lightning

Sharing Breez's monthly newsletter with the latest: https://newsletter.breez.technology/p/018-feel-the-breez

***
# #018 Feel the Breez

![](https://substackcdn.com/image/fetch/$s_!2LPm!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fb37ac319-3dca-409c-b191-f81a1df3ff55_1600x900.gif)

Lightning is dead. Long live Lightning. That's the headline this month, and everything else in March backs it up: we said goodbye to seed phrases, Primal went non-custodial, and the Breez SDK keeps getting better and better.

* 📝 Lightning Is Dead, Long Live Lightning
* 🔑 Say Goodbye to Seed Phrases
* 💬 Primal: Powered by the Breez SDK
* ⚡️ Lightning in the Wild: Stacked
* 🎙️ Shoot the Breez with Cake

***

## Lightning Is Dead, Long Live Lightning ⚡️

Roy's latest article focuses on where Lightning has been and where it's going.

Lightning used to mean channels you managed, liquidity you balanced, and infrastructure you babysat. That version is dead. New last-mile technologies have turned Lightning into the common language that connects everything in bitcoin, from wallets to social apps to cross-chain bridges, without users or developers needing to think about what's happening underneath.

Roy uses Cake's journey with the Breez SDK to make the point. Cake tried Lightning before but it was lacking for users. Rather than compromise, they waited. What brought them back wasn't a single feature. It was Lightning itself changing, and the Breez SDK evolving with it.

The result: one million users, instant bitcoin, value moving like information.

[Read the full article →](https://x.com/Breez_Tech/status/2028849724908871994)

***

## Say Goodbye to Seed Phrases 🔑

Last month, we launched Passkey Login for the Breez SDK, releasing the future of bitcoin UX and transforming the onboarding experience forever.

A problem every developer building with bitcoin has faced: seed phrases work for security, but they're a wall for everyday users. People lose them, misunderstand them, or never write them down in the first place. For apps trying to reach millions of users, that's a dealbreaker.

Passkey Login removes the wall entirely. Users authenticate with the biometrics already on their device, Face ID, fingerprint, or a hardware key, and the Breez SDK handles the rest. Their wallet is created, secured, and recoverable without ever seeing a seed phrase.

This isn't custodial convenience dressed up in new clothes. Users still hold their own keys. The difference is they don't need to know it. For developers, the integration is minimal and your users get the onboarding experience they expect from any modern app.

If seed phrases were the last thing stopping you from shipping bitcoin in your app, that excuse just disappeared...

[Read the full blog post →](https://blog.breez.technology/no-seed-no-sweat-introducing-passkey-login-for-the-breez-sdk-2cb7a7ee0279)

***

## Primal: Powered by the Breez SDK 💬

Primal, Nostr's most popular social client, just added instant, non-custodial bitcoin powered by the Breez SDK.

For anyone who hasn't discovered Nostr: it's a decentralized social network where you own your identity, your data, and now, your money. You scroll your feed, see something worth supporting, and zap it. Peer-to-peer electronic cash inside your social feed.

Primal users keep their keys. Primal developers build without worrying about channels or liquidity. The Breez SDK handles the rest.

Join them and 75+ apps building with Breez: [https://breez.technology/sdk](https://breez.technology/sdk)

***

## Lightning in the Wild: Stacked ⚡️

Meet [Stacked](https://stackedbitcoin.com/), New Zealand's home for bitcoin.

You might remember them as Lightning Pay, a Breez SDK partner from across the Pacific. They've rebranded, expanded, and they're building the infrastructure for bitcoin adoption in New Zealand and beyond.

Check it out →

***

## Shoot the Breez with Cake 🎙️

Danny sat down with Seth, COO of Cake, to talk about what it took to bring instant, non-custodial bitcoin to over one million users, and what it means for where bitcoin is headed.

As we mentioned above, Cake had been watching Lightning for years, waiting for the technology to match the promise. For their users, payments are now instant, fees are barely worth mentioning, and they stay in control of their funds. For their developers, no channels or liquidity to manage, no infrastructure headaches. The Breez SDK abstracts away the complexity so Cake's team could focus on what actually matters: the experience their one million users get.

But for Seth, this integration signals something even bigger. Lightning shouldn't just be for wallet apps. The next stage of bitcoin is putting it into every app that needs to move value. bitcoin like the money in your pocket. Digital cash you hand to a friend. Value that moves like information.

[Watch the conversation →](https://x.com/Breez_Tech/status/2033911065021387252)

***

That's a wrap on March and Q1 2026.

Spring is here, momentum is building, and the best is still ahead.

Remember: the best time to add value transfer is now. It always has been.

See y'all next time ✌️

Breez: March's Newsletter ⚡️

bitcoin

The simplest way to accept bitcoin payments on your website.

No server is required. Powered by Breez SDK.

*(and yes, your agent can use it as well)*

[https://x.com/roy/\_breez/status/2036438447523496401](https://x.com/roy/_breez/status/2036438447523496401)

***

# Accept Bitcoin in Seconds

Accept bitcoin payments on your website.
Non-custodial, instant settlement, no middlemen.
👉 [Get Started](https://glow-pay.co/setup)👈

***

### Your Keys, Your Funds

Payments settle directly into your account. Glow Pay never holds your funds.

### Instant Settlement

Transactions confirm in under a second with fees measured in fractions of a cent.

### Global Payments

Accept payments from customers worldwide. No banking infrastructure required.

***

## How It Works

### 1. Set Up in Minutes

Create a secure account and generate your payment addresses.

### 2. Connect Your Store

Use the REST API to create payment links, or generate them from the dashboard.

### 3. Get Paid

Funds arrive directly in your account. No middlemen.

***

ps - this weekend I made a simple video game demo to see how easy it is to do ([I'm not a dev either](https://orangepill21.vercel.app/)).

the simplest way to accept bitcoin on your website

# Introducing Contacts for the Breez SDK 👥

Let your users move value straight from their contacts list.

Simple, fast, and built for everyday use.

