# AsyncAPI extensions

AsyncAPI supports [extensions to the specification](https://www.asyncapi.com/docs/concepts/asyncapi-document/extending-specification).

The list of extensions supported in AsyncAPI by Redoc is as follows:

- [x-additionalPropertiesName](/docs/realm/content/api-docs/asyncapi-extensions/x-additional-properties-name) - Display a field name for an `additionalProperties` description.
- [x-badges](/docs/realm/content/api-docs/asyncapi-extensions/x-badges) - Add visible badges as indicators to API operations.
- [x-enumDescriptions](/docs/realm/content/api-docs/asyncapi-extensions/x-enum-descriptions) - Readable labels for enum values.
- [x-rbac](/docs/realm/content/api-docs/asyncapi-extensions/x-rbac) - Control access to AsyncAPI objects.
- [x-tagGroups](/docs/realm/content/api-docs/asyncapi-extensions/x-tag-groups) - Higher-level grouping for tags, used in the sidebar.
- [x-metadata](/docs/realm/content/api-docs/asyncapi-extensions/x-metadata) - Add custom metadata at the top of the info section.


## Resources

- How to [add AsyncAPI description to your project](/docs/realm/content/api-docs/add-asyncapi-docs).