FV, LV, Lease Support

[blainedwards8]

I noticed that txns don't allow for fv, lv and lease support. This would be very beneficial.

[joe-p]

Can you explain where exactly you want these fields supported? They don't apply to inner transactions and I'm not sure why you'd want to check them in an app.

[blainedwards8]

These are useful to ensure you don't have a duplicate transaction within a given set of blocks based on a given lease value. One example would be a contract that allows a receiver to receive x amount of token every 1000 blocks. When receiving a request, the smart contract would make the check and if the request hasn't been performed in that set of blocks, it would issue an inner transaction to give the receiver the coins. I can give you an example in Teal if you would like to see it.

These values are defined here under the block Common Fields for Teal:
https://developer.algorand.org/docs/get-details/transactions/transactions/

FirstValid - fv
LastValid - lv
Lease - lx

I am an attorney and these are useful in creating spend thrift trusts (or allowances).

[pbennett]

It's a [sender / lease ] pair thats tracked up through its LastValid round. So any duplicate wouldn't even be allowed into the mempool at all. A contract would never find a conflict because one would never be submitted.