LUD21: A proposal for currencies on payRequest

The proposal facilitates the creation of invoices in various currencies by users, enabling amounts to be denominated based on the exchange rates of target wallets. Furthermore, it permits receivers to express their preference to convert received Bitcoin into another currency at the time of payment. It also allows sending services to provide information regarding exchange rates when currencies other than Bitcoin are utilized on the sender's side.

The utility of this enhancement is manifold, providing a framework for a remittance-like experience that leverages the capabilities of the Lightning Network and LNURL. It simplifies the process for wallets to generate invoices tied directly to the prevailing exchange rates of the recipient's wallet, adding flexibility and efficiency to transactions.

Feedback is sought for this initiative, and interested parties can review the details of the proposal in the provided GitHub pull request. Bipa is currently developing an implementation of this feature, which can be observed at their website under the /lnurlp/lorenzolfm directory. Other services or wallets that are considering support for this functionality are encouraged to collaborate and contribute to its development.