The GCW Data Portal offers a number of machine interfaces to the data catalogue. The pyCSW software is being used for this and MET contributes to development of this software. Currently OAI-PMH, OGC CSW and OpenSearch can be used. the relevant endpoint is available at https://gcw2.csw.met.no/.
Please beware that the end point can change as the pycsw software implementation is continously updated to improve interfaces to the underlying catalogue.