[codegen][python-experimental] Composed schema with additionalProperties (#6290)

* Mustache template should use invokerPackage tag to generate import * Add a unit test for allOf and additionalProperties * Fix getAdditionalProperties * Add code comments * Add code comments * set nullable for additionalproperties * add variants of additionalProperties * Add more unit tests * Handle additionalProperties for composed schemas * improve code comments * Add code comments * Add code comments * Add code comments * Add code comments * Add code comments * Add assertions in unit tests * Add new property to support the 'additionalProperties' keyword with composed schemas * run sample scripts * fix unit tests to handle additionalProperties * Handle additional properties and composed schema * Handle additional properties and composed schema * Add support for additionalProperties and composed schema * Format java code * Add more unit tests for Python * Handle reference in additionalProperty keyword * Handle reference in additionalProperty keyword * Add use case for additionalProperties and reference * run sample scripts * resolve schema reference * Add OpenAPI argument * Add OpenAPI argument * Add OpenAPI argument * Add OpenAPI argument * Add OpenAPI argument * Handle additional property keyword with reference * Handle additional property keyword with reference * Handle additional property keyword with reference * Handle additional property keyword with reference * add additionalproperties attribute with boolean values * Run sample scripts * handle additional properties * Handle additionalProperties boolean values * Run sample scripts * fix javadoc issues * fix javadoc issues * Add Locale to String.toLowerCase * execute sample scripts * handle additional properties * Add code comments * Handle imports of referenced models in additional properties * Handle isNullable class * handle nullable type * improve documentation, run sample scripts * improve documentation, run sample scripts * execute sample scripts * execute sample scripts * Execute sample scripts * Run samples scripts * set legacyAdditionalPropertiesBehavior to true by default, except python * create separate yaml file to avoid having lots of changes in the pr * create separate yaml file to avoid having lots of changes in the pr * create separate yaml file to avoid having lots of changes in the pr * create separate yaml file to avoid having lots of changes in the pr * create separate yaml file to avoid having lots of changes in the pr * create separate yaml file to avoid having lots of changes in the pr * Change name of CLI option * Generate doc * Add TODO statement * add code comments * run samples scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * refactor cli option for additional properties * refactor cli option for additional properties * run samples scripts * run sample scripts * run sample scripts * run sample scripts * run sample scripts * Add yaml comments * small refactor * small refactor * run sample scripts * run sample scripts * fix unit tests * Set disallowAdditionalPropertiesIfNotPresent flag * reduced size of test yaml file * simplify code and add imports directly * rename some of the properties used in tests * Handle more scenarios for nullable types * add code comments * Adds *args input to __init__ method to fix test testFruitNullValue * Resolve merge issues * run samples scripts * run doc generator * fix merge conflicts Co-authored-by: Justin Black <justin.a.black@gmail.com>
2020-05-28 09:40:48 -07:00 · 2020-05-28 09:40:48 -07:00 · f7f41410e7
commit f7f41410e7
parent 07647b1a31
369 changed files with 4312 additions and 465 deletions
--- a/bin/python-experimental-petstore.sh
+++ b/bin/python-experimental-petstore.sh
@ -27,6 +27,6 @@ fi

 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="generate -t modules/openapi-generator/src/main/resources/python -i modules/openapi-generator/src/test/resources/2_0/python-client-experimental/petstore-with-fake-endpoints-models-for-testing.yaml -g python-experimental -o samples/client/petstore/python-experimental --additional-properties packageName=petstore_api $@"
+ags="generate -t modules/openapi-generator/src/main/resources/python -i modules/openapi-generator/src/test/resources/2_0/python-client-experimental/petstore-with-fake-endpoints-models-for-testing.yaml -g python-experimental -o samples/client/petstore/python-experimental --additional-properties packageName=petstore_api --additional-properties disallowAdditionalPropertiesIfNotPresent=true $@"

