diff --git a/data/blog/fifteenth-wave-of-bitcoin-grants.mdx b/data/blog/fifteenth-wave-of-bitcoin-grants.mdx new file mode 100644 index 000000000..75e0bfb7c --- /dev/null +++ b/data/blog/fifteenth-wave-of-bitcoin-grants.mdx @@ -0,0 +1,352 @@ +--- +title: "Fifteenth Wave of Bitcoin Grants" +date: '2025-12-16' +tags: ['OpenSats', 'grants', 'bitcoin', 'wave'] +authors: ['default', 'arvin'] +images: ['/static/images/blog/92-fifteenth-wave-of-bitcoin-grants.jpg'] +draft: false +summary: "OpenSats is funding fifteen more open-source projects advancing the Bitcoin ecosystem." +--- + +We’re pleased to announce our latest wave of grants, supporting a mix of +protocol research, core infrastructure maintenance, privacy-preserving wallets, +and mining decentralization—work that benefits Bitcoin’s resilience as an open +monetary network. + +This wave includes eight first-time grants and seven grant renewals. The +projects and contributors in this round span different layers of the stack, from +protocol-level work and Lightning infrastructure to operating systems, wallets, +mining coordination, and Bitcoin Core maintenance. Together, they reflect a +shared focus on strengthening Bitcoin as a public good by improving safety, +decentralization, usability, and the ability for independent contributors to +participate over the long term. + +The eight first-time grants in this wave go to: + +- [BlindBit Suite](#blindbit-suite) +- [Dana Wallet](#dana-wallet) +- [Daniel Pfeifer](#daniel-pfeifer) +- [FreeBSD](#freebsd) +- [Janb84](#janb84) +- [LaWallet](#lawallet) +- [LNHANCE](#lnhance) +- [Mohd Zaid](#mohd-zaid) + +The seven grant renewals have been awarded to: + +- Bitcoin Dev Kit ([Aug. 2023](/blog/bitcoin-and-nostr-grants-august-2023#bdk)) +- Satoshi Nakamoto Institute ([Jul. 2024](/blog/announcing-the-opensats-education-initiative#satoshi-nakamoto-institute)) +- Africa Free Routing ([Sep. 2024](/blog/second-wave-of-education-grants#africa-free-routing)) +- Floresta ([Sep. 2024](/blog/bitcoin-grants-september-2024-7th-wave#floresta)) +- Yes Bitcoin Haiti ([Nov. 2024](/blog/3rd-wave-of-education-grants#yes-bitcoin-haiti)) +- Swift Bitcoin ([Jul. 2025](/blog/twelfth-wave-of-bitcoin-grants#swift-bitcoin)) +- Silent Payments Shepherd ([Aug. 2025](/blog/thirteenth-wave-of-bitcoin-grants#silent-payments-shepherd)) + +These grants are made possible by donations to our [General +Fund](/funds/general). If you’d like to help sustain free and open-source work, +please consider donating: + +
+ +
+ +Below, we take a closer look at each grant and the work being supported. + +--- + +### BlindBit Suite + +BlindBit Suite is a collection of open-source tools focused on making Silent +Payments practical and easy to use across different Bitcoin setups. The suite +includes [BlindBit Oracle], an indexer that serves Silent Payments–specific data +in a privacy-preserving way, and [BlindBit Desktop], a background wallet that +continuously scans for incoming Silent Payments. [BlindBit Scan] is a +lightweight, self-hostable service that keeps wallets up to date by querying +Oracle. [BlindBit Spend] is a mobile wallet that connects to Scan to spend +discovered UTXOs without doing on-device scanning. Together with supporting +libraries, these components aim to reduce the heavy scanning burden that Silent +Payments impose while preserving strong privacy for users and developers. + +With support from this grant, the project will focus on making each component +stable and ready for regular use. BlindBit Desktop will move through alpha and +beta testing toward a 1.0.0 release, while BlindBit Oracle will be optimized for +higher performance and heavier loads, including work on faster sync and improved +storage backends. BlindBit Scan will be prepared for a 1.0.0 release as a +private scanner with easy self-hosting via Docker on platforms like [Umbrel] and +[Start9]. BlindBit Spend will be cleaned up, tested, and prepared for wider +distribution on Android and iOS. The project will also explore enhancements such +as DM-style notifications between senders and receivers and GPU-accelerated +scanning, with the goal of making Silent Payments adoption more accessible for +both desktop and mobile users relying on remote scanners. + +Repositories: [blindbitbtc] +License: MIT + +[BlindBit Oracle]: https://github.com/setavenger/blindbit-oracle +[BlindBit Desktop]: https://github.com/setavenger/blindbit-desktop +[BlindBit Scan]: https://github.com/setavenger/blindbit-scan +[BlindBit Spend]: https://github.com/setavenger/blindbit-spend +[blindbitbtc]: https://github.com/blindbitbtc +[Umbrel]: https://umbrel.com/ +[Start9]: https://start9.com/ + +### Dana Wallet + +[Dana Wallet] is a mobile bitcoin wallet built