A <constraint /> can define the distance between two ports or components or other mathematical constraints to help layout or place components.

export const MyCircuit = () => (
  <constrainedlayout>
    <resistor name="R1" resistance="1k" footprint="0402" />
    <resistor name="R2" resistance="1k" footprint="0402" />
    <constraint pcb xdist="10mm" left=".R1" right=".R2" />
  </constrainedlayout>
)
<constrainedlayout />Circuit JSON Specification