This paper presents a novel numerical evaluation of the vertical uplift resistance of rectangular anchors in heterogeneous and anisotropic clays, using the Anisotropic Undrained Shear (AUS) failure criterion. The study focuses on the uplift capacity factor ($F_c$), which is determined using the finite element limit analysis (FELA) technique. This factor is related to four dimensionless parameters: the embedment ratio ($H/B$), the shaped ratio ($L/B$), the increasing strength factor ($\rho B/s_{uTC0}$), and the anisotropic ratio ($r_s$). The influence of these parameters on the failure mechanisms of rectangular anchors is analyzed. Additionally, the study explores the capabilities of the eXtreme Gradient Boosting (XGBoost) machine learning model in forecasting the uplift capacity factor of rectangular anchors in such soils. This is the first application of XGBoost to create a surrogate model for predicting the capacity of rectangular anchors in anisotropic and heterogeneous clays. The research aims to enhance the understanding and design of offshore foundation systems, particularly those using rectangular plate anchors.This paper presents a novel numerical evaluation of the vertical uplift resistance of rectangular anchors in heterogeneous and anisotropic clays, using the Anisotropic Undrained Shear (AUS) failure criterion. The study focuses on the uplift capacity factor ($F_c$), which is determined using the finite element limit analysis (FELA) technique. This factor is related to four dimensionless parameters: the embedment ratio ($H/B$), the shaped ratio ($L/B$), the increasing strength factor ($\rho B/s_{uTC0}$), and the anisotropic ratio ($r_s$). The influence of these parameters on the failure mechanisms of rectangular anchors is analyzed. Additionally, the study explores the capabilities of the eXtreme Gradient Boosting (XGBoost) machine learning model in forecasting the uplift capacity factor of rectangular anchors in such soils. This is the first application of XGBoost to create a surrogate model for predicting the capacity of rectangular anchors in anisotropic and heterogeneous clays. The research aims to enhance the understanding and design of offshore foundation systems, particularly those using rectangular plate anchors.