The advanced side of instant Bitcoin

How the Liquid Network works

The Liquid Network is a Bitcoin sidechain, a separate network pegged 1:1 to Bitcoin. You "peg in" your Bitcoin, transact quickly and cheaply on Liquid, and "peg out" back to the main Bitcoin network whenever you want.

Your Liquid Bitcoin (L-BTC) is always backed by real Bitcoin. The peg is maintained by a federation of functionaries, established Bitcoin companies with a vested interest in the network's integrity.

How the Lightning Network integration works

Here's the trick: COINCUBE Liquid only ever holds L-BTC, the Liquid Network's Bitcoin-pegged asset. You don't run a Lightning node, open channels, or manage channel liquidity. And yet you can still send and receive Lightning payments, thanks to something called a submarine swap.

When you send a Lightning payment, the wallet atomically swaps a small amount of your L-BTC for a Lightning payment to the destination. When you receive one, the same mechanism runs in reverse: Lightning sats come in, L-BTC lands in your wallet. Both sides of the swap are cryptographically linked, so either the whole thing succeeds or nothing moves. There is no trusted middleman who could run off with your funds.

Under the hood, COINCUBE uses the Breez Liquid SDK to coordinate these swaps, routed through Boltz Exchange as the swap provider. You just see a Lightning invoice scan and a confirmation, the same flow as any Lightning wallet, but your balance stays in L-BTC. For day-to-day Lightning spending, Spark is the default wallet — swap-based Lightning is here for when you want your funds to stay on Liquid.