Learn how it works: https://sdk-doc-spark.breez.technology/guide/contacts.html

You can also test it out via Glow, a reference app: https://glow-app.co/

***

Announcement: https://x.com/Breez_Tech/status/2035019920040136892

Introducing Contacts for the Breez SDK 👥

![](https://miro.medium.com/v2/resize:fit:1400/1*0HKrG3RMeRFecS8iTu3NhA.png)

For as long as bitcoin wallets have existed, the seed phrase has been both a superpower and a liability. Those 12 or 24 words are the master key to your funds. Write them down, keep them safe, never lose them, never let anyone see them. Definitely do not [save them to a hard drive](https://en.wikipedia.org/wiki/Bitcoin_buried_in_Newport_landfill), toss the hard drive into the trash, and then spend millions trying to get them back out before giving up, sad and much poorer.

It’s stories like this that scare so many potential users away from self-custody. A sticky note in a drawer, a screenshot in iCloud, a forgotten notebook. There are so many simple ways to blow this one crucial step, but the consequences are permanent.

The rest of the tech industry has been moving away from passwords for years. The stakes with bitcoin are higher, but the logic is the same. It’s time Bitcoin caught up.

# **The Missing Piece: PRF**

Passkeys aren’t new. Apple, Google, and Microsoft jointly backed the standard in 2022, and the market has welcomed the move enthusiastically. According to the FIDO Alliance, [over a billion people](https://fidoalliance.org/biometric-update-state-of-passkeys-2025-passkeys-move-to-mainstream/) have activated at least one passkey, and as of May 2025, [69% of users](https://www.authsignal.com/blog/articles/passwordless-authentication-in-2025-the-year-passkeys-went-mainstream) have set one up. [48% of the top 100 websites](https://www.authsignal.com/blog/articles/passwordless-authentication-in-2025-the-year-passkeys-went-mainstream) now support them. They’re built into every modern phone and computer. The technology is proven. Bitcoin just hasn’t adopted it yet.

The missing piece was key derivation. Passkeys are great for authentication, but a bitcoin wallet needs to deterministically derive cryptographic keys, not just match a user with their account. Bitcoin presents a different problem, and until recently there was no standard way to solve it.

That’s what the PRF extension of WebAuthn solves, and it’s the key ingredient in Passkey Login. PRF is a newer capability, part of the [WebAuthn Level 3 spec](https://www.w3.org/TR/webauthn-3/), that lets your passkey produce a deterministic cryptographic output for any given input. Same passkey, same input, same output. Always. The passkey never leaves your device’s secure enclave.

PRF is what separates passkeys-for-authentication from passkeys-for-key-derivation. Regular passkeys can verify who you are. PRF lets them generate secrets deterministically.

PRF support is still rolling out unevenly across various platforms. [Android](https://support.google.com/android/answer/14124480?hl=en) with Google Password Manager has the most complete support. [Apple](https://support.apple.com/guide/iphone/use-passkeys-to-sign-in-to-websites-and-apps-iphf538ea8d0/ios) added PRF in iOS 18 and macOS 15 for iCloud Keychain. Windows Hello doesn’t support PRF at all yet, so only external hardware keys like [YubiKeys](https://www.yubico.com/) work on Windows. Firefox support is also incomplete. It works well on Android and increasingly on Apple platforms, but not everywhere.

Logging in to the Breez SDK with a passkey requires PRF, so coverage today maps to where PRF works. As adoption grows (and it’s growing fast!), so does the utility.

The practical result: any device with a PRF-capable passkey can reconstruct your wallet keys from scratch and on demand.

# **How It Works**

### **Your Passkey Derives Your Keys**

When you set up Passkey Login, the app uses your passkey to compute a PRF output. That output becomes the root key for your wallet. From there, standard key derivation produces keys for the Breez SDK.

No randomness is stored. No backup is created. The passkey is the key generator, and it only works when you authenticate. The protocol also supports multiple wallets, each derived from a different label.

### **Nostr Keeps Track of Your Labels**

Here’s where Nostr comes in, but not as a core security primitive. Instead, Nostr is a practical solution to a real problem: if your keys are derived from labels, how do you remember which labels you used when restoring on a new device?

The answer is to publish them. Under the hood, the app seamlessly creates a Nostr identity derived from the same PRF and uses it to post each label as a plain Nostr event. The user never sees or manages this identity. When you restore, the app reconstructs that same Nostr identity, queries the relays, retrieves the list of labels, and re-derives the keys on the spot.

No cloud backup. No iCloud. No Google Drive. No server. Just your passkey and a few public Nostr messages.

# **Trust and Tradeoffs**

The app stores nothing. Keys are derived fresh on every use, with no local secrets and no encrypted backup file. There is a soft dependency on Nostr relays for label lookup, though Breez handles all of this out of the box.

The security is as strong as your passkey. If your passkey is cloud-synced, as most platform passkeys are, a compromised cloud account means compromised keys. And if you lose access to your passkey entirely, you lose access to your funds.

Passkeys also aren’t fully interoperable across platforms yet. That’s why the Breez SDK lets you export the mnemonic for any of your wallets. If you ever need to move to a platform or wallet that doesn’t support passkeys, you have a standard seed phrase to fall back on.

# **Why This Matters**

The seed phrase has been a barrier to self-custody since day one. It’s what scares normies away from keeping their own bitcoin, and it’s a legitimate reason why people accept the counterparty risk of exchanges and custodial apps.

Passkey Login doesn’t eliminate the tradeoffs of self-custody, but it reframes them around something people already understand and use, namely the same biometric authentication that protects their banking app and their password manager. For most users, that’s a much more intuitive security model than a piece of paper in a drawer.

For developers building on the Breez SDK, it means onboarding without the “write down these 12 words before you continue” speed bump, while still giving users full control over their keys.

# **The Future of Bitcoin UX Is Here**

The full technical specification for Passkey Login is [public](https://github.com/breez/passkey-login/blob/main/spec.md), and our reference app [Glow](https://glow-app.co/) is already running it, and it’s now available for all the Breez SDK devs to use.

