The Breez SDK has been a resounding success. Preserving the ethos of our original Lightning payment app, the Lightning SDK is a flexible solution designed to scale with the network and any number of yet-to-be-imagined use cases. That’s why it has attracted a great cast of partners pursuing different goals in different markets. Change has proven to be good. Really good.

And just like the Bitcoin economy and Breez are constantly expanding, it’s time for the next stage in the expansion of our SDK. To make the SDK even more versatile, to give more people even more options in how they use their bitcoin, we’ve added a new implementation.

It’s time to go nodeless.

What’s Nodeless?

The Breez SDK - Nodeless is a Liquid implementation of the SDK. Liquid is a sidechain built to interact with Bitcoin and optimize its performance in new contexts. It’s one of those “last-mile technologies” we’ve been talking about lately. The basic idea is that users swap their bitcoin for LBTC at a fixed peg, and LBTC transactions run on the Liquid blockchain, which is overseen by a federation of 15 functionary operators. It is highly interoperable with the Bitcoin mainnet and other last-mile technologies using Lightning as the common language.

Why Add a Nodeless Implementation?

The choice between traveling by car, train, or plane depends on many factors, like cost, distance, duration, cargo, etc. No option is objectively better than the others. Each offers different benefits under different constraints. Similarly, the Native (Greenlight) and Nodeless (Liquid) implementations of the SDK both move money in cool, but different, ways.

One major difference is that the nodeless implementation does not use payment channels, so there are no setup fees to get started, nor are LSPs required to manage nodes’ connectivity and liquidity. Furthermore, the absence of channels means that there are no fees or delays for channel closures, minimizing friction for end users. Without channels, there aren’t any nodes either. Instead, users see a simple balance in their Liquid wallets, which they can use to send and receive payments on Lightning.

As with all Breez products, users always retain custody of their own funds. However, those funds are stored as LBTC, which has a different trust profile than bitcoin on a Greenlight node like the native implementation. Since the Liquid blockchain is run by a federation, it’s not strictly a permissionless, decentralized network. Train vs. plane, right?

The nodeless implementation is also candy for developers. Since there are fewer operations to worry about, there’s less to learn, less to code, and less to test. Developers are Breez’s users, so their UX is always a priority.

How Does Nodeless Work?

Just as submarine swaps let funds move back and forth between Lightning and the Bitcoin blockchain, they also enable Lightning to interact with Liquid. When a user makes a payment, the SDK performs a submarine swap on the LBTC in their Liquid wallet and converts the funds into satoshis on the Lightning Network before forwarding them to the recipient. When a user receives a payment, the SDK performs a reverse submarine swap on the incoming satoshis, converting them automatically to LBTC and depositing them in the user’s Liquid wallet.

Sending and receiving Lightning payments is great, but the nodeless implementation also supports more advanced features we all need and expect: interoperability with the Bitcoin blockchain, fiat on and off-ramps, as well as multi-device and multi-app support—so users can interact with the same balance across various platforms.

Ready to Let the Bitcoin Flow?

If you’re ready to get started or just looking for more information, check out the documentation or drop us a line.

This blog was adapted from a post by Roy Sheinfeld on Breez’s Medium.