Here following the ghost Cheatsheet for the developers :

General Snippets

{{body_class}} - To show the body class
{{meta_title}} - To show the meta title
{{ghost_head}} - To Show the header meta and other codes
{{ghost_foot}} - To Show the footer codes

@site Data

{{@site.lang}} - Configured site language. ( Ex: en, es )
{{@site.url}} - To Show the site URL
{{@site.description}} - To Show the site Description / Slogan
{{@site.logo}} - To Show the site logo URL
{{@site.facebook}} - Facebook URL from general settings
{{@site.twitter}} - Twitter URL from general settings
{{@site.icon}} - The publication icon from general settings
{{@site.cover_image}}- Site cover image from general settings
{{@site.timezone}} - Timezone as configured in general settings
{{@site.navigation}} - Navigation information configured in settings/design

A navigation item has the following attributes which can be used inside your ./partials/navigation.hbs template file...

{{label}} - The text to display for the link
{{url}} - The URL to link to - see the url helper for more options
{{current}} - Boolean true/false - whether the URL matches the current page
{{slug} - Slugified name of the page, eg about-us. Can be used as a class to target specific menu items with CSS or jQuery.

Example:

<div>
<ul>
<!-- Loop through the navigation items -->
{{#foreach navigation}}
<li><a href="{{url absolute="true"}}">{{label}}</a></li>
{{/foreach}}
<!-- End the loop -->
</ul>
</div>

Condition to Detect index, page, post etc

{{#is "index"}}{{/is}} - To detect the index page
{{#is "home"}}{{/is}} - To detect the home page
{{#is "post"}}{{/is}} - To detect the single post page
{{#is "page"}}{{/is}} - To detect the single page
{{#is "author"}}{{/is}} - To detect the author page
{{#is "tag"}}{{/is}} - To detect the tag page
{{#is "paged"}}{{/is}} - To detect if this is page 2, or page 3 of a list, but not on the first page
{{#is "private"}}{{/is}} - To detect the private page shown for password-protected sites
Example:

{{#is "home"}}
  ... output something special for the home page ...
{{else}}
  ... output something different on all other pages ...
{{/is}}

Example:

{{#is "post, page"}}
   ... content to render if the current route represents a post or a page ...
{{/is}}

foreach

{{#foreach data}}{{/foreach}} - Special loop helper for lists of posts, tags or users
Example:

{{#foreach posts limit="3"}}
<a href="{{url}}">{{name}}</a>
{{/foreach}}

Example 4:

{{#foreach posts from="2" to="5"}}
<a href="{{url}}">{{name}}</a>
{{/foreach}}

Data Variables For foreach

@index (number) - the 0-based index of the current iteration
@number (number) - the 1-based index of the current iteration
@key (string) - if iterating over an object, rather than an array, this contains the object key
@first (boolean) - true if this is the first iteration of the collection
@last (boolean) - true if this is the last iteration of the collection
@odd (boolean) - true if the @index is odd
@even (boolean) - true if the @index is even
@rowStart (boolean) - true if columns is passed and this iteration signals a row start
@rowEnd (boolean) - true if columns is passed and this iteration signals a row-end
Example:

{{#foreach posts}}
{{#if @first}}
<div>First post</div>
{{/if}}
{{/foreach}}

Example:

{{#foreach posts}}
<div>{{title}}</div>
{{/foreach}}

has

{{#has}} is like {{#if}} but with the ability to do more than test a boolean. It allows theme developers to ask questions about the current context and provide more flexibility for creating different layouts.
{{#has tag="value1,value2" author="value"}}
{{#has slug=../slug}}
{{#has number="nth:3"}}
{{#has any="twitter, facebook"}}
{{#has all="twitter, facebook"}}

Inject widget partial every 3rd post

Example:

{{#foreach posts}}
  {{#has number="nth:3"}}
     {{> "widget"}}
  {{/has}}
  {{> "post-card"}}
{{/foreach}}

Foreach loop number or index

Example:

{{#has number="3"}}{{/has}} // A single number
{{#has number="3, 6, 9"}}{{/has}} // list of numbers
{{#has number="nth:3"}}{{/has}} // special syntax for nth item
{{!-- All of these work exactly the same for index --}}

if

{{#if featured}}{{/if}} - allows for testing if the featured post
Example:

{{#post}}
{{#if feature_image}}
<img src="{{img_url feature_image}}" />
{{else}}
<img src="{{asset "img/default-img.jpg"}}" />
{{/if}}
{{else}}
<p>No posts to display!</p>
{{/post}}

unless

{{#unless featured}}{{/unless}} -That is essentially the opposite of {{#if}}

get

That makes a custom query to the Ghost API to fetch publicly available data
{{#get "posts" limit="20"}}{{/get}} - Fetch the 20 most recently published posts
{{#get "posts" limit="all"}}{{/get}} - Fetch all published posts
{{#get "posts" [email protected]_per_page}}{{/get}} - Use the posts_per_page setting
{{#get "posts" limit="5" page="4"}}{{/get}} - Fetch the 4th page of results - In this case where limit = 5, we are accessing posts 16 - 20
{{#get "posts" limit="5" order="published_at asc"}}{{/get}} - Fetch the oldest 5 posts
{{#get "posts" limit="5" order="published_at desc"}}{{/get}} - Fetch the 5 most recently published posts
{{#get "posts" limit="5" order="title asc"}}{{/get}} - Fetch posts in alphabetical order of title ([0-9], A->Z)
{{#get "posts" limit="all" filter="featured:true"}} {{/get}} - Fetch all featured post
{{#get "posts" filter="authors:{{primary_author.slug}}+id:-{{id}}" limit="3"}} {{/get}} - Fetch primary_authors 3 posts
{{#get "posts" filter="primary_tag:{{primary_tag.slug}}" limit="3"}}{{/get}} - Fetch 3 posts of same primary tag
{{#get "posts" limit="5" include="authors,tags"}}{{/get}} - Fetch posts with author and tags