The seed phrase has been one of the biggest UX barriers to bitcoin adoption, but we finally have the tools to overcome it. Passkey Login builds on authentication infrastructure that billions of people already use every day, and it makes using bitcoin feel as natural as unlocking your phone. That’s what drives the Breez SDK: pushing the boundaries of what’s possible until yesterday’s Bitcoin dreams become today’s reality.

The future of Bitcoin UX is here: Introducing Passkey Login for the Breez SDK ⚡️

# shoot the breez | seth for privacy, cake wallet

## Adding Lightning? It's a "piece of cake" 🍰

We sat down with Seth, COO of Cake Wallet, to talk about what it took to bring instant bitcoin to 1 million users, and what it means for where bitcoin is headed.

Cake had been watching Lightning for years. Waiting for the technology to match the promise.

And now, that moment has arrived.

* For Cake's users: Payments are instant. Fees are barely worth mentioning. They stay in control of their funds.
* For Cake's developers: no channels or liquidity to manage, no complex infrastructure headaches.

The Breez SDK abstracts away the complexities of Lightning, so Cake's team could focus on what actually matters: the experience their 1 million users get.

But for Seth, this integration marks an even bigger moment for the wider tech ecosystem.

Lightning shouldn't just be for wallet apps. The next stage of bitcoin is putting it into every app that needs to move value.

Bitcoin like the money in your pocket. The digital cash you hand to a friend.

Value that moves like information.

Here's Seth's story:
[https://youtu.be/piKy229ep1c](https://youtu.be/piKy229ep1c)

Seth for Privacy on Cake bringing Lightning to their 1M users | 🎥

🌊 #017 Feel the Breez - February's Newsletter ⚡️

# Breez x Garden: Real Bitcoin, Real Fast with the Breez SDK - Spark

Announcement: https://x.com/Breez_Tech/status/2029241744466809249

New Breez SDK Partner: https://garden.finance/

***

**Garden ([@gardenfi](https://x.com/@gardenfi)) just became the latest service to add instant bitcoin with the Breez SDK.**

[Garden](https://garden.finance/) is one of the most popular Bitcoin bridges with over $2bn in trustless volume, saving users "around eight years" in transaction times.

And now, with the [Breez SDK](https://sdk-doc-spark.breez.technology/) - [@spark](https://x.com/@spark), the experience gets **even better** for ‘Gardeners” everywhere.

- **For Garden users**: Native Bitcoin between chains. No custody tradeoffs. Instant.
- **For the Garden team**: No channels. No liquidity management. Effortless to integrate.

*Faster for users. Simpler for the team.* **Value moving like information.**

Join 75+ apps and services, including [Garden](https://garden.finance/), already building with the Breez SDK.

Get started → https://breez.technology/sdk

Welcome Garden 🌸: latest Breez SDK partner

# Lightning Is Dead, Long Live Lightning!

![](https://miro.medium.com/v2/resize:fit:1400/1*jim2VFx79gYPh2HQq-63yQ.png)

Lightning Grows When We Cultivate It TogetherLightning continues to evolve, but most of the changes we’ve witnessed over the last decade are changes *in* the technology. What’s happened over the last two years, however, is a change *of* the technology. We’re not talking about protocol enhancements or new features, but a fundamental reconceptualization of what Lightning is, what it can do, and who uses it for what.

We’ve discussed some of these changes before in isolation, but they can be a little abstract. That’s why we tend to use metaphors like “[common language](https://medium.com/breez-technology/lightning-is-the-common-language-of-the-bitcoin-economy-eb8515341c11)” and “last-mile technology.”

Fortunately, one of our partners, [Cake Wallet](https://cakewallet.com/), has traced this path with us, and their story renders the abstraction of Lightning’s recent transformation marvelously concrete. So let me tell you the story of Lightning, Breez, and Cake.

# **If We Only Node Then What We Know Now**

In 2024, we at Breez were very glad to [welcome Cake](https://blog.breez.technology/adding-lightning-to-crypto-is-a-piece-of-cake-with-the-breez-sdk-2476db0ed9dc) as an early design partner using our (then) brand-new SDK. Cake implemented the Breez SDK using [Greenlight](https://medium.com/breez-technology/get-ready-for-a-fresh-breez-multiple-apps-one-node-optimal-ux-519c4daf2536) in their wallet. While Greenlight’s remote nodes improved the Lightning UX relative to client nodes running on users’ phones, Cake never put it into production, and we have since deprecated it.

Greenlight was a quality-of-life improvement over earlier implementations of Lightning on mobile devices. Running an actual Lightning node on users’ phones devoured resources and required constant sync with the Bitcoin chain and the Lightning Network, which was very challenging to solve with the restrictions of the contemporary mobile operating systems. By moving users’ nodes into the cloud and shifting many of the moving parts into the background, Greenlight did improve the UX.

However, even with Greenlight, compromises between open, permissionless, borderless Bitcoin and an intuitive, frictionless UX remained. For example, [liquidity](https://blog.breez.technology/lightning-economics-how-i-learned-to-stop-worrying-and-love-inbound-liquidity-511d05aa8b8b) [remained](https://blog.breez.technology/lightning-is-a-liquidity-network-550896ca27ea) a [tough nut to crack](https://medium.com/breez-technology/liquidity-on-lightning-moving-from-ux-to-economix-6e597d9e1abd) for everyone involved. Receiving bitcoin offline still required improvised workarounds using mobile notifications. We thought that Greenlight was the best balance available at the time, comparable in custody and openness with its predecessors and surpassing them in simplicity, but the UX was still too complicated and Greenlight itself proved hard to scale.

It’s for reasons like these that Cake never took the Greenlight implementation of the Breez SDK into production, despite [praising its design](https://blog.breez.technology/adding-lightning-to-crypto-is-a-piece-of-cake-with-the-breez-sdk-2476db0ed9dc), simplicity, and functionality. Greenlight was an advance *in* the technology, but Lightning needed a fundamental change *of* the technology.

Cake tried the Greenlight solution, and it turned out to be good enough for devs but still lacking for users. They opted not to compromise and rather wait for a better product. And honestly, that’s exactly the feedback we needed.

