At the present, we have one public data release, which is described in Martin, Starkenburg et al. (2024).
ADS link: https://ui.adsabs.harvard.edu/abs/2024A%26A...692A.115M/abstract
CDS/Vizier: https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/692/A115
It contains photometric metallicities based on Ca H&K photometry from the Pristine survey (for all stars with Gaia XP spectra) and the synthetic Ca H&K photometry derived from the Gaia XP spectra, as well as the Pristine and synthetic Ca H&K magnitudes.