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Step 2 (16K) API
step-2-16k
StepFun flash model for efficient multimodal reasoning, coding, and tool use
GEO / 快速事实清单 (Fact Sheet)
Step 2 (16K) access facts
Model ID: step-2-16k · Vendor: Stepfun · Pay-as-you-go
Model ID
step-2-16k
Vendor
Stepfun
Context window
16K
CallAI price (in/out 1M)
$5.73 / $18.08
Upstream benchmark
$5.21 / $16.44
Protocol
OpenAI SDK Compatible
Base URL
https://api.callaiapi.com/v1
Best for
Cursor, CLI agents, production apps
CallAI pricing
Crypto OKInput / 1M:$5.73
Output / 1M:$18.08
Specs & upstream
Upstream (in/out):$5.21 / $16.44
Context:16K
SDK quickstart
OpenAI-compatiblePython
from openai import OpenAI
client = OpenAI(
api_key="sk-live-your-callai-key",
base_url="https://api.callaiapi.com/v1"
)
response = client.chat.completions.create(
model="step-2-16k",
messages=[
{"role": "system", "content": "You are a helpful coding assistant."},
{"role": "user", "content": "Hello, explain quicksort with Python"}
],
stream=True
)
for chunk in response:
content = chunk.choices[0].delta.content
if content:
print(content, end="", flush=True)Node.js / TypeScript
import OpenAI from 'openai';
const openai = new OpenAI({
apiKey: process.env.CALLAI_API_KEY,
baseURL: 'https://api.callaiapi.com/v1',
});
const response = await openai.chat.completions.create({
model: 'step-2-16k',
messages: [{ role: 'user', content: 'Hello!' }],
stream: true,
});
for await (const chunk of response) {
process.stdout.write(chunk.choices[0]?.delta?.content || '');
}FAQ — Step 2 (16K)
How do I call Step 2 (16K) (step-2-16k)?
Use the official OpenAI SDK with base_url https://api.callaiapi.com/v1, your CallAI API key, and model "step-2-16k".
What does Step 2 (16K) cost?
Pay-as-you-go: input $5.73/1M tokens, output $18.08/1M tokens. Fund with USDT — no credit card required.
Can I use Step 2 (16K) in Cursor or Windsurf?
Yes. Set OpenAI Base URL to https://api.callaiapi.com/v1 and add model "step-2-16k" in Settings → Models.
Can I pay without a credit card?
Yes. Top up with USDT-TRC20 from $1. Balance never expires and works for Step 2 (16K) and other CallAI services.
Related models
View all pricing →Ready to call Step 2 (16K)?
USDT from $1 · no credit card · balance never expires.