diff --git a/generate.sh b/generate.sh
index c913cd4..4401550 100755
--- a/generate.sh
+++ b/generate.sh
@@ -60,7 +60,7 @@ fi
 if [ $2 = 'ruby' ]
 then
     python3 remove-cookie-auth.py
-    $container_exec run -u $(id -u) --rm -v ${PWD}:$volume_name openapitools/openapi-generator-cli:v4.3.1 generate \
+    $container_exec run -u $(id -u) --rm -v ${PWD}:$volume_name openapitools/openapi-generator-cli:v5.3.0 generate \
         -i /local/api.json \
         -g ruby \
         -o /local/$1-client \
diff --git a/templates/ruby/api_client_faraday_partial.mustache b/templates/ruby/api_client_faraday_partial.mustache
index 38bceaf..605cf61 100644
--- a/templates/ruby/api_client_faraday_partial.mustache
+++ b/templates/ruby/api_client_faraday_partial.mustache
@@ -14,7 +14,8 @@
         :params_encoder => @config.params_encoder
       }
       connection = Faraday.new(:url => config.base_url, :ssl => ssl_options, :request => request_options) do |conn|
-        conn.basic_auth(config.username, config.password)
+        conn.request(:basic_auth, config.username, config.password)
+        @config.configure_middleware(conn)
         if opts[:header_params]["Content-Type"] == "multipart/form-data"
           conn.request :multipart
           conn.request :url_encoded
@@ -65,7 +66,7 @@
     # @option opts [Object] :body HTTP body (JSON/XML)
     # @return [Typhoeus::Request] A Typhoeus Request
     def build_request(http_method, path, request, opts = {})
-      url = build_request_url(path)
+      url = build_request_url(path, opts)
       http_method = http_method.to_sym.downcase
 
       header_params = @default_headers.merge(opts[:header_params] || {})
@@ -75,9 +76,6 @@
       update_params_for_auth! header_params, query_params, opts[:auth_names]
 
       req_opts = {
-        :method => http_method,
-        :headers => header_params,
-        :params => query_params,
         :params_encoding => @config.params_encoding,
         :timeout => @config.timeout,
         :verbose => @config.debugging
@@ -85,13 +83,13 @@
 
       if [:post, :patch, :put, :delete].include?(http_method)
         req_body = build_request_body(header_params, form_params, opts[:body])
-        req_opts.update :body => req_body
         if @config.debugging
           @config.logger.debug "HTTP request body param ~BEGIN~\n#{req_body}\n~END~\n"
         end
       end
       request.headers = header_params
       request.body = req_body
+      request.options = OpenStruct.new(req_opts)
       request.url url
       request.params = query_params
       download_file(request) if opts[:return_type] == 'File'
@@ -129,3 +127,12 @@
       end
       data
     end
+
+    def download_file(request)
+      @stream = []
+
+      # handle streaming Responses
+      request.options.on_data = Proc.new do |chunk, overall_received_bytes|
+        @stream << chunk
+      end
+    end
diff --git a/templates/ruby/configuration.mustache b/templates/ruby/configuration.mustache
index 1468e2d..d1d5f47 100644
--- a/templates/ruby/configuration.mustache
+++ b/templates/ruby/configuration.mustache
@@ -13,6 +13,18 @@ module {{moduleName}}
     # Defines url base path
     attr_accessor :base_path
 
+    # Define server configuration index
+    attr_accessor :server_index
+
+    # Define server operation configuration index
+    attr_accessor :server_operation_index
+
+    # Default server variables
+    attr_accessor :server_variables
+
+    # Default server operation variables
+    attr_accessor :server_operation_variables
+
     # Defines API keys used with API Key authentications.
     #
     # @return [Hash] key: parameter name, value: parameter value (API key)
@@ -90,11 +102,14 @@ module {{moduleName}}
 
     def initialize
       @scheme = '{{scheme}}'
-      @host = '{{host}}'
+      @host = '{{host}}{{#port}}:{{{.}}}{{/port}}'
       @base_path = '{{contextPath}}'
+      @server_index = 0
+      @server_operation_index = {}
+      @server_variables = {}
+      @server_operation_variables = {}
       @api_key = {}
       @api_key_prefix = {}
-      @timeout = 0
       @client_side_validation = true
       {{#isFaraday}}
       @ssl_verify = true
@@ -103,6 +118,10 @@ module {{moduleName}}
       @ssl_client_cert = nil
       @ssl_client_key = nil
       @params_encoder = nil
+      @middlewares = []
+      @request_middlewares = []
+      @response_middlewares = []
+      @timeout = 60
       {{/isFaraday}}
       {{^isFaraday}}
       @verify_ssl = true
@@ -110,6 +129,7 @@ module {{moduleName}}
       @params_encoding = nil
       @cert_file = nil
       @key_file = nil
+      @timeout = 0
       {{/isFaraday}}
       @debugging = false
       @inject_format = false
@@ -144,17 +164,23 @@ module {{moduleName}}
       @base_path = '' if @base_path == '/'
     end
 
