diff --git a/modules/openapi-generator/src/main/resources/r/README.mustache b/modules/openapi-generator/src/main/resources/r/README.mustache
index 1da3dffd0cd37cc70e5e05b21f89874470e3d95e..40b284a54ccbe132876b28fcd419748e7041e346 100644
--- a/modules/openapi-generator/src/main/resources/r/README.mustache
+++ b/modules/openapi-generator/src/main/resources/r/README.mustache
@@ -83,13 +83,27 @@ Class | Method | HTTP request | Description
 {{/authMethods}}{{#authMethods}}{{#last}} Authentication schemes defined for the API:{{/last}}{{/authMethods}}
 {{#authMethods}}### {{name}}
 
-{{#isApiKey}}- **Type**: API key
+{{#isApiKey}}
+- **Type**: API key
 - **API key parameter name**: {{keyParamName}}
 - **Location**: {{#isKeyInQuery}}URL query string{{/isKeyInQuery}}{{#isKeyInHeader}}HTTP header{{/isKeyInHeader}}
 {{/isApiKey}}
-{{#isBasic}}- **Type**: HTTP basic authentication
+{{#isBasic}}
+{{#isHttpSignature}}
+- **Type**: HTTP signature authentication
+{{/isHttpSignature}}
+{{#isBasicBasic}}
+- **Type**: HTTP basic authentication
+{{/isBasicBasic}}
+{{#isBasicBearer}}
+- **Type**: Bearer authentication
+{{#bearerFormat}}
+- **Bearer Format**: {{{.}}}
+{{/bearerFormat}}
+{{/isBasicBearer}}
 {{/isBasic}}
-{{#isOAuth}}- **Type**: OAuth
+{{#isOAuth}}
+- **Type**: OAuth
 - **Flow**: {{flow}}
 - **Authorization URL**: {{authorizationUrl}}
 - **Scopes**: {{^scopes}}N/A{{/scopes}}
diff --git a/modules/openapi-generator/src/main/resources/r/api.mustache b/modules/openapi-generator/src/main/resources/r/api.mustache
index 55b6a70106682b36796e3aa78ebdf259b0916e33..2d1bf6affd1231c1a59174babb38a2352acfec60 100644
--- a/modules/openapi-generator/src/main/resources/r/api.mustache
+++ b/modules/openapi-generator/src/main/resources/r/api.mustache
@@ -321,7 +321,10 @@
       header_params["Authorization"] <- paste("Basic", base64enc::base64encode(charToRaw(paste(self$api_client$username, self$api_client$password, sep = ":"))))
       {{/isBasicBasic}}
       {{#isBasicBearer}}
-      header_params["Authorization"] <- paste("Bearer", self$api_client$bearer_token, sep = " ")
+      # Bearer token
+      if (!is.null(self$api_client$bearer_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$bearer_token, sep = " ")
+      }
       {{/isBasicBearer}}
       {{/isBasic}}
       {{#isApiKey}}
@@ -339,7 +342,9 @@
       {{/isApiKey}}
       {{#isOAuth}}
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
       {{/isOAuth}}
       {{/authMethods}}
 
diff --git a/modules/openapi-generator/src/main/resources/r/api_doc.mustache b/modules/openapi-generator/src/main/resources/r/api_doc.mustache
index a96041721150bb9479481544174586d89c0907ea..16379784be85a957c7d8fda59912cb340ed0da24 100644
--- a/modules/openapi-generator/src/main/resources/r/api_doc.mustache
+++ b/modules/openapi-generator/src/main/resources/r/api_doc.mustache
@@ -22,7 +22,7 @@ Method | HTTP request | Description
 library({{{packageName}}})
 
 {{#allParams}}
-var_{{{paramName}}} <- {{{vendorExtensions.x-r-example}}} # {{{dataType}}} | {{{description}}}
+var_{{{paramName}}} <- {{{vendorExtensions.x-r-example}}} # {{{dataType}}} | {{{description}}}{{^required}} (Optional){{/required}}
 {{/allParams}}
 
