proxy_filter.rb

require 'goliath'
require 'em-http'

class SecureCallStream < Goliath::API
  use Goliath::Rack::Params

  def response(env)
    src_url = 'http://remoteurl'
    http = EM::HttpRequest.new(src_url).get
    
# TODO: filter chunks
    http.stream { |chunk| env.chunked_stream_send(chunk) }
    http.callback { env.chunked_stream_close }

    chunked_streaming_response(200, {'Content-Type' => 'audio/wav'})
  end

end