Redeem voucher to wallet

[baebb]

Hi there! I am looking for a solution to create redeemable gift vouchers on LN and your solution is very, very close to it. I just would like the functionality on https://donnerlab.com/voucher/{id} page to be able to send the funds to a LN wallet.

Would this be possible? I can make a PR with the front-end html & JS if you can prove the C# wallet function.

[sputn1ck]

You would need to create an Invoice from the target wallet to be able to send funds to it. Then you can use the "/api/pay/{voucher}/{pay_req}" endpoint.

[baebb]

Thanks for the fast response @sputn1ck !

With the target wallet's public address, I think you can open a channel to it and specify a "push amount" that will be immediately sent to their wallet. See below capture from https://dev.lightning.community/overview/

[sputn1ck]

Ah I see, the problem with 'OpenChannel' is that it creates an on-chain Bitcoin transaction and would thus require a large amount of satoshi per voucher. I think I want to leave the functionality of the service to be off-chain only.

[sputn1ck]

But I may look into it. The problem is that at the moment of creating the OpenChannel Request I do not know the exact fee of the on-chain transaction and thus wouldn't know if the satoshi amount of a voucher would be sufficient

[baebb]

@sputn1ck ahhh i didn't consider that. How much would the onchain transaction cost? I am not super familiar with transaction fees.

An even better alternative to OpenChannel and push amount, if it gets approved, might be sphinx send: send: lightningnetwork/lnd#2455

This is separate to this issue but when would do you plan to increase voucher size? I would like to implement lightning voucher in a game where players could find voucher codes

[sputn1ck]

As soon as sphinx is included in a stable release I will support it.
What voucher size would you want?

[baebb]

@sputn1ck that's awesome news! Would 300000 be possible?

Big thanks for making this :)