grape-streaming.rb

REDIS = Redis.new

class API < Grape::API
  # allow swappable transports, defaults to http
  imbue Grape::Stream, transport: :http

  # mark an endpoint as streaming
  get '/firehose', stream: true do
    # can still set headers
    headers 'X-API' => 'somekey'

    REDIS.subscribe 'events' do |on|
      on.message do |channel, message|
        flush Event.find_by_id(message)
      end
    end

    # irresponsible client, write a message and close the connection
    flush! "boom: all done"

    # hitting the end of a streaming endpoint will
    # set the correct headers and keep the connection
    # alive
  end

  post '/events' do
    evt = Event.create!(params[:event])
    REDIS.publish 'events', evt.id
  end
end

where Grape::Stream comes from?