Bark

Fast, low-cost, self-custodial payments on bitcoin.

Docs

• Issues
• Website
• Blog
• YouTube Bark is an implementation of the Ark protocol on bitcoin, led by Second. The Ark protocol is a bitcoin layer 2 for making fast, low-cost, self-custodial payments at scale. Ark uses a client-server model to enable users to transact off-chain while still being able to "exit" their balances on-chain at any time.The project consists of:No Rust, no problem!barkd is an Ark wallet that runs as a daemon and exposes a REST API over HTTP. It's well suited for power users and great for automation—think web shops, Telegram/Discord bots, and similar use cases. The barkd-clients repository provides clients in TypeScript and C#.uniffi-bindings are the better choice if you're building a native desktop or mobile application. The bindings are available in the bark-ffi repository and power the published Bark SDK packages.As bitcoin adoption grows, on-chain fees spike during busy periods, making everyday transactions impractical. While Lightning has been revolutionary for bitcoin scaling, it's beginning to show its limitations-channel management and liquidity requirements create complexity for developers and users.Ark offers a complementary scaling solution that simplifies bitcoin self-custody:🏃‍♂️ Smooth onboarding: No channels to open, no on-chain setup required-create a wallet and start transacting 🤌 Simplified UX: Send and receive without managing channels, liquidity, or routing 🌐 Universal payments: Send Ark, Lightning, and on-chain payments from a single off-chain balance 🔌 Easier integration: Client-server architecture reduces complexity compared to P2P protocols 💸 Lower costs: Instant payments at a fraction of on-chain fees 🔒 Self-custodial: Users maintain full control of their funds at all timesPerfect for users who want self-custody without the hassle, and developers who want to build bitcoin apps without the complexity.Learn more about Ark's benefits →The Ark protocol enables multiple users to share control of a single bitcoin UTXO through a tree of pre-signed, off-chain transactions. This allows instant, off-chain payments while maintaining self-custody-users can always withdraw their bitcoin either cooperatively with the Ark server or unilaterally on-chain.For a detailed technical explanation, see our protocol documentation. A transaction tree showing how Ark enables multiple users to share control of a single UTXO through pre-signed transactions.Most of our crates do not yet specify a MSRV, but we will commit to one once we make an official release.The ark-lib crate (and by extension the bark-bitcoin-ext crate) have a MSRV of v1.74.0.Thinking of opening a pull request? See our contribution guide for dependencies, style guidelines, and code hygiene expectations.Please report any vulnerability or any bug that could potentially affect the security of users' funds by e-mail to [email protected] may use the following PGP keys to encrypt your e-mail:Both keys can be found on the keys.openpgp.org keyserver.If you run into any issues at all, let us know:Released under the MIT license-see the LICENSE file for details.Powered by Forgejo