MJS+ modding guide
By using mjs+ you can pratically replace every single thing in the client, going from meme mods to poorfagging """premium""" .png.
Mods are divided in resourcepacks (replacing audio or pictures) and extensions (running javascript code). Download one of each from the repository to look at them.

Mods are stored in the MJS+ folder, under either "extension" or "resourcepack" folders. They are nothing more than a folder, containing at least these files:

1) extension/resourcepack .json, depending on which type
2) preview image
3) script.js/assets folder

1) extension.json, or resourcepack.json
This file contains the basic mod info.
This is the template
{
  "id": "name_of_folder",  ##id given to the mod, must be the same name as the folder
  "version": "1.0.0",      ##version of the mod, format must be "x.x.x"
  "name": "anonmod",        ##name shown in the MJS+
  "author": ["anon"],       ##author name shown in MJS+
  "description": "mod for /mjg/",  ##description shown in MJS+
  "preview": "preview.png",    ##image used as prewiev in MJS+
  "resourcepack": [             ##list of files that will be replaced by the mod //use for resourcepack
    "aa/bb/cc/file1.png",
    "aa/bb/file2.mp3"
  ],
  "entry": "script.js"          ##script that will be run //use for extension
}

If you want to only replace files, use only resourcepack line, and make a "resourcepack" mod.
If you want to only run a script, use only entry line, and make a "extension" mod.
If you want both, write both, but you must make an "extension" mod.

2) preview image
Nothing much to say, it's shown in the starting client

3) script.js and assets folder
If your .json has the line  "entry": "script.js", script.js is the code that will be run. Sadly, I don't know JS, and the only thing I can do is modify other people scripts.

If your .json has the lines "resourcepack: ...", the assets folder is where you'll place the files that will overwrite MJS standard ones.
The original files are stored in the MJS+ folder, under static/2/v.06.xxx/
2 should stand for EN server, so if you play in chink it could be 0 or 1.
v.06.xxx is the version in which that file was first used, so while most of the files are under the lowest version number, newer things (like files for events) are under newer folders.
Now search inside the folder for what you wish to replace. Note that most abbreviations are in english, but things longer than 4 character are usually in chink.
Assuming the file you want to replace is "/static/2/v.06.11/en/myres2/treasurehead/treasure_pic0709.png",
you will write in the .json
"resourcepack": [
    "en/myres2/treasurehead/treasure_pic0709.png"
],
and you will place in the assets folder the replacing file, with the same path (ie idofmod/assets/en/myres2/treasurehead/treasure_pic0709.png).


If you haven't fucked up, the mod should show in the MJS client, and work when enabled.

If it doesn't, it probably is something stupid such as
>id is different from folder name
>version isn't x.x.x
>comma on the last element of the files to replace in the json
>confused extensions from resourcepacks
>put folders in wrong places
>...

If it does start but doesn't work in game:
>script is wrong
>chinks use different files than the one you're replacing (the v.06.xxx storage convention is hell to go through)
>chinks use 10 different versions of the same files, and you didn't replace them all
>...


Other things:
>As of now, there are mods that replace tiles, characters, buttons, audio, tablecloths and some other things, so take a look to avoid wasting your time, and take what you need
>you can export/import from MJS client, it just expands/compress the mod folder into a renamed .zip
>there is tablecloth tool, it will make by itself a resourcepack mod with your desired tablecloth.png replacing the standard blue one