npm install --save-dev eyeglass-file-text

@import 'file-text';

// Fetch text file:
$text  : file-text('./loremipsum.txt');
    // encoding can be explicitly specified by 2nd argument

// Fetch binary file:
$base64: file-binary('./test.jpg');
    // binary file content is represented as base64 text


// The string can then be used as usual in sass:
.test-text {
  content: $text;
}

.test-binary {
  background: url("data:image/jpeg;base64,#{$base64}");
}