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Fifteenth Wave of Bitcoin Grants

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  • avatar
    Name
    OpenSats
    Twitter
  • avatar
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    Arvin
    Twitter
    @arvin

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:

The seven grant renewals have been awarded to:

These grants are made possible by donations to our General Fund. 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

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

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

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

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 READMEs 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

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

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), 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

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

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. Any amount helps.

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If you’re building free and open-source Bitcoin software that advances decentralization, privacy, and user sovereignty, we encourage you to apply for funding.

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