Single-stage gradient-based stellarator coil design: Optimization for near-axis quasi-symmetry

•A novel, one-stage approach to stellarator coil optimization.•Objective function targets near-axis quasi-symmetry, a desirable property for plasma confinement.•Analytical gradients by adjoint and forward sensitivity approaches.•Numerical examples reveal that there is substantial freedom to design buildable coils with good magnetic confinement.