Merge trains API to start merge train?

We are on GitLab Enterprise Edition [13.3.9-ee].

We need to be able to add an MR to a merge train/start a merge train via the API. The docs don’t list a way to do this. I thought maybe PUT /projects/:id/merge_requests/:merge_request_iid/merge would start/add the MR to a merge train but it just merges the MR immediately, ignoring any running merge train.

Our problem is that we have downstream projects and our builds produce packages needed by the downstream project’s build. We are looking for a way to atomically merge code into master and deploy packages that match the new code in master. Merge trains almost work but because we need to able to coordinate them between projects.

Hi @benhsmith
Such API endpoints are currently not available. You can follow this issue which adds Merge Trains APIs.