Step 5 Preview

stepfun/step-5-preview

by StepFun

Input price: $1/ M tokens
Output price: $2.7/ M tokens
Context window: 977Ktokens
Max output: 63Ktokens

Step 5 Preview is StepFun's flagship model for coding, software engineering, and professional knowledge work. Its sparse MoE architecture uses 600B total and 27B active parameters, with a 1M-token context window and up to 64K output tokens. It accepts text, images, and video and supports tool calling, structured JSON output, three reasoning effort levels, streaming, and prompt caching.

Features

Serverless API

Docs

stepfun/step-5-preview is available via Novita's serverless API, where you pay per token. There are several ways to call the API, including OpenAI-compatible endpoints with exceptional reasoning performance.

Available Serverless

Run queries immediately, pay only for usage

Input$1 / M Tokens

Cache Read$0.1 / M Tokens

Output$2.7 / M Tokens

Get your API key
Sign up and create a key to run the code below. The API is OpenAI-compatible.
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Make your first request

The API is OpenAI-compatible: point any OpenAI SDK at the base URL and pass this model ID.

Base URL: https://api.novita.ai/openaihttps://api.novita.ai/anthropic
Model ID: stepfun/step-5-preview
API Endpoint: chat/completions

1from openai import OpenAI
2
3client = OpenAI(
4    api_key="<Your API Key>",
5    base_url="https://api.novita.ai/openai"
6)
7
8response = client.chat.completions.create(
9    model="stepfun/step-5-preview",
10    messages=[
11        {"role": "system", "content": "You are a helpful assistant."},
12        {"role": "user", "content": "Hello, how are you?"}
13    ],
14    max_tokens=64000,
15    temperature=0.7
16)
17
18print(response.choices[0].message.content)