Built p2psats — alerts for NIP-69 P2P trade orders across Nostr

The P2P bitcoin market today is fragmented across siloed platforms. Robosats users only see Robosats offers. lnp2pbot users only see lnp2pbot offers. Mostro the same. That fragmentation costs both sides real money: you need fiat in a hurry, post a sell order at a discount on your platform of choice, and hear crickets, even though there are probably users on another platform, or just lurkers, who would have taken it in a heartbeat if they'd known it existed. Multiply that across every fiat currency and every payment method and it's a lot of trades that simply never happen.

p2psats (https://p2psats.app) is an attempt to fix that with two pieces: an aggregated, NIP-69-based order book that pulls offers from across platforms, and an alerts system so you don't have to babysit it.

Under the hood it:

- Subscribes to NIP-69 (`kind:38383`) order events across the main P2P relays and builds a fiat-currency-aggregated order book.

- Lets you define alerts: "notify me when there's a sell order in EUR under +3% premium for ≥ 100k sats" (or whatever combination of side / fiat / amount / premium you care about)

- Pings you the moment a matching order hits a relay, via email or Nostr DM (NIP-17 gift-wrap, so the DM itself is private)

It's platform-agnostic by design: NIP-69 is an open event spec, so any P2P platform publishing those events is covered: robosats, lnp2pbot, Mostro, Peach whatever comes next. No custody, no order routing, no fees, no account beyond an email or an npub. It just watches relays and tells you when something interesting shows up. You still go execute the trade in your usual client.

A few design choices worth calling out:

- DMs use NIP-17, not legacy NIP-04

- Auth is either a magic link or a NIP-07 sign-in. Your choice, no passwords

- No global order book, I feel it's more useful to have fiat-scoped views

Still rough around the edges and I'd love any feedback you might have.

Happy to answer questions about the stack or NIP-69 parsing quirks if anyone's curious about building on top of the event model.

PS: I know the fiat currency list is incomplete, the next release will fix that.