 java $JAVA_OPTS -jar $executable $ags
--- a/docs/generators/ada-server.md
+++ b/docs/generators/ada-server.md
@ -6,6 +6,8 @@ sidebar_label: ada-server
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/ada.md
+++ b/docs/generators/ada.md
@ -6,6 +6,8 @@ sidebar_label: ada
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/android.md
+++ b/docs/generators/android.md
@ -12,6 +12,8 @@ sidebar_label: android
 |apiPackage|package for generated api classes| |null|
 |artifactId|artifactId for use in the generated build.gradle and pom.xml| |null|
 |artifactVersion|artifact version for use in the generated build.gradle and pom.xml| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId for use in the generated build.gradle and pom.xml| |null|
 |invokerPackage|root package for generated code| |null|
--- a/docs/generators/apache2.md
+++ b/docs/generators/apache2.md
@ -6,6 +6,8 @@ sidebar_label: apache2
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/apex.md
+++ b/docs/generators/apex.md
@ -9,6 +9,8 @@ sidebar_label: apex
 |apiVersion|The Metadata API version number to use for components in this package.| |null|
 |buildMethod|The build method for this package.| |null|
 |classPrefix|Prefix for generated classes. Set this to avoid overwriting existing classes in your org.| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |namedCredential|The named credential name for the HTTP callouts| |null|
--- a/docs/generators/asciidoc.md
+++ b/docs/generators/asciidoc.md
@ -10,6 +10,8 @@ sidebar_label: asciidoc
 |appName|short name of the application| |null|
 |artifactId|artifactId in generated pom.xml. This also becomes part of the generated library's filename| |null|
 |artifactVersion|artifact version in generated pom.xml. This also becomes part of the generated library's filename| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId in generated pom.xml| |null|
 |headerAttributes|generation of asciidoc header meta data attributes (set to false to suppress, default: true)| |true|
--- a/docs/generators/avro-schema.md
+++ b/docs/generators/avro-schema.md
@ -6,6 +6,8 @@ sidebar_label: avro-schema
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |packageName|package for generated classes (where supported)| |null|
--- a/docs/generators/bash.md
+++ b/docs/generators/bash.md
@ -9,6 +9,8 @@ sidebar_label: bash
 |apiKeyAuthEnvironmentVariable|Name of environment variable where API key can be defined (e.g. PETSTORE_APIKEY='kjhasdGASDa5asdASD')| |false|
 |basicAuthEnvironmentVariable|Name of environment variable where username and password can be defined (e.g. PETSTORE_CREDS='username:password')| |null|
 |curlOptions|Default cURL options| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |generateBashCompletion|Whether to generate the Bash completion script| |false|
 |generateZshCompletion|Whether to generate the Zsh completion script| |false|
--- a/docs/generators/c.md
+++ b/docs/generators/c.md
@ -6,6 +6,8 @@ sidebar_label: c
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/clojure.md
+++ b/docs/generators/clojure.md
@ -7,6 +7,8 @@ sidebar_label: clojure
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |baseNamespace|the base/top namespace (Default: generated from projectName)| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/cpp-qt5-client.md
+++ b/docs/generators/cpp-qt5-client.md
@ -8,6 +8,8 @@ sidebar_label: cpp-qt5-client
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |contentCompression|Enable Compressed Content Encoding for requests and responses| |false|
 |cppNamespace|C++ namespace (convention: name::space::for::api).| |OpenAPI|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelNamePrefix|Prefix that will be prepended to all model names.| |OAI|
--- a/docs/generators/cpp-qt5-qhttpengine-server.md
+++ b/docs/generators/cpp-qt5-qhttpengine-server.md
@ -8,6 +8,8 @@ sidebar_label: cpp-qt5-qhttpengine-server
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |contentCompression|Enable Compressed Content Encoding for requests and responses| |false|
 |cppNamespace|C++ namespace (convention: name::space::for::api).| |OpenAPI|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelNamePrefix|Prefix that will be prepended to all model names.| |OAI|
--- a/docs/generators/cpp-tizen.md
+++ b/docs/generators/cpp-tizen.md
@ -6,6 +6,8 @@ sidebar_label: cpp-tizen
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/cpp-ue4.md
+++ b/docs/generators/cpp-ue4.md
@ -7,6 +7,8 @@ sidebar_label: cpp-ue4
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |cppNamespace|C++ namespace (convention: name::space::for::api).| |OpenAPI|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |optionalProjectFile|Generate Build.cs| |true|
--- a/docs/generators/cwiki.md
+++ b/docs/generators/cwiki.md
@ -10,6 +10,8 @@ sidebar_label: cwiki
 |appName|short name of the application| |null|
 |artifactId|artifactId in generated pom.xml. This also becomes part of the generated library's filename| |null|
 |artifactVersion|artifact version in generated pom.xml. This also becomes part of the generated library's filename| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId in generated pom.xml| |null|
 |infoEmail|an email address to contact for inquiries about the application| |null|
--- a/docs/generators/dart-dio.md
+++ b/docs/generators/dart-dio.md
@ -8,6 +8,8 @@ sidebar_label: dart-dio
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |browserClient|Is the client browser based (for Dart 1.x only)| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**core**</dt><dd>Dart core library (DateTime)</dd><dt>**timemachine**</dt><dd>Time Machine is date and time library for Flutter, Web, and Server with support for timezones, calendars, cultures, formatting and parsing.</dd></dl>|core|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |nullableFields|Is the null fields should be in the JSON payload| |null|
--- a/docs/generators/dart-jaguar.md
+++ b/docs/generators/dart-jaguar.md
@ -7,6 +7,8 @@ sidebar_label: dart-jaguar
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |browserClient|Is the client browser based (for Dart 1.x only)| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |nullableFields|Is the null fields should be in the JSON payload| |null|
--- a/docs/generators/dart.md
+++ b/docs/generators/dart.md
@ -7,6 +7,8 @@ sidebar_label: dart
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |browserClient|Is the client browser based (for Dart 1.x only)| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/dynamic-html.md
+++ b/docs/generators/dynamic-html.md
@ -8,6 +8,8 @@ sidebar_label: dynamic-html
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |artifactId|artifactId in generated pom.xml. This also becomes part of the generated library's filename| |null|
 |artifactVersion|artifact version in generated pom.xml. This also becomes part of the generated library's filename| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId in generated pom.xml| |null|
 |invokerPackage|root package for generated code| |null|
--- a/docs/generators/elixir.md
+++ b/docs/generators/elixir.md
@ -6,6 +6,8 @@ sidebar_label: elixir
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay.Pets| |null|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/fsharp-functions.md
+++ b/docs/generators/fsharp-functions.md
@ -6,6 +6,8 @@ sidebar_label: fsharp-functions
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |licenseName|The name of the license| |NoLicense|
--- a/docs/generators/groovy.md
+++ b/docs/generators/groovy.md
@ -18,6 +18,8 @@ sidebar_label: groovy
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/haskell-http-client.md
+++ b/docs/generators/haskell-http-client.md
@ -17,6 +17,8 @@ sidebar_label: haskell-http-client
 |dateFormat|format string used to parse/render a date| |%Y-%m-%d|
 |dateTimeFormat|format string used to parse/render a datetime| |null|
 |dateTimeParseFormat|overrides the format string used to parse a datetime| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |generateEnums|Generate specific datatypes for OpenAPI enums| |true|
 |generateFormUrlEncodedInstances|Generate FromForm/ToForm instances for models that are used by operations that produce or consume application/x-www-form-urlencoded| |true|
--- a/docs/generators/haskell.md
+++ b/docs/generators/haskell.md
@ -7,6 +7,8 @@ sidebar_label: haskell
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelPackage|package for generated models| |null|
--- a/docs/generators/html.md
+++ b/docs/generators/html.md
@ -10,6 +10,8 @@ sidebar_label: html
 |appName|short name of the application| |null|
 |artifactId|artifactId in generated pom.xml. This also becomes part of the generated library's filename| |null|
 |artifactVersion|artifact version in generated pom.xml. This also becomes part of the generated library's filename| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId in generated pom.xml| |null|
 |infoEmail|an email address to contact for inquiries about the application| |null|
--- a/docs/generators/html2.md
+++ b/docs/generators/html2.md
@ -10,6 +10,8 @@ sidebar_label: html2
 |appName|short name of the application| |null|
 |artifactId|artifactId in generated pom.xml. This also becomes part of the generated library's filename| |null|
 |artifactVersion|artifact version in generated pom.xml. This also becomes part of the generated library's filename| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId in generated pom.xml| |null|
 |infoEmail|an email address to contact for inquiries about the application| |null|
--- a/docs/generators/java-inflector.md
+++ b/docs/generators/java-inflector.md
@ -20,6 +20,8 @@ sidebar_label: java-inflector
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/java-msf4j.md
+++ b/docs/generators/java-msf4j.md
@ -20,6 +20,8 @@ sidebar_label: java-msf4j
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/java-pkmst.md
+++ b/docs/generators/java-pkmst.md
@ -21,6 +21,8 @@ sidebar_label: java-pkmst
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |eurekaUri|Eureka URI| |null|
--- a/docs/generators/java-play-framework.md
+++ b/docs/generators/java-play-framework.md
@ -23,6 +23,8 @@ sidebar_label: java-play-framework
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/java-undertow-server.md
+++ b/docs/generators/java-undertow-server.md
@ -20,6 +20,8 @@ sidebar_label: java-undertow-server
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/java-vertx-web.md
+++ b/docs/generators/java-vertx-web.md
@ -20,6 +20,8 @@ sidebar_label: java-vertx-web
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/java-vertx.md
+++ b/docs/generators/java-vertx.md
@ -20,6 +20,8 @@ sidebar_label: java-vertx
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/java.md
+++ b/docs/generators/java.md
@ -22,6 +22,8 @@ sidebar_label: java
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |feignVersion|Version of OpenFeign: '10.x' (default), '9.x' (deprecated)| |false|
--- a/docs/generators/javascript-apollo.md
+++ b/docs/generators/javascript-apollo.md
@ -7,6 +7,8 @@ sidebar_label: javascript-apollo
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |emitJSDoc|generate JSDoc comments| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
--- a/docs/generators/javascript-closure-angular.md
+++ b/docs/generators/javascript-closure-angular.md
@ -6,6 +6,8 @@ sidebar_label: javascript-closure-angular
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/javascript-flowtyped.md
+++ b/docs/generators/javascript-flowtyped.md
@ -6,6 +6,8 @@ sidebar_label: javascript-flowtyped
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/javascript.md
+++ b/docs/generators/javascript.md
@ -7,6 +7,8 @@ sidebar_label: javascript
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |emitJSDoc|generate JSDoc comments| |true|
 |emitModelMethods|generate getters and setters for model properties| |false|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
--- a/docs/generators/jaxrs-cxf-cdi.md
+++ b/docs/generators/jaxrs-cxf-cdi.md
@ -20,6 +20,8 @@ sidebar_label: jaxrs-cxf-cdi
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-cxf-client.md
+++ b/docs/generators/jaxrs-cxf-client.md
@ -20,6 +20,8 @@ sidebar_label: jaxrs-cxf-client
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-cxf-extended.md
+++ b/docs/generators/jaxrs-cxf-extended.md
@ -21,6 +21,8 @@ sidebar_label: jaxrs-cxf-extended
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-cxf.md
+++ b/docs/generators/jaxrs-cxf.md
@ -21,6 +21,8 @@ sidebar_label: jaxrs-cxf
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-jersey.md
+++ b/docs/generators/jaxrs-jersey.md
@ -20,6 +20,8 @@ sidebar_label: jaxrs-jersey
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-resteasy-eap.md
+++ b/docs/generators/jaxrs-resteasy-eap.md
@ -20,6 +20,8 @@ sidebar_label: jaxrs-resteasy-eap
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-resteasy.md
+++ b/docs/generators/jaxrs-resteasy.md
@ -20,6 +20,8 @@ sidebar_label: jaxrs-resteasy
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jaxrs-spec.md
+++ b/docs/generators/jaxrs-spec.md
@ -20,6 +20,8 @@ sidebar_label: jaxrs-spec
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/jmeter.md
+++ b/docs/generators/jmeter.md
@ -6,6 +6,8 @@ sidebar_label: jmeter
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/k6.md
+++ b/docs/generators/k6.md
@ -6,6 +6,8 @@ sidebar_label: k6
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/markdown.md
+++ b/docs/generators/markdown.md
@ -6,6 +6,8 @@ sidebar_label: markdown
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/nim.md
+++ b/docs/generators/nim.md
@ -6,6 +6,8 @@ sidebar_label: nim
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/nodejs-express-server.md
+++ b/docs/generators/nodejs-express-server.md
@ -6,6 +6,8 @@ sidebar_label: nodejs-express-server
