author: fiatjaf
author: lafaire
discussion: https://t.me/lnurl/9729
This optional property works together with balanceCheck
to make it instant. It works as follows:
- If
LN SERVICE
supportsbalanceCheck
, thenLN WALLET
may decide to send an query-string-encoded HTTP URL along with the payment request when first making a withdrawal. LN SERVICE
may store that URL and make a blankHTTP POST
call to it the next time the given user has a balance in its account on the service.- Upon receiving that
HTTP POST
, the wallet may decide to perform a balance check and withdraw the funds immediately. - The scheme works for custodial wallets, Lightning nodes that have a domain name and an always-online online presence, and also for noncustodial mobile wallets that have a friendly server online that is able to receive that
HTTP POST
and notify them somehow.
The callback URL sent by the WALLET
is modified as follows:
-<callback><?|&>k1=<k1>&pr=<lightning invoice>
+<callback><?|&>k1=<k1>&pr=<lightning invoice>&balanceNotify=<URL>