Combat, Trading and Systems for Roblox

TradeService×

-- both sides are re-checked on the server
function Trade.confirm(a, b)
    local offerA, offerB = Offers[a], Offers[b]
    if not (offerA and offerB) then return false end
    if not Inventory:has(a, offerA) then return false end
    if not Inventory:has(b, offerB) then return false end
 
    Inventory:swap(a, b, offerA, offerB)
    Data:save(a); Data:save(b)
    return true
end