Legal..., but Kansas City can regulate Open Carry per Missouri State Law 21.750(3), but..., [Kansas City] [may]Regulate the Open Carrying of Firearms readily capable of Lethal Use or the Discharge of Firearms within [the Jurisdiciton of Kansas City], provided; such Ordinance complies with the provisions of section 252.243, R.S.Mo. [as it applies to Hunting].
If you have a Permit, especially if you have a Permit, per R.S.Mo. 571-030(4), then, you are OK. If Kansas City has adopted an Ordinance banning Open Carry, though, you have to Conceal Carry, per 21.750(3).
Kansas City does not, per Kansas City Code, Regulate Open Carry.
Kansas City does not, per Kansas City Code, Regualte Park Carry..., and even if Kansas City did..., only Open Carry Park Carry could be Regualted, per R.S.Mo. 21-750(3), but Concealed Carry, with an Concealed Carry Permit, would be Preempted under R.S.Mo. 21-750(1) and R.S.Mo. 21-750(2).