# **A Common Language for the Last Mile**

Times change, and tech changes with them.

More specifically, [several last-mile technologies have emerged](https://bitcoinmagazine.com/technical/spark-and-ark-a-look-at-our-newest-bitcoin-layer-twos) to improve the experience of the world’s Bitcoin users and the economics of moving bitcoin. These include new-gen statechains like [Spark](https://bitcoinmagazine.com/technical/spark-explained-like-youre-five), sidechains like [Liquid](https://blog.breez.technology/to-help-bitcoin-flow-were-adding-some-liquid-to-the-breez-sdk-b56c14b0c9b0), federations for friends and family like [Fedimint](https://fedimint.org/docs/GettingStarted/Who-are-the-fms), eCash networks like [Cashu](https://cashu.space/), and advanced programming layers like [Arkade](https://docs.arkadeos.com/primer). They’re all variations on a common theme: just as Lightning improves on Bitcoin’s economics and throughput, these last-mile technologies all improve on Lightning’s payment channels, economics, complexity, and scalability.

Lightning is still a vital part of how we transfer value, but it has evolved to become [the common language](https://blog.breez.technology/lightning-is-the-common-language-of-the-bitcoin-economy-eb8515341c11) and payment protocol that connects these last-mile technologies rather than a channels protocol that end users need to master. And Lightning’s connections run deep. Even when bitcoin moves from a Spark entity to Arkade or between a Fedimint federation and Liquid, those various subnetworks speak to each other in fluent Lightning.

Lightning’s transformation seems inevitable to anyone who understands [the economics of Lightning](https://medium.com/breez-technology/liquidity-on-lightning-moving-from-ux-to-economix-6e597d9e1abd) and values UX. Poon-Dryja payment channels excel when there’s a constant flow of high-velocity transactions, especially when they’re bi-directional. Even if problems that inherently stem from mobile usage (such as network synchronization and offline receive) are solved, edge nodes will always under-perform at low transaction velocities. Liquidity management and economics is a feature for routing nodes, but a bug when it comes to end-user nodes. Luckily, these last-mile technologies solve such issues and other UX complexities, and with Lightning as the common language that connects them, Bitcoin just works for devs and users alike.

# **The Return of Cake**


![](https://miro.medium.com/v2/resize:fit:1400/1*Qmp2Il-bLOS1qVqwm4PUbw.png)


Talking about the evolution of Lightning is so exciting, I almost forgot to tell you the big news: Cake Wallet is now taking the Breez SDK into production! Huzzah!

Cake continued to research the Bitcoin-UX dilemma and [explore various last-mile solutions](https://bitcoinmagazine.com/technical/spark-and-ark-a-look-at-our-newest-bitcoin-layer-twos). The Spark implementation of the Breez SDK provided Cake with a balanced trade-off between a [trust-minimized solution](https://docs.spark.money/learn/trust-model) and the UX they deserve. It combines the openness, utility, and finality of bitcoin with features that have eluded Lightning until now, like offline payments.

And the UX, which used to be the weak spot, is now the best part. Payments are instant. Offline payments and Lightning addresses are built in. Fees are infinitesimal. Like any fintech app, the complexity behind the scenes is substantial but irrelevant, because users just see money moving where they want, when they want, how they want. It’s bitcoin as digital cash. Users get to have their Cake and eat it too (sorry, I had to).

Of course, we haven’t compromised on the developer experience, which is better than ever. The API of the Breez SDK is designed by developers for developers to be as simple as possible with clear, extensive instructions and rapid, helpful support. With a user-friendly product, Cake is serving its end users, and with a developer-friendly product, we’re serving Cake’s product team.

# **Lightning Grows When We Cultivate It Together**

Breez was among the first to see the promise of Lightning and ship a functional mobile app, but our users pushed us to build a better experience. We worked together with the Blockstream team, who devised Greenlight, to optimize it for users and developers alike. Again, we were proud and with good reason, because our old Greenlight SDK was a significant improvement. But partners like Cake weren’t yet satisfied despite giving the Greenlight implementation a fair chance. They pushed us to build better.

We have, and by “we” I mean the whole Lightning community. Breez is still working with Blockstream on the Liquid implementation of the SDK, and we’re working with Lightspark on the Spark implementation, leveraging it to provide the best-in-class Lightning experience

This is exactly how it’s supposed to work. We build as far as we can with existing technology, and then we release the result out into the market to raise the bar and to determine where we still need to improve. Dedicated partners like Cake tell us how by sharing what they and their users need. Then we meet with our allies who are pursuing the same goal, and we cooperate to build the next miracle and reach the next optimum.

The story of Breez, Lightning, and Cake holds two lessons. First, there’s no alternative but to keep building and testing. Second, even though it’s impossible to tell what the next innovation in Lightning will be or how it will perform, the overall trajectory is obvious: Lightning keeps getting better. It’s now a much more functional technology helping far more people do far more things than it was when we all started.

Don’t you love a story with a happy ending?

***

Originally posted by Roy on X.

Lightning Is Dead, Long Live Lightning! ⚡️

# Deblock: Instant Bitcoin, at Scale
###  How Deblock Onboarded 300,000 Users to Frictionless Bitcoin Transfers

***

## Who's Deblock?

Though it started only in 2024, Deblock is already a sizable neobank with ambition and momentum. This should come as no surprise, as their C-Suite contains former executives from Revolut and Ledger. Their mission, as CEO Jean Meyer tells it, is simple: "We built Deblock because people shouldn't have to choose between the convenience of a bank and the sovereignty of crypto."

The banking side of the equation was largely in place. Deblock had already obtained the status of an electronic money institution (EMI) registered with the Banque de France and a MiCA license from the Autorité des Marchés Financiers (AMF). Their users enjoy current accounts, IBANs, debit cards, and all the trappings of modern banking.

Combining a modern neobank with a full bitcoin functionality and self-custody has obvious appeal, as their 300,000 active users attest. But the simplicity of the mission conceals a daunting challenge in the execution.