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/nodejs-server-deprecated.md
+++ b/docs/generators/nodejs-server-deprecated.md
@ -6,6 +6,8 @@ sidebar_label: nodejs-server-deprecated
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |exportedName|When the generated code will be deployed to Google Cloud Functions, this option can be used to update the name of the exported function. By default, it refers to the basePath. This does not affect normal standalone nodejs server code.| |null|
 |googleCloudFunctions|When specified, it will generate the code which runs within Google Cloud Functions instead of standalone Node.JS server. See https://cloud.google.com/functions/docs/quickstart for the details of how to deploy the generated code.| |false|
--- a/docs/generators/ocaml.md
+++ b/docs/generators/ocaml.md
@ -6,6 +6,8 @@ sidebar_label: ocaml
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/openapi-yaml.md
+++ b/docs/generators/openapi-yaml.md
@ -6,6 +6,8 @@ sidebar_label: openapi-yaml
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |outputFile|Output filename| |openapi/openapi.yaml|
--- a/docs/generators/openapi.md
+++ b/docs/generators/openapi.md
@ -6,6 +6,8 @@ sidebar_label: openapi
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/php-laravel.md
+++ b/docs/generators/php-laravel.md
@ -8,6 +8,8 @@ sidebar_label: php-laravel
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |artifactVersion|The version to use in the composer package version field. e.g. 1.2.3| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/php-lumen.md
+++ b/docs/generators/php-lumen.md
@ -8,6 +8,8 @@ sidebar_label: php-lumen
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |artifactVersion|The version to use in the composer package version field. e.g. 1.2.3| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/php-silex-deprecated.md
+++ b/docs/generators/php-silex-deprecated.md
@ -6,6 +6,8 @@ sidebar_label: php-silex-deprecated
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/php-slim-deprecated.md
+++ b/docs/generators/php-slim-deprecated.md
@ -8,6 +8,8 @@ sidebar_label: php-slim-deprecated
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |artifactVersion|The version to use in the composer package version field. e.g. 1.2.3| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/php-slim4.md
+++ b/docs/generators/php-slim4.md
@ -8,6 +8,8 @@ sidebar_label: php-slim4
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |artifactVersion|The version to use in the composer package version field. e.g. 1.2.3| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/php-symfony.md
+++ b/docs/generators/php-symfony.md
@ -12,6 +12,8 @@ sidebar_label: php-symfony
 |bundleName|The name of the Symfony bundle. The template uses {{bundleName}}| |null|
 |composerProjectName|The project name used in the composer package name. The template uses {{composerVendorName}}/{{composerProjectName}} for the composer package name. e.g. petstore-client| |null|
 |composerVendorName|The vendor name used in the composer package name. The template uses {{composerVendorName}}/{{composerProjectName}} for the composer package name. e.g. yaypets| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
--- a/docs/generators/php-ze-ph.md
+++ b/docs/generators/php-ze-ph.md
@ -8,6 +8,8 @@ sidebar_label: php-ze-ph
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |artifactVersion|The version to use in the composer package version field. e.g. 1.2.3| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/php.md
+++ b/docs/generators/php.md
@ -8,6 +8,8 @@ sidebar_label: php
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |artifactVersion|The version to use in the composer package version field. e.g. 1.2.3| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |true|
 |invokerPackage|The main namespace to use for all classes. e.g. Yay\Pets| |null|
--- a/docs/generators/plantuml.md
+++ b/docs/generators/plantuml.md
@ -6,6 +6,8 @@ sidebar_label: plantuml
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |prependFormOrBodyParameters|Add form or body parameters to the beginning of the parameter list.| |false|
--- a/docs/generators/python-aiohttp.md
+++ b/docs/generators/python-aiohttp.md
@ -8,6 +8,8 @@ sidebar_label: python-aiohttp
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |controllerPackage|controller package| |controllers|
 |defaultController|default controller| |default_controller|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |packageName|python package name (convention: snake_case).| |openapi_server|
--- a/docs/generators/python-blueplanet.md
+++ b/docs/generators/python-blueplanet.md
@ -8,6 +8,8 @@ sidebar_label: python-blueplanet
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |controllerPackage|controller package| |controllers|
 |defaultController|default controller| |default_controller|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |packageName|python package name (convention: snake_case).| |openapi_server|
--- a/docs/generators/python-flask.md
+++ b/docs/generators/python-flask.md
@ -8,6 +8,8 @@ sidebar_label: python-flask
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |controllerPackage|controller package| |controllers|
 |defaultController|default controller| |default_controller|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |packageName|python package name (convention: snake_case).| |openapi_server|
--- a/docs/generators/ruby.md
+++ b/docs/generators/ruby.md
@ -6,6 +6,8 @@ sidebar_label: ruby
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |gemAuthor|gem author (only one is supported).| |null|
 |gemAuthorEmail|gem author email (only one is supported).| |null|
--- a/docs/generators/scala-akka-http-server.md
+++ b/docs/generators/scala-akka-http-server.md
@ -11,6 +11,8 @@ sidebar_label: scala-akka-http-server
 |artifactId|artifactId| |openapi-scala-akka-http-server|
 |artifactVersion|artifact version in generated pom.xml. This also becomes part of the generated library's filename| |1.0.0|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |groupId|groupId in generated pom.xml| |org.openapitools|
 |invokerPackage|root package for generated code| |org.openapitools.server|
--- a/docs/generators/scala-akka.md
+++ b/docs/generators/scala-akka.md
@ -8,6 +8,8 @@ sidebar_label: scala-akka
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |mainPackage|Top-level package name, which defines 'apiPackage', 'modelPackage', 'invokerPackage'| |org.openapitools.client|
--- a/docs/generators/scala-gatling.md
+++ b/docs/generators/scala-gatling.md
@ -8,6 +8,8 @@ sidebar_label: scala-gatling
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelPackage|package for generated models| |null|
--- a/docs/generators/scala-httpclient-deprecated.md
+++ b/docs/generators/scala-httpclient-deprecated.md
@ -8,6 +8,8 @@ sidebar_label: scala-httpclient-deprecated
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelPackage|package for generated models| |null|
--- a/docs/generators/scala-lagom-server.md
+++ b/docs/generators/scala-lagom-server.md
@ -8,6 +8,8 @@ sidebar_label: scala-lagom-server
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelPackage|package for generated models| |null|
--- a/docs/generators/scala-play-server.md
+++ b/docs/generators/scala-play-server.md
@ -8,6 +8,8 @@ sidebar_label: scala-play-server
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |basePackage|Base package in which supporting classes are generated.| |org.openapitools|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |generateCustomExceptions|If set, generates custom exception types.| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/scala-sttp.md
+++ b/docs/generators/scala-sttp.md
@ -8,6 +8,8 @@ sidebar_label: scala-sttp
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |mainPackage|Top-level package name, which defines 'apiPackage', 'modelPackage', 'invokerPackage'| |org.openapitools.client|
--- a/docs/generators/scalatra.md
+++ b/docs/generators/scalatra.md
@ -8,6 +8,8 @@ sidebar_label: scalatra
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelPackage|package for generated models| |null|
--- a/docs/generators/scalaz.md
+++ b/docs/generators/scalaz.md
@ -8,6 +8,8 @@ sidebar_label: scalaz
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiPackage|package for generated api classes| |null|
 |dateLibrary|Option. Date library to use|<dl><dt>**joda**</dt><dd>Joda (for legacy app)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (prefered for JDK 1.8+)</dd></dl>|java8|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |modelPackage|package for generated models| |null|
--- a/docs/generators/spring.md
+++ b/docs/generators/spring.md
@ -25,6 +25,8 @@ sidebar_label: spring
 |developerOrganization|developer organization in generated pom.xml| |OpenAPITools.org|
 |developerOrganizationUrl|developer organization URL in generated pom.xml| |http://openapitools.org|
 |disableHtmlEscaping|Disable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |discriminatorCaseSensitive|Whether the discriminator value lookup should be case-sensitive or not. This option only works for Java API client| |true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
--- a/docs/generators/swift4-deprecated.md
+++ b/docs/generators/swift4-deprecated.md
@ -6,6 +6,8 @@ sidebar_label: swift4-deprecated
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/swift5.md
+++ b/docs/generators/swift5.md
@ -7,6 +7,8 @@ sidebar_label: swift5
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiNamePrefix|Prefix that will be appended to all API names ('tags'). Default: empty string. e.g. Pet =&gt; Pet.| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
 |legacyDiscriminatorBehavior|This flag is used by OpenAPITools codegen to influence the processing of the discriminator attribute in OpenAPI documents. This flag has no impact if the OAS document does not use the discriminator attribute. The default value of this flag is set in each language-specific code generator (e.g. Python, Java, go...)using the method toModelName. Note to developers supporting a language generator in OpenAPITools; to fully support the discriminator attribute as defined in the OAS specification 3.x, language generators should set this flag to true by default; however this requires updating the mustache templates to generate a language-specific discriminator lookup function that iterates over {{#mappedModels}} and does not iterate over {{children}}, {{#anyOf}}, or {{#oneOf}}.|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
--- a/docs/generators/typescript-angular.md
+++ b/docs/generators/typescript-angular.md
@ -7,6 +7,8 @@ sidebar_label: typescript-angular
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
 |apiModulePrefix|The prefix of the generated ApiModule.| |null|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-angularjs.md
+++ b/docs/generators/typescript-angularjs.md
@ -6,6 +6,8 @@ sidebar_label: typescript-angularjs
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-aurelia.md
+++ b/docs/generators/typescript-aurelia.md
@ -6,6 +6,8 @@ sidebar_label: typescript-aurelia
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-axios.md
+++ b/docs/generators/typescript-axios.md
@ -6,6 +6,8 @@ sidebar_label: typescript-axios
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-fetch.md
+++ b/docs/generators/typescript-fetch.md
@ -6,6 +6,8 @@ sidebar_label: typescript-fetch
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-inversify.md
+++ b/docs/generators/typescript-inversify.md
@ -6,6 +6,8 @@ sidebar_label: typescript-inversify
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-jquery.md
+++ b/docs/generators/typescript-jquery.md
@ -6,6 +6,8 @@ sidebar_label: typescript-jquery
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-node.md
+++ b/docs/generators/typescript-node.md
@ -6,6 +6,8 @@ sidebar_label: typescript-node
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-redux-query.md
+++ b/docs/generators/typescript-redux-query.md
@ -6,6 +6,8 @@ sidebar_label: typescript-redux-query
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/docs/generators/typescript-rxjs.md
+++ b/docs/generators/typescript-rxjs.md
@ -6,6 +6,8 @@ sidebar_label: typescript-rxjs
 | Option | Description | Values | Default |
 | ------ | ----------- | ------ | ------- |
 |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false|
+|disallowAdditionalPropertiesIfNotPresent|Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document
+If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. If true: when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.This setting is currently ignored for OAS 2.0 documents:  1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed.  2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed.Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>when the 'additionalProperties' keyword is not present in a schema, the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. Note: this mode is not compliant with the JSON schema specification. This is the original openapi-generator behavior.</dd></dl>|true|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumNameSuffix|Suffix that will be appended to all enum names.| |Enum|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |PascalCase|
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConstants.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConstants.java
@ -359,4 +359,20 @@ public class CodegenConstants {
    public static final String USE_SINGLE_REQUEST_PARAMETER = "useSingleRequestParameter";
    public static final String USE_SINGLE_REQUEST_PARAMETER_DESC = "Setting this property to true will generate functions with a single argument containing all API endpoint parameters instead of one argument per parameter.";