 {{#summary}}
@@ -34,21 +34,21 @@ api_instance <- {{{classname}}}$new()
 {{#isBasic}}
 {{#isBasicBasic}}
 # Configure HTTP basic authorization: {{{name}}}
-api_instance$api_client$username <- 'TODO_YOUR_USERNAME';
-api_instance$api_client$password <- 'TODO_YOUR_PASSWORD';
+api_instance$api_client$username <- Sys.getenv("USERNAME")
+api_instance$api_client$password <- Sys.getenv("PASSWORD")
 {{/isBasicBasic}}
 {{#isBasicBearer}}
 # Configure HTTP bearer authorization: {{{name}}}
-api.instance$api_client$bearer_token <- 'TODO_YOUR_BEARER_TOKEN';
+api_instance$api_client$bearer_token <- Sys.getenv("BEARER_TOKEN")
 {{/isBasicBearer}}
 {{/isBasic}}
 {{#isApiKey}}
 # Configure API key authorization: {{{name}}}
-api_instance$api_client$api_keys['{{{keyParamName}}}'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["{{{keyParamName}}}"] <- Sys.getenv("API_KEY")
 {{/isApiKey}}
 {{#isOAuth}}
 # Configure OAuth2 access token for authorization: {{{name}}}
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 {{/isOAuth}}
 {{/authMethods}}
 {{/hasAuthMethods}}
@@ -68,21 +68,22 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `{{{operationId}}}`:")
+  dput(result$ApiException$toString())
   {{#errorObjectType}}
   # error object
   dput(result$ApiException$error_object)
   {{/errorObjectType}}
-} else {
-  {{#returnType}}
+}{{#returnType}} else {
   # deserialized response object
-  dput(result$content)
-  {{/returnType}}
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+{{/returnType}}
+
+{{^returnType}}
+# This endpoint doesn't return data
+{{/returnType}}
 {{/useRlangExceptionHandling}}
 {{/returnExceptionOnFailure}}
 {{^useRlangExceptionHandling}}
diff --git a/samples/client/petstore/R-httr2/R/pet_api.R b/samples/client/petstore/R-httr2/R/pet_api.R
index a5653aa8001a6432b6ed950fbbced468cc38a0fe..6b2bd6fe54275beeea0d3d19dd3c5f32f5d0b5ee 100644
--- a/samples/client/petstore/R-httr2/R/pet_api.R
+++ b/samples/client/petstore/R-httr2/R/pet_api.R
@@ -770,7 +770,9 @@ PetApi <- R6::R6Class(
       }
 
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list()
@@ -869,7 +871,9 @@ PetApi <- R6::R6Class(
 
       local_var_url_path <- "/pet/findByStatus"
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -981,7 +985,9 @@ PetApi <- R6::R6Class(
 
       local_var_url_path <- "/pet/findByTags"
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -1094,7 +1100,10 @@ PetApi <- R6::R6Class(
         local_var_url_path <- gsub(paste0("\\{", "petId", "\\}"), URLencode(as.character(`pet_id`), reserved = TRUE), local_var_url_path)
       }
 
-      header_params["Authorization"] <- paste("Bearer", self$api_client$bearer_token, sep = " ")
+      # Bearer token
+      if (!is.null(self$api_client$bearer_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$bearer_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -1462,7 +1471,9 @@ PetApi <- R6::R6Class(
 
       local_var_url_path <- "/pet"
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -1580,7 +1591,9 @@ PetApi <- R6::R6Class(
       }
 
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list()
@@ -1687,7 +1700,9 @@ PetApi <- R6::R6Class(
       }
 
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/json")
diff --git a/samples/client/petstore/R-httr2/README.md b/samples/client/petstore/R-httr2/README.md
index 94e6f1a2cd7a24e7a7ebb48408384b46a071c9fc..8c9b2a188f412cbdacace86dc938a96bf582d062 100644
--- a/samples/client/petstore/R-httr2/README.md
+++ b/samples/client/petstore/R-httr2/README.md
@@ -114,7 +114,7 @@ Class | Method | HTTP request | Description
 
 ### BearerToken
 
-- **Type**: HTTP basic authentication
+- **Type**: Bearer authentication
 
 ### api_key
 
diff --git a/samples/client/petstore/R-httr2/docs/FakeApi.md b/samples/client/petstore/R-httr2/docs/FakeApi.md
index cdd8f8d38e7017942473b8996dd9385f5c32e8eb..2d1643663193292dc346921b87f7c63a50a1b1dd 100644
--- a/samples/client/petstore/R-httr2/docs/FakeApi.md
+++ b/samples/client/petstore/R-httr2/docs/FakeApi.md
@@ -19,7 +19,7 @@ test data_file to ensure it's escaped correctly
 library(petstore)
 
 var_dummy <- "dummy_example" # character | dummy required parameter
-var_var_data_file <- "var_data_file_example" # character | header data file
+var_var_data_file <- "var_data_file_example" # character | header data file (Optional)
 
