Open-Source Bitcoin Projects

The reference implementation of the Bitcoin protocol, maintained since Satoshi's original release. Running Bitcoin Core makes you a full node: it independently validates every rule, so you trust the network rather than any single provider. This is the software that defines what a valid bitcoin actually is.

Bitcoin Improvement Proposals are the design documents behind every major protocol change, from SegWit to Taproot. The repository is the canonical record of how Bitcoin evolves through open review rather than a central authority. If you want to understand why the network behaves the way it does, this is the primary source.

One of the oldest and most trusted desktop Bitcoin wallets, built for speed and self-custody. Electrum connects to the network without downloading the full blockchain, supports hardware wallets, and gives advanced users fine control over fees and coin selection.

A privacy-focused desktop wallet that uses coinjoin to break the on-chain link between your coins and your identity. Wasabi is open source end to end, so its privacy claims can be audited rather than taken on faith — the whole point of self-sovereign money.

Andreas Schildbach's Android wallet was one of the first mobile Bitcoin wallets and remains a non-custodial, standalone client. It holds your keys on your device and connects directly to the network, with no company sitting between you and your coins.

The Lightning Network Daemon is the most widely deployed implementation of Lightning, the payment layer built on top of Bitcoin. LND powers instant, low-fee payments and is the backbone of most Lightning apps, node dashboards, and merchant tools.

A self-hosted payment processor that lets merchants accept Bitcoin directly, with no middleman and no fees. BTCPay Server gives you the invoicing, point-of-sale, and store integrations of a commercial processor while keeping full custody of the funds and the infrastructure.

The de facto JavaScript library for building Bitcoin applications in the browser or Node.js. bitcoinjs-lib handles key generation, address formats, transaction building, and signing, and underpins a large share of the web-based Bitcoin ecosystem.

A mature Java library implementing the Bitcoin protocol, usable without a full node via simplified payment verification. bitcoinj has long been the foundation for Android and JVM Bitcoin apps that need to build and broadcast transactions programmatically.

The reference implementation of the Ordinals protocol, which assigns identities to individual satoshis and enables inscriptions on Bitcoin. ord is both a wallet and a block explorer for this data, and a useful window into how arbitrary content can live on the base chain.