Mass-metallicity relation (MZR) at high redshift (z). We plot the gas metallicity (Z_g) as a function of stellar mass (M_⋆) for the SERRA simulated galaxies (Pallottini et al. 2022, z ≃ 7) and the JWST observations from CEERS Nakajima et al. (2023, z ≃ 4 − 10), JADES (Curti et al. 2024, z ≃ 3 − 6 and 6–10), and UNCOVER (Chemerynska et al. 2024b, z ≃ 6 − 8). To guide the eye, the observational fits from Nakajima et al. (2023) and Curti et al. (2024) are also reported as lines with the same colors of corresponding data. As a reference, the log(Z_g/Z_⊙) = 0.37 log(M_⋆/M_⊙)−4.3 fit from FIRE-2 simulations (Marszewski et al. 2024, z = 5 − 12) is shown, along with their binned data and scatter at z = 8. The right axis reports the logarithmic oxygen abundance [O/H], assuming a solar composition (Asplund et al. 2009), i.e., 12 + [O/H]_⊙ = 8.69.