In the linked presentation by Benedict Bünz, it's worth listening to the first audience question/answer. Questioner is spot on that an SPV client polling the network to gain probabilistic confidence of unspentness could easily subsume the task of gaining input inclusion proofs from the network, with no forking change necessary.

On Wednesday, April 29, 2026 at 2:03:36 PM UTC-7 Zac Mitton wrote:

Hi, Ive been looking into FlyClient first described here. I don't see any BIPs, or previous discussion in this forum about it either.

On bitcoin It could allow a light-client to verify the entire work of the heaviest chain with a single ~100KB proof.

It can theoretically be done as a soft-fork by injecting a single hash into the coinbase tx (similar to how segwit is committed to).

What do you guy's think?

--
You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to bitcoindev+unsubscribe@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/0aadce7a-b08b-4fd2-8bae-37df1cfc54afn%40googlegroups.com.