Self-custodial payments without channel management now live
Second, a Bitcoin development lab, has officially launched Bark on the Bitcoin mainnet on June 9, 2026. Bark is Second’s implementation of the Ark protocol, a layer-2 solution that enables self-custodial bitcoin payments without the complexity of Lightning Network channel management or on-chain transaction fees.
The protocol allows large numbers of users to share on-chain UTXOs via trees of pre-signed, off-chain transactions. This structure spreads fee costs across participants while preserving individual self-custody, according to the protocol design.
Steven Roose, CEO of Second, framed the launch as a simplification of self-custody workflows. “We wanted to make it ridiculously easy for users to get started with self-custodial bitcoin, hold it, and spend it, without surprise fees, and without having to manage channels or liquidity,” Roose said.
Five applications are mainnet-enabled at launch. Noah is a full-stack mobile Ark wallet. Arke is a native iOS wallet. Satsigner is a mobile UTXO management wallet. Bark Wallet is available as an Umbrel app. BTCPay Server, a merchant payment processor, also has a Bark plugin.
The Bark SDK is written in Rust with language bindings for Kotlin, Swift, React Native, Flutter, Go, Python, and WebAssembly. Barkd, a standalone wallet daemon, exposes a REST interface with an OpenAPI spec, enabling developers to integrate Ark functionality into custom applications.
Second raised $5.1 million in private funding and operates a team of 11. The company has drawn talent from Blockstream, a major Bitcoin infrastructure firm.
Second is hosting an AMA on Stacker News at 10:00 AM EST on June 9, 2026, to discuss the launch and answer technical questions from developers and users.
Ark Labs operates Arkade, a competing Bitcoin layer-2 protocol in the same design space. Multiple statechain-based solutions also compete in the Bitcoin layer-2 ecosystem.
