Wallet support for pre-defined amounts using QR-code

StigAleksander

Dear community,

My name is Stig Aleksander Kjos-Mathisen and I am managing director at Norwegian Block Exchange (NBX). NBX will besides from starting and operating a crypto exchange, lead the adaption of DLT for Norwegian Air Shuttle (NAS). Norwegian Air Shuttle is Europe's third largest low-cost carrier and is at the moment operating 150 aircrafts and expected to carrie about 40 million passengers this year.

A part of the Digital strategy to NAS is to implement cryptocurrency as method of payment in the business to consumer ecosystem. Stellar XLM is a strong candidate to be chosen as primary choice of crypto currency, since speed and reliability are important factors when considering transactions at point of sales, e.g in-flight sales.

To allow speedy transactions an important functionality is to allow wallets to read a QR code with pre-defined amount, address and memo (maybe also RFID at a later point). Unfortunately, at least to my knowledge none of the app-wallets have this functionality today, as purposed in the SEP 007? We can of course develop our own app, and most likely will at a point or integrate a wallet in one of the apps we already have. My point is that the lack of this functionality across the ecosystem may lead us to look at other currencies to build the b2c around, which I really don't want to do.

brds,
Stig Aleksander

MisterTicot

StigAleksander
NeilAmbikar

Hi,

I'm developing a set of open source tools that aims at establishing a standard way of transmitting transaction for Stellar ecosystem. While QRs is not the primary focus, it is definitely part of it. The protocol is called Cosmic Links. Did you tried it Neil?

If you want a taste of it :

https://cosmic.link/?payment&memo=MyMemo&destination=tips*cosmic.link&amount=20&network=test

Any Stellar operation is supported, including multi-operation transactions. You can pass XDR as well using:

https://cosmic.link/?xdr=...&network=...

You can add support for cosmic links in your own tools using the library. You'll also find more info in the docs.

Please note that's I'm going to release the beta 2 around the 15th with new features, partial sep0007 support and syntactic changes, as I'm heading toward the stable iteration.

If it is what you need, you can also clone of the cosmic.link website and customize it to your needs. While I didn't released the doc to do that yet, I'm willing to offer support for that operation.

If anything I'm avalaible on Stellar Slack (@mister.Ticot) and on the cosmiclink telegram group.

NeilAmbikar

Hi Stig.

good point. we were also looking for this. there are a few open source QR initiatives for stellar but we ran into a lot of problems trying to integrating them. I know lot of of people here have been talking about this as it makes transactions a lot easier and hopefully a few people are working on it!

cheersneil

StigAleksander

dzham
NeilAmbikar
MisterTicot
antb123
StellarGuard

Thank you all for the replies and information, good article btw.
We have been watching the development of cosmic.link and been playing around with it a bit. Same of course with Stargazer, we have not really got that functionality to work, possibly a problem with the newer versions of android, the screen turn white and freezes app, on the device reading the QR code.

Our main concern are on the limitations on the user side, them not being able to pay with their preferred wallet.

brds,
Stig

antb123

I wrote an article regarding this.. And there is a kind of QR standard from one of the SEPs.

https://medium.com/lumenauts/stellar-payments-thoughts-on-federation-qr-codes-uris-and-point-of-sale-systems-within-the-2c6fcdc3fa4d

I like the IETF proposed payto standard (but it doesn't handle fees):
payto://stellar/orderid*store.tempo.eu.com?amount=EURT:200.0

Stellar SEP-007
web+stellar:pay?destination=GCALNQQBXAPZ2WIRSDDBMSTAKCUH5SG6U76YBFLQLIXJTF7FE5AX7AOO&amount=100.123&asset_code=EURT&asset_issuer=GAP5LETOV6YIE62YAM56STDANPRDO7ZFDBGSNHJQIYGGKSMOZAHOOS2S&memo=tempo&callback=url%3Ahttps%3A%2F%2FsomeSigningService.com%2Fhasysda987fs%3Fasset%3DUSD

The trick would be to extend SEP-007 to be close to the Bitcoin Payment Protocol (BIP-0070)

This would allow for modification of FEES (in the event of Stellar congestion).

MisterTicot

antb123
StellarGuard

Sep0007 have not been implemented so far, so I guess that's not an option. I'm likely to implement it gradually in cosmic-lib, though.

Edit: Another reason I would let it aside is that it leads to terribly wrong user experience when one didn't installed a compatible wallet (that is: a cryptic error).

dzham

antb123 This would allow for modification of FEES (in the event of Stellar congestion).

Wouldn't fees be better handled by the client?

StellarGuard

Are there any libraries out there already for parsing/validating/creating SEP-0007 links? Probably people are waiting for the base infrastructure to be built out to support it, and maybe a chicken-and-egg problem of waiting to see how other wallets handle it.

StellarGuard probably isn't your target here (since it's not a wallet), but I was just discussing how I could possibly implement it here: https://github.com/stellar/account-viewer/pull/68#issuecomment-411414041. And I'll create a JS library for it if none exist yet that will suffice.

antb123

I did in python already... Plus deposit and withdraw..

But on the back end.

dzham

As Ant mentions (and shows) in his Medium article, Stargazer supports QR codes with predefined destinations and amounts, and uses path payments to make sure the customer can pay his coffee in whatever asset he sees fit.

If I had to do it over again (this was done 1.5 years ago, at least), I'd go for a binary format. Something compact. Like... XDR.

MisterTicot

StigAleksander

Well the tools are ready now, what is missing is having wallet developpers playing the game. Nothing prevent them to do so.

I would assume that when a company such as yours jump in, some wallets will get compatible rather quickly.

Do you have any comment about your experience with the library so far?