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Twelfth Wave of Bitcoin Grants
We're excited to announce the twelfth wave of grants from our General Fund, supporting twelve open-source projects advancing the Bitcoin ecosystem. This round features five first-time grants and seven grant renewals for ongoing efforts that continue to deliver meaningful results.
New project grantees in this wave are building tools for deeper bitcoin analytics, anonymous mining payouts, mobile ecash payments, and Lightning and full-node development within the .NET and Swift ecosystems.
The five first-time project grants in this wave are:
The seven project grant renewals in this wave are:
Together, these twelve projects highlight a shared goal: making Bitcoin more decentralized, transparent, and user-driven—while keeping it robust, usable, and open to anyone who chooses to participate.
None of this would be possible without the generosity of our donors. If you'd like to help move Bitcoin forward by supporting projects like those in this wave, consider donating to our General Fund.
Let's explore our first-time project grants to understand what they're building and how it strengthens the broader Bitcoin landscape.
Sovran
Sovran is a free and open-source ecash and Lightning wallet built for iOS. It is designed to improve usability across Cashu-based payments. The app supports multiple mints, NFC-based transactions, and integrates native connectivity tools like eSIM and VPN. Sovran has reached a stable release and ships with core Cashu functionality.
Support from this grant will fund multipath payment support, new tools for managing balances across mints, and a specification for unified payment addresses. The team will improve NFC performance and begin development of an Android version. These upgrades will make Sovran more flexible, more accessible, and better suited for everyday ecash use.
Repository: SovranBitcoin/Sovran
License: Mozilla Public License 2.0
NLightning
NLightning is an open-source Lightning Network node written in C# for the .NET ecosystem, implementing core BOLT specifications including BOLT 1-3 and 8-11. The project focuses on delivering a modular, efficient, and production-grade solution tailored for enterprise and open-source developers already working within the .NET stack. NLightning has published NuGet packages, supports invoice generation through BOLT11, and maintains over 70% test coverage.
Support from this grant will fund further implementation of BOLT 4, BOLT 5, and BOLT 7. The project aims to complete a full Lightning daemon with channel operations, HTLC handling, and payment routing. Additional work will improve data structures, backup systems, developer tooling, and documentation. One of the upcoming goals of the project is to expand test coverage and fuzz testing to make the implementation more robust and production-ready.
Repository: ipms-io/nlightning
License: MIT
Swift Bitcoin
Swift Bitcoin is an open-source software development kit (SDK) and network client written entirely in Swift. It offers a full node implementation with PSBT support, miniscript domain-specific language, and non-blocking I/O. The project has evolved over three years and already syncs and validates blocks, processes transactions, and matches Bitcoin Core on regtest. It delivers modular libraries for crypto, base protocol, wallet, blockchain, transport, and RPC use.
Support from this grant will fund testnet4 syncing and completion of the wire protocol. Development will focus on peer-to-peer messaging, protocol alignment with Bitcoin Core, and expanded network testing. The project will also refine core modules, increase cross-platform stability, and move closer to a full-featured Swift-native node.
Repository: swift-bitcoin/swift‑bitcoin
License: MIT
Bitcoin Research Kit
Bitcoin Research Kit (BRK) is a toolchain that parses, indexes, computes, and visualizes data from a Bitcoin Core node. It aims to combine the functions of Glassnode, mempool.space, and electrs in one self-hostable package. The project focuses on performance, low resource requirements, and ease of use. Users can run it from a command line interface or the public site Kibo.Money. The system includes modular Rust crates, open APIs, and time-based charts. It supports a wide range of use cases for researchers, miners, node operators, and analysts.
This grant will support the development of a full-featured explorer. Planned features include block, address, and transaction explorers, and support for both mempool.space and Electrum protocols. The explorer will include original data visualizations such as price distribution by block. The team will also improve the user experience for self-hosting with pre-built binaries, optional Cloudflare tunnels, and integrated bitcoind support. A terminal view for complex queries, a toggle to disable price data, and server monitoring with Prometheus are also planned. The project will launch a dedicated website for bitcoinresearchkit.org and create independent branding for BRK and Kibo.
Repository: bitcoinresearchkit/brk
License: MIT
Hashpool and Axepool
Hashpool is an accountless mining pool that issues eHash ecash tokens for each accepted mining share. It runs a modified Stratum V2 pool, mints blinded tokens, and enables anonymous mining and trading of shares. Axepool is a proxy layer for small-scale miners, such as Bitaxes. It uses the Cashu protocol to simplify setup, eliminate accounts, and support frequent ecash payouts.
With support from this grant, the project will complete NUT-04 compliant ecash issuance. It will launch a mint daemon, set up Redis for share tracking, and apply a PPLNS valuation model. It will add scheduled keyset rotation and create full developer documentation, CI builds, and test coverage. Axepool will add SV1 multiplexing, Bolt 12 callbacks, Bitaxe wallet integration, and releases for home node platforms. A stretch goal will add a Proof of Liabilities protocol with share validation.
Repository: vnprc/hashpool
License: MIT
From data-rich research dashboards and anonymous mining payouts to mobile ecash wallets and cross-platform developer tooling, the projects in this twelfth wave help reinforce the foundations that keep Bitcoin decentralized, robust, and open to all. By supporting both new efforts and ongoing work, we aim to expand access, improve usability, and strengthen privacy throughout the ecosystem.
As with earlier waves, grant applications were reviewed against clear criteria aligned with our mission of supporting free and open-source software. If you're working on a project that advances Bitcoin, we encourage you to apply for funding.
In total, OpenSats has now issued over 300 grants since the start of our grant program, underscoring the scale and reach of our commitment to open-source builders.
Our work is made possible by the generosity of our donors. If you'd like to help make the future of free and open-source Bitcoin development more sustainable, consider setting up a recurring donation to one of our funds. Any amount helps.