PRIVATE-TOKEN:

[1] gitlabhq/doc/api at master · gitlabhq/gitlabhq (2015-03-06 10:43:54 +09:00 版) <https://github.com/gitlabhq/gitlabhq/tree/master/doc/api>

Example of a valid API request:
GET http://example.com/api/v3/projects?private_token=QVy1PB7sTxfy4pqfZM1U
Example for a valid API request using curl and authentication via header:
curl --header "PRIVATE-TOKEN: QVy1PB7sTxfy4pqfZM1U" "http://example.com/api/v3/projects"