
DevPass (LLM Gateway)step-3.7-flash
$0.20 / $1.15$0.04 cache
CommandCodestepfun/Step-3.7-Flash
$0.20 / $1.15$0.04 cache
Deep Infrastepfun-ai/Step-3.7-Flash
$0.20 / $1.15$0.04 cache
Requestystep-3.7-flash
$0.20 / $1.15$0.04 cache

Rates in USD per 1M tokens. Rates synchronized from models.dev public catalog.

Prompt Caching Active

This model supports prompt caching at $0.04 / 1M tokens, saving up to 80% on repetitive MCP tool definitions and system instructions.