• Scoped to the Current Request:
  • The Items collection is specific to a single HTTP request and exists only for the duration of that request.
  • Once the request is complete, the data in the Items collection is discarded.
• Stored In-Memory on the Server:
  • The Items dictionary resides in memory on the server as part of the HttpContext object. It is never sent to the client and is not persistent across requests.
• Designed for Temporary, Per-Request Storage:
  • It is useful for storing and sharing data within the context of a single HTTP request, particularly between middleware, handlers, or components that process the request.

Use cases

• Set dynamic configuration values to be able to retrieve those in the same Server Request, like:
  • Get those in OnAfterRequest callback to Refresh the IdP Token. (Since isn't possible to pass dynamic attribute)
  • Keep "Cookies" updated. 
    • If you update an cookie, and try to get it again inside of the same Server Request, you will notice that contains the old value.
    • This can help you maintain the updated value inside of the Server request, until it sync with the browser at the end of the same.
    • This is very case specific.
• Edit existing collection values. (Advanced)
• Etc... (Didn't explore more use cases, but certainly they exist)