Overview
ModelStack is fully compatible with the OpenAI SDK. Just change base_url and api_key — everything else works the same, including streaming, function calling, and all chat completion parameters.
Python
Installation
bash
pip install openai
Setup
python
from openai import OpenAI
client = OpenAI(
api_key="your_api_key",
base_url="https://api.modelstack.cc/v1"
)
Chat Completion
python
response = client.chat.completions.create(
model="claude-sonnet-4-5",
messages=[
{"role": "system", "content": "You are a helpful assistant."},
{"role": "user", "content": "Explain quantum computing."}
],
temperature=0.7,
max_tokens=500
)
print(response.choices[0].message.content)
Streaming
python
stream = client.chat.completions.create(
model="claude-sonnet-4-5",
messages=[{"role": "user", "content": "Write a poem about coding."}],
stream=True
)
for chunk in stream:
if chunk.choices[0].delta.content is not None:
print(chunk.choices[0].delta.content, end="")
List Models
python
models = client.models.list()
for model in models.data:
print(f"{model.id} ({model.owned_by})")
Using Different Models
python
# Switch between providers by changing the model parameter
providers = {
"Anthropic": "claude-sonnet-4-5",
"OpenAI": "gpt-4o",
"Google": "gemini-2.5-pro",
}
for provider, model in providers.items():
response = client.chat.completions.create(
model=model,
messages=[{"role": "user", "content": "Say hello!"}]
)
print(f"{provider}: {response.choices[0].message.content}")
Environment Variable
Instead of hardcoding your API key, use an environment variable:
bash
export OPENAI_API_KEY="your_api_key"
export OPENAI_BASE_URL="https://api.modelstack.cc/v1"
python
# No need to pass api_key or base_url — the SDK reads from env vars
client = OpenAI()
Node.js / TypeScript
Installation
bash
npm install openai
Setup
javascript
import OpenAI from 'openai'
const client = new OpenAI({
apiKey: 'your_api_key',
baseURL: 'https://api.modelstack.cc/v1',
})
Chat Completion
javascript
const response = await client.chat.completions.create({
model: 'claude-sonnet-4-5',
messages: [
{ role: 'system', content: 'You are a helpful assistant.' },
{ role: 'user', content: 'Explain quantum computing.' },
],
temperature: 0.7,
max_tokens: 500,
})
console.log(response.choices[0].message.content)
Streaming
javascript
const stream = await client.chat.completions.create({
model: 'claude-sonnet-4-5',
messages: [{ role: 'user', content: 'Write a poem about coding.' }],
stream: true,
})
for await (const chunk of stream) {
const content = chunk.choices[0]?.delta?.content || ''
process.stdout.write(content)
}
Environment Variables
bash
export OPENAI_API_KEY="your_api_key"
export OPENAI_BASE_URL="https://api.modelstack.cc/v1"
javascript
// SDK reads from env vars automatically
const client = new OpenAI()