Wrote up a guide on accepting Monero via BTCPay Server: sethforprivacy.com/guides/accepting-monero-via-btcpay-server

Would love any feedback you all have on it, and hopefully will help onboard more merchants to Monero!

One little thing about that: I noticed that in the actual payment thingy you can choose to specify the amount only in usd/gbp/eur/btc - but not actually Monero. Is it possible to enable that option (define amount directly in xmr), or is that a btcpayserver limitation?

<Encore> cryptogrampy: awesome dude

reddit mods - i just posted a reddit thread with a question mark in the title, which triggered automod. can someone check it when they get a chance, thank you in advance.

Hey Seth For Privacy do you happen to know if payments with BTCPay Server are automatically marked as "paid" in Shopify?

For the monerokon website, we are using NowPayments and with their plugin, we have to manually check confirmed payments and then mark them as "paid" in Shopify.

This is a real headache to do when we have many orders that come in and we need to check each one.

cryptogrampy[m] is doing a really good job with the POS software.

We have some electronics projects (customers with payment networks requiring NFC wallet transmission) beginning, but the Hotshop and Kasisto codes are IA32/AMD64 and ARMv8 based, so it may or may not be (re)usable.

ajs_[m]: I think the signalling of 'paid' is done by the integration isn't it? The BTCPay server does automatically mark 'paid' in Prestashop, but only if the administrator configures it properly.

Let's wait to hear what sethforprivacy reports.

Man, submitting a payment transaction via nfc directly to the PoS terminal would be an awesome feature

It would also bring bonus protection for the recipient, because they could test broadcasting the tx themselves to the network to verify its validity

So you don't have to wait for the customer's potentially spotty mobile connection to some remote node to do it properly, because you can submit it yourself (presumably through a much more stable wifi/wired connection, to your own node)

merope: Payments for coffee, shirts, entrance, and beers is exactly what we just did this weekend at Paralelni Polis, using NFC badges from Monero Devices and Point of Sales machines from General Bytes.

You are acting as if this is a theoretical experiment, when we have implement the idea since a few years.

But there is only Bitcoin transactions, because of abandonment on the Monero side. No Monero community members have ever contributed work hours to making the NFC badge system work with Monero blockchains.

The new (Bitcoin) host groups are also not interested in doing the Monero community's work for them, so it may be another unfortunate year of NFC powered payments with no Monero option.

We will keep working to avoid the most unfortunate thing, like a ten year period without Monero. But we haven't succeeded in the past at convincing non Monero groups to do the Monero community's work for them.

That's why it would be good to find out how much Hotshop and Kasisto logic can be ported to Cortex-M.

<msvb-web> "You are acting as if this is a..." <- I'm not acting, I was genuinely unaware of any implementation for *submitting* (not sending the payment request to a mobile device) Monero payments via nfc

How do these nfc badges handle tx generation for Monero?

* I'm not acting, I was genuinely unaware of any implementation for *submitting* Monero payments via nfc (not sending the payment request to a mobile device)

<msvb-web> "But there is only Bitcoin..." <- Any links to repos/projects aspiring contributors might want to check out?

It's no accusation, and perfectly fine for you merope to learn about the NFC badge payments happening, sorry if that sounded offensive.

My bad, I must have misinterpreted the tone of the message :)

A future hardware revision of the current NFC circuit design will use RISC-V and secure elements to generate keys on the device, but the current implementations require the user to generate keys and store them on the NFC media (EEPROMs) that are user selectable when making or taking payments. There is no blockchain or transaction logic on the NFC

carrier, just a bunch of EEPROMs, antenna, switches, and a I2C serial bus.

You can study the public designs (schematics, layout, and bill of materials) of current NFC badges here:

There is considerable nonpublic development happening, but like I wrote it's exclusively Bitcoin and other currencies doing the work, so I'm not sure about the repositories.

Cool!

We failed to design and produce a electronic badge for Konferenco next month, due to abandoning the deadlines in 2021. So if you think the Monero community can afford the time, patience, and generosity to supply ideas, funds, workhours, and other resources, then you should get started.

It takes about one man year to design and produce a simple badge, maybe 1000 man hours.

So starting now would almost guarantee a new badge distribution in time for Konferenco 2023 or Defcon 31.

I have the supply chain ready to order parts, we can get up to 100K EEPROMs and switches which would serve about two events. Lead time is 36-55 weeks.

Well, I'm no hardware developer - but publishing these links and related resources in a place where everyone can see them (starting from this room) is a great way to maximize the odds that someone with the right skillset sees them and decides to step up

And I'm sure the community would be more than happy to fund a ccs request to pay for the dev time and manufacturing costs

An active Monero community effort will almost certainly not happen, but for whoever is willing to use Bitcoin instead of Monero they will have some nice surprises in Europe during the Autumn 2022 and Summer 2023.

I hope a group (half dozen would be enough) proves me wrong, and actually succeeds at NFC payments in 2023.

In case you merope will go to Konferenco, we will no have any POS that accepts Monero but we will have a BATM that exchanges Monero using the NFC devices produced from the designs published at the URLs you asked for.

A very expensive BATM (Bitcoin Automated Teller Machine) was purchased specifically to support this at Konferenco.

Is there an open standard for pushing signed txes via nfc from a wallet device to a pos device? Perhaps that could allow wallet devs like Cake and Monerujo to get a head start on the issue, and generate the "demand" for the feature

Monerjuo has implemented its NFC interface since about one year, so that is finished.

You can use the Monero Devices NFC badges (all of them) together with Monerujo, but I was talking about POS (Point of Sales) before, which is a different situation.

Because Hotshop and Kasisto do not have the same Monerjuo NFC abilities.

Cake can port Monerujo's NFC (NDK logic) to Flutter, but they are really busy with other things.

midipoet: I approved your thread

msvb-web: Right, but afaik that's just to transmit the payment request - is it not? I.e.: "Please send X monero to Y address with Z payment id"

Or does it also support submitting the signed tx after that?

The payment requesting and transaction signing is done at the POS or ATM device, which simiply reads the keys (for spending or receiving) from the NFC carrier, which in this case is a dumb badge with a EEPROM and antenna.

We avoid that way, that 20K new IP connections are needed along with expensive batteries, charging, and a lot of complexity in the badges themselves. The badges do energy harvesting over the specially designed antenna.

Electromagnetic induction is the proper word for the power supply in the badge circuits.

<ajs_[m]> "Hey Seth For Privacy do you..." <- I can't say for sure, have not tested with Shopify but will see what I can find!

It should, though

Docs here: docs.btcpayserver.org/Shopify

interesting discussion msvb-web , mobile-apps would have an easier time integrating NFC payments (a MyMonero type service would be 'ready' to swipe without the need to sync your wallet at the point of service -> place phone near PoS -> user must confirm/swipe if payment > 50$ else its instant). I have no idea what is possible with these badges though, i would think for monero it would need to essentially be a 'Hardware wallet + NFC'

or some other workaround method that i can't think of at the moment

Yes plowsof[m], it's all a bit difficult to define and understand because of the wide range of options.

You can hang a 1000 USD phone on a lanyard and call it a badge, then have a crypto expert criticize for using such a low security general purpose device for a financial application.

Our badges are made for poor planners with low budgets, so the standard (approx) 4000 man years for a new phone design is reduced to about one (!) man year for a dedicated badge.

So with the badge (I've never used one), is the flow that you somehow load it up with xmr (it has its own unknown private key but has a known public key), you touch the badge to a capable PoS, the PoS generates the tx and you press a button on the badge to approve? Any good documentation / overview of this stuff for 85 year olds?

And the PoS submits the tx, presumably to its own private node and gets confirmation?

cryptogrampy[m]: The workflow you describe is almost correct, just that the badge requires one user interaction to connect the antenna with the data filled EEPROM. All other interation is done on the high voltage POS device and it's bright touchscreen.

did you say monerujo already supports nfc?

i'm just curious if there are any devices that support nfc offline tx signing for monero currently/have any sort of documentation

Seth For Privacy: if you still have a server up and interested, we could test out Shopify integration with a dummy product on monerokon website

Yes, can send an invite for a new user (note that testing funds will go to my wallet, but obviously I will refund anything), just DM me an email address for you!

cryptogrampy[m]: Yes, Monerujo has worked with our (Monero Devices) badges for a long time, probably a year or more.

You need to please avoid using the words NFC and transactions in the same sentence because NFC stores data just like paper or USB drives. None of these things have logic to handle transactions.

So if you want your USB drive to inspect the data stored and identify signed or unsigned transactions that would require a completely new circuit.

Which is the same with NFC data carrying devices. Does that help?

Yes 😎, now where can I get a badge dev kit

Or maybe just a badge 🙂

Also will take a look at what monerujo is doing. I guess I'm mostly looking for any sort of documentation on this besides the code 🙃

cryptogrampy[m]: That's the best way to learn, to be a user first and a pruducer after that.

ELI85

finally I get to send gingeropolous moooneros without him sending me back more \o/

lol

<cryptogrampy[m]> "did you say monerujo already..." <- yes it does. afaik working both ways, to send or receive

but I haven't used it in ages

will test

Can you also relay a signed tx to another device via nfc, rather/in addition to going through the node you're connected to?

<anhdres[m]> "yes it does. afaik working..." <- If you can point me to any to any documentation or lines of code that are the messages to and from the NFC, that would be great 😎

There's an experimental webNFC API that works with chrome+android... May not be too crazy to add to HotShop 😎

<cryptogrampy[m]> "If you can point me to any to..." <- pinging m2049r

do we have any russian ressources for syncing / restoring?

theres someone on monerosupport who sent funds to their own subaddress and doesnt have them show up

When sending to yourself, in my experience, the tx history shows the send + 0xmr and doesnt show the receive or receive amount