Documentation Index
Fetch the complete documentation index at: https://docs.modelstack.cc/llms.txt
Use this file to discover all available pages before exploring further.
Overview
While ModelStack uses an OpenAI-compatible API format, you can also use the Anthropic SDK by pointing it to ModelStack’s API endpoint. This lets you use Anthropic-specific features while routing through ModelStack’s unified billing and gateway.
We recommend using the OpenAI SDK for the best compatibility across all providers. The Anthropic SDK only works with Claude models. Python
Installation
Setup
import anthropic
client = anthropic.Anthropic(
api_key="your_api_key",
base_url="https://api.modelstack.cc"
)
Chat Completion
message = client.messages.create(
model="claude-sonnet-4-5",
max_tokens=1024,
messages=[
{"role": "user", "content": "Explain quantum computing in simple terms."}
]
)
print(message.content[0].text)
Streaming
with client.messages.stream(
model="claude-sonnet-4-5",
max_tokens=1024,
messages=[{"role": "user", "content": "Write a poem about coding."}]
) as stream:
for text in stream.text_stream:
print(text, end="")
TypeScript / Node.js
Installation
npm install @anthropic-ai/sdk
Setup
import Anthropic from "@anthropic-ai/sdk";
const client = new Anthropic({
apiKey: "your_api_key",
baseURL: "https://api.modelstack.cc",
});
Chat Completion
const message = await client.messages.create({
model: "claude-sonnet-4-5",
max_tokens: 1024,
messages: [
{ role: "user", content: "Explain quantum computing in simple terms." },
],
});
console.log(message.content[0].text);
Streaming
const stream = client.messages.stream({
model: "claude-sonnet-4-5",
max_tokens: 1024,
messages: [{ role: "user", content: "Write a poem about coding." }],
});
stream.on("text", (text) => {
process.stdout.write(text);
});
await stream.finalMessage();
When to Use the Anthropic SDK
Use the Anthropic SDK when you:
- Need Anthropic-specific features (tool use with Anthropic’s format, prompt caching)
- Are only using Claude models
- Have existing Anthropic SDK code and want minimal changes
Use the OpenAI SDK when you:
- Want to switch between providers (Claude, GPT, Gemini) without changing SDKs
- Need a single SDK for all models
- Want maximum flexibility
