> ## Documentation Index
> Fetch the complete documentation index at: https://apidoc.deerapi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Quick Start

> DeerAPI quick start guide.

## 30-second switch from OpenAI

Use this two-setting diff when you switch an OpenAI SDK client to DeerAPI:

```diff theme={null}
- base_url="https://api.openai.com/v1"
- api_key=os.environ["OPENAI_API_KEY"]
+ base_url="https://api.deerapi.com/v1"
+ api_key=os.environ["DEERAPI_KEY"]
```

## Make your first call

The following example sends a chat completion request:

```bash theme={null}
curl https://api.deerapi.com/v1/chat/completions \
  -H "Authorization: Bearer $DEERAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "your-model-id",
    "messages": [
      {"role": "user", "content": "Write a one-sentence product tagline."}
    ]
  }'
```

## Next steps

* Choose a model ID from the [live pricing page](https://api.deerapi.com/pricing).
* Read [Chat Completions](/api/text/openai/chat) for OpenAI-compatible text calls.
* Read [Common Mistakes](/help/common-mistakes) if a tool returns `401`, `404`, or a model-not-found error.