A named extension that should be added to the OpenAPI definition. The names of all extensions MUST begin with x- or else an invalid document will potentially be created.

Although this annotation may currently be placed directly on a Java language element target, application developers should instead utilize the extensions property of the particular annotation that corresponds to the model being extended. Use of the annotation directly on a Java element is often ambiguous and it may result in the extension being added to an incorrect location in the OpenAPI model. Future releases of MicroProfile OpenAPI may remove the capability of placing this annotation directly on a Java element.

When @Extension annotations are used both directly on a Java element as well as within another annotation that targets the same Java element, implementations will apply only the nested extensions to the resulting model.

Example of preferred use with @Extension nested within an @Schema annotation:

class MyPojo {

    @Schema(
        type = SchemaType.STRING,
        extensions = @Extension(
            name = "x-custom-property",
            value = "custom-value")
    String property1;

}

Example of deprecated use with @Extension placed directly on a field implied to be a schema property:

class MyPojo {

    @Extension(
        name = "x-custom-property",
        value = "custom-value")
    String property1;

}