Here, we introduce BuildAMol, a general-purpose Python library designed for fragment-based molecular modeling. BuildAMol is designed to work on consumergrade machines and can be used to manually and semi-automatically assemble models for diverse and complex molecular structures. BuildAMol is not restricted to specific molecule classes or limited by pre-defined chemical reasoning but offers complete user freedom in assembling fragments, akin to the familiar analog molecule building kits used by chemists. Furthermore, BuildAMol's functionalities extend beyond de novo assembly. It enables modification and optimization of existing structures, conformational sampling, generation of customizable and interactive visualizations, and seamless integration with other cheminformatics libraries. This comprehensive suite of tools fosters a streamlined workflow for diverse applications. BuildAMol prioritizes user-friendliness through a streamlined interface, minimizing manual input while maximizing user control over the assembly process.