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

# Authentication

> Learn how to authenticate your API requests using API keys

All API requests require authentication using an API key. Include your API key in the `Authorization` header:

```shellscript theme={null}
Authorization: YOUR_API_KEY
```

## **Generate API Keys**

Generate API keys in your [**Skipcall account settings**](https://web.withallo.com/settings/api).

## **Example Request**

```shellscript theme={null}
curl -X GET "https://api-public.skipcall.app/v1/api/contacts" \
  -H "Authorization: YOUR_API_KEY"
```

## **Error Responses**

If your API key is invalid or missing, you’ll receive a`401 Unauthorized`response:

```json theme={null}
{
  "code": "API_KEY_INVALID",
  "details": null
}
```