diff --git a/data/blog/sixteenth-wave-of-bitcoin-grants.mdx b/data/blog/sixteenth-wave-of-bitcoin-grants.mdx new file mode 100644 index 000000000..7e0cf3cfd --- /dev/null +++ b/data/blog/sixteenth-wave-of-bitcoin-grants.mdx @@ -0,0 +1,394 @@ +--- +title: "Sixteenth Wave of Bitcoin Grants" +date: '2026-02-04' +tags: ['OpenSats', 'grants', 'bitcoin', 'wave'] +authors: ['default', 'arvin'] +images: ['/static/images/blog/99-sixteenth-wave-of-bitcoin-grants.jpg'] +draft: false +summary: "OpenSats is funding 17 more open-source projects advancing the Bitcoin ecosystem." +--- + +OpenSats is pleased to announce the 16th wave of grants from our General +Fund, supporting seventeen open-source projects across the Bitcoin ecosystem. +This round includes ten first-time project grants and seven grant renewals. + +The projects in this wave strengthen Bitcoin's ecosystem at several layers. They +improve script tooling and developer libraries, apply formal methods to critical +cryptographic code, and advance ecash infrastructure that mint operators can run +themselves. Additional grants support self-custodial wallets, DIY signing +hardware and installer software, alternative node and mining software, and +education programs that help new developers become contributors. + +The first-time project grants highlighted in this wave are: + +- [Advancing Formal Verification for Bitcoin Cryptography](#advancing-formal-verification-for-bitcoin-cryptography) +- [BitcoinerLAB and RewindBitcoin](#bitcoinerlab-and-rewindbitcoin) +- [BTCaaron and Mastering Taproot](#btcaaron-and-mastering-taproot) +- [Cashu Dev Kit (CDK)](#cashu-dev-kit-cdk) +- [Cashu TS and Coco](#cashu-ts-and-coco) +- [Krux-Installer](#krux-installer) +- [Libbitcoin](#libbitcoin) +- [Noah](#noah) +- [Rust-Bitcoin](#rust-bitcoin) +- [Stratum V2](#stratum-v2) + +Grant renewals have been awarded to: + +- Stable Channels ([Mar. 2025](/blog/tenth-wave-of-bitcoin-grants#stable-channels)) +- Rust-Bitcoin ([Jan. 2025](/blog/ninth-wave-of-bitcoin-grants#rust-bitcoin)) +- Nutshell ([Oct. 2024](/blog/8th-wave-of-bitcoin-grants#cashu-nutshell)) +- Minibits Wallet ([Sep. 2024](/blog/bitcoin-grants-september-2024-7th-wave#minibits)) +- Summer of Bitcoin ([Jul. 2024](/blog/announcing-the-opensats-education-initiative#summer-of-bitcoin)) +- Macadamia ([Jul. 2024](/blog/bitcoin-grants-july-2024#macadamia)) +- Cove ([Jul. 2024](/blog/bitcoin-grants-july-2024#cove)) + +These grants are made possible by donations to our General Fund. To help sustain +free and open-source Bitcoin development, please consider setting up a recurring +donation. + +
+ +
+ +Let's take a closer look at the projects in this wave and how they will make an +impact on the Bitcoin ecosystem. + +--- + +### Advancing Formal Verification for Bitcoin Cryptography + +Advancing Formal Verification for Bitcoin Cryptography is a research effort by +developer [remix7531] on the cryptographic building blocks that secure Bitcoin +software. The project focuses on [RustCrypto's] `sha2` and `k256` crates and on +multi-scalar multiplication for the `secp256k1` curve, a key operation for batch +signature verification in Bitcoin. Remix7531 applies proof assistants and formal +methods to construct machine-checked proofs for critical cryptographic routines +and to connect them to Rust and C implementations. + +This grant will support formal verification on these RustCrypto crates and on +multi-scalar multiplication for the `secp256k1` curve. The project will use the +[HAX toolchain] with [F*] to verify that the code does what it is supposed to do +and runs safely, ruling out panics, integer overflows, out-of-bounds errors, and +infinite loops. It will also develop precise specifications and proofs for +multi-scalar multiplication and will compare proof assistants for verifying +performance-critical C implementations. The resulting code, proofs, and +technical reports will be released under a free software license and will serve +as a blueprint for future formal verification of Bitcoin cryptographic +libraries. + +Repositories: [/remix7531] +License: MIT + +[remix7531]: https://github.com/remix7531 +[RustCrypto's]: https://github.com/RustCrypto/#about +[/remix7531]: https://github.com/remix7531?tab=repositories +[HAX toolchain]: https://cryspen.com/hax-toolchain/ +[F*]: https://fstar-lang.org/ + +### BitcoinerLAB and RewindBitcoin + +[BitcoinerLAB] is a TypeScript toolkit by developer [Landabaso] for building +Bitcoin applications with descriptors and Miniscript. It provides modules for +address and transaction construction, signers and blockchain backends, and it +integrates with bitcoinjs-lib for use in existing JavaScript codebases. +Thousands of public repositories depend on BitcoinerLAB, including Ledger APIs, +Bitcoin Keeper, LN Markets, and RewindBitcoin. + +[RewindBitcoin] is another project by Landabaso. It is a self-custody mobile +wallet for iOS and Android that applies vault-style spending controls. It uses +timelocks, pre-signed transactions, and an emergency spending path to protect +funds in situations of theft or coercion. + +This grant will support BitcoinerLAB and RewindBitcoin. For BitcoinerLAB, work +will include Taproot Miniscript support in TypeScript, broader hardware wallet +integration through a general signer API, and a cleared backlog of features such +as MuSig-style multisig, CPFP, and RBF in the coin selector, plus new +documentation and use-case guides. Planned work on RewindBitcoin will explore +Pay-to-Anchor and TRUC-based rescue flows, add hardware wallet support on top of +that design, and improve coin control, labeling, fee management, and overall UX. +These projects aim to create stronger Miniscript foundations for TypeScript +developers and a practical vault wallet for people facing real risks of theft or +coercion of their Bitcoin. + +Repositories: [/bitcoinerlab]; [/rewindbitcoin] +Licenses: MIT; GPL-3.0 + +[BitcoinerLAB]: https://bitcoinerlab.com/ +[Landabaso]: https://github.com/landabaso +[RewindBitcoin]: https://rewindbitcoin.com/ +[/bitcoinerlab]: https://github.com/bitcoinerlab +[/rewindbitcoin]: https://github.com/rewindbitcoin + +### BTCaaron and Mastering Taproot + +The btcaaron project is a lightweight Python toolkit by developer +[aaron-recompile] for Bitcoin Layer 1 development with a focus on Taproot. It +runs on testnet and supports Legacy, SegWit, and Taproot address types, UTXO +scanning, transaction construction, signing, and broadcasting for testnet flows. +It also exposes a Taproot-native API for building script trees, key-path and +script-path spends, and automatic witness construction for common spend paths. + +Mastering Taproot is Aaron Zhang's open-access [developer guide to Taproot], +with full Python code samples, testnet transactions, and step-by-step stack +execution, published in English and Chinese as a reproducible online book. The +text uses clear examples, control block diagrams, and verifiable transaction IDs +so readers can inspect and replay every construction. + +This grant will support btcaaron and Mastering Taproot. Planned work for +btcaaron includes a refactored core structure, new helpers for Taproot +script-path spending, PSBT v2 support, multi-leaf Taproot construction utilities +and visualization and simulation features for Taproot scripts, along with a 1.0 +release for testnet and regtest workflows. Planned work for Mastering Taproot +includes finalizing the English manuscript, expanding runnable examples, +releasing Chinese translations of key chapters, and publishing tutorial videos, +walkthroughs, and workshop materials for Bitcoin scripting education. The goal +is a cohesive toolkit and curriculum that lowers the barrier for new Bitcoin +developers, especially in Chinese-speaking communities, and accelerates +practical Taproot experimentation. + +Repositories: [aaron-recompile/btcaaron]; [aaron-recompile/mastering-taproot] +Licenses: MIT; CC BY-SA 4.0 + +[aaron-recompile]: https://github.com/aaron-recompile +[developer guide to Taproot]: https://github.com/aaron-recompile/mastering-taproot/tree/main/book/manuscript +[aaron-recompile/btcaaron]: https://github.com/aaron-recompile/btcaaron +[aaron-recompile/mastering-taproot]: https://github.com/aaron-recompile/mastering-taproot + +### Cashu Dev Kit (CDK) + +Although we have [supported the CDK project] in the past, this additional grant +supports developer [Asmo] for his work on CDK operability across cloud +environments. [Cashu Dev Kit] is the core Rust toolkit for operating Cashu mints +and services. It supports Postgres for storage, Prometheus for metrics, and +provides Docker images for common environments, including ARM64. Asmo triages +bugs, reviews pull requests, and adds features for operators and integrators. +His work includes the Prometheus exporter and Grafana dashboard, improvements to +Postgres and FFI support, and the Blink payment processor backend. + +With this grant, Asmo will turn CDK into a cloud-native infrastructure for Cashu +mints. The roadmap expands Prometheus metrics to cover database and payment +activity and feeds them into Orchard dashboards for mint operators. He plans to +build a Cashu [Kubernetes Controller] that manages CDK mints and Orchard on +Kubernetes clusters and handles rolling upgrades, configuration secrets, health +probes, backups, and restores. Logging will move to structured JSON formats, and +configuration will be simplified and documented so deployments stay predictable +at different scales. Build pipelines will migrate to self-hosted GitHub runners, +and CDK will publish several image profiles for minimal, base, standalone, and +cloud deployments. In parallel, Asmo will prototype secure deployments on Amazon +Nitro Enclaves and extend gRPC-based payment backends such as +`cdk-blink-payment-processor` to support BOLT12, on-chain payments, and +additional providers including Stripe, Strike, and LNbits. + +Repository: [cashubtc/cdk] +License: MIT + +[supported the CDK project]: https://opensats.org/blog/advancements-in-ecash#cashu-dev-kit +[Asmo]: https://github.com/asmogo +[Cashu Dev