Integrating Spark and ARK into the Breez SDK offers a more Bitcoin-native, self-custodial experience than using Liquid. With Spark, users hold real BTC off-chain without relying on a federation and can open Lightning channels instantly. ARK allows them to receive payments privately and instantly, even without inbound liquidity or running a node. Unlike Liquid, this setup doesn’t require swaps or trust in a third party, and offers better privacy, simplicity, and user control.

However, both Spark and ARK rely on coordinators to function. These coordinators can’t steal user funds, but they can censor, delay, or go offline, affecting access and usability. While the trust model is minimized, it’s not fully trustless; users depend on the availability and honesty of these coordinators.

More broadly, Bitcoin is evolving into a layered ecosystem with different trust models for different use cases. Cold storage remains the standard for long-term savings and high-value holdings. For everyday use and smaller amounts, users can choose between hot wallets, Lightning, statechains, sidechains, or ARK, depending on their needs for speed, privacy, self-custody, and convenience. Each tool represents a trade-off between security, usability, and trust; giving users more choice and flexibility than ever before.