How do I create a VSAM KSDS or ESDS cluster through the gateway?

POST /dataset with datasetName, vsamType (KSDS or ESDS), key length/position for KSDS, recordLength, and space. IDCAMS DEFINE CLUSTER runs as the caller’s RACF user and still requires the write surface. Success is 201. The caller must be allowed on the HLQ/volume/SMS policy.