 #test data_file to ensure it's escaped correctly
 api_instance <- FakeApi$new()
@@ -31,17 +31,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `fake_data_file`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R-httr2/docs/PetApi.md b/samples/client/petstore/R-httr2/docs/PetApi.md
index 1bbb4f200cd95190f9fb2aa9ad0a5b0797ce177b..2498a03ae7a56a6cf280be74a5506406096329dc 100644
--- a/samples/client/petstore/R-httr2/docs/PetApi.md
+++ b/samples/client/petstore/R-httr2/docs/PetApi.md
@@ -32,8 +32,8 @@ var_pet <- Pet$new("name_example", list("photoUrls_example"), 123, Category$new(
 #Add a new pet to the store
 api_instance <- PetApi$new()
 # Configure HTTP basic authorization: http_auth
-api_instance$api_client$username <- 'TODO_YOUR_USERNAME';
-api_instance$api_client$password <- 'TODO_YOUR_PASSWORD';
+api_instance$api_client$username <- Sys.getenv("USERNAME")
+api_instance$api_client$password <- Sys.getenv("PASSWORD")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$add_pet(var_pet, data_file = "result.txt"),
@@ -42,17 +42,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `add_pet`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -92,27 +91,24 @@ Deletes a pet
 library(petstore)
 
 var_pet_id <- 56 # integer | Pet id to delete
-var_api_key <- "api_key_example" # character | 
+var_api_key <- "api_key_example" # character |  (Optional)
 
 #Deletes a pet
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              api_instance$delete_pet(var_pet_id, api_key = var_api_key),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `delete_pet`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -156,7 +152,7 @@ var_status <- list("available") # array[character] | Status values that need to
 #Finds Pets by status
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$find_pets_by_status(var_status, data_file = "result.txt"),
@@ -165,17 +161,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `find_pets_by_status`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -219,7 +214,7 @@ var_tags <- list("inner_example") # array[character] | Tags to filter by
 #Finds Pets by tags
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$find_pets_by_tags(var_tags, data_file = "result.txt"),
@@ -228,17 +223,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `find_pets_by_tags`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -282,7 +276,7 @@ var_pet_id <- 56 # integer | ID of pet to return
 #Find pet by ID
 api_instance <- PetApi$new()
 # Configure HTTP bearer authorization: BearerToken
-api.instance$api_client$bearer_token <- 'TODO_YOUR_BEARER_TOKEN';
+api_instance$api_client$bearer_token <- Sys.getenv("BEARER_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$get_pet_by_id(var_pet_id, data_file = "result.txt"),
@@ -291,17 +285,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `get_pet_by_id`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -346,7 +339,7 @@ var_pet_id <- 56 # integer | ID of pet to return
 #Find pet by ID (streaming)
 api_instance <- PetApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$get_pet_by_id_streaming(var_pet_id, data_file = "result.txt"),
@@ -357,17 +350,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `get_pet_by_id_streaming`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -412,7 +404,7 @@ var_header_test_int <- 56 # integer | header test int
 #Header test
 api_instance <- PetApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$test_header(var_header_test_int, data_file = "result.txt"),
@@ -423,17 +415,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `test_header`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -478,7 +469,7 @@ var_pet <- Pet$new("name_example", list("photoUrls_example"), 123, Category$new(
 #Update an existing pet
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$update_pet(var_pet, data_file = "result.txt"),
@@ -487,17 +478,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `update_pet`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -539,28 +529,25 @@ Updates a pet in the store with form data
 library(petstore)
 
 var_pet_id <- 56 # integer | ID of pet that needs to be updated
-var_name <- "name_example" # character | Updated name of the pet
-var_status <- "status_example" # character | Updated status of the pet
+var_name <- "name_example" # character | Updated name of the pet (Optional)
+var_status <- "status_example" # character | Updated status of the pet (Optional)
 
 #Updates a pet in the store with form data
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              api_instance$update_pet_with_form(var_pet_id, name = var_name, status = var_status),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `update_pet_with_form`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -601,13 +588,13 @@ uploads an image
 library(petstore)
 
 var_pet_id <- 56 # integer | ID of pet to update
-var_additional_metadata <- "additional_metadata_example" # character | Additional data to pass to server
-var_file <- File.new('/path/to/file') # data.frame | file to upload
+var_additional_metadata <- "additional_metadata_example" # character | Additional data to pass to server (Optional)
+var_file <- File.new('/path/to/file') # data.frame | file to upload (Optional)
 
