From rusty at rustcorp.com.au  Tue Jun 29 05:34:18 2021
From: rusty at rustcorp.com.au (Rusty Russell)
Date: Tue, 29 Jun 2021 15:04:18 +0930
Subject: [Lightning-dev] Turbo channels spec?
Message-ID: <871r8lcjz9.fsf@rustcorp.com.au>

Hi all!

        John Carvalo recently pointed out that not every implementation
accepts zero-conf channels, but they are useful.  Roasbeef also recently
noted that they're not spec'd.

How do you all do it?  Here's a strawman proposal:

1. Assign a new feature bit "I accept zeroconf channels".
2. If both negotiate this, you can send update_add_htlc (etc) *before*
   funding_locked without the peer getting upset.
3. Nodes are advised *not* to forward HTLCs from an unconfirmed channel
   unless they have explicit reason to trust that node (they can still
   send *out* that channel, because that's not their problem!).

It's a pretty simple change, TBH (this zeroconf feature would also
create a new set of channel_types, altering that PR).

I can draft something this week?

Thanks!
Rusty.