+    public static final String DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT = "disallowAdditionalPropertiesIfNotPresent";
+    public static final String DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT_DESC =
+        "Specify the behavior when the 'additionalProperties' keyword is not present in the OAS document\n" +
+        
+        "If false: the 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications. " +
+
+        "If true: when the 'additionalProperties' keyword is not present in a schema, " +
+        "the value of 'additionalProperties' is set to false, i.e. no additional properties are allowed. " +
+        "Note: this mode is not compliant with the JSON schema specification. " +
+        "This is the original openapi-generator behavior." +
+
+        "This setting is currently ignored for OAS 2.0 documents: " +
+        " 1) When the 'additionalProperties' keyword is not present in a 2.0 schema, additional properties are NOT allowed. " +
+        " 2) Boolean values of the 'additionalProperties' keyword are ignored. It's as if additional properties are NOT allowed." +
+        "Note: the root cause are issues #1369 and #1371, which must be resolved in the swagger-parser project.";
+
 }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java
@ -102,7 +102,31 @@ public class CodegenModel implements IJsonSchemaValidationProperties {

    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();

-    //The type of the value from additional properties. Used in map like objects.
+    /**
+     * The type of the value for the additionalProperties keyword in the OAS document.
+     * Used in map like objects, including composed schemas.
+     * 
+     * In most programming languages, the additional (undeclared) properties are stored
+     * in a map data structure, such as HashMap in Java, map in golang, or a dict in Python.
+     * There are multiple ways to implement the additionalProperties keyword, depending
+     * on the programming language and mustache template.
+     * One way is to use class inheritance. For example in the generated Java code, the
+     * generated model class may extend from HashMap to store the additional properties.
+     * In that case 'CodegenModel.parent' is set to represent the class hierarchy.
+     * Another way is to use CodegenModel.additionalPropertiesType. A code generator
+     * such as Python does not use class inheritance to model additional properties.
+     *
+     * For example, in the OAS schema below, the schema has a declared 'id' property
+     * and additional, undeclared properties of type 'integer' are allowed.
+     * 
+     * type: object
+     * properties:
+     *   id:
+     *     type: integer
+     * additionalProperties:
+     *   type: integer
+     *
+     */
    public String additionalPropertiesType;

    private Integer maxProperties;
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@ -59,6 +59,7 @@ import org.openapitools.codegen.templating.MustacheEngineAdapter;
 import org.openapitools.codegen.templating.mustache.*;
 import org.openapitools.codegen.utils.ModelUtils;
 import org.openapitools.codegen.utils.OneOfImplementorAdditionalData;
+import org.openapitools.codegen.utils.SemVer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

@ -176,8 +177,28 @@ public class DefaultCodegen implements CodegenConfig {
    protected List<CliOption> cliOptions = new ArrayList<CliOption>();
    protected boolean skipOverwrite;
    protected boolean removeOperationIdPrefix;
+
+    /**
+     * True if the code generator supports multiple class inheritance.
+     * This is used to model the parent hierarchy based on the 'allOf' composed schemas.
+     */
    protected boolean supportsMultipleInheritance;
+    /**
+     * True if the code generator supports single class inheritance.
+     * This is used to model the parent hierarchy based on the 'allOf' composed schemas.
+     * Note: the single-class inheritance technique has inherent limitations because
+     * a 'allOf' composed schema may have multiple $ref child schemas, each one
+     * potentially representing a "parent" in the class inheritance hierarchy.
+     * Some language generators also use class inheritance to implement the `additionalProperties`
+     * keyword. For example, the Java code generator may generate 'extends HashMap'.
+     */
    protected boolean supportsInheritance;
+    /**
+     * True if the language generator supports the 'additionalProperties' keyword
+     * as sibling of a composed (allOf/anyOf/oneOf) schema.
+     * Note: all language generators should support this to comply with the OAS specification.
+     */
+    protected boolean supportsAdditionalPropertiesWithComposedSchema;
    protected boolean supportsMixins;
    protected Map<String, String> supportedLibraries = new LinkedHashMap<String, String>();
    protected String library;
@ -218,6 +239,10 @@ public class DefaultCodegen implements CodegenConfig {
    // Support legacy logic for evaluating discriminators
    protected boolean legacyDiscriminatorBehavior = true;

