At.js is a Javascript library for having Github like mentions in an app. The library is here. It’s a very good library and simple to use however when I tried it, it didn’t work out of the box for froala editor. The problem is At.js surrounds the range with spans and since WebKit browsers insert spans, the editor accepts spans only if

data-fr-verified=”true”

is set to true. So to counter this, when initiating the function, a small tweak is required.

$(‘.froala-view’).atwho({
at: “@”,
editableAtwhoQueryAttrs: {“data-fr-verified”: true},

data:[‘Peter’, ‘Tom’, ‘Anne’]
})

This should get it working as it did for me.

Reference: Github issue

Hope  it helps