If you’re trying to access an array element for a computed value in handlebars, like @index inside a loop, use lookup.

Inside a loop, use lookup along with the special index variable, like this

{{lookup <array_ref> @index}}

Remember that inside a loop you may need to refer to the higher level scope, so say your model is

{someArray: ['a', 'b', 'c', 'd'], toIterate: ['x', 'y', 'z']}

And your template

{{#each toIterate}}
  {{lookup ../someArray @index}} {{this}}

Then you get

a x
b y
c z

Why are hipsters so bad at documenting things? It’s like a rule of thumb about hip JS things that the documentation never covers obvious tricky cases that arise as soon as the thing isn’t being used like a toy.