for the donation use case and +designed around [silent payments]. It does not offer receiving on legacy +addresses, which removes the risk of accidental address reuse and helps protect +user privacy. Incoming payments are discovered using a [BIP158]-like structure +with local scanning, meaning no external server learns which addresses belong to +the user. The wallet is also built around [BIP353] “email-like” payment +identifiers, replacing copy-and-paste address flows with a more familiar and +streamlined experience for donors and recipients. + +With support from this grant, Dana Wallet aims to move into a production-ready +release, including a stable build on the Google Play Store. The work will focus +on error handling, reliable recovery through chain rescans, and basic security +features such as PIN or biometric protection. Beyond those core milestones, the +project plans to improve the speed and consistency of scanning, allow users to +register their own `username@danawallet.app` addresses, improve the +transaction history view, and add features like offline mode and flexible +denomination display. Over time, the project may introduce a contact list, and +notifications between Dana Wallet users to make receiving silent payments more +seamless. + +Repository: [cygnet3/danawallet] +License: MIT + +[Dana Wallet]: https://danawallet.app/ +[silent payments]: https://gist.github.com/RubenSomsen/c43b79517e7cb701ebf77eec6dbb46b8#file-silent_payments-md +[BIP158]: https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki +[BIP353]: https://github.com/bitcoin/bips/blob/master/bip-0353.mediawiki +[cygnet3/danawallet]: https://github.com/cygnet3/danawallet + +### Daniel Pfeifer + +[Daniel Pfeifer] is focused on improving the long-term maintainability, safety, +and clarity of the Bitcoin Core codebase. His work centers on cleaning up the +build system by replacing ad-hoc scripts and undocumented conventions with +declarative, reproducible [CMake] configurations, and on refactoring C++ +components so they are easier to understand and work on in isolation. This +includes enforcing clear ownership rules in the code and removing unsafe +constructs. He also aims to define, document, and promote modern [C++ coding +guidelines] within the Bitcoin community, drawing on his involvement with the +ISO C++ Committee, and to develop the [BtcK] multi-language API so that +different programming languages can talk to Bitcoin Core through consistent, +idiomatic bindings. Alongside this, Daniel prioritizes C++ education and +mentorship by teaching fundamentals, sharing best practices, and helping new +maintainers grow into long-term contributors. + +With support from this grant, Daniel will focus on concrete near-term milestones +that support future architectural improvements. These include helping to prepare +a stable C API for the [Bitcoin Kernel library], making sure its SDK is deployed +cleanly with the correct headers, library artifacts, and package configuration, +and replacing a patchwork of platform-specific packaging scripts with a unified +CPack definition. Because improving maintainability and educating future +developers is an ongoing effort, progress will be iterative and aimed at the +long-term sustainability of the Bitcoin Core project. + +Repositories: [purpleKarrot/btck]; [bitcoin/bitcoin] +Licenses: MIT + +[Daniel Pfeifer]: https://github.com/purpleKarrot +[CMake]: https://cmake.org/ +[C++ coding guidelines]: https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines +[BtcK]: https://purplekarrot.github.io/btck/ +[Bitcoin Kernel library]: https://github.com/bitcoin/bitcoin/issues/27587 +[purpleKarrot/btck]: https://github.com/purpleKarrot/btck +[bitcoin/bitcoin]: https://github.com/bitcoin/bitcoin + +### FreeBSD + +[FreeBSD] is an operating system used across servers, desktops, and embedded +platforms, and is the most widely deployed of the [BSD family], second only to +Linux among open-source operating systems. This project maintains the +FreeBSD/EC2 platform, ensuring that FreeBSD runs reliably on [Amazon EC2] by +producing and supporting cloud images and coordinating with the wider project. +This work underpins operating system diversity for critical infrastructure, +which is important for Bitcoin operators who cannot rely on a single-kernel +monoculture. + +With support from this grant, [Colin Percival] will continue engineering work +around the newly released [FreeBSD 15.0], including EC2 image builds and +coordination needed to keep the release stable and supported. Additional work +will extend to [future branches], addressing larger changes and issues deferred +from 15.0 and improving the robustness and security of FreeBSD in cloud +environments. The