 #uploads an image
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$upload_file(var_pet_id, additional_metadata = var_additional_metadata, file = var_file, data_file = "result.txt"),
@@ -616,17 +603,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `upload_file`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R-httr2/docs/StoreApi.md b/samples/client/petstore/R-httr2/docs/StoreApi.md
index be64f9ba72bac8ecac7677e3147c1eac1ff98886..d393fbe337027076b9a7a335a17a85ebb32ed5af 100644
--- a/samples/client/petstore/R-httr2/docs/StoreApi.md
+++ b/samples/client/petstore/R-httr2/docs/StoreApi.md
@@ -31,15 +31,12 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `delete_order`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -82,7 +79,7 @@ library(petstore)
 #Returns pet inventories by status
 api_instance <- StoreApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$get_inventory(data_file = "result.txt"),
@@ -91,17 +88,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `get_inventory`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -148,17 +144,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `get_order_by_id`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -210,17 +205,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `place_order`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R-httr2/docs/UserApi.md b/samples/client/petstore/R-httr2/docs/UserApi.md
index 55b9970fab54d625a04ea3a0ea33a2cf6aac36ce..369d723f5141cc67bae2e48f098806d5d1baae6f 100644
--- a/samples/client/petstore/R-httr2/docs/UserApi.md
+++ b/samples/client/petstore/R-httr2/docs/UserApi.md
@@ -30,22 +30,19 @@ var_user <- User$new(123, "username_example", "firstName_example", "lastName_exa
 #Create user
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$create_user(var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `create_user`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -88,22 +85,19 @@ var_user <- list(User$new(123, "username_example", "firstName_example", "lastNam
 #Creates list of users with given input array
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$create_users_with_array_input(var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `create_users_with_array_input`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -146,22 +140,19 @@ var_user <- list(User$new(123, "username_example", "firstName_example", "lastNam
 #Creates list of users with given input array
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$create_users_with_list_input(var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `create_users_with_list_input`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -204,22 +195,19 @@ var_username <- "username_example" # character | The name that needs to be delet
 #Delete user
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$delete_user(var_username),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `delete_user`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -270,17 +258,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `get_user_by_name`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -333,17 +320,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `login_user`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -387,22 +373,19 @@ library(petstore)
 #Logs out current logged in user session
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$logout_user(),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `logout_user`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -443,22 +426,19 @@ var_user <- User$new(123, "username_example", "firstName_example", "lastName_exa
 #Updated user
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$update_user(var_username, var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `update_user`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R/R/pet_api.R b/samples/client/petstore/R/R/pet_api.R
index cd03160159b5dfb4cde1598c32052de10d507553..ecb93b4fe679a4aa17652c1d863956935b61bc3e 100644
--- a/samples/client/petstore/R/R/pet_api.R
+++ b/samples/client/petstore/R/R/pet_api.R
@@ -770,7 +770,9 @@ PetApi <- R6::R6Class(
       }
 
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list()
@@ -869,7 +871,9 @@ PetApi <- R6::R6Class(
 
       local_var_url_path <- "/pet/findByStatus"
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -981,7 +985,9 @@ PetApi <- R6::R6Class(
 
       local_var_url_path <- "/pet/findByTags"
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -1094,7 +1100,10 @@ PetApi <- R6::R6Class(
         local_var_url_path <- gsub(paste0("\\{", "petId", "\\}"), URLencode(as.character(`pet_id`), reserved = TRUE), local_var_url_path)
       }
 
-      header_params["Authorization"] <- paste("Bearer", self$api_client$bearer_token, sep = " ")
+      # Bearer token
+      if (!is.null(self$api_client$bearer_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$bearer_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -1462,7 +1471,9 @@ PetApi <- R6::R6Class(
 
       local_var_url_path <- "/pet"
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/xml", "application/json")
@@ -1580,7 +1591,9 @@ PetApi <- R6::R6Class(
       }
 
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list()
@@ -1687,7 +1700,9 @@ PetApi <- R6::R6Class(
       }
 
       # OAuth token
-      header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      if (!is.null(self$api_client$access_token)) {
+        header_params["Authorization"] <- paste("Bearer", self$api_client$access_token, sep = " ")
+      }
 
       # The Accept request HTTP header
       local_var_accepts = list("application/json")
diff --git a/samples/client/petstore/R/README.md b/samples/client/petstore/R/README.md
index ced7db355d69aea90cbb53b8b330a5c5e8345572..6dbc7c274169d6ec7645c14ea044f59bac2a5810 100644
--- a/samples/client/petstore/R/README.md
+++ b/samples/client/petstore/R/README.md
@@ -114,7 +114,7 @@ Class | Method | HTTP request | Description
 
