# Quickstart

Make a successful authenticated Chat Completions request in a few minutes.

## 1. Set your API key

Store the key in an environment variable. Do not commit it or place it in browser-side code.

```bash
export KOSCOMPUTE_API_KEY="your-api-key"
```

## 2. Send a request

```bash
curl https://api.koscompute.com/v1/chat/completions \
  -H "Authorization: Bearer $KOSCOMPUTE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "qwen/qwen3.8-27b",
    "messages": [
      {"role": "system", "content": "Answer clearly and briefly."},
      {"role": "user", "content": "What is speculative decoding?"}
    ],
    "max_completion_tokens": 180
  }'
```

A successful response contains `choices[0].message.content` and a `usage` object. `max_completion_tokens` is the total completion budget, including reasoning tokens when reasoning is enabled.

## 3. Use an SDK

```python
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["KOSCOMPUTE_API_KEY"],
    base_url="https://api.koscompute.com/v1",
)

response = client.chat.completions.create(
    model="qwen/qwen3.8-27b",
    messages=[{"role": "user", "content": "Return one practical use for embeddings."}],
    max_completion_tokens=120,
)
print(response.choices[0].message.content)
```

## 4. Handle temporary capacity

Retry `429`, `503`, and `504` responses according to `Retry-After` when present. Use exponential backoff with jitter and do not retry invalid `400` requests unchanged.

## Where to go next

- Query the [live model catalog](/docs/models/overview/).
- Add [streaming](/docs/guides/streaming/).
- Learn [tool calling](/docs/guides/tool-calling/) or [structured output](/docs/guides/structured-output/).
- Review [errors and retries](/docs/reliability/errors/) before production rollout.