Step 5 Preview · vercel
Step 5 Preview is StepFun’s flagship AI model for agentic coding, professional knowledge work, and financial analysis. Built on a sparse Mixture-of-Experts architecture with 600B total parameters and 27B active per token, it combines a 1M-token context window with vision input. From building interactive applications and debugging code to conducting research and producing analytical reports, it supports complex workflows that require sustained reasoning, tool use, and iterative refinement.
Input, $/1M $1.00
Output, $/1M $2.70
Cache read $0.10
Cache write —
Context 1 048 576
Max output 1 048 576
Accepts images, text, video
Last checked 04.11.2026 12:00:14 UTC
Source provider's page
Price alerts
API
OpenAI-compatible API: the official OpenAI SDKs work with this base URL. Replace YOUR_API_KEY with your key from the provider.
| API base URL | |
|---|---|
| Endpoint | |
| Model id | |
curl
curl https://ai-gateway.vercel.sh/v1/chat/completions \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "stepfun/step-5-preview", "messages": [{"role": "user", "content": "Hello!"}], "max_tokens": 256}'Python
import requests
r = requests.post(
"https://ai-gateway.vercel.sh/v1/chat/completions",
headers={"Authorization": "Bearer YOUR_API_KEY"},
json={
"model": "stepfun/step-5-preview",
"messages": [
{
"role": "user",
"content": "Hello!"
}
],
"max_tokens": 256
},
)
print(r.json())JavaScript
const r = await fetch("https://ai-gateway.vercel.sh/v1/chat/completions", {
method: "POST",
headers: {Authorization: "Bearer YOUR_API_KEY", "Content-Type": "application/json"},
body: JSON.stringify({
"model": "stepfun/step-5-preview",
"messages": [
{
"role": "user",
"content": "Hello!"
}
],
"max_tokens": 256
}),
});
console.log(await r.json());Request (JSON)
{
"model": "stepfun/step-5-preview",
"messages": [
{
"role": "user",
"content": "Hello!"
}
],
"max_tokens": 256
}Response (JSON)
{
"id": "chatcmpl-...",
"object": "chat.completion",
"model": "stepfun/step-5-preview",
"choices": [
{
"index": 0,
"message": {
"role": "assistant",
"content": "Hi! How can I help?"
},
"finish_reason": "stop"
}
],
"usage": {
"prompt_tokens": 9,
"completion_tokens": 12,
"total_tokens": 21
}
}The address is taken from the provider's model list; check it against the provider's documentation.
Source: AI Rate Card, https://airatecard.com/en/c/offer%3Avercel%7Cstepfun/step-5-preview, prices checked 2026-11-04; seller's page: https://vercel.com/ai-gateway/models/step-5-preview
Technical details
ID: offer:vercel|stepfun/step-5-preview