Blogs & Articles: Get Ready for a Fresh Breez: Multiple Apps, One Node, Optimal UX 🔗 2 years ago

Swiss Army Knives are little miracles. The idea of putting a knife, a corkscrew, tweezers, a couple of screwdrivers, and a can opener onto a single device is pretty absurd. But they’re still so useful! No camping trip or pocket is complete without one. And what makes them so useful is their versatility: one gadget, many functions.

But while a Swiss Army Knife can help with a great many tasks, they’re not great at performing any of them. No chef will use the folding blade in the kitchen, no mechanic will use those screwdrivers in the workshop, and no manicurist will use that nail file in the salon. Swiss Army Knives are jacks of all trades, but masters of none.

While you admired the cuckoo clocks, while you ate the chocolate, I studied the blade. (Image: James Case)

Breez is like a Swiss Army Knife. When we launched the app three years ago, it was pretty much just a nice, little, non-custodial wallet — a blade. We have since added two other services that are effectively different apps: the point-of-sale mode and the podcast player. Now we’re thinking ahead to new services that we’d like to add: streaming video and chat. Adding them to the existing Breez app could result in an unwieldy mess. We can’t just add more gizmos to the Swiss Army Knife without it becoming unusable. It is no longer enough for Breez to grow; now we must evolve.

New Node, New Apps

Packing Breez’s services into a single app wasn’t really a choice; it was a technological necessity. We’ve always been committed to user sovereignty, and the only way to provide users with sovereign access to these different services was to make the local Neutrino node the conduit. As long as the node is located in the app on the user’s device, any service has to go through that app. As a matter of fact, that’s one of the reasons the Breez app has never graduated from beta: we simply weren’t sure whether packing more services into the app was viable.

We’ve now found a way to have our sovereignty and distribute it too: Greenlight, a recent flash of brilliance built on top of Core Lightning, the lightweight, highly customizable, BOLT-compliant implementation of the Lightning Network.

Greenlight offers remote, non-custodial nodes, and it’s vital to the next leap forward in the Breez user experience. With Greenlight, the keys reside on the user’s device, and the node resides on a remote machine. Whenever a user sends or receives a Lightning payment, be it streaming sats for streaming content, a point-of-sale purchase, or a P2P transaction, the locally held keys authorize the transaction on the remote node.

Remote nodes remove a major technical constraint. Breez no longer has to be a Swiss Army Knife because moving a user’s node off their local device means that different apps can access it. A wallet app can access the user’s Greenlight node. A separate point-of-sale app can access that same node. And yes, you guessed it, a separate podcast app can stream sats from that same node. Video, chat, pizza and DeFi can all get their own, dedicated apps while all connecting to the same node. The Swiss Army Knife becomes a toolbox.

On the left: a Swiss Army Knife trying to do everything; on the right: a toolbox able to do anything.

Breez and Greenlight agree on the fundamental virtue of user sovereignty, and we ensure it together. But there is still a division of labor. For example, Greenlight provides some handy services for nodes on their servers, like encrypted backups and watchtowers. Breez powers Greenlight with its LSP backend, ensuring seamless connectivity to the network and automatically managing channels. By integrating Greenlight, Breez can continue to provide the same services we always have and more with a better UX. It’s a fundamentally different, superior architecture.

The UX improvements come from the ability to tailor different front-end apps. Instead of cramming all the tools into a single app, like the Swiss Army Knife, we can now create tools dedicated to specific purposes and usage patterns.

And removing the node from the device in the user’s hand means that it could potentially be accessed from any device. For example, many people spend all day on their work computers, but as long as their nodes are on their phones, they can’t pay from the device they’re using. With Greenlight they can. A local app or web interface on a laptop is just another point of access to the remote Greenlight node. Since we think Lightning should be accessible anywhere, we see a future where Breez will let users access their nodes from a range of apps running on any number of devices.

Privacy

You can do a lot more with a toolbox than with a Swiss Army Knife, but you can’t put it in your pocket. All improvements imply change, and change implies tradeoffs.

The major tradeoff with remote Greenlight nodes is privacy, which is obvious because they’re running on third-party machines. Those machines have access to metadata about users’ payments.

Many users won’t care, but many others will. And so do we — we at Breez along with Rusty and Christian at Blockstream too. Since we take users’ privacy seriously, we are also taking measures to safeguard it. The existing, local Neutrino nodes are the first measure. They’re very private and remain available.

Another way we’re working together to ensure privacy is to expand the encryption on Greenlight servers beyond backups to include invoices and payments at rest. User data on third-party servers should be legible on the most restrictive need-to-know terms.

The third way to enhance users’ privacy is to enable the Greenlight protocol to run on users’ own machines. In this scenario, Breez provides the front-end apps and the LSP, Greenlight is just the interface software between the machines, and all the devices are the user’s own. It doesn’t get much more private than open-source software running on your own rig.

We reject the custodial dichotomy of privacy/sovereignty vs. usability. Both are possible, and we’re doing it.

Satisfied Breez users enjoying their new Greenlight nodes. (Image: freestock)

Balancing Change and Continuity

Some of our innovations have been pretty revolutionary, like streaming sats and inventing the LSP. We want to continue revolutionizing Lightning, bitcoin, and money, but our little app can only handle so many revolutions. It’s time to evolve with a new architecture that will allow us to grow the technology without constraints. Lightning is getting too big to be locked in a phone.

Breez is changing … gradually. The Greenlight nodes will probably be ready sometime this summer. They’re the first big change that will enable innovations we haven’t even imagined yet and a few that we’ve been wanting to try for some time. Change is good.

But some things must never change, or Breez simply wouldn’t be Breez anymore. We won’t take custody of users’ funds, we won’t compromise on bitcoin’s ideals, and we’ll always try to deliver the best UX that is technologically possible. Blockstream agrees with us on each point, and that’s why we’re working together.

Enjoy the new apps and the fresh Breez coming your way!

Get Ready for a Fresh Breez: Multiple Apps, One Node, Optimal UX was originally published in Breez Technology on Medium, where people are continuing the conversation by highlighting and responding to this story.