GJ 9827 is a compact system hosting three close-in planets in near-resonant orbits that span the radius gap, a deficit of close-in planets separating super-Earths and mini-Neptunes. We analysed transit observations from the ESPRESSO GTO program acquired on each planet and performed a joint Rossiter-McLaughlin (RM) analysis of the three planets using the ANTARESS workflow. We measured the sky-projected spin-orbit angle of each transiting planet (λb = 9−64+67°, λc = −21−44+43°, and λd = −1 ± 26°) and found them, within uncertainties, to be consistent with an alignment with the stellar spin axis. These results, derived with the RM Revolutions technique, are fully compatible with a classical analysis of the RM anomaly. By combining information on the stellar radius and rotation period, we derived the true 3D spin-orbit angles. Our results indicate that the star is viewed equator-on, with 3D spin-orbit angles of Ψb = 54−38+26°, Ψc = 46−30+22°, and Ψd = 33−24+16°. The 3D spin-orbit angles are broadly consistent with a coplanar system but remain weakly constrained, with posterior distributions peaking at moderate misalignments. An aligned architecture remains compatible at the 2 σ level. These findings support a scenario of smooth disc-driven migration for the three planets, potentially allowing for a moderate primordial misalignment between the protoplanetary disc and the stellar spin axis. Further observations are encouraged to confirm these conclusions.