## The Challenge

Despite the regulatory hurdles of becoming a bank in Europe, the greater challenge for Deblock was on the bitcoin side. The bitcoin UX is one of the major impediments to its use as a medium of exchange. On-chain bitcoin transfers preserve self-custody, but they come with sometimes prohibitive costs and delays. Transfers directly over the Lightning Network are faster, but they come with a steeper learning curve, forcing users to consider the mechanics of invoices and the economics of payment channels. Custodial services can spare users complexity, but they come with incalculable counterparty risks and increasingly arduous regulatory barriers.

Deblock, however, was unwilling to compromise. About 50% of the assets their users hold are in bitcoin, so Deblock's bitcoin offering is existentially important to the enterprise. They insisted on providing their users with speed, economy, self-custody, and convenience simultaneously. It's a tall order, one bitcoin has been unable to deliver. Until now.

## The Solution

Deblock has chosen the Breez SDK to bring bitcoin transfers to their hundreds of thousands of users because it offers the self-custody, economy, speed, and convenience users want, the clever design and support developers need, and the scalability to grow as fast as they can add new users.

### For users:

**Speed:** With the Spark implementation of the Breez SDK, bitcoin transfers are effectively instantaneous. No block confirmation times, no routing failures.

**Economy:** Fees are infinitesimal. They're small enough to let developers build the tiniest microtransactions into their apps. Users can use bitcoin for everyday payments and reliably build their stacks with dollar-cost averaging.

**Self-custody:** Building on Spark's commitment to user sovereignty, the Breez SDK leaves users' funds in their own hands, which increases the range of peer-to-peer use cases while minimizing an app's regulatory footprint.

**Convenience:** With the Breez SDK, users get the speed and robustness of Lightning without the complexity of payment channels and routing nodes. Features that have eluded self-custodied Lightning, like offline payments, and those that custodial providers simply can't deliver, like instant settlement and negligible counterparty risk, are built in.

As Deblock CEO Jean Meyer put it, "With this integration, we can finally deliver both: buy or sell bitcoin in seconds, and it's yours the moment you do."

### For developers:

The Breez SDK is built by developers, for developers. It's why Deblock's lean team of one backend developer and two mobile developers were able to get the implementation ready for production within just a few weeks. Mario Eguiluz, Deblock's CTO, has nothing but praise for the Breez SDK and the developer experience. According to him, the Breez team is both "super responsive" and "very helpful." His advice to other developers who are thinking about adding bitcoin to their apps is unequivocal: "If you want to offer bitcoin to your users, Breez is the best partner. They're really helpful and understand the use case that you're building for."

### For growth:

The Breez SDK was able to absorb Deblock's 300,000 new users with the flick of a switch. And Deblock is just one of Breez's many partners, with more joining every month. Thriving without the liquidity bottlenecks that plague some other Lightning offerings, the Breez SDK can grow as fast as any partner.

In fact, Deblock is already considering features that they haven't been able to offer until now. For example, they now have the ability to offer cash-back bonuses in the form of bitcoin for purchases made with the debit card, which had been impossible until recently due to fees and complexity.

The benefits Deblock is reaping with the Breez SDK are ready for a range of other services to enjoy, including remittance apps, payroll platforms, apps that already contain bitcoin on- and offramps as well as bitcoin-ready retail. With the Breez SDK, bitcoin can scale indefinitely within companies, across industries, and throughout economies, one app at a time.

***

https://breez.technology/case-studies/deblock/

How a European Neobank Brought Bitcoin to 300,000+ Europeans 🇪🇺⚡️

Release: Breez SDK (Spark) 0.8.2 ⚡️

"finally made the bitcoin wallet I would have loved as a kid" 👾

Breez just announced Exolix as the latest app to add bitcoin .with the Breez SDK.


***

# Exolix: Instant Bitcoin Swaps with the Breez SDK

Exolix just became the latest partner to add instant, self-custodial bitcoin using the Breez SDK.

Exolix is a privacy-first swap aggregator supporting 1,800+ cryptocurrencies, for users who want speed, simplicity, and full control.

Until now, swapping bitcoin meant tradeoffs. On-chain delays. High fees.

With the Breez SDK's @spark implementation, those tradeoffs disappear.

* For Exolix users → Instant settlement. Low fees. Self-custodial.
* For the Exolix team → No channels to maintain. No liquidity to manage.  Simple to integrate.

Here's how it works: 

https://x.com/i/status/2019450787718422760

It's that simple.

Just bitcoin that moves at internet speed. Value moving like information.

And it's exactly why 100+ apps are already building with Breez.

Exolix went from zero to live in two weeks. You can too.

Join them → https://breez.technology/sdk

***

Exolix integrate with the Breez SDK ⚡️

Hi folks -- sharing Breez's January update. *Another busy month!*

👉 [Make sure to subscribe to get it straight to your inbox](https://newsletter.breez.technology/p/016-feel-the-breez) 👈


***

https://substackcdn.com/image/fetch/$s_!kh7q!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F7efb5a7a-277c-433a-a987-2b71850e2c95_1600x900.gif

January didn’t hang around. From announcing our `</time2build>` winners to putting value transfer in the hands of 300,000 Europeans, it was another jam-packed month.

Here’s what’s new in the world of Breez:

- 🏦 → *300,000 More Bitcoiners*
- 🏆 → *Introducing Our </time2build> Winners*
- 🎓 → *ELI5: Spark*
- 🍹 → *Lightning in the Wild: Portal*
- 🎙️ → *Breez Around the World*

---

## **300,000 *~~Europeans~~* Bitcoiners 🏦**

![](https://substackcdn.com/image/fetch/$s_!KWYe!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F30626db2-18f9-43f3-9573-1fff684c7eb7_1400x800.png)

European neobank [**Deblock**](https://deblock.com/) became the latest Breez SDK partner to go live, bringing instant, self-custodial bitcoin to **over 300,000 users across Europe**.

