Available from: https://github.com/petertodd/bitcoin/tree/full-rbf-v26.0

eg:

git clone -b full-rbf-v26.0 https://github.com/petertodd/bitcoin.git

What is this? It's Bitcoin Core v26.0, with Antoine Riard's full-rbf peering code, and some additional minor updates to it. This does two things for full-rbf nodes:

1) Advertises a FULL_RBF service bit when mempoolfullrbf=1 is set.

2) Connects to four additional FULL_RBF peers.

Doing this ensures that a core group of nodes are reliably propagating full-rbf replacements. We don't need everyone to run this. But it'd be helpful if more people did.

As for why you should run full-rbf, see my blog post:

https://petertodd.org/2023/why-you-should-run-mempoolfullrbf

I'm already running v26.0 on a few nodes with v2transport=1 enabled. You should too!