Sign In App API uses the basic authentication header. The header comprises of the key and secret that were generated when the API client was created.
Basic authentication: The UserID is your key and the password is the secret.
Example
Authorization: Basic PGtleT46PHNlY3JldD4
> curl -u <key>:<secret> \
-H "Content-type: application/json" \
-H "Accept: application/json" \
-X GET \
https://<base-url>/client-api/v1/<resource-path>
> curl -u <key>:<secret> \
-H "Content-type: application/json" \
-H "Accept: application/json" \
-X POST \
-d '{"key1": "value1", "key2": "value2"}' \
https://<base-url>/client-api/v1/<resource-path>