+    // Specify what to do if the 'additionalProperties' keyword is not present in a schema.
+    // See CodegenConstants.java for more details.
+    protected boolean disallowAdditionalPropertiesIfNotPresent = true;
+
    // make openapi available to all methods
    protected OpenAPI openAPI;

@ -314,6 +339,10 @@ public class DefaultCodegen implements CodegenConfig {
            this.setLegacyDiscriminatorBehavior(Boolean.valueOf(additionalProperties
                    .get(CodegenConstants.LEGACY_DISCRIMINATOR_BEHAVIOR).toString()));
        }
+        if (additionalProperties.containsKey(CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT)) {
+            this.setDisallowAdditionalPropertiesIfNotPresent(Boolean.valueOf(additionalProperties
+                    .get(CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT).toString()));
+        }
    }

    /***
@ -687,9 +716,16 @@ public class DefaultCodegen implements CodegenConfig {
        }
    }

+    /**
+     * Set the OpenAPI document.
+     * This method is invoked when the input OpenAPI document has been parsed and validated.
+     */
    @Override
    public void setOpenAPI(OpenAPI openAPI) {
        this.openAPI = openAPI;
+        // Set global settings such that helper functions in ModelUtils can lookup the value
+        // of the CLI option.
+        ModelUtils.setDisallowAdditionalPropertiesIfNotPresent(getDisallowAdditionalPropertiesIfNotPresent());
    }

    // override with any special post-processing
@ -786,7 +822,7 @@ public class DefaultCodegen implements CodegenConfig {
                        addOneOfInterfaceModel((ComposedSchema) items, nOneOf, openAPI);
                    }
                } else if (ModelUtils.isMapSchema(s)) {
-                    Schema addProps = ModelUtils.getAdditionalProperties(s);
+                    Schema addProps = getAdditionalProperties(s);
                    if (addProps != null && ModelUtils.isComposedSchema(addProps)) {
                        addOneOfNameExtension((ComposedSchema) addProps, nOneOf);
                        addOneOfInterfaceModel((ComposedSchema) addProps, nOneOf, openAPI);
@ -1126,6 +1162,14 @@ public class DefaultCodegen implements CodegenConfig {
        this.legacyDiscriminatorBehavior = val;
    }

+    public Boolean getDisallowAdditionalPropertiesIfNotPresent() {
+        return disallowAdditionalPropertiesIfNotPresent;
+    }
+
+    public void setDisallowAdditionalPropertiesIfNotPresent(boolean val) {
+        this.disallowAdditionalPropertiesIfNotPresent = val;
+    }
+
    public Boolean getAllowUnicodeIdentifiers() {
        return allowUnicodeIdentifiers;
    }
@ -1453,6 +1497,22 @@ public class DefaultCodegen implements CodegenConfig {
        legacyDiscriminatorBehaviorOpt.setEnum(legacyDiscriminatorBehaviorOpts);
        cliOptions.add(legacyDiscriminatorBehaviorOpt);

+        // option to change how we process + set the data in the 'additionalProperties' keyword.
+        CliOption disallowAdditionalPropertiesIfNotPresentOpt = CliOption.newBoolean(
+            CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT,
+            CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT_DESC).defaultValue(Boolean.TRUE.toString());
+        Map<String, String> disallowAdditionalPropertiesIfNotPresentOpts = new HashMap<>();
+        disallowAdditionalPropertiesIfNotPresentOpts.put("false",
+            "The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.");
+        disallowAdditionalPropertiesIfNotPresentOpts.put("true",
+            "when the 'additionalProperties' keyword is not present in a schema, " +
+            "the value of 'additionalProperties' is automatically set to false, i.e. no additional properties are allowed. " +
+            "Note: this mode is not compliant with the JSON schema specification. " +
+            "This is the original openapi-generator behavior.");
+        disallowAdditionalPropertiesIfNotPresentOpt.setEnum(disallowAdditionalPropertiesIfNotPresentOpts);
+        cliOptions.add(disallowAdditionalPropertiesIfNotPresentOpt);
+        this.setDisallowAdditionalPropertiesIfNotPresent(true);
+        
        // initialize special character mapping
        initalizeSpecialCharacterMapping();

@ -1585,7 +1645,7 @@ public class DefaultCodegen implements CodegenConfig {
     */
    public String toInstantiationType(Schema schema) {
        if (ModelUtils.isMapSchema(schema)) {
-            Schema additionalProperties = ModelUtils.getAdditionalProperties(schema);
+            Schema additionalProperties = getAdditionalProperties(schema);
            String inner = getSchemaType(additionalProperties);
            return instantiationTypes.get("map") + "<String, " + inner + ">";
        } else if (ModelUtils.isArraySchema(schema)) {
@ -1843,7 +1903,7 @@ public class DefaultCodegen implements CodegenConfig {
    }

    protected Schema<?> getSchemaAdditionalProperties(Schema schema) {
-        Schema<?> inner = ModelUtils.getAdditionalProperties(schema);
+        Schema<?> inner = getAdditionalProperties(schema);
        if (inner == null) {
            LOGGER.error("`{}` (map property) does not have a proper inner type defined. Default to type:string", schema.getName());
            inner = new StringSchema().description("TODO default missing map inner type to string");
@ -2006,13 +2066,13 @@ public class DefaultCodegen implements CodegenConfig {
                return schema.getFormat();
            }
            return "string";
-        } else if (ModelUtils.isFreeFormObject(schema)) {
+        } else if (isFreeFormObject(schema)) {
            // Note: the value of a free-form object cannot be an arbitrary type. Per OAS specification,
            // it must be a map of string to values.
            return "object";
        } else if (schema.getProperties() != null && !schema.getProperties().isEmpty()) { // having property implies it's a model
            return "object";
-        } else if (ModelUtils.isAnyTypeSchema(schema)) {
+        } else if (isAnyTypeSchema(schema)) {
            return "AnyType";
        } else if (StringUtils.isNotEmpty(schema.getType())) {
            LOGGER.warn("Unknown type found in the schema: " + schema.getType());
@ -2193,7 +2253,7 @@ public class DefaultCodegen implements CodegenConfig {
            m.xmlNamespace = schema.getXml().getNamespace();
            m.xmlName = schema.getXml().getName();
        }
-        if (ModelUtils.isAnyTypeSchema(schema)) {
+        if (isAnyTypeSchema(schema)) {
            // The 'null' value is allowed when the OAS schema is 'any type'.
            // See https://github.com/OAI/OpenAPI-Specification/issues/1389
            if (Boolean.FALSE.equals(schema.getNullable())) {
@ -2365,6 +2425,24 @@ public class DefaultCodegen implements CodegenConfig {

            addVars(m, unaliasPropertySchema(properties), required, unaliasPropertySchema(allProperties), allRequired);

+            // Per OAS specification, composed schemas may use the 'additionalProperties' keyword.
+            if (supportsAdditionalPropertiesWithComposedSchema) {
+                // Process the schema specified with the 'additionalProperties' keyword.
+                // This will set the 'CodegenModel.additionalPropertiesType' field
+                // and potentially 'Codegen.parent'.
+                //
+                // Note: it's not a good idea to use single class inheritance to implement
+                // the 'additionalProperties' keyword. Code generators that use single class
+                // inheritance sometimes use the 'Codegen.parent' field to implement the
+                // 'additionalProperties' keyword. However, that would be in conflict with
+                // 'allOf' composed schemas, because these code generators also want to set
+                // 'Codegen.parent' to the first child schema of the 'allOf' schema.
+                addAdditionPropertiesToCodeGenModel(m, schema);
+            }
+
+            if (Boolean.TRUE.equals(schema.getNullable())) {
+                m.isNullable = Boolean.TRUE;
+            }
            // end of code block for composed schema
        } else {
            m.dataType = getSchemaType(schema);
@ -2806,6 +2884,12 @@ public class DefaultCodegen implements CodegenConfig {
        return discriminator;
    }

