Optimal Euclid photometry AGN selection criteria derived in Euclid Collaboration: Bisigello et al. (2024) for the EWS applied to our data. We show two-dimensional density plots for AGN that are detected above the 5σ point-source depths in all four relevant bands. The coloured regions show the selected AGN and grey regions show non-selected AGN. Panels show selections for unobscured AGN with Euclid photometry only (top), unobscured AGN with Euclid and Rubin/LSST photometry (middle) and all AGN with Euclid and Rubin/LSST photometry (bottom). In the top panel we plot the colour-space redshift evolution of our unobscured AGN template with E(B − V) = 0 (green) and E(B − V) = 0.1 (orange) for z ∈ [0, 7] in steps of δz = 1. White circles show the z = 0 points and white squares denote the z = 5 points. The E(B − V) = 0 green crosses in the selection region correspond to z = 1 and z = 2.