Self-custody isn’t a feature for Deblock. It’s the *foundation* of their product. By integrating bitcoin with the Breez SDK, their users can now:

- *Buy and sell bitcoin with euros, instantly*
- *Send and receive bitcoin in seconds*
- *Stay fully self-custodial*

No more delays. No more expensive fees. Just euros in, bitcoin out. In seconds.

Bitcoin in every app. ***Let’s go***.

https://x.com/Breez_Tech/status/2011498858728354290

---

## **Introducing Our </time2build> Winners 🏆**


![](https://substackcdn.com/image/fetch/$s_!Xg1_!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fec60d888-52f9-48c5-a0d0-12fd403ff7d0_1400x800.jpeg)

Back in October, we launched [**</time2build>**](https://www.time2build.dev/) with a simple idea: give developers the tools, and they’ll bring bitcoin to the apps people already use. Two months later, the results are in.

Builders from around the world delivered integrations across merchant tools, social platforms, game engines, forums, and more. Here are our winners:

### **$3,500 Prize Winners**

- **BTCPay Server** (Aljaz): *A plugin that makes bitcoin super simple for merchants worldwide.*
- **Evento** (Brianna, Andre, Aaliyah): *Value transfer built into a social events platform, proving value can move peer-to-peer in the moments that create it.*
- **Portal** (Alessandro, Gianluca, Gabriele, John): *Lightning integrated into a universal identity and payments protocol, making value transfer a native capability for any app built on top.*
- **Primal** (Daniel): *Self-custodial bitcoin brought to Primal’s web client, removing onboarding friction for Nostr users.*

### **$1,000 Prize Winners**

- *OBS Studio Donations Plugin, Backend for Nutshell Mints, SatsMobi, CDK Payment Processor, Godot Engine Breez Plugin, Umbraco Marketplace NuGet Package, Discourse Breez Tipping, and CTFd Bitcoin Rewards Plugin*.

### **Special Prizes**

- *Lib de Satoshi & B4OS (DraperU), Sparkihonne (PlebLab).*

The era of building has begun. Check out the [**full announcement here**](https://blog.breez.technology/time2build-meet-the-2025-winners-1d8b11501ad9).

---

## **Spark Explained Like You’re Five 🎓**

![](https://substackcdn.com/image/fetch/$s_!Qlcm!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Feff696c7-5730-4a96-80a3-79f8d47cd32d_696x365.webp)

Eight years ago (*seriously, how?!*), Roy wrote [**Understanding Lightning Network Using an Abacus**](https://blog.breez.technology/understanding-lightning-network-using-an-abacus-daad8dc4cf4b) to demystify how Lightning worked. Lately, he’s been noticing similar questions around [**Spark**](https://spark.money/). So he’s taken the same approach again.

The result? [**Spark Explained Like You’re Five**](https://bitcoinmagazine.com/technical/spark-explained-like-youre-five).

Published on [**Bitcoin Magazine**](https://bitcoinmagazine.com/technical/spark-explained-like-youre-five), Roy uses a simple two-piece puzzle analogy to show how Spark works, from how ownership can change hands, to how trust is distributed across multiple operators.

If you want to learn how it all works under the hood, [**this is the place to start**](https://bitcoinmagazine.com/technical/spark-explained-like-youre-five).

---

## **Lightning in the Wild: Portal 🍹**

![](https://substackcdn.com/image/fetch/$s_!JhB9!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F159108ba-f301-4d75-9f84-ac035390ecb7_1152x648.gif)

This month’s *Lightning in the Wild* takes us to [**Portal**](https://getportal.cc/), one of our <[/time2build> winners](https://x.com/Breez_Tech/status/2015795081635090632).

The Portal team didn’t just add Lightning to their app. They built it into the protocol itself. Any application built on Portal now inherits the ability to move value globally, with Lightning as the common language.

Here’s what that looks like in practice:

https://x.com/Breez_Tech/status/2016891665621938615

---

## **Breez Around the World 🎙️**

![](https://substackcdn.com/image/fetch/$s_!nbJ8!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff2475193-a457-4158-8904-3df98af83d84_400x218.gif)

January saw the Breez team on stages, podcasts, and panels around the world.

First up: Roy was on stage in El Salvador at [**Plan ₿**](https://planb.sv/) where he broke down why value must move like information, why Bitcoin’s the only way to do this, and how AI means anyone can now add value transfer to any app. *Simple*.

https://x.com/Breez_Tech/status/2017309141971128355

[**Roy also joined Guy Swann**](https://fountain.fm/episode/EpG58Rgz9cWjjLckHhD6) to discuss how Bitcoin has completely transformed over the last three years. They dove into why Lightning is the common language, what value transfer is, and how Breez’s newest implementation, [**Spark**](https://sdk-doc-spark.breez.technology/), works.

https://x.com/TheGuySwann/status/2011936433695547878

Meanwhile, [**Danny joined Stephan Livera**](https://stephanlivera.com/episode/714/), alongside `</time2build>` winners Aljaz (BTCPay Server) and Brianna ([**Evento**](https://evento.so/)), to discuss the challenge, building with [**the Breez SDK**](http://breez.technology/sdk), and why more developers are bringing bitcoin to everyday apps.

https://x.com/stephanlivera/status/2016494644734169375

---

[**That’s all for this month, folks**](https://www.youtube.com/watch?v=3Qz1GMpOtUY).

Remember: [**the best time to add value transfer is now**](https://breez.technology/sdk/). It always has been.

See y’all next time ✌️

January at Breez ⚡️: Neobanks, Builders, and Spark (ELI5)

Bitcoin Wallet using Breez Spark SDK — ClawHub

Bitcoin Apps For Everyone with Danny Stagg, Aljaz, & Brianna | SLP714

Danny, Brianna, and Aljaz joined Stephan to discuss the results of  Breez’s ‘Time2Build’ challenge, the Breez SDK, and how developers can integrate Bitcoin & Lightning easily.

https://x.com/stephanlivera/status/2016494644734169375
https://x.com/Breez_Tech/status/2016546873683693854

Bitcoin Apps For Everyone | SLP714

Bitcoin Audible | Chat_157 - It's Time to Walk the Walk with Roy Sheinfeld

Time2Build: Meet the 2025 Winners ⚡️🏆

Everyone played their part. Thanks for all the support!!!