-    def base_url
-      "#{scheme}://#{[host, base_path].join('/').gsub(/\/+/, '/')}".sub(/\/+\z/, '')
+    # Returns base URL for specified operation based on server settings
+    def base_url(operation = nil)
+      index = server_operation_index.fetch(operation, server_index)
+      return "#{scheme}://#{[host, base_path].join('/').gsub(/\/+/, '/')}".sub(/\/+\z/, '') if index == nil
+
+      server_url(index, server_operation_variables.fetch(operation, server_variables), operation_server_settings[operation])
     end
 
     # Gets API key (with prefix if set).
     # @param [String] param_name the parameter name of API key auth
-    def api_key_with_prefix(param_name)
+    def api_key_with_prefix(param_name, param_alias = nil)
+      key = @api_key[param_name]
+      key = @api_key.fetch(param_alias, key) unless param_alias.nil?
       if @api_key_prefix[param_name]
-        "#{@api_key_prefix[param_name]} #{@api_key[param_name]}"
+        "#{@api_key_prefix[param_name]} #{key}"
       else
-        @api_key[param_name]
+        key
       end
     end
 
@@ -173,7 +199,7 @@ module {{moduleName}}
             type: 'api_key',
             in: {{#isKeyInHeader}}'header'{{/isKeyInHeader}}{{#isKeyInQuery}}'query'{{/isKeyInQuery}},
             key: '{{keyParamName}}',
-            value: api_key_with_prefix('{{keyParamName}}')
+            value: api_key_with_prefix('{{name}}'{{#vendorExtensions.x-auth-id-alias}}, '{{.}}'{{/vendorExtensions.x-auth-id-alias}})
           },
 {{/isApiKey}}
 {{#isBasic}}
@@ -245,12 +271,58 @@ module {{moduleName}}
       ]
     end
 
+    def operation_server_settings
+      {
+        {{#apiInfo}}
+        {{#apis}}
+        {{#operations}}
+        {{#operation}}
+        {{#servers}}
+        {{#-first}}
+        "{{{classname}}}.{{{nickname}}}": [
+        {{/-first}}
+          {
+          url: "{{{url}}}",
+          description: "{{{description}}}{{^description}}No description provided{{/description}}",
+          {{#variables}}
+          {{#-first}}
+          variables: {
+          {{/-first}}
+            {{{name}}}: {
+                description: "{{{description}}}{{^description}}No description provided{{/description}}",
+                default_value: "{{{defaultValue}}}",
+                {{#enumValues}}
+                {{#-first}}
+                enum_values: [
+                {{/-first}}
+                  "{{{.}}}"{{^-last}},{{/-last}}
+                {{#-last}}
+                ]
+                {{/-last}}
+                {{/enumValues}}
+              }{{^-last}},{{/-last}}
+            {{#-last}}
+            }
+            {{/-last}}
+          {{/variables}}
+          }{{^-last}},{{/-last}}
+        {{#-last}}
+        ],
+        {{/-last}}
+        {{/servers}}
+        {{/operation}}
+        {{/operations}}
+        {{/apis}}
+        {{/apiInfo}}
+      }
+    end
+
     # Returns URL based on server settings
     #
     # @param index array index of the server settings
     # @param variables hash of variable and the corresponding value
-    def server_url(index, variables = {})
-      servers = server_settings
+    def server_url(index, variables = {}, servers = nil)
+      servers = server_settings if servers == nil
 
       # check array index out of bound
       if (index < 0 || index >= servers.size)
@@ -260,10 +332,12 @@ module {{moduleName}}
       server = servers[index]
       url = server[:url]
 
+      return url unless server.key? :variables
+
       # go through variable and assign a value
       server[:variables].each do |name, variable|
         if variables.key?(name)
-          if (server[:variables][name][:enum_values].include? variables[name])
+          if (!server[:variables][name].key?(:enum_values) || server[:variables][name][:enum_values].include?(variables[name]))
             url.gsub! "{" + name.to_s + "}", variables[name]
           else
             fail ArgumentError, "The variable `#{name}` in the server URL has invalid value #{variables[name]}. Must be #{server[:variables][name][:enum_values]}."
@@ -276,5 +350,37 @@ module {{moduleName}}
 
       url
     end
+
+    {{#isFaraday}}
+    # Adds middleware to the stack
+    def use(*middleware)
+      @middlewares << middleware
+    end
+
+    # Adds request middleware to the stack
+    def request(*middleware)
+      @request_middlewares << middleware
+    end
+
+    # Adds response middleware to the stack
+    def response(*middleware)
+      @response_middlewares << middleware
+    end
+
+    # Set up middleware on the connection
+    def configure_middleware(connection)
+      @middlewares.each do |middleware|
+        connection.use(*middleware)
+      end
+
+      @request_middlewares.each do |middleware|
+        connection.request(*middleware)
+      end
+
+      @response_middlewares.each do |middleware|
+        connection.response(*middleware)
+      end
+    end
+    {{/isFaraday}}
   end
 end