goal is to ensure that FreeBSD remains a well-maintained +operating system option for long-term infrastructure, including those in the +Bitcoin ecosystem that rely on operating system diversity to reduce systemic +risk. + +Repository: [freebsd/freebsd-src] +License: BSD-2-Clause + +[FreeBSD]: https://www.freebsd.org/ +[BSD family]: https://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/share/misc/bsd-family-tree +[Amazon EC2]: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts.html +[Colin Percival]: https://github.com/cperciva/ +[FreeBSD 15.0]: https://www.freebsd.org/releases/15.0R/announce/ +[future branches]: https://wiki.freebsd.org/Releng/16.0ISSUES +[freebsd/freebsd-src]: https://github.com/freebsd/freebsd-src + +### Janb84 + +[Janb84] contributes to Bitcoin Core with a focus on coordinating software +release testing and improving the supporting documentation and feedback loop +around that work. This includes maintaining Release Candidate Testing Guides and +running dedicated feedback threads for testers, as well as facilitating group +review and discussion of the testing process through the [PR Review Club]. + +With support from this grant, janb84 will continue to expand his work on Bitcoin +Core, including in-depth PR review and contributor-facing documentation such as +[README]s and testing guides, with the goal of improving the quality of review +and testing so changes are easier to evaluate and safer to release. + +Repository: [bitcoin/bitcoin] +License: MIT + +[Janb84]: https://github.com/janb84 +[PR Review Club]: https://bitcoincore.reviews/ +[README]: https://github.com/bitcoin/bitcoin/blob/master/doc/README.md +[bitcoin/bitcoin]: https://github.com/bitcoin/bitcoin + +### LaWallet + +[LaWallet] is a Lightning wallet stack designed to make bitcoin onboarding +simple and practical for communities. It provides Lightning Addresses, +[BoltCards] for NFC payments, [Nostr Wallet Connect] as the backend, and can be +deployed for free on platforms like [Vercel] or [Netlify] to give users an +instant Lightning wallet experience. The same stack can run on self-hosted +platforms such as Umbrel or Start9, where communities offer courtesy NWC +accounts and guide users toward operating their own infrastructure. LaWallet’s +core idea is progressive custody, where users can start with hosted providers +and later move to their own node without changing their interface or habits. +This model is already being deployed with [VEINTIUNO.LAT] across several +circular economies. + +With support from this grant, LaWallet will focus on improving the stack through +heavy testing, bug fixes, and completion of the admin dashboard. The project +aims to have at least ten circular communities running the platform, improving +the simple wallet frontend, NWC integrations, and BoltCard flows based on user +feedback. Additional work will refine the deployment and management experience +for operators, making it easier for grassroots initiatives to roll out Lightning +Addresses, POS devices, and NFC cards while progressively guiding new users +toward self-custody. + +Repository: [lawalletio/lawallet-nwc] +License: MIT + +[LaWallet]: https://lawallet.io/ +[BoltCards]: https://www.boltcard.org/ +[Nostr Wallet Connect]: https://nwc.dev/ +[Vercel]: https://vercel.com/ +[Netlify]: https://www.netlify.com/ +[VEINTIUNO.LAT]: https://veintiuno.lat/ +[lawalletio/lawallet-nwc]: https://github.com/lawalletio/lawallet-nwc + +### LNHANCE + +The LNHANCE Expedition project explores the proposed [LNhance soft fork] for +Bitcoin by building and analyzing proof-of-concept implementations of [Eltoo] +channels, hash-lock Ark ([hArk]), and [vaults], with a focus on +OP_CHECKTEMPLATEVERIFY ([CTV]) and OP_CHECKSIGFROMSTACK ([CSFS]). Its goal is to +understand the practical viability, limitations, and tradeoffs of these new +opcodes in real-world channel, Ark, and vault designs. Current work centers on a +CTV-only vault that uses a predefined spending plan to control how quickly funds +can be moved, support a large number of deposits and withdrawals, and provide a +secure recovery path with clear limitations for users, alongside tools, +documentation, educational materials, and reusable libraries that help other +developers adopt these designs. + +With support from this grant, the project will complete the CTV-only vault proof +of concept, refine its command-line and minimal graphical interfaces, and +document the CTV precomputed state machine design for both general and technical +audiences. It will then implement Eltoo channels using CTV and CSFS in [LDK] and +extend this work to multiparty Eltoo using a precomputed settlement state +machine, comparing on-chain efficiency