routes.rb

      post "events", to: "events#create", constraints: ->(req) do
        req.user_agent == "SavvyCal Webhooks (https://savvycal.com)" &&
          req.params["type"] == "event.created"
      end

      post "events", to: "events#update", constraints: ->(req) do
        req.user_agent == "SavvyCal Webhooks (https://savvycal.com)" &&
          ["event.rescheduled", "event.canceled"].include?(req.params["type"])
      end