We present SigPy.RF, an extensive set of open-source, Python-based tools for MRI RF pulse design. This toolbox extends the SigPy Python software package and leverages SigPy’s existing capabilities for GPU computation, iterative optimization, and powerful abstractions for linear operators, proximal operators, and applications. Tools are available for all steps of the excitation design process including trajectory/gradient design, pulse design, and simulation. Our implemented functions for pulse design include advanced SLR, multiband, adiabatic, optimal control, B$$$_1^+$$$-selective and small-tip pTx designers. SigPy.RF pulse designs were validated in simulations and a pTx experiment.