gem install parcelwing

# config/providers/parcelwing.rb
Hanami.app.register_provider :parcelwing do
  prepare do
    require "parcelwing"
  end
 
  start do
    register "parcelwing.client", ParcelWing::Client.new(
      api_key: target["settings"].parcelwing_api_key
    )
  end
end

# app/actions/send_welcome.rb
module Acme
  module Actions
    class SendWelcome < Acme::Action
      include Deps[parcelwing: "parcelwing.client"]
 
      params do
        required(:email).filled(:string)
        optional(:first_name).maybe(:string)
      end
 
      def handle(request, response)
        halt 422, request.params.errors.to_h.to_json unless request.params.valid?
 
        emails = parcelwing.emails.send(
          from: ENV.fetch("PARCELWING_FROM_EMAIL"),
          to: request.params[:email],
          template_alias: "welcome",
          template_params: { first_name: request.params[:first_name] || "friend" }
        )
 
        response.format = :json
        response.body = { id: emails.first.fetch("id") }.to_json
      end
    end
  end
end