mastodon/app/views/stream_entries/show.html.haml

- content_for :header_tags do
  %link{ rel: 'alternate', type: 'application/atom+xml', href: account_stream_entry_url(@account, @stream_entry, format: 'atom') }/

.activity-stream.activity-stream-headless
  = render partial: @type, locals: { @type.to_sym => @stream_entry.activity, include_threads: true }