Kit]: https://cashudevkit.org/ +[Kubernetes Controller]: https://kubernetes.io/docs/concepts/architecture/controller/ +[cashubtc/cdk]: https://github.com/cashubtc/cdk + +### Cashu TS and Coco + +[Cashu TS] is a TypeScript library for building Cashu wallets and applications. +Maintained by returning grantee [Egge], lead developer of [npub.cash], `cashu-ts` +wraps the Cashu protocol and NUTs into a reusable wallet toolkit so developers +can connect to mints, mint and melt ecash, and manage tokens without +reimplementing low-level logic. The library is widely used in the Cashu +ecosystem and powers web, mobile, and backend integrations in projects ranging +from wallets to merchant tools. + +Coco builds on `cashu-ts` and adds networking, storage, key management, and a +unified API so developers can embed a full Cashu wallet in browsers, Node.js, +and React Native with minimal connective code. + +With this grant, Egge will keep `cashu-ts` aligned with new Cashu NUTs and +protocol changes and complete its ongoing API migration while maintaining +stability for existing dependents. He plans to refine documentation and examples +so application teams can adopt new features without friction. He will also push +Coco toward its first stable release and add missing protocol features such as +automatic key handling for locked and BOLT12 mint quotes, tools for managing +balances across multiple mints, multi-nut payments that combine funds from +several mints for one invoice, and payment request flows with nostr integration. +The goal is a pair of libraries that keep TypeScript Cashu support robust and +give developers a toolkit for integrating ecash into new applications. + +Repositories: [cashubtc/cashu-ts]; [cashubtc/coco] +License: MIT + +[Cashu TS]: https://github.com/cashubtc/cashu-ts?tab=readme-ov-file#cashu-ts +[Egge]: https://github.com/Egge21M +[npub.cash]: /blog/advancements-in-ecash#npubcash +[cashubtc/cashu-ts]: https://github.com/cashubtc/cashu-ts +[cashubtc/coco]: https://github.com/cashubtc/coco + +### Krux-Installer + +We have [supported the krux-installer project in the past], and this additional +support goes to developer [joazinhom] for his work on the installer and its +platform reach. Krux is open-source firmware that turns inexpensive [Kendryte +K210 devices] into air-gapped Bitcoin signing devices, and Krux-installer is the +desktop application that flashes and upgrades this firmware on supported +hardware. The installer replaces complicated command-line tools with a guided +GUI so non-technical users can install and update Krux from official releases on +their own devices. + +With this grant, joazinhom will work on modernizing Krux-installer and expanding +its platform support by refactoring the codebase, migrating dependency +management from Poetry to UV, and adding a device registry system that reduces +duplication when onboarding new devices. He will move the build system to the +[BeeWare]/Briefcase framework to produce native installers for Android and +Flatpak-based desktops and to create a sustainable pattern for future platforms. +In the final phase, he will focus on testing and stabilizing these builds, +fixing touch and installation issues, and improving overall reliability for +users flashing and upgrading Krux devices. + +Repository: [selfcustody/krux-installer] +License: MIT + +[supported the krux-installer project in the past]: /blog/bitcoin-grants-july-2024#krux-installer +[joazinhom]: https://github.com/joaozinhom +[Kendryte K210 devices]: https://selfcustody.github.io/krux/ +[BeeWare]: https://beeware.org/ +[selfcustody/krux-installer]: https://github.com/selfcustody/krux-installer + +### Libbitcoin + +[Libbitcoin] is a C++ Bitcoin development toolkit and an alternative full node +implementation. It provides a modular node, server, and explorer stack together +with cross-platform libraries for building Bitcoin applications. The project +began in 2011 and produced the first independently implemented Bitcoin full node +separate from Bitcoin Core, and it remains under active maintenance with work +toward a version 4 release that emphasizes faster initial block download and +better scaling with modern hardware. + +This grant will support work on libbitcoin v4 by developer [pmienk]. Planned +work targets an early preview of the v4 node, followed by a full release of the +node, explorer, and server components. The focus includes further optimization +of initial block download, performance scaling across available CPU, disk, and +network resources, integration and testing of the consolidated stack, and +improvements to documentation for operators and developers. The goal is a +well-engineered Bitcoin node, server, and explorer that provides an independent +implementation of the protocol and a practical toolkit for downstream +applications. + +Repositories: [/libbitcoin] +License: AGPL-3.0 + +[Libbitcoin]: https://libbitcoin.info/ +[pmienk]: https://github.com/pmienk +[/libbitcoin]: https://github.com/libbitcoin + +### Noah + +Noah is a self-custodial