direct_upload_json

# File activestorage/app/controllers/active_storage/direct_uploads_controller.rb, line 17
    def direct_upload_json(blob)
      blob.as_json(root: false, methods: :signed_id).merge(direct_upload: {
        url: blob.service_url_for_direct_upload,
        headers: blob.service_headers_for_direct_upload
      })
    end