ESGF Data Visibility API - ESGF/esgf.github.io GitHub Wiki
There is now a publicly accesible API for querying counts of datasets published on ESGF. This service currently serves information for CORDEX, CMIP5, obs4MIPs and ana4MIPs projects. The url is https://esg-dn1.nsc.liu.se/api/datavisibility
It lists number of datasets published on datanodes, by project and also the number of datasets 'seen' by each federation index node. This information is refreshed once every four hours. More features and documentation will follow.