Script events

A game mode that needs something on the client — a marker, a sound, a bit of UI, a value read from the game — ships a client script and talks to it through named events with a string payload, in both directions. The client half is the game’s own Lua plus the kcd2mp table.

Server side

Function
SendClientEvent(pid, name, payload)	to one player’s client script; pid nil = everyone
SendClientEventToAll(name, payload)	to everyone’s

function OnClientEvent(pid, name, payload) end   -- from a client: at most 30 a second and 4 KB each

Both halves

the mode (server)

SendClientEvent(pid, "marker", "1280.5,1088.0,3")   -- to one client; SendClientEventToAll for everyone

function OnClientEvent(pid, name, payload)
  if name == "used" then
    Log(GetPlayerName(pid) .. " used " .. payload)
  end
end

the client script

kcd2mp.on_event("marker", function(payload)         -- one handler per name ...
  local x, y, z = payload:match("^([^,]+),([^,]+),(.+)$")
  System.LogAlways("[kcd2mp] marker at " .. x .. " " .. y)
end)

kcd2mp.on_any_event = function(name, payload) end   -- ... or a catch-all for the rest

kcd2mp.send_event("used", "door 7")                 -- to the mode's OnClientEvent

The payload is a string: JSON, a comma list, whatever the two halves agree on. A handler error on the client is logged ([kcd2mp] event 'name' handler: ...), never fatal.

When a state bag is the better tool

An event is a message; it reaches the clients that are connected when it is sent and is gone. A value every client should be able to read at any time — a team, a round number, who carries the flag — belongs in a state bag: set once on the server, replicated to every client’s kcd2mp.state, delivered whole to newcomers.