The API of cxserver is currently exposed through RESTbase. In order to unblock RESTbase deprecation, the services needs and requirements have to be assessed according to https://www.mediawiki.org/wiki/RESTBase/service_migration.
Note that this API seems to be exposed in two ways: on https://cxserver.wikimedia.org/v1 as well as on all wikis under /api/rest_v1/. The rest_v1 path receives less than one requests per second, while the cxserver.wikimedia.org serves abotu one request per second. cxsever.wikimedia-org is [[https://gerrit.wikimedia.org/g/operations/puppet/+/production/hieradata/common/profile/trafficserver/backend.yaml#33|directly mapped to the backend service]].
Given that cxserver's API is already used mostly without RESTbase, the remaining task is probably just to deprecate/remove the endpoints exposed through RESTbase.