Passing JSON to Twig
The answer is to create a custom plugin that will read the json files from the folders in the public directory, parse the json, and pull them into the template.

An alternative solution is to use Craft custom config files. (Not the answer you're looking for but would work very well.)

In craft/config create a file like localedata.php and make it something like this:

&lt;?php

/**
 * Return an array indexed by locale code
 */
return [
    'ar' =&gt; [
        'serviceName' =&gt; 'arabic',
        'language' =&gt; 'ar',
        'textDirection' =&gt; 'rtl',
        'socialMediaButtons' =&gt; ['twitter', 'facebook'],
    ],
    'en' =&gt; [
        //...
    ],
    // etc
];


Then in your template you could do something like this:

{#
    If the current locale is `ar` (Arabic) then this will set `localeData`
    from the array index "ar" in the config file
#}
{% set localeData = craft.config.get(craft.locale, 'localedata') %}
&lt;!DOCTYPE html&gt;
&lt;html xmlns="http://www.w3.org/1999/xhtml" lang="{{ craft.locale }}" dir="{{ localeData.textDirection }}"&gt;
&lt;head&gt;
  ...
&lt;/head&gt;