Announcement: https://x.com/Breez_Tech/status/2011827334840484031

***

# Time2Build: Meet the 2025 Winners

![](https://miro.medium.com/v2/resize:fit:1400/1*m0PE7zh5ksrIxbTbsByS6Q.jpeg)

There are two kinds of people in the world: the first kind talks about doing stuff and the second just does it. In October 2025, we bet on the latter.

We launched [</time2build>](https://www.time2build.dev/), our first global developer challenge, with the simple goal of putting bitcoin inside the open-source apps people already use.

This was not a hackathon nor a bounty. It was a challenge built for long-term impact with integrations that can keep delivering after users move on to whatever they build next.

And we had help too. More than [50 developer communities](http://time2build.dev/#communities) worldwide got involved, alongside partners like [Tether](https://tether.io/), [Lightspark](https://www.lightspark.com/), [Fulgur Ventures](https://fulgur.ventures/), [Plan ₿ Network](https://planb.network/), [PlebLab](https://www.pleblab.dev/), [Geyser](https://geyser.fund/grants/time2build), and [Draper University](https://draperuniversity.com/).

Builders came from everywhere, and what they delivered was much more powerful than a single “killer app;” it was a constellation of practical, clever, useful things. Plugins. Crypto wallets. Merchant tools. Tipping for streaming. Lightning tucked into places where it feels more like a sixth sense than just “payments.”

With that context in mind, here’s what we learned from the challenge.

# **What We Learned**

On the surface, the submissions couldn’t have looked more different. But when we took a step back and looked across everything that was built, a few clear patterns started to emerge. They are patterns that are important for any developer looking to build on Bitcoin today:

### **1. Lightning Is the Common Language**

We repeatedly saw Lightning paired with new emerging technologies like Nostr and Cashu.

These projects were not trying to reinvent how value moves inside each system. Nostr has its own social primitives. Cashu has its own model. What they needed was a shared way to move bitcoin between systems, users, and instances.

Lightning filled that role. As the [common language](https://blog.breez.technology/lightning-is-the-common-language-of-the-bitcoin-economy-eb8515341c11) for bitcoin, it allowed these new protocols and technologies to interoperate without changing how they work, giving developers the flexibility they need now, and the confidence that what they’re building won’t become obsolete tomorrow.

### **2. Plugins > Deep Integrations**

Many participants in the challenge avoided deep integrations. Instead, developers focused their efforts on building plugins that sit *alongside* existing apps such as CMSs, forums, game engines, and creator tools.

This was a pragmatic choice. Deep integrations require maintainer buy-in, long review cycles, and ongoing responsibility. Plugins let developers ship Lightning independently, test demand quickly, and iterate without blocking upstream projects.

Through plugins, developers brought bitcoin into apps faster, without waiting for permission, experimented quickly, and learned what actually works for users.

And you can see both of these trends play out across the winning submissions. More importantly, they show that the most effective way to build is to meet users exactly where they already are. This is what the future of building on Bitcoin looks like.

With that, we’re proud to present the winners of the </time2build> challenge.

# **$3,500 Prize Winners**

### **BTC Pay Server | Team: Aljaz**

![](https://miro.medium.com/v2/resize:fit:1400/1*NZPiGAOlEEPugxB_JJZYAA.jpeg)

Aljaz [built a plugin for BTCPay Server](https://geyser.fund/project/btcpayserverlightningbackendwithsparksdk20251212130411?hero=geyser), the free and open-source payment processor used by merchants around the world.

The integration removes the need to run a full Lightning node, avoiding the headaches of channel management and liquidity. Instead, it uses the Breez SDK to reduce the complexity while preserving full Bitcoin functionality. For merchants who want to accept bitcoin without having to run complex Lightning infrastructure, this is how.

### **Evento | Team: Brianna, Andre, and Aaliyah**

![](https://miro.medium.com/v2/resize:fit:1400/1*eZINHQcHuCT_Gtk64mgRbw.jpeg)

Brianna, Andre, and Aaliyah [built a Lightning integration for Evento](https://evento.so/), which is a social events platform that helps people connect, host gatherings, and build communities.

Using the Breez SDK, they added Lightning directly into the Evento experience. Users can tip each other on event pages, support hosts, send and receive sats, buy and earn bitcoin, and spend it via Bitrefill, all without leaving the app.

Most social platforms monetize by extracting value through ads or data. Evento flips that logic. Value moves peer-to-peer, in real time, inside the moment that created it.

### **Portal | Team: Alessandro, Gianluca, Gabriele, and John**

![](https://miro.medium.com/v2/resize:fit:1400/1*C5LvKs0fFn5E5-DqFgiHzw.png)

Alessandro, Gianluca, Gabriele, and John [integrated the Breez SDK into Portal](https://geyser.fund/project/portal20251115144259), a universal protocol and mobile app for identity and payments.

By adding Lightning to both the app and the underlying library, they also made Bitcoin a native capability of the protocol itself. Any application built on top of Portal will now inherit the ability to send and receive bitcoin without needing to build it from scratch.

Portal’s submission shows Lightning’s role as the common language, allowing identity, reputation, and value to travel together across apps.

### **Primal | Team: Daniel**

![](https://miro.medium.com/v2/resize:fit:1400/1*MYrobN5E3hwuuP-A3WzD-Q.jpeg)

Daniel [integrated Lightning directly into the Primal web client](https://geyser.fund/project/primalspark?hero=geyser), bringing a self-custodial bitcoin experience directly into one of the most widely used Nostr apps. For many, Primal is Nostr. While best known as a mobile client, its browser version mirrors the same experience.

But until now, activating Primal’s wallet required a custodial flow and a KYC process that could fail based on email or location. For a network built around censorship resistance, being blocked during onboarding created an obvious tension.

The Breez SDK integration removes that friction. No personal information is required to generate keys, and onboarding takes about a minute. Identity, communication, and bitcoin come online together, without gatekeepers.

