Webhhok is not triggered after creating merger equest by API

We have a web hook to Jenkins which is triggered when somebody creates merge request.
When we use web gui, everything works, but if the merge request is created by the API call, the web hook is not triggerd.
We use API according to this doc: http://doc.gitlab.com/ce/api/merge_requests.html#create-mr
Our GitLab version: Community Edition 8.6.6
Any ideas?
Thanks

This is a long shot as it was a very specific care – but I know I broke this once by manipulating the repo data outside of gitlab – maybe that’s what happened to yours

Might want to take a look at the repo content itself (on the server) and see if the hook appears in the repo. On our setup it’s in /var/opt/gitlab/git-data/repositories/{group | owner}/{repo}.git. The hook folder in the repo should be a symlink to /{gitlab install dir}/gitlab/embedded/service/gitlab-shell/hooks

Mine was a empty dir with no hooks in it. Fixing the link fixed the issue.