+    /**
+     * Handle the model for the 'additionalProperties' keyword in the OAS schema.
+     *
+     * @param codegenModel The codegen representation of the schema.
+     * @param schema the input OAS schema.
+     */
    protected void addAdditionPropertiesToCodeGenModel(CodegenModel codegenModel, Schema schema) {
        addParentContainer(codegenModel, codegenModel.name, schema);
    }
@ -3051,9 +3135,9 @@ public class DefaultCodegen implements CodegenConfig {
                property.hasValidation = true;
            }

-        } else if (ModelUtils.isFreeFormObject(p)) {
+        } else if (isFreeFormObject(p)) {
            property.isFreeFormObject = true;
-        } else if (ModelUtils.isAnyTypeSchema(p)) {
+        } else if (isAnyTypeSchema(p)) {
            // The 'null' value is allowed when the OAS schema is 'any type'.
            // See https://github.com/OAI/OpenAPI-Specification/issues/1389
            if (Boolean.FALSE.equals(p.getNullable())) {
@ -3066,7 +3150,7 @@ public class DefaultCodegen implements CodegenConfig {
            ArraySchema arraySchema = (ArraySchema) p;
            Schema innerSchema = ModelUtils.unaliasSchema(this.openAPI, getSchemaItems(arraySchema), importMapping);
        } else if (ModelUtils.isMapSchema(p)) {
-            Schema innerSchema = ModelUtils.unaliasSchema(this.openAPI, ModelUtils.getAdditionalProperties(p),
+            Schema innerSchema = ModelUtils.unaliasSchema(this.openAPI, getAdditionalProperties(p),
                    importMapping);
            if (innerSchema == null) {
                LOGGER.error("Undefined map inner type for `{}`. Default to String.", p.getName());
@ -3159,7 +3243,7 @@ public class DefaultCodegen implements CodegenConfig {
            property.maxItems = p.getMaxProperties();

            // handle inner property
-            Schema innerSchema = ModelUtils.unaliasSchema(this.openAPI, ModelUtils.getAdditionalProperties(p),
+            Schema innerSchema = ModelUtils.unaliasSchema(this.openAPI, getAdditionalProperties(p),
                    importMapping);
            if (innerSchema == null) {
                LOGGER.error("Undefined map inner type for `{}`. Default to String.", p.getName());
@ -3168,13 +3252,13 @@ public class DefaultCodegen implements CodegenConfig {
            }
            CodegenProperty cp = fromProperty("inner", innerSchema);
            updatePropertyForMap(property, cp);
-        } else if (ModelUtils.isFreeFormObject(p)) {
+        } else if (isFreeFormObject(p)) {
            property.isFreeFormObject = true;
            property.baseType = getSchemaType(p);
            if (languageSpecificPrimitives.contains(property.dataType)) {
                property.isPrimitiveType = true;
            }
-        } else if (ModelUtils.isAnyTypeSchema(p)) {
+        } else if (isAnyTypeSchema(p)) {
            property.isAnyType = true;
            property.baseType = getSchemaType(p);
            if (languageSpecificPrimitives.contains(property.dataType)) {
@ -3410,7 +3494,7 @@ public class DefaultCodegen implements CodegenConfig {
                CodegenProperty innerProperty = fromProperty("response", getSchemaItems(as));
                op.returnBaseType = innerProperty.baseType;
            } else if (ModelUtils.isMapSchema(responseSchema)) {
-                CodegenProperty innerProperty = fromProperty("response", ModelUtils.getAdditionalProperties(responseSchema));
+                CodegenProperty innerProperty = fromProperty("response", getAdditionalProperties(responseSchema));
                op.returnBaseType = innerProperty.baseType;
            } else {
                if (cm.complexType != null) {
@ -4083,7 +4167,7 @@ public class DefaultCodegen implements CodegenConfig {
                }

            } else if (ModelUtils.isMapSchema(parameterSchema)) { // for map parameter
-                CodegenProperty codegenProperty = fromProperty("inner", ModelUtils.getAdditionalProperties(parameterSchema));
+                CodegenProperty codegenProperty = fromProperty("inner", getAdditionalProperties(parameterSchema));
                codegenParameter.items = codegenProperty;
                codegenParameter.mostInnerItems = codegenProperty.mostInnerItems;
                codegenParameter.baseType = codegenProperty.dataType;
@ -4505,6 +4589,22 @@ public class DefaultCodegen implements CodegenConfig {
        co.baseName = tag;
    }

+    /**
+     * Sets the value of the 'model.parent' property in CodegenModel, based on the value
+     * of the 'additionalProperties' keyword. Some language generator use class inheritance
+     * to implement additional properties. For example, in Java the generated model class
+     * has 'extends HashMap' to represent the additional properties.
+     * 
+     * TODO: it's not a good idea to use single class inheritance to implement
+     * additionalProperties. That may work for non-composed schemas, but that does not
+     * work for composed 'allOf' schemas. For example, in Java, if additionalProperties
+     * is set to true (which it should be by default, per OAS spec), then the generated
+     * code has extends HashMap. That wouldn't work for composed 'allOf' schemas.
+     * 
+     * @param model the codegen representation of the OAS schema.
+     * @param name the name of the model.
+     * @param schema the input OAS schema.
+     */
    protected void addParentContainer(CodegenModel model, String name, Schema schema) {
        final CodegenProperty property = fromProperty(name, schema);
        addImport(model, property.complexType);
@ -5783,7 +5883,7 @@ public class DefaultCodegen implements CodegenConfig {
            if (ModelUtils.isGenerateAliasAsModel() && StringUtils.isNotBlank(name)) {
                this.addBodyModelSchema(codegenParameter, name, schema, imports, bodyParameterName, true);
            } else {
-                Schema inner = ModelUtils.getAdditionalProperties(schema);
+                Schema inner = getAdditionalProperties(schema);
                if (inner == null) {
                    LOGGER.error("No inner type supplied for map parameter `{}`. Default to type:string", schema.getName());
                    inner = new StringSchema().description("//TODO automatically added by openapi-generator");
@ -5865,7 +5965,7 @@ public class DefaultCodegen implements CodegenConfig {
                    codegenProperty = codegenProperty.items;
                }
            }
-        } else if (ModelUtils.isFreeFormObject(schema)) {
+        } else if (isFreeFormObject(schema)) {
            // HTTP request body is free form object
            CodegenProperty codegenProperty = fromProperty("FREE_FORM_REQUEST_BODY", schema);
            if (codegenProperty != null) {
@ -6262,4 +6362,100 @@ public class DefaultCodegen implements CodegenConfig {
            return Objects.hash(getName(), getRemoveCharRegEx(), getExceptions());
        }
    }
+
+    /**
+     * Return true if the schema value can be any type, i.e. it can be
+     * the null value, integer, number, string, object or array.
+     * One use case is when the "type" attribute in the OAS schema is unspecified.
+     *
+     * Examples:
+     *
+     *     arbitraryTypeValue:
+     *       description: This is an arbitrary type schema.
+     *         It is not a free-form object.
+     *         The value can be any type except the 'null' value.
+     *     arbitraryTypeNullableValue:
+     *       description: This is an arbitrary type schema.
+     *         It is not a free-form object.
+     *         The value can be any type, including the 'null' value.
+     *       nullable: true
+     *
+     * @param schema the OAS schema.
+     * @return true if the schema value can be an arbitrary type.
+     */
+    public boolean isAnyTypeSchema(Schema schema) {
+        if (schema == null) {
+            once(LOGGER).error("Schema cannot be null in isAnyTypeSchema check");
+            return false;
+        }
+
+        if (isFreeFormObject(schema)) {
+            // make sure it's not free form object
+            return false;
+        }
+
+        if (schema.getClass().equals(Schema.class) && schema.get$ref() == null && schema.getType() == null &&
+                (schema.getProperties() == null || schema.getProperties().isEmpty()) &&
+                schema.getAdditionalProperties() == null && schema.getNot() == null &&
+                schema.getEnum() == null) {
+            return true;
+            // If and when type arrays are supported in a future OAS specification,
+            // we could return true if the type array includes all possible JSON schema types.
+        }
+        return false;
+    }
+
+    /**
+     * Check to see if the schema is a free form object.
+     *
+     * A free form object is an object (i.e. 'type: object' in a OAS document) that:
+     * 1) Does not define properties, and
+     * 2) Is not a composed schema (no anyOf, oneOf, allOf), and
+     * 3) additionalproperties is not defined, or additionalproperties: true, or additionalproperties: {}.
+     *
+     * Examples:
+     *
+     * components:
+     *   schemas:
+     *     arbitraryObject:
+     *       type: object
+     *       description: This is a free-form object.
+     *         The value must be a map of strings to values. The value cannot be 'null'.
+     *         It cannot be array, string, integer, number.
+     *     arbitraryNullableObject:
+     *       type: object
+     *       description: This is a free-form object.
+     *         The value must be a map of strings to values. The value can be 'null',
+     *         It cannot be array, string, integer, number.
+     *       nullable: true
+     *     arbitraryTypeValue:
+     *       description: This is NOT a free-form object.
+     *         The value can be any type except the 'null' value.
+     *
+     * @param schema potentially containing a '$ref'
+     * @return true if it's a free-form object
+     */
+    protected boolean isFreeFormObject(Schema schema) {
+        return ModelUtils.isFreeFormObject(this.openAPI, schema);
+    }
+
+    /**
+     * Returns the additionalProperties Schema for the specified input schema.
+     * 
+     * The additionalProperties keyword is used to control the handling of additional, undeclared
+     * properties, that is, properties whose names are not listed in the properties keyword.
+     * The additionalProperties keyword may be either a boolean or an object.
+     * If additionalProperties is a boolean and set to false, no additional properties are allowed.
+     * By default when the additionalProperties keyword is not specified in the input schema,
+     * any additional properties are allowed. This is equivalent to setting additionalProperties
+     * to the boolean value True or setting additionalProperties: {}
+     * 
+     * @param schema the input schema that may or may not have the additionalProperties keyword.
+     * @return the Schema of the additionalProperties. The null value is returned if no additional
+     *         properties are allowed.
+     */
+    protected Schema getAdditionalProperties(Schema schema) {
+        return ModelUtils.getAdditionalProperties(openAPI, schema);
+    }
+
 }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java
@ -469,7 +469,7 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {

