Returns the build that the answering server runs. Each server answers for itself, so behind a load balancer hostname shows which one replied. To check the API's dependencies rather than its build, use GET /health.No authentication is needed. Without a token the response carries only apiversion, git-commit, hostname and current-time. Send a valid token (Authorization: Bearer ..., an API key or the ns_access_token cookie) to also get the full commit hash, branch, build date and the PHP and framework versions. A token that is sent but is invalid or expired is refused with 401 (an invalid API key with 403), not answered with the shorter response.