Query a user's last activity

[adamstallard]

We should show on the /users endpoint when a user last used BrightID. The main evidence we can use is if they linked an app or blind signatures were updated which happens automatically when they open the app. Last activity is helpful for Aura players evaluating subjects.

If we show a "last activity" element, it can also use connection activity (last connection made or updated).

[adamstallard]

@siftal asks:

You mentioned using the /verifications/blinded/sig/:id endpoint to track the last activity time. right?
Two things I’m wondering:
Node Specificity: Since this request only hits one node, would other nodes miss out on this activity data?
Edge Case: If a user already has all their blind sigs, this route never gets called. That means even active users might look inactive.
Also, I don't know
How crucial is "last activity" for Aura? Is spoofing a concern? Should we check the signature to keep it tamper-proof?

@siftal For the Aura use-case, it makes most sense to the BrightID, not a blinded id that would be used by a certain app. Aura is a super app and therefore has access to actual BrightIDs.

We aren't creating a new operation to record activity. Instead we are reading aggregated data by their BrightID to compute their last activity.

Maybe at the beginning we will only look at connection timestamps. Later it will be useful to look at blind sig timestamps or linking timestamps. There may be other data.