Obtain OAuth2 Client Credentials Token

The Authorization HTTP header for this request is a Base64 encoded value of apikey and apiSecret concatenated with a colon. For example if your API Key was 123abc and your Secret was 456def your HTTP header would look like this:
Authorization: Basic MTIzYWJjOjQ1NmRlZg==

curl -X POST -H "Authorization: Basic MTIzYWJjOjQ1NmRlZg==" -H "Content-Type: application/x-www-form-urlencoded" -d 'grant_type=client_credentials'

The result!

As long as everything else went OK you will receive a response that looks like this:

{
  "refresh_token_expires_in": "0",
  "api_product_list": "[Basic Plan]",
  "organization_name": "connectedhome",
  "developer.email": "developerinfo@resideo.com",
  "token_type": "BearerToken",
  "issued_at": "1487281223451",
  "client_id": "123abc",
  "access_token": "456def",
  "application_name": "b1bd4907-924a-4470-a641-0effeb279834",
  "scope": "user",
  "expires_in": "3599",
  "refresh_count": "0",
  "status": "approved"
}