Start indexing from the 'tip'

[KtorZ]

Discussed in https://github.com/CardanoSolutions/kupo/discussions/134

^{Originally posted by KtorZ September 14, 2023}

What is your idea? Provide a use case.

The --since flag at the moment only accept a slot+header or the 'origin' keyword. However, it could also allow starting from the 'tip' of the node.

Why is it a good idea?

There are use-cases where you only need to watch future blocks that are arriving now.

What is the current alternative and why is it not good enough?

At the moment, doing this requires client to hold on a particular tip and have external ways of querying that tip. This is inconvenient, especially for deploying instances.