First measurements of the opposite-sign W boson pair production cross section in proton-proton collisions at sqrt(s) = 13.6 TeV are presented. The data used in this study were collected collisions at sqrt(s) = 13 TeV is presented. The data used in this study were collected with with the CMS detector at the CERN LHC in 2022, and correspond to an integrated luminosity of 34.8 fb-1. Events are selected by requiring one electron and one muon of opposite charges. A maximum likelihood fit leptons (electrons or muons). Two methods for reducing background contributions is performed in event categories defined by the flavour and charge of the leptons, the number of jets, and number of jets identified as originating from b quarks. An inclusive WW production cross section of 125.7 +/- 5.6 pb is measured, in agreement with standard model predictions. Cross sections are also reported in a fiducial region close to that of the detector acceptance, both inclusively and differentially as a function of the jet multiplicity in the event.