Super basic example of Roda + Trailblazer

roda.rb

# This app is an API only, that's why we set :json as response and as params.
# This is the Roda Router.
# This app used roda + hanami model + TRB;
# Those methods `present Ami::V1::Customer::Collection` are calls to the app Operations
# #present and #run are helper methods added to handle the response of an Operation.
# Basically when I `run` and operation and it is successful I'll just call Operation#decorated hash and transform it into JSON;
# If the operation failed then I'll create a json response with status: :unprocessable_entity and call the Operation#error.messages and add it to the json response.
module Ami
  module V1
    class Routes < Roda
      plugin MyApp::RodaHelper

      route do |r|

        uuid_matcher = /(\w{8}-\w{4}-\w{4}-\w{4}-\w{12})/.freeze

        r.on 'customers' do
          puts 'customers'

          r.is do
            # GET /customers
            r.get do
              puts 'index'
              present Ami::V1::Customer::Collection
            end

            # POST /customers
            r.post do
              puts 'create'
              run Ami::V1::Customer::Create
            end
          end

          r.on uuid_matcher do |customer_id|
            puts customer_id
            params.merge!(id: customer_id)

            r.is do
              # GET /customers/:id
              r.get do
                puts 'show'
                present Ami::V1::Customer::Resource
              end

              # PUT /customers/:id
              r.put do
                puts 'update'
                run Ami::V1::Customer::Update
              end

              # DELETE /customers/:id
              r.delete do
                puts 'destroy'
                run Ami::V1::Customer::Destroy
              end
            end

            # Customer Addresses
            r.on 'addresses' do
              puts 'addresses'
              params.delete(:id)
              params.merge!(customer_id: customer_id)

              r.is do
                # GET /professsionals/:customer_id/addresses
                r.get do
                  puts 'index'
                  present Ami::V1::Customer::Address::Collection
                end

                # POST /customers/:customer_id/addresses
                r.post do
                  puts 'create'
                  run Ami::V1::Customer::Address::Create
                end
              end

              r.on uuid_matcher do |address_id|
                puts address_id
                params.merge!(id: address_id)

                r.is do
                  # GET /customers/:customer_id/addresses/:id
                  r.get do
                    puts 'show'
                    present Ami::V1::Customer::Address::Resource
                  end

                  # PUT /customers/:customer_id/addresses/:id
                  r.put do
                    puts 'update'
                    run Ami::V1::Customer::Address::Update
                  end

                  # DELETE /customers/:profesional_id/addresses/:id
                  r.delete do
                    puts 'delete'
                    run Ami::V1::Customer::Address::Destroy
                  end
                end
              end
            end
          end
        end

        r.on 'professionals' do
          puts 'professionals'

          r.is do
            # GET /professionals
            r.get do
              puts 'index'
              present Ami::V1::Professional::Collection
            end

            # POST /professionals
            r.post do
              puts 'create'
              run Ami::V1::Professional::Create
            end
          end

          r.on uuid_matcher do |professional_id|
            puts professional_id
            params.merge!(id: professional_id)

            r.is do
              # GET /professionals/:id
              r.get do
                puts 'show'
                present Ami::V1::Professional::Resource
              end

              # PUT /professionals/:id
              r.put do
                puts 'update'
                run Ami::V1::Professional::Update
              end

              # DELETE /professionals/:id
              r.delete do
                puts 'destroy'
                run Ami::V1::Professional::Destroy
              end
            end

            # Professional BankAccounts
            r.on 'bank_accounts' do
              puts 'bank_accounts'
              params.delete(:id)
              params.merge!(professional_id: professional_id)

              r.is do
                # GET /professsionals/:professional_id/bank_accounts
                r.get do
                  puts 'index'
                  present Ami::V1::Professional::BankAccount::Collection
                end

                # POST /professionals/:professional_id/bank_accounts
                r.post do
                  puts 'create'
                  run Ami::V1::Professional::BankAccount::Create
                end
              end

              r.on :id do |bank_account_id|
                puts bank_account_id
                params.merge!(id: bank_account_id)

                r.is do
                  # GET /professionals/:professional_id/bank_accounts/:id
                  r.get do
                    puts 'show'
                    present Ami::V1::Professional::BankAccount::Resource
                  end

                  # PUT /professionals/:professional_id/bank_accounts/:id
                  r.put do
                    puts 'update'
                    run Ami::V1::Professional::BankAccount::Update
                  end

                  # DELETE /professionals/:profesional_id/bank_accounts/:id
                  r.delete do
                    puts 'delete'
                    run Ami::V1::Professional::BankAccount::Destroy
                  end
                end
              end
            end

            # Professional Addresses
            r.on 'addresses' do
              puts 'addresses'
              params.delete(:id)
              params.merge!(professional_id: professional_id)

              r.is do
                # GET /professsionals/:professional_id/addresses
                r.get do
                  puts 'index'
                  present Ami::V1::Professional::Address::Collection
                end

                # POST /professionals/:professional_id/addresses
                r.post do
                  puts 'create'
                  run Ami::V1::Professional::Address::Create
                end
              end

              r.on uuid_matcher do |address_id|
                puts address_id
                params.merge!(id: address_id)

                r.is do
                  # GET /professionals/:professional_id/addresses/:id
                  r.get do
                    puts 'show'
                    present Ami::V1::Professional::Address::Resource
                  end

                  # PUT /professionals/:professional_id/addresses/:id
                  r.put do
                    puts 'update'
                    run Ami::V1::Professional::Address::Update
                  end

                  # DELETE /professionals/:profesional_id/addresses/:id
                  r.delete do
                    puts 'delete'
                    run Ami::V1::Professional::Address::Destroy
                  end
                end
              end
            end
          end
        end
      end
    end
  end
end

roda_helper.rb

module MyApp
  module RodaHelper

    def self.load_dependencies(app)
      app.plugin :all_verbs
      app.plugin :symbolized_params
      app.plugin :json_parser,
                 parser: proc { |o| MultiJson.load(o) },
                 error_handler: MYApp::JsonParserErrorHandler
      app.plugin :json,
                 serializer: proc { |o| MultiJson.dump(o, pretty: true) }
    end

    module InstanceMethods

      private

      def run(operation_class)
        op = operation_class.run(params) do |op|
          return valid_operation_response(op)
        end
        invalid_operation_response(op)
      end

      def present(operation_class)
        operation_class.present(params).decorated.to_hash
      end

      def valid_operation_response(operation)
        if operation.decorated
          operation.decorated.to_hash
        else
          response.status = 204
        end
      end

      def invalid_operation_response(operation)
        response.status = 422
        {
          code: 422,
          message: 'Validation Failed',
          description: 'Check the errors field for detail information.',
          errors: operation.errors
        }
      end
    end
  end
end