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

# Authentication

> All EURI API requests are authenticated using Bearer tokens.

## API key authentication

Every request to the EURI API must include your API key in the `Authorization` header:

```
Authorization: Bearer YOUR_EURI_API_KEY
```

## Getting your API key

1. Sign in at [euron.one/euri](https://euron.one/euri).
2. Go to **Billing & API Keys**.
3. Click **Create API Key**.
4. Copy and store the key securely — it won't be shown again.

## Example request

```bash theme={null}
curl -X POST https://api.euron.one/api/v1/euri/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer euri-sk_abc123..." \
  -d '{"model": "gpt-4o-mini", "messages": [{"role": "user", "content": "Hello"}]}'
```

## Using with OpenAI SDKs

Set the `api_key` and `base_url` parameters:

```python theme={null}
from openai import OpenAI

client = OpenAI(
    api_key="YOUR_EURI_API_KEY",
    base_url="https://api.euron.one/api/v1/euri"
)
```

## Security best practices

* **Never** expose your API key in client-side code (browser, mobile app).
* Store keys in environment variables or a secrets manager.
* Rotate keys periodically from the dashboard.
* Use separate keys for development and production.

## Error responses

If your key is missing or invalid, you'll receive:

```json theme={null}
{
  "error": {
    "message": "Invalid API key provided.",
    "type": "authentication_error",
    "code": "invalid_api_key"
  }
}
```