and design tradeoffs with existing +approaches. Further work will apply CTV and CSFS to [Ark-like protocols] by +implementing hArk in [bark] and exploring related designs such as [Erk]. The +project will also simulate multiparty Eltoo coinpools as non-custodial payout +mechanisms for decentralized miners such as +([Braidpool](/blog/bitcoin-grants-feb-2024#braidpool)), and investigate +additional vault designs, including social recovery, offline key delegation, and +deleted key recursion aimed at reducing precomputation overhead to levels +suitable for hardware wallets. + +Repositories: [LNHANCE-Expedition] +Licenses: CC0-1.0, CC BY 4.0, MIT + +[LNhance soft fork]: https://lnhance.org/ +[Eltoo]: https://bitcoinops.org/en/topics/eltoo/ +[hArk]: https://delvingbitcoin.org/t/evolving-the-ark-protocol-using-ctv-and-csfs/1602#p-4785-hark-hash-lock-ark-10 +[vaults]: https://bitcoinops.org/en/topics/vaults/ +[CTV]: https://bitcoinops.org/en/topics/op_checktemplateverify/ +[CSFS]: https://bitcoinops.org/en/topics/op_checksigfromstack/ +[LDK]: https://github.com/lightningdevkit +[Ark-like protocols]: https://bitcoinops.org/en/topics/ark/ +[bark]: https://docs.rs/bark-wallet/latest/bark/ +[Erk]: https://blog.second.tech/erk-update/ +[LNHANCE-Expedition]: https://github.com/LNHANCE-Expedition + +### Mohd Zaid + +[Mohd Zaid] is a developer contributing to [Braidpool], zero-fee Bitcoin mining +pool that aims to reduce centralization in the Bitcoin mining landscape. +Braidpool replaces the single-operator model of traditional pools with a shared +Directed Acyclic Graph ([DAG]) of “[beads]” (shares or weak blocks) that records +miners’ work quickly and with less waste. Building on this braid-like structure, +Mohd has been working on two core pieces of infrastructure: an [Audit Mode] +proxy that transparently logs mining activity into the DAG to create a +tamper-evident record of work performed, and an Unspent Hash Payout Output +([UHPO]) module that serves as an auditable accounting layer for tracking what +each miner is owed and how payouts are constructed. + +With support from this grant, Mohd will focus on turning these components into +robust tools that miners and ecosystem partners can rely on. He will implement +and strengthen Audit Mode, including the pass-through proxy, the DAG logic for +anchoring mining events, and privacy features that let miners selectively share +contribution data with contract counterparties. Mohd will then design and build +out the UHPO module, defining its data model, core operations for tracking +balances and settlement, and the logic to generate valid payout transactions. In +the final phase, he plans to integrate Audit Mode and UHPO while researching and +prototyping decentralized signing with [FROST] or similar threshold schemes, +followed by comprehensive functional and integration testing. The goal is to +provide an open-source foundation for transparent mining accounting and +hashrate-linked financial tools, reducing dependence on centralized pool +infrastructure. + +Repositories: [braidpool/braidpool] +License: AGPL-3.0 + +[Mohd Zaid]: https://github.com/zaidmstrr +[Braidpool]: https://github.com/braidpool/braidpool +[DAG]: https://en.wikipedia.org/wiki/Directed_acyclic_graph +[beads]: https://github.com/braidpool/braidpool/blob/main/docs/braid_consensus.md +[Audit Mode]: https://github.com/braidpool/braidpool/pull/305 +[UHPO]: https://github.com/braidpool/braidpool/blob/main/docs/braidpool_spec.md#unspent-hasher-payment-output +[FROST]: https://www.rfc-editor.org/rfc/rfc9591.html +[braidpool/braidpool]: https://github.com/braidpool/braidpool + +--- + +From Silent Payments tooling and donation-focused wallet UX to long-term Bitcoin +Core maintainability, operating system diversity, and mining decentralization +research, this fifteenth wave supports the kind of work that keeps Bitcoin +robust and usable without sacrificing privacy or decentralization. + +By funding both new contributors and ongoing maintenance, we aim to reduce +bottlenecks that would otherwise limit review capacity, user choice, and the +ability for independent builders to participate over the long term. + +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](/funds). Any +amount helps. + +
+ +
+ +If you’re building free and open-source Bitcoin software that advances +decentralization, privacy, and user sovereignty, we encourage you to [apply for +funding](/apply). diff --git a/public/static/images/blog/92-fifteenth-wave-of-bitcoin-grants.jpg b/public/static/images/blog/92-fifteenth-wave-of-bitcoin-grants.jpg new file mode 100644 index 000000000..fef193423 Binary files /dev/null and b/public/static/images/blog/92-fifteenth-wave-of-bitcoin-grants.jpg differ