Difference between uploading and attaching a file to an assistant?

[greffgreff]

I was wondering what the difference between attaching and uploading a file to an assistant? Both ways seems to create a file for an assistant to OpenAI's endpoint here. Thanks in advanced!

[StephenHodgson]

Assistant files are really only used for tools, like Code Interpreter and Knowledge Retrieval.

• Files that are passed at the Assistant level are accessible by all Runs with this Assistant.
• Files can also be passed at the Thread level. These files are only accessible in the specific Thread.
• When a file is attached at the Message-level, it is only accessible within the specific Thread the Message is attached to.

[StephenHodgson]

Attaching attaches a file that was previously uploaded, to the assistant,

Uploading is just a convenance method, that performs both upload and attach to assistant. whereas file endpoint upload only uploads the file, but does not attach it to the assistant.

In each case you'll still need to perform the file upload to then reference when using files for assistants, threads or messages.