# Tut 0x010

## Baby's first addon

A quick primer on addons for Garry's Mod, and Artery.

You may have seen on the gmod wiki, instructions on running lua code. One way is to place files in your `garrysmod/lua/autorun` directory, and they will be run automatically when you enter single player. This can get messy though, another way to run lua is by making a folder in `garrysmod/addons/<addon_name>/lua/autorun`, and placing your scripts in that (i.e. so that `garrysmod/addons/my_first_addon/lua/autorun/hello.lua` is a valid file). As it turns out, all folders under `garrysmod/addons/<addon_name>` get reflected! This means that if you have a file `garrysmod/addons/my_addon/data/pac3/my_pac.txt` it will appear in the pac editor as a pac you can load!

This is the method used by addons for Artery. Since Garry's Mod loads addons's autorun BEFORE gamemodes, Artery uses the `data/artery/global/` folder to run scripts after the gamemode has loaded (and therefore has access to the nrequire() function, more on this later).

## Lets get started

Start by creating a new folder under `garrysmod/addons/` called `artery_rougelite`. We'll be using this folder for the rest of the tutorials to build a small rougelike gamemode to explore the different features artery provides.

Now create another folder under the folder you just made `garrysmod/addons/artery_rougelite/data`

Now another `garrysmod/addons/artery_rougelite/data/artery/`

And another `garrysmod/addons/artery_rougelite/data/artery/global/`

With the folder structure set up, we're ready to actually write some lua.

Create a file `garrysmod/addons/artery_routelite/data/artery/global/helloworld.txt`

and copy+paste the following code into it.

	print("Hello, world!")

Now start up garrysmod with the Artery gamemode selected. Head into flatgrass or something. Open your console, you should see "Hello, world!" printed in your console(~)!

Next tutorial: @{tut020_nrequire.md}