Add a {capo: ...} directive to a song and Songhub automatically adjusts the chords shown so they're correct for that capo position — a chord of C with a capo on 3 will display as A.
This means you can keep the chart written in the shape you actually play (easy open chords with a capo) while Songhub tracks the sounding key underneath, so a singer or another instrument still knows the real key.
It also plays well with transposing: if a song needs to move to a different key for a gig, adjusting the {capo: ...} value is often simpler than re-fingering the whole chart.
Capo position isn't applied to guitar tab sections — those render exactly as typed, since tab notation already encodes fret position directly.