 ### BearerToken
 
-- **Type**: HTTP basic authentication
+- **Type**: Bearer authentication
 
 ### api_key
 
diff --git a/samples/client/petstore/R/docs/FakeApi.md b/samples/client/petstore/R/docs/FakeApi.md
index 558584fe6970f6db3389987005bdc958017a7a7e..22ab9383e7ddc05385e58985243b2ac1af631ca5 100644
--- a/samples/client/petstore/R/docs/FakeApi.md
+++ b/samples/client/petstore/R/docs/FakeApi.md
@@ -19,7 +19,7 @@ test data_file to ensure it's escaped correctly
 library(petstore)
 
 var_dummy <- "dummy_example" # character | dummy required parameter
-var_var_data_file <- "var_data_file_example" # character | header data file
+var_var_data_file <- "var_data_file_example" # character | header data file (Optional)
 
 #test data_file to ensure it's escaped correctly
 api_instance <- FakeApi$new()
@@ -31,17 +31,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `FakeDataFile`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R/docs/PetApi.md b/samples/client/petstore/R/docs/PetApi.md
index daf84841e7bd450af4359e767526920adb4f7adf..4c6bae4a7e51177a208968b6e9ef779ea2fe7a0e 100644
--- a/samples/client/petstore/R/docs/PetApi.md
+++ b/samples/client/petstore/R/docs/PetApi.md
@@ -32,8 +32,8 @@ var_pet <- Pet$new("name_example", list("photoUrls_example"), 123, Category$new(
 #Add a new pet to the store
 api_instance <- PetApi$new()
 # Configure HTTP basic authorization: http_auth
-api_instance$api_client$username <- 'TODO_YOUR_USERNAME';
-api_instance$api_client$password <- 'TODO_YOUR_PASSWORD';
+api_instance$api_client$username <- Sys.getenv("USERNAME")
+api_instance$api_client$password <- Sys.getenv("PASSWORD")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$AddPet(var_pet, data_file = "result.txt"),
@@ -42,17 +42,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `AddPet`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -92,27 +91,24 @@ Deletes a pet
 library(petstore)
 
 var_pet_id <- 56 # integer | Pet id to delete
-var_api_key <- "api_key_example" # character | 
+var_api_key <- "api_key_example" # character |  (Optional)
 
 #Deletes a pet
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              api_instance$DeletePet(var_pet_id, api_key = var_api_key),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `DeletePet`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -156,7 +152,7 @@ var_status <- list("available") # array[character] | Status values that need to
 #Finds Pets by status
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$FindPetsByStatus(var_status, data_file = "result.txt"),
@@ -165,17 +161,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `FindPetsByStatus`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -219,7 +214,7 @@ var_tags <- list("inner_example") # array[character] | Tags to filter by
 #Finds Pets by tags
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$FindPetsByTags(var_tags, data_file = "result.txt"),
@@ -228,17 +223,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `FindPetsByTags`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -282,7 +276,7 @@ var_pet_id <- 56 # integer | ID of pet to return
 #Find pet by ID
 api_instance <- PetApi$new()
 # Configure HTTP bearer authorization: BearerToken
-api.instance$api_client$bearer_token <- 'TODO_YOUR_BEARER_TOKEN';
+api_instance$api_client$bearer_token <- Sys.getenv("BEARER_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$GetPetById(var_pet_id, data_file = "result.txt"),
@@ -291,17 +285,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `GetPetById`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -346,7 +339,7 @@ var_pet_id <- 56 # integer | ID of pet to return
 #Find pet by ID (streaming)
 api_instance <- PetApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$GetPetByIdStreaming(var_pet_id, data_file = "result.txt"),
@@ -357,17 +350,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `GetPetByIdStreaming`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -412,7 +404,7 @@ var_header_test_int <- 56 # integer | header test int
 #Header test
 api_instance <- PetApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$TestHeader(var_header_test_int, data_file = "result.txt"),
@@ -423,17 +415,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `TestHeader`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -478,7 +469,7 @@ var_pet <- Pet$new("name_example", list("photoUrls_example"), 123, Category$new(
 #Update an existing pet
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$UpdatePet(var_pet, data_file = "result.txt"),
@@ -487,17 +478,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `UpdatePet`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -539,28 +529,25 @@ Updates a pet in the store with form data
 library(petstore)
 
 var_pet_id <- 56 # integer | ID of pet that needs to be updated
-var_name <- "name_example" # character | Updated name of the pet
-var_status <- "status_example" # character | Updated status of the pet
+var_name <- "name_example" # character | Updated name of the pet (Optional)
+var_status <- "status_example" # character | Updated status of the pet (Optional)
 
