Yes, starting from the original spec: https://github.com/hoytech/strfry/blob/master/docs/negentropy.md , the nostr pr: https://github.com/nostr-protocol/nips/pull/1494 https://github.com/nostr-protocol/nips/blob/negentropy/77.md I dont know why its not merged in main and it just live in a branch
Discussion
nostr:nprofile1qqsypwwgtll74lqu4huvxzjwtjyxvrlkujt35rw8y026ke6ttesmg5gpzemhxue69uhkummnw3ex2mrfw3jhxtn0wfnj7qghwaehxw309aex2mrp0yhxummnw3ezucnpdejz7wzpxlr is there a reason that clients don't already include e-cash in the negopen messages to pay relays for their computer? And more crash upon requesting notes to pay for bandwidth?
With NIP60 + PoW, there is no "I don't have e-cash" excuse...