Author: fiatjaf 2021-09-21 13:05:48
Published on: 2021-09-21T13:05:48+00:00
The conversation between two individuals discusses the implementation of stateless invoices. The proposal is for the payee to generate a stateless invoice using some secret to compute the preimage upon receiving the HTLC. One way to achieve this is via the payment_secret, which is already an arbitrary invoice id that gets sent as a tlv record. Implementations should expose a "stateless invoice" API for receiving using the payment_secret and when sending, implementations should attach a TLV record with encoded order details. While 1 is simple to do, 2 requires full network compatibility, but it is much needed; otherwise, the payee has to keep track of all the invoice ids related to the orders they refer to. There are application-specific workarounds that can be applied for 2, such as having a fixed, hardcoded set of possible orders, encoding the order minimally in the payment secret or route hint, storing order details on redis for only 3 minutes, and using lnurlpay to reduce the delay between invoice issuance and user confirmation to zero. A clever workaround was used by fiatjaf on @lntxbot, but it required low-level code in a c-lightning plugin and a hack with route hints since TLV payloads were not an option.
Updated on: 2023-06-03T05:57:43.213661+00:00