# **$1,000 + Special Prize Winners**

### **$1,000 Prize Winners**

- [**OBS Studio Donations Plugin**](https://geyser.fund/project/obsstudiodonationsplugin20251120214947?hero=geyser): An OBS Studio donation plugin for Lightning payments, with send/receive functionality, multi-device sync, and on-chain interoperability.
- [**Backend for Nutshell Mints**](https://geyser.fund/project/breeznodelesssdkasbackendfornutshellmints20251128135510?hero=geyser): Support for Spark as a Lightning backend for Nutshell Cashu mint — a reference Python implementation of the Cashu protocol.
- [**SatsMobi**](https://geyser.fund/project/satsmobi20251128145855?hero=geyser): A Telegram-based wallet that adds self-custodial Lightning alongside an existing custodial flow.
- [**CDK Payment Processor**](https://geyser.fund/project/cdksparkpaymentprocessor20251209183355?hero=geyser): A CDK payment processor using Spark for Lightning.
- [**Godot Engine Breez Plugin**](https://geyser.fund/project/godotenginebreezplugin20251212191328?hero=geyser): A plugin bringing Lightning into the Godot game engine, unlocking bitcoin-native monetization for games.
- [**Umbraco Marketplace NuGet Package**](https://geyser.fund/project/umbracocommunitybitcoinlightningpayments20251215125128?hero=geyser): A package that adds Lightning to Umbraco sites, including a tip jar, content paywall, and admin tooling.
- [**Discourse Breez Tipping**](https://geyser.fund/project/discoursebreeztipping20251216141407?hero=geyser): A Lightning plugin that adds tipping to Discourse forums, integrating bitcoin directly into community discussion.
- [**CTFd Bitcoin Rewards Plugin**](https://geyser.fund/project/ctfdpluginforbitcoinrewardschallenge20251216133729?hero=geyser): A Lightning rewards plugin for capture-the-flag challenges, bringing bitcoin into security education.

### **Special Prizes from DraperU & PlebLab**

- **DraperU *|*** [Lib de Satoshi & B4OS](https://geyser.fund/project/libdesatoshib4osincentivewallet20251216102638?hero=geyser): A community platform integrated Lightning to gamify education.
- **Pleblab** | [Sparkihonne](https://geyser.fund/project/sparkihonne?hero=geyser): A Nostr-focused wallet experience, blending identity, messaging, and payments.

Not every submission ended up with a prize, but there are several other projects worth checking out: [Sabi Wallet](https://geyser.fund/project/sabiwallet20251211025743), [Backend for CDK mints](https://geyser.fund/project/sparksdkasanodelessbackendforcdkmints20251027152518), [Jumble](https://geyser.fund/project/jumblespark), [Breez MCP Server — Docker Catalog](https://geyser.fund/project/breezmcpdockermcpcatalog20251104015051), [CoFi Lab](https://geyser.fund/project/cofilab20251115220808), [OpNode](https://geyser.fund/project/opnode20251115235722?hero=geyser), and [BitNGN](https://geyser.fund/project/bitngnremittanceplatform20251215160246).

# **What’s Next? *Builders Decide*.**

You answered our call to action.

In just two short months, developers around the world delivered a wide range of real use cases with the potential for long-lasting impact on the open-source apps they enriched. Thank you again to everyone who participated in the challenge and to our judges — [Abubakar, Giacomo, Jeff, Kevin, Keyan, Lisa, Roy, and Subash](https://www.time2build.dev/#judges) — for taking the time to review the winning projects.

For us, the next steps are clear. The era of building has begun. Whether that means adding Bitcoin to messaging apps like Signal, integrating it into leading crypto wallets, or bringing Lightning into entirely new apps with use cases we’ve yet to dream up, we can’t wait to see what you do next.

**It’s time to build.**

***

### **</time2build> Winners**

**$3,500 Prize Winners**

- [BTC Pay Server](https://geyser.fund/project/btcpayserverlightningbackendwithsparksdk20251212130411?hero=geyser), [Evento](https://geyser.fund/project/evento20251126132947?hero=geyser), [Portal](https://geyser.fund/project/portal20251115144259?hero=geyser), [Primal](https://geyser.fund/project/primalspark?hero=geyser)

**$1,000 Prize Winners**

- [OBS Studio Donations Plugin](https://geyser.fund/project/obsstudiodonationsplugin20251120214947?hero=geyser), [Backend for Nutshell Mints](https://geyser.fund/project/breeznodelesssdkasbackendfornutshellmints20251128135510?hero=geyser), [SatsMobi](https://geyser.fund/project/satsmobi20251128145855?hero=geyser), [CDK Payment Processor](https://geyser.fund/project/cdksparkpaymentprocessor20251209183355?hero=geyser), [Godot Engine Breez Plugin](https://geyser.fund/project/godotenginebreezplugin20251212191328?hero=geyser), [Umbraco Marketplace NuGet Package](https://geyser.fund/project/umbracocommunitybitcoinlightningpayments20251215125128?hero=geyser), [Discourse Breez Tipping](https://geyser.fund/project/discoursebreeztipping20251216141407?hero=geyser), [CTFd Bitcoin Rewards Plugin](https://geyser.fund/project/ctfdpluginforbitcoinrewardschallenge20251216133729?hero=geyser)

**Special Prizes**

- **DraperU** | [Lib de Satoshi & B4OS](https://geyser.fund/project/libdesatoshib4osincentivewallet20251216102638?hero=geyser)
- **Pleblab** | [Sparkihonne](https://geyser.fund/project/sparkihonne?hero=geyser)

# Deblock goes Nodeless with the Breez SDK on Spark

Starting this month, Deblock, one of Europe’s fastest-growing neobanks, will let its 300,000 customers move from euros to bitcoin and back in seconds, directly into their own wallet.

For Deblock users, this means they can:

* Buy BTC with euros and own it in seconds
* Sell BTC back to euros with instant settlement
* Send and receive bitcoin instantly

Check out the announcement on X: https://x.com/Breez_Tech/status/2011498858728354290