Handling XML namespace in Swagger file

Hi neerajdahiya,

OpenAPI Specification does not support multiple XML namespaces within a single element. As a workaround, you can define additional namespaces as regular attributes (that is, schema properties with xml.attribute=true).

openapi: 3.0.0

components:
  schemas:
    Prov:
      type: object
      xml:
        namespace: http://www.example.com/provisioning/services
      properties:
        "xmlns:xsi":   # <----------
          type: string
          enum:
            - "http://www.w3.org/2001/XMLSchema-instance"
          xml:
            attribute: true
        Header:
          ...

There's an existing enhancement request to add support for alternative schema formats, such as XSL Schema (XSD), which would enable your scenario.