I believe providing economic incentives to relay operators is essential for the nostr ecosystem, and among the possible approaches, attaching e-cash when publishing events seems optimal to me. I’ve been skeptical of subscription-based payment models, and more importantly, with standards like NIP-17, users send their DMs not from their main pubkey but a temporary one—making subscription models fundamentally incompatible.
Recently, I noticed increasing spam accumulating on my personal relay, which became quite unpleasant. I thought there must already be a NIP addressing this, so I went looking—but found nothing. Hmm? I decided to try implementing a solution myself, even if just according to my own idea. But immediately after starting, I understood why such a standard hasn’t emerged yet.
It turned out to be too complicated. When publishing an event, devs familiar with the nostr ecosystem typically use an outbox model, publishing across different sets of relays dynamically. However, most clients don’t publish to individual relays one by one, but broadcast to all target relays via nostr-tools(or something like that). This means if we want to attach e-cash to a *specific relay only*, implementation complexity spikes dramatically.
Moreover, what happens if the relay’s price changes? How should the relay behave if it receives the same event again (e.g., due to a re-synchronization or backfill)? Should already-sent e-cash be refunded, and if so, how? And if refunded, must that e-cash be redeemable again? When you dig into all these edge cases one by one, the feasibility of such a system becomes questionable.
The most practical implementation so far might be keychat approach, but even that was designed for a messaging app rather than a social network—and still doesn’t integrate well with the idea of an inbox-relay model for DMs.