Age-metallicity relation (top panel) and MDF (bottom panel) as predicted by the reference chemical evolution model adopting Rubele et al. (2018) SFH (blue line, circles and histogram, respectively). The predicted age-metallicity relation is compared with the CMD-extracted relation by Rubele et al. (2018, grey line with confidence intervals), the theoretical curve by Pagel & Tautvaisiene (1998, bursting model, black dashed line), SMC GCs from low-resolution (Parisi et al. 2009, 2015, 2022; Dias et al. 2021, magenta empty circles) and high-resolution studies (Mucciarelli et al. 2023b, red filled squares). Observed MDFs are from Mucciarelli et al. (2023a, red histogram) and Hasselquist et al. (2021, APOGEE DR17, grey histogram).