Bitcoin is currently my main research and development focus.
These projects explore different aspects of Bitcoin security, programmability and developer tooling, from vault-based self-custody to open-source descriptor libraries and test networks.

Rewind Bitcoin Wallet

Rewind Bitcoin App Screenshot

Rewind is a self-custody wallet designed to resist theft, coercion and physical attacks.
It introduces a vault-based model using time-locks and pre-signed transactions to protect funds, even when the owner is under duress.
Available on iOS and Android and soon to be released as open source.

Rewind’s security model combines several components that work together:

Vault Model

Funds are locked with a programmable delay that only starts when an unfreeze attempt is made.
If an attacker tries to access them, you have time to rescue your coins to a safe address before the countdown ends.

Delegated Rescue

You can assign trusted 3rd parties (family or friends) who hold pre-signed cancellation transactions.
They can intervene on your behalf during the countdown to cancel unauthorized access.
Delegates receive a file containing a transaction map and usage instructions, which they can execute manually or automatically through rescue.rewindbitcoin.com.

P2P Community Backups

Rewinds Community Backups store encrypted vault data on a peer-to-peer network.
Peers only host encrypted data and keys never leave your devices.
The network eliminates Rewind (and me) as a single point of failure and allows you to run your own peer for maximum availability for you and the rest of the community, including your loved ones.

Users only need to back up their seed phrase.
When importing the same seed on a new device, Rewind automatically retrieves the vault data from the network and restores the entire vault setup seamlessly.

Streamlined Testing

In addition to regular testnets, Rewind features its own Tape Network, a Bitcoin-like environment designed for risk-free experimentation.
When users create a test wallet, they automatically receive test funds from a built-in faucet, allowing them to explore vault creation and rescue flows instantly.

BitcoinerLAB (FOSS Libraries)

3D Presence Project

BitcoinerLAB is my open-source suite of TypeScript/JavaScript modules for building Bitcoin apps with descriptors and Miniscript.
It simplifies wallet development by abstracting low-level logic into tested, composable tools.

More than 2,000 public repositories depend on its combined modules. They’re used by major projects, including the JavaScript APIs provided by Ledger hardware wallets and the Bitcoin Keeper app and serve as the foundation for Rewind’s vaulting architecture.

Selected Modules

GitHub org: github.com/bitcoinerlab

Coding Playgrounds

In addition to the libraries themselves, I built a dedicated site focused on learning and experimentation.
It combines API references, guided tutorials and interactive playgrounds that run real code directly in the browser. Developers can modify examples, connect to test networks, and see results instantly. No setup required.

bitcoinerlab.com/guides

The playgrounds cover practical cases such as building standard transactions, modeling time-locked vaults with Miniscript or programming HWWs. All runnable in the browser for quick experimentation.

Beyond production use, BitcoinerLAB has also gained traction in education. It’s frequently used by university students, especially in Spain, to explore Bitcoin development.
Coding with Lunaticoin The combination of TypeScript’s accessibility, BitcoinerLAB’s modular structure and hands-on guides makes it a natural starting point for learning how Bitcoin scripts, descriptors and wallets work in practice.

Tape Network

A Bitcoin-like test network I operate for testing wallets and transaction logic. Anyone can join, use the public faucet and access Electrum and Esplora endpoints. Rewind Bitcoin uses it for vault simulation, but it’s also open to the developer community for experimentation.

Learn more: tape.rewindbitcoin.com