Should `att` be required ?

[Gozala]

I just noticed that spec states that att is optional, which seems odd. What would be the use case for the UCAN which does not delegate any capabilities ?

If there is no real use case for it should it be made mandatory ?

[expede]

You can use UCAN to prove that you have access to something without delegating capabilities, sign challenges, and so on. We use this in AWAKE, for instance.

I agree that the field should be mandatory, and [] in the (e.g.) AWAKE case. Will fix 👍