add fiat balance

app/graphql/types/fiat_balance_type.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+module Types
+  class FiatBalanceType < Types::BaseObject
+    implements GraphQL::Types::Relay::Node
+    global_id_field :id
+
+    graphql_name "FiatBalance"
+
+    field :id, ID, null: false
+    field :amount_cents, Integer, null: false
+    field :amount_currency, String, null: false
+    field :created_at, GraphQL::Types::ISO8601DateTime, null: false
+    field :updated_at, GraphQL::Types::ISO8601DateTime, null: false
+  end
+end

app/graphql/types/query_type.rb

@@ -13,5 +13,10 @@ module Types
     def balances
       Pundit.policy_scope(current_user, Balance)
     end
+
+    field :fiat_balances, FiatBalanceType.connection_type, null: false
+    def fiat_balances
+      Pundit.policy_scope(current_user, FiatBalance)
+    end
   end
 end