# Create Add-ons
## How it works
Any add-on uses this format: \
`CoolAddon` is the module that will only run in the plugin.\
`game` module will be synced to game-module's add-ons folder\
\
\
\
`CoolAddon` will use the ui-library to make ui and should return a table like this:
```luau
return {
api = gameapi, -- require(script.game)
name = "Screen effects",
icon = 97990680261359,
description = [[
- ImpactFrames (CCE)
- CameraShake (with presets)
- Camera weld (VFX on screen)
ImpactFrames emit others enable
]],
uninstall = function()
-- optional
end
}
```
Which will show this in **Manage Add-ons**:
`game` module can return anything, and whatever it returns will be put in the API\
ex: `return { customFunc = function() }` will be `shared.fx.CoolAddon.customFunc()`\
also it will be renamed to `CoolAddon` when put under `ReplicatedStorage.vfx.addons`:\
The main function `game` module should use most is THIS:
```luau
shared.fx.api.add {
emit = function(vfx, attributes, ..),
enable = function(vfx, attributes, ..),
disable = function(vfx, attributes, ..),
retime = function(vfx, timeScale, origins),
rescale = function(vfx, sizeScale, origins),
recolor = function(vfx, hue, sat, lightness, origins)
selector = ".Tag,[$Attribute]" -- :QueryDescendants(selector)
} -- everything here is optional
```
`emit` happens with `.emit(vfx)` and with Emit button in plugin (same for `enable` and `disable`)\
`retime`, `rescale`, and `recolor` happen with module's functions too (AND plugin sliders!!!!!1)\
so everything here is used in-game (with funcs like `.recolor()`) and in plugin with Sliders!!
## Installation
Add-ons can be installed by clicking the  button in **Manage Add-ons**\
Or with a shortcut for quick reinstalling when debugging/developing an add-on
## Debugging
To easily make, edit, and debug add-ons, they will be placed in `ServerStorage.vfx_addons`\
That folder is made and reserved by the plugin to store add-ons in the place (for debugging & more)\
Errors, warnings, and prints will point to the script in `vfx_addons` even if the add-on is published\
\
Add-ons are automatically uninstalled when they error or take too long to return.\
When an add-on is uninstalled, all connections and objects it created are cleaned up-\
except things made independently, which should be cleaned up by the custom `uninstall` function
## Limitations
1. Add-ons must return in max 2 seconds\
(*this is to make sure the game-module loads fast in-game)*
2. Add-ons can only have classes `ModuleScript` and `Folder`\
\&#xNAN;*(it will support all types of instances soon since roblox released* [*ReflectionService*](https://create.roblox.com/docs/reference/engine/classes/ReflectionService)*)*
3. Add-ons in-game can't be uninstalled like in plugin
{% hint style="info" %}
You can use task.spawn to not yield the main thread if you need more time than 2s
{% endhint %}
## Publishing
Add-ons can be published so anyone with the plugin can install and use them
You can choose to make your add-on open-source where anyone can get the source and edit-\
by clicking this  or choose not to. but the `game` module will be exposed to be used in games.
You can also make a license/terms that user must agree upon to install your add-on, like this:
```luau
local agreed = shared.fx.ui.okPopup("title", "terms here", "i agree to the terms")
-- this can be even used in the command bar
```
This is done using the `canInstall` callback, which will only allow installing if it returns `true`\
It can also be used to make add-ons **paid** by checking if user owns a gamepass or through http
## How to start
Start by reading an open-source add-on as a template, then add your own functionality, or-\
by reading the ui-library document and learn how to make UI like a properties UI for your add-on