 #Updates a pet in the store with form data
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              api_instance$UpdatePetWithForm(var_pet_id, name = var_name, status = var_status),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `UpdatePetWithForm`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -601,13 +588,13 @@ uploads an image
 library(petstore)
 
 var_pet_id <- 56 # integer | ID of pet to update
-var_additional_metadata <- "additional_metadata_example" # character | Additional data to pass to server
-var_file <- File.new('/path/to/file') # data.frame | file to upload
+var_additional_metadata <- "additional_metadata_example" # character | Additional data to pass to server (Optional)
+var_file <- File.new('/path/to/file') # data.frame | file to upload (Optional)
 
 #uploads an image
 api_instance <- PetApi$new()
 # Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+api_instance$api_client$access_token <- Sys.getenv("ACCESS_TOKEN")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$UploadFile(var_pet_id, additional_metadata = var_additional_metadata, file = var_file, data_file = "result.txt"),
@@ -616,17 +603,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `UploadFile`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R/docs/StoreApi.md b/samples/client/petstore/R/docs/StoreApi.md
index b79108126815d89c0ae7a5d91d5111c3434cdad7..35a21aec9d8a6bf4eaf7b4c12d2871054616ed2b 100644
--- a/samples/client/petstore/R/docs/StoreApi.md
+++ b/samples/client/petstore/R/docs/StoreApi.md
@@ -31,15 +31,12 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `DeleteOrder`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -82,7 +79,7 @@ library(petstore)
 #Returns pet inventories by status
 api_instance <- StoreApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              # to save the result into a file, simply add the optional `data_file` parameter, e.g.
              # api_instance$GetInventory(data_file = "result.txt"),
@@ -91,17 +88,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `GetInventory`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -148,17 +144,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `GetOrderById`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -210,17 +205,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `PlaceOrder`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
diff --git a/samples/client/petstore/R/docs/UserApi.md b/samples/client/petstore/R/docs/UserApi.md
index a9d8a646d90d25746b0b7ae7f280476e70a4a25d..767c36cb69a1339294ff3f361f7d394b260bf511 100644
--- a/samples/client/petstore/R/docs/UserApi.md
+++ b/samples/client/petstore/R/docs/UserApi.md
@@ -30,22 +30,19 @@ var_user <- User$new(123, "username_example", "firstName_example", "lastName_exa
 #Create user
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$CreateUser(var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `CreateUser`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -88,22 +85,19 @@ var_user <- list(User$new(123, "username_example", "firstName_example", "lastNam
 #Creates list of users with given input array
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$CreateUsersWithArrayInput(var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `CreateUsersWithArrayInput`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -146,22 +140,19 @@ var_user <- list(User$new(123, "username_example", "firstName_example", "lastNam
 #Creates list of users with given input array
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$CreateUsersWithListInput(var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `CreateUsersWithListInput`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -204,22 +195,19 @@ var_username <- "username_example" # character | The name that needs to be delet
 #Delete user
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$DeleteUser(var_username),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `DeleteUser`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -270,17 +258,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `GetUserByName`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -333,17 +320,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `LoginUser`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  dput(result$content)
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
+  print("The response is ...")
+  dput(result$toString())
 }
+
 ```
 
 ### Parameters
@@ -387,22 +373,19 @@ library(petstore)
 #Logs out current logged in user session
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$LogoutUser(),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `LogoutUser`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters
@@ -443,22 +426,19 @@ var_user <- User$new(123, "username_example", "firstName_example", "lastName_exa
 #Updated user
 api_instance <- UserApi$new()
 # Configure API key authorization: api_key
-api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+api_instance$api_client$api_keys["api_key"] <- Sys.getenv("API_KEY")
 result <- tryCatch(
              api_instance$UpdateUser(var_username, var_user),
              ApiException = function(ex) ex
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  dput(result$ApiException)
+  print("Exception occurs when calling `UpdateUser`:")
+  dput(result$ApiException$toString())
   # error object
   dput(result$ApiException$error_object)
-} else {
-  # response headers
-  dput(result$response$headers)
-  # response status code
-  dput(result$response$status_code)
 }
+# This endpoint doesn't return data
 ```
 
 ### Parameters