Windy.com should figure out a way to offer a license that includes the ECMWF. Perhaps some sort of pass thru license where user x pays the license to you which you send off to the ECMWF people.
ECMWF is on Windy since a long time!
I guess @windinaction means API, which does not offer ECMWF anymore.
@windinaction Please contact firstname.lastname@example.org for more information.