To authenticate you have to generate an API key. Each channel has 2 environments. The demo for development and testing puproses and the live for your production.
In order to authenticate use the following headers:
GET /api/documents
Content-Type: application/json
Lucent-Channel: {channel-id}
Authorization: Bearer {api-key}
Accept-Language: en-US
Host: api.lucentcms.com
The channel-id can be found in your channel "settings > access" along with your api-key.
The Accept-Language header is optional. If you send this header, the response will contain only the content of this locale, otherwise the response will contain all locales.