                Schema schema = schemas.get(name);

-                if (ModelUtils.isFreeFormObject(schema)) { // check to see if it'a a free-form object
+                if (ModelUtils.isFreeFormObject(this.openAPI, schema)) { // check to see if it'a a free-form object
                    LOGGER.info("Model {} not generated since it's a free-form object", name);
                    continue;
                } else if (ModelUtils.isMapSchema(schema)) { // check to see if it's a "map" model
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
@ -105,7 +105,7 @@ public class InlineModelResolver {
            Schema obj = (Schema) model;
            if (obj.getType() == null || "object".equals(obj.getType())) {
                if (obj.getProperties() != null && obj.getProperties().size() > 0) {
-                    flattenProperties(obj.getProperties(), pathname);
+                    flattenProperties(openAPI, obj.getProperties(), pathname);
                    // for model name, use "title" if defined, otherwise default to 'inline_object'
                    String modelName = resolveModelName(obj.getTitle(), "inline_object");
                    addGenerated(modelName, model);
@ -156,10 +156,10 @@ public class InlineModelResolver {
            if (inner instanceof ObjectSchema) {
                ObjectSchema op = (ObjectSchema) inner;
                if (op.getProperties() != null && op.getProperties().size() > 0) {
-                    flattenProperties(op.getProperties(), pathname);
+                    flattenProperties(openAPI, op.getProperties(), pathname);
                    // Generate a unique model name based on the title.
                    String modelName = resolveModelName(op.getTitle(), null);
-                    Schema innerModel = modelFromProperty(op, modelName);
+                    Schema innerModel = modelFromProperty(openAPI, op, modelName);
                    String existing = matchGenerated(innerModel);
                    if (existing != null) {
                        Schema schema = new Schema().$ref(existing);
@ -200,7 +200,7 @@ public class InlineModelResolver {
                Schema obj = (Schema) model;
                if (obj.getType() == null || "object".equals(obj.getType())) {
                    if (obj.getProperties() != null && obj.getProperties().size() > 0) {
-                        flattenProperties(obj.getProperties(), pathname);
+                        flattenProperties(openAPI, obj.getProperties(), pathname);
                        String modelName = resolveModelName(obj.getTitle(), parameter.getName());

                        parameter.$ref(modelName);
@ -214,9 +214,9 @@ public class InlineModelResolver {
                if (inner instanceof ObjectSchema) {
                    ObjectSchema op = (ObjectSchema) inner;
                    if (op.getProperties() != null && op.getProperties().size() > 0) {
-                        flattenProperties(op.getProperties(), pathname);
+                        flattenProperties(openAPI, op.getProperties(), pathname);
                        String modelName = resolveModelName(op.getTitle(), parameter.getName());
-                        Schema innerModel = modelFromProperty(op, modelName);
+                        Schema innerModel = modelFromProperty(openAPI, op, modelName);
                        String existing = matchGenerated(innerModel);
                        if (existing != null) {
                            Schema schema = new Schema().$ref(existing);
@ -259,7 +259,7 @@ public class InlineModelResolver {
                ObjectSchema op = (ObjectSchema) property;
                if (op.getProperties() != null && op.getProperties().size() > 0) {
                    String modelName = resolveModelName(op.getTitle(), "inline_response_" + key);
-                    Schema model = modelFromProperty(op, modelName);
+                    Schema model = modelFromProperty(openAPI, op, modelName);
                    String existing = matchGenerated(model);
                    Content content = response.getContent();
                    for (MediaType mediaType : content.values()) {
@ -282,10 +282,10 @@ public class InlineModelResolver {
                if (inner instanceof ObjectSchema) {
                    ObjectSchema op = (ObjectSchema) inner;
                    if (op.getProperties() != null && op.getProperties().size() > 0) {
-                        flattenProperties(op.getProperties(), pathname);
+                        flattenProperties(openAPI, op.getProperties(), pathname);
                        String modelName = resolveModelName(op.getTitle(),
                                "inline_response_" + key);
-                        Schema innerModel = modelFromProperty(op, modelName);
+                        Schema innerModel = modelFromProperty(openAPI, op, modelName);
                        String existing = matchGenerated(innerModel);
                        if (existing != null) {
                            Schema schema = this.makeSchema(existing, op);
@ -302,14 +302,14 @@ public class InlineModelResolver {
                }
            } else if (property instanceof MapSchema) {
                MapSchema mp = (MapSchema) property;
-                Schema innerProperty = ModelUtils.getAdditionalProperties(mp);
+                Schema innerProperty = ModelUtils.getAdditionalProperties(openAPI, mp);
                if (innerProperty instanceof ObjectSchema) {
                    ObjectSchema op = (ObjectSchema) innerProperty;
                    if (op.getProperties() != null && op.getProperties().size() > 0) {
-                        flattenProperties(op.getProperties(), pathname);
+                        flattenProperties(openAPI, op.getProperties(), pathname);
                        String modelName = resolveModelName(op.getTitle(),
                                "inline_response_" + key);
-                        Schema innerModel = modelFromProperty(op, modelName);
+                        Schema innerModel = modelFromProperty(openAPI, op, modelName);
                        String existing = matchGenerated(innerModel);
                        if (existing != null) {
                            Schema schema = new Schema().$ref(existing);
@ -378,7 +378,7 @@ public class InlineModelResolver {
                    // To have complete control of the model naming, one can define the model separately
                    // instead of inline.
                    String innerModelName = resolveModelName(op.getTitle(), key);
-                    Schema innerModel = modelFromProperty(op, innerModelName);
+                    Schema innerModel = modelFromProperty(openAPI, op, innerModelName);
                    String existing = matchGenerated(innerModel);
                    if (existing == null) {
                        openAPI.getComponents().addSchemas(innerModelName, innerModel);
@ -421,7 +421,7 @@ public class InlineModelResolver {
            } else if (model instanceof Schema) {
                Schema m = (Schema) model;
                Map<String, Schema> properties = m.getProperties();
-                flattenProperties(properties, modelName);
+                flattenProperties(openAPI, properties, modelName);
                fixStringModel(m);
            } else if (ModelUtils.isArraySchema(model)) {
                ArraySchema m = (ArraySchema) model;
@ -430,7 +430,7 @@ public class InlineModelResolver {
                    ObjectSchema op = (ObjectSchema) inner;
                    if (op.getProperties() != null && op.getProperties().size() > 0) {
                        String innerModelName = resolveModelName(op.getTitle(), modelName + "_inner");
-                        Schema innerModel = modelFromProperty(op, innerModelName);
+                        Schema innerModel = modelFromProperty(openAPI, op, innerModelName);
                        String existing = matchGenerated(innerModel);
                        if (existing == null) {
                            openAPI.getComponents().addSchemas(innerModelName, innerModel);
@ -526,7 +526,7 @@ public class InlineModelResolver {
        // TODO it would probably be a good idea to check against a list of used uniqueNames to make sure there are no collisions
    }

