Keychat on Nostr: Attaching a Stamp (Client → Relay) When publishing an event to a relay that ...
Attaching a Stamp (Client → Relay)
When publishing an event to a relay that requires stamps, the client appends a Cashu token as the third element of the EVENT message array:
["EVENT", <event JSON>, "<cashu_token>"]
This NIP defines a mechanism for clients to attach ecash tokens (Cashu) to Nostr events as stamps — anonymous per-event micropayments to relays. Stamps solve two fundamental problems for the Nostr relay ecosystem: spam prevention and relay sustainability.
https://github.com/keychat-io/keychat-protocol/blob/main/nips/nip-estamp.md
Published at
2026-03-08 13:27:52 UTCEvent JSON
{
"id": "d5756d603d5528420e949ca6cabfa158d954f1ede868db1e2445a8ee9b106bee",
"pubkey": "bbf923aa9246065f88c40c7d9bf61cccc0ff3fcff065a8cb2ff4cfbb62088f1e",
"created_at": 1772976472,
"kind": 1,
"tags": [
[
"q",
"5dbf57b5f2a17c20871010dae7b7c1224e26d364ca7bc2c7ce7512dec43665d0",
"wss://nostr.wine",
"bbf923aa9246065f88c40c7d9bf61cccc0ff3fcff065a8cb2ff4cfbb62088f1e"
],
[
"client",
"nosotros",
"31990:c6603b0f1ccfec625d9c08b753e4f774eaf7d1cf2769223125b5fd4da728019e:1728437063755"
]
],
"content": "Attaching a Stamp (Client → Relay)\n\nWhen publishing an event to a relay that requires stamps, the client appends a Cashu token as the third element of the EVENT message array:\n\n[\"EVENT\", \u003cevent JSON\u003e, \"\u003ccashu_token\u003e\"]\n \nnostr:nevent1qvzqqqqqqypzpwleyw4fy3sxt7yvgrran0mpenxqlululur94r9jlax0hd3q3rc7qyg8wumn8ghj7mn0wd68ytnhd9hx2qgkwaehxw309aex2mrp0yh8qunfd4skctnwv46qqgzahatmtu4p0ssgwyqsmtnm0sfzfcndxex200pv0nn4zt0vgdn96qk7egfz",
"sig": "0003ad9231d06cf06e61eae7c9c05049ebee4fea7cbe8b6b1d0993f87467e07b9b73e30bad6c4049205d0a1fd5e95da96d5406e6344dc5d533d4aa9aff6537db"
}
