# Events between client and server

> How to register custom events with addEvent and send them between client and server using triggerServerEvent, triggerClientEvent and latent events in MY Multiplayer (MYMP).

- **Platform**: MY Multiplayer (MYMP) — Lua 5.4
- **Sections**: Documentation › Guides
- **Language**: English
- **URL**: https://wiki.mymp.gg/en/docs/custom-events

In **MY Multiplayer** (**MYMP**), client and server scripts communicate across the network by registering custom events and triggering them on the opposite side.

## Creating and listening for an event

- `addEvent(name, remote)` registers an event name. Only an event created with `remote` set to `true` can arrive over the network from the other side; any other incoming remote event is dropped and logged.
- `addEventHandler(name, element, callback)` attaches a Lua handler function to the event on the element tree.

## From the client to the server

`triggerServerEvent(name, source, ...)` sends an event from the client to the server.

- **Server-known elements only**: `source` and any elements passed as arguments must exist on the server. Passing a client-only element raises an error.
- **Sender verification**: on the server, the [global variable](https://wiki.mymp.gg/en/docs/globals.md) `client` holds the player whose connection sent the packet. Always rely on `client` — never `source` or a handler argument — to identify who sent the event, because the client chooses both `source` and the arguments.

## From the server to the client

`triggerClientEvent([to,] name, source, ...)` sends an event from the server to one or more clients:

- `to`: a single `player`, a table of players or any element in the tree (sending to every player below it). When omitted, the event goes to **every connected player**.
- For large payloads, `triggerLatentServerEvent` and `triggerLatentClientEvent` transfer data gradually within a bandwidth limit.

## Complete example

Server:

```lua
addEvent("onShopBuy", true)

addEventHandler("onShopBuy", resourceRoot, function(itemId)
    if type(itemId) ~= "string" then return end
    triggerClientEvent(client, "onShopBought", resourceRoot, itemId)
end)
```

Client:

```lua
addEvent("onShopBought", true)

addEventHandler("onShopBought", resourceRoot, function(itemId)
    outputDebugString("You bought " .. itemId)
end)

triggerServerEvent("onShopBuy", resourceRoot, "burger")
```

## Per-player rate limit

A player who triggers more than `max_player_triggered_events_per_interval` events (default: `100`) within `player_triggered_event_interval` ms (default: `1000`, both configured in [server.cfg](https://wiki.mymp.gg/en/docs/server-config.md)) causes the server to fire `onPlayerTriggerEventThreshold`. What happens next is up to the script — for example disconnecting the player with `kickPlayer`.