-    private void flattenProperties(Map<String, Schema> properties, String path) {
+    private void flattenProperties(OpenAPI openAPI, Map<String, Schema> properties, String path) {
        if (properties == null) {
            return;
        }
@ -538,7 +538,7 @@ public class InlineModelResolver {
                    && ((ObjectSchema) property).getProperties().size() > 0) {
                ObjectSchema op = (ObjectSchema) property;
                String modelName = resolveModelName(op.getTitle(), path + "_" + key);
-                Schema model = modelFromProperty(op, modelName);
+                Schema model = modelFromProperty(openAPI, op, modelName);
                String existing = matchGenerated(model);
                if (existing != null) {
                    Schema schema = new Schema().$ref(existing);
@ -558,9 +558,9 @@ public class InlineModelResolver {
                if (inner instanceof ObjectSchema) {
                    ObjectSchema op = (ObjectSchema) inner;
                    if (op.getProperties() != null && op.getProperties().size() > 0) {
-                        flattenProperties(op.getProperties(), path);
+                        flattenProperties(openAPI, op.getProperties(), path);
                        String modelName = resolveModelName(op.getTitle(), path + "_" + key);
-                        Schema innerModel = modelFromProperty(op, modelName);
+                        Schema innerModel = modelFromProperty(openAPI, op, modelName);
                        String existing = matchGenerated(innerModel);
                        if (existing != null) {
                            Schema schema = new Schema().$ref(existing);
@ -577,13 +577,13 @@ public class InlineModelResolver {
                }
            }
            if (ModelUtils.isMapSchema(property)) {
-                Schema inner = ModelUtils.getAdditionalProperties(property);
+                Schema inner = ModelUtils.getAdditionalProperties(openAPI, property);
                if (inner instanceof ObjectSchema) {
                    ObjectSchema op = (ObjectSchema) inner;
                    if (op.getProperties() != null && op.getProperties().size() > 0) {
-                        flattenProperties(op.getProperties(), path);
+                        flattenProperties(openAPI, op.getProperties(), path);
                        String modelName = resolveModelName(op.getTitle(), path + "_" + key);
-                        Schema innerModel = modelFromProperty(op, modelName);
+                        Schema innerModel = modelFromProperty(openAPI, op, modelName);
                        String existing = matchGenerated(innerModel);
                        if (existing != null) {
                            Schema schema = new Schema().$ref(existing);
@ -611,7 +611,7 @@ public class InlineModelResolver {
        }
    }

-    private Schema modelFromProperty(Schema object, String path) {
+    private Schema modelFromProperty(OpenAPI openAPI, Schema object, String path) {
        String description = object.getDescription();
        String example = null;
        Object obj = object.getExample();
@ -628,7 +628,7 @@ public class InlineModelResolver {
        model.setRequired(object.getRequired());
        model.setNullable(object.getNullable());
        if (properties != null) {
-            flattenProperties(properties, path);
+            flattenProperties(openAPI, properties, path);
            model.setProperties(properties);
        }
        return model;
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java
@ -463,6 +463,10 @@ public class CodegenConfigurator {
        // TODO: Move custom validations to a separate type as part of a "Workflow"
        Set<String> validationMessages = new HashSet<>(result.getMessages());
        OpenAPI specification = result.getOpenAPI();
+        // TODO: The line below could be removed when at least one of the issue below has been resolved.
+        // https://github.com/swagger-api/swagger-parser/issues/1369
+        // https://github.com/swagger-api/swagger-parser/pull/1374
+        //ModelUtils.getOpenApiVersion(specification, inputSpec, authorizationValues);

        // NOTE: We will only expose errors+warnings if there are already errors in the spec.
        if (validationMessages.size() > 0) {
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
@ -269,10 +269,10 @@ public class ExampleGenerator {
            Map<String, Object> mp = new HashMap<String, Object>();
            if (property.getName() != null) {
                mp.put(property.getName(),
-                        resolvePropertyToExample(propertyName, mediaType, ModelUtils.getAdditionalProperties(property), processedModels));
+                        resolvePropertyToExample(propertyName, mediaType, ModelUtils.getAdditionalProperties(openAPI, property), processedModels));
            } else {
                mp.put("key",
-                        resolvePropertyToExample(propertyName, mediaType, ModelUtils.getAdditionalProperties(property), processedModels));
+                        resolvePropertyToExample(propertyName, mediaType, ModelUtils.getAdditionalProperties(openAPI, property), processedModels));
            }
            return mp;
        } else if (ModelUtils.isUUIDSchema(property)) {
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java
@ -347,7 +347,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
            return getTypeDeclaration(inner) + "_Vectors.Vector";
        }
        if (ModelUtils.isMapSchema(p)) {
-            Schema inner = ModelUtils.getAdditionalProperties(p);
+            Schema inner = getAdditionalProperties(p);
            String name = getTypeDeclaration(inner) + "_Map";
            if (name.startsWith("Swagger.")) {
                return name;
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractApexCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractApexCodegen.java
@ -195,7 +195,7 @@ public abstract class AbstractApexCodegen extends DefaultCodegen implements Code
            }
            return getSchemaType(p) + "<" + getTypeDeclaration(inner) + ">";
        } else if (ModelUtils.isMapSchema(p)) {
-            Schema inner = ModelUtils.getAdditionalProperties(p);
+            Schema inner = getAdditionalProperties(p);

            if (inner == null) {
                LOGGER.warn(p.getName() + "(map property) does not have a proper inner type defined");
@ -228,11 +228,11 @@ public abstract class AbstractApexCodegen extends DefaultCodegen implements Code
        } else if (ModelUtils.isMapSchema(p)) {
            final MapSchema ap = (MapSchema) p;
            final String pattern = "new HashMap<%s>()";
-            if (ModelUtils.getAdditionalProperties(ap) == null) {
+            if (getAdditionalProperties(ap) == null) {
                return null;
            }

-            return String.format(Locale.ROOT, pattern, String.format(Locale.ROOT, "String, %s", getTypeDeclaration(ModelUtils.getAdditionalProperties(ap))));
+            return String.format(Locale.ROOT, pattern, String.format(Locale.ROOT, "String, %s", getTypeDeclaration(getAdditionalProperties(ap))));
        } else if (ModelUtils.isLongSchema(p)) {
            if (p.getDefault() != null) {
                return p.getDefault().toString() + "l";
@ -365,7 +365,7 @@ public abstract class AbstractApexCodegen extends DefaultCodegen implements Code
        } else if (ModelUtils.isLongSchema(p)) {
            example = example.isEmpty() ? "123456789L" : example + "L";
        } else if (ModelUtils.isMapSchema(p)) {
-            example = "new " + getTypeDeclaration(p) + "{'key'=>" + toExampleValue(ModelUtils.getAdditionalProperties(p)) + "}";
+            example = "new " + getTypeDeclaration(p) + "{'key'=>" + toExampleValue(getAdditionalProperties(p)) + "}";

        } else if (ModelUtils.isPasswordSchema(p)) {
            example = example.isEmpty() ? "password123" : escapeText(example);
--- a/Show More
+++ b/Show More