The new version of Zotero's translation server does not (yet) support exporting references to bibtex, so we need to remove it from the public API.
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Event Timeline
If this graph is accurate, it seems to suggest that 1/4 of our traffic is bibtex :/ https://grafana.wikimedia.org/dashboard/db/service-citoid?orgId=1
As per https://github.com/zotero/translation-server-v2/issues/5#issuecomment-412031329 it's going to be done soon so I think we should actually not do this :).
This was all due to our automated checking infrastructure which requested bibtex. After [removing it from spec.yaml](https://gerrit.wikimedia.org/r/#/c/mediawiki/services/citoid/+/451835/) all of the bibtex request went away. Therefore, no external clients are actually using bibtex.
This is very interesting info. Nevertheless, I reopened the ticket for now. Let's keep our eyes on the resolution of the issue, and if exporting is ready by the time we are ready to deploy zotero v2, we can keep bibtex. Alternatively, we can re-add it once it's ready on their side if it happens to be after our deployment.