1.6`attributes`

Attributes describe metadata associated with the message.

For an HTTP request, attributes might contain:

attributes.method
attributes.requestPath
attributes.queryParams
attributes.headers
attributes.uriParams

Example:

GET /customers/123?details=true
Authorization: Bearer abc

You might access:

attributes.uriParams.id

attributes.queryParams.details

attributes.headers.authorization

So:

payload    = request BODY
attributes = request METADATA

That distinction is worth memorizing.