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August 28, 2022

Burner Wallet at ETHDenver was 🔥

The biggest pop-up economy powered by crypto in history! Image from Rich@Maker Burner Wallet TL;DR The Burner wallet works in your mobile web browser like Safari so no app download and no seed phrase. It runs on the xDai network so transactions always completed within five seconds, you can do hundreds of them for a penny, and it’s pegged to the dollar so there is low cognitive overhead. The best part is onboarding is as easy as opening your camera.

The biggest pop-up economy powered by crypto in history!

Image from Rich@Maker

Burner Wallet TL;DR

The Burner wallet works in your mobile web browser like Safari so no app download and no seed phrase. It runs on the xDai network so transactions always completed within five seconds, you can do hundreds of them for a penny, and it’s pegged to the dollar so there is low cognitive overhead. The best part is onboarding is as easy as opening your camera.


It was incredibly stressful to get it right; it took months of building, weeks of user testing, and days of pacing food trucks. The Burner Wallet at ETHDenver was straight up 🔥 AF.

Image from Rich@Maker

There were 11 food trucks that sold a total of 4405 meals over the course of the weekend. Here is an example of a meal being purchased. Notice the transaction cost of $0.000046 USD? That means for all of the transactions for all of the meals the cost of running the wallet on xDai was $0.20!!! That’s pretty good for a total of $38,432.56 being paid in DAI to the trucks:

(not all truck off-ramps pictured here)

That isn’t even the best part! The key here is that it was so easy to use that the user adoption rate was through the roof…

User Flow

Let’s start from the perspective of a developer or participant in ETHDenver. They arrived at the Denver Sports Castle early Friday morning with excitement to #buidl the next big thing in Ethereum. At the front desk they received a swag bag with goodies and a SolidCoin:

This SolidCoin had an Ethereum private key in the form of a QR code on the back. An attendee could pull out their phone’s camera and point it at the QR to seed a wallet:

Scanning an #ETHDenver token to claim my bufficoins to buy lunch. Thanks @austingriffith and friends!

— alexfisher.eth (@AlexanderFisher) February 16, 2019

One quick scan and they had a wallet with money in it. No app download, no seed phrases, instant onboarding into crypto.

Image from Rich@Maker

From there the participant could approach a food truck, order their meal, and scan a QR code to purchase it:

Five seconds later, the purchase is displayed on the food truck’s iPad and they hand you your food:

Participants, sponsors, and vendors could also move funds between themselves to purchase items other than food:

We were super busy so we weren’t able to execute on collectibles as well as I wanted, but they are in the wallet and you should look for them at the next Burner event:

Food Truck Flow

Okay, now from the perspective of a food truck. We asked all eleven food trucks to sign up for a Wyre account before arriving Friday morning. When they showed up we used their iPad to scan a special vendor private key. Then we printed a QR code for them to display at their truck:

Image from Rich@Maker

This QR code pointed to a page within the wallet that prompts the participant to pay for the meal:

It was really fascinating to watch the operators of the trucks train some of the crypto-initiated on how to use their Burner wallet.

Image from Rich@Maker

There was a special clause in the smart contracts to only allow vendors to off-ramp. At the end of the night each vendor pressed a “Cash Out” button to initiate a Wyre transfer of the revenue they earned that day to their bank account.

(Off-ramped buffiDai)

Throughout the event there were a few rumors of hacks. These turned out to be misunderstandings or frontend wizardry. The contracts held up and the wallet worked great. You can read about these events in depth here: Demystifying Burner Wallet Hacks.

Other neat projects at ETHDenver:


I’m really excited to see how the Moloch progresses. They were able to deploy the contracts after an audit and the frontend is shaping up quickly. This thin layer of governance will power so many projects in the very near future:

CLR Matching from Gitcoin

Gitcoin announced the winners of their CLR matching experiment and we couldn’t be happier with the results. Alex Van de Sande posted a really good graphic to Twitter that explains how to calculate the donation matching. Be sure to check out the full article and keep an ear open from more. However, my favorite part was the swag and giant plinko board. Kevin Owocki, the sultan of shill:

Decentralized Meta Transaction Relays

There were so many great talks at ETHDenver that I can’t list them all here, but of course I am going shill my talk with Yoav Weiss. We demoed the live production functionality of his Gas Station Network powering link claiming in the Burner Wallet:


A lot of cool projects built on top of the Burner wallet including one of the main winners zDai and I will write a full blog post about that soon, but my favorite project at ETHDenver was EthDevTools by billy rennekamp’s team.

It’s a chrome extension that allows web3 developers to easily view so many different things while building a dapp: logs, txs, abi explorer, graphql, etc.

If you are interested in updates on the project, sign up here. Student Competition

I had the honor of judging the student competition with Rhys Lindmark and the project submissions were really insightful for our little ecosystem. One was a platform for exchanging social network accounts in crypto and another was a fruit mixing ERC-721 system. Very cool stuff!

Griff Riff!

Another fun thing I participated in was the Griff Riff! It’s a chance for we three Griffs to Riff about the space. In this episode we talked about hacking, the vibe of ETHDenver, zDai, charities, Gitcoin CLR matching, Billy’s web3 tool, my Joe Lubin shout out for chugging a beer, token bonding curves, the Ethereum family, Simona’s birthday and water jugs of beer, Maker dappy hour, Burner collectibles, QR codes, and MORE!


The event was absolutely fantastic and if you want to host something similar please connect with me on Twitter or Telegram: @austingriffith

We have a huge list of things to do and a few different directions to go. I’m excited for the next chapter of the 🔥Burner Wallet. Thanks for reading along!

If you are interested in how all this got started checkout this article: Ethereum in Emerging Economies.

Also, here is the all-encompassing tweet for the Burner Wallet at ETHDenver:


It would take me forever to thank everyone who came together to make this work. First are my two main homies Brian Ethier and Rich@Maker. These two guys have been hustling on this project for the last couple months. If Brian didn’t clean up my work everything would have fallen apart. Don’t forget the Burner intern Eduardo!

Huge thanks to the teams at MakerDAO and POA!

Igor, without your xDai network none of this would have existed. Sky, thanks for helping us bang out the bugs.

Thanks to everyone who made it out to a Cypherpunk Speakeasy to help us user test.

Thanks to Consensys and the Gitcoin guys for letting me hack down this rabbit hole.

Finally, we should thank the organizers of ETHDenver! Specifically Coury, John, Justin, and Will. See you jabronies next year!

Image from Rich@Maker
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