n2p.net
Peer-to-peer had a long quiet period and became interesting again through federated social protocols, local-first software and content addressing. Node to peer sits exactly there, and the .net is native for it.
N2P also reads as need to purchase, describing the front half of every procurement process and a large software category, or notes to product, suiting the growing set of tools that turn raw capture into something structured.
The X-to-Y form is what makes three letters readable rather than arbitrary, handing the reader a relationship instead of an abbreviation.
Whatever the reading, three characters on a major extension is a permanently constrained asset. Each year a few more leave circulation into long-term corporate use, and the number available never increases.
Short, structured, technical. Offers welcome.