Passing Order notes

How can I attach notes to an order at the time of creation? I would like to pass information regarding packaging type and specific delivery instructions supplied by the customer on a third party site.

An Order object has an optional metadata field which is a Map of strings. You can pretty much put whatever you want in there, so you could definitely use it for a notes field. For more information take a look here:

How do I pass custom information to the Square Dashboard? I need to relate shipping information (package requirements, box size, etc) that can be viewed on the Order Details page in the Square Dashboard. Metadata is not viewable in this scenario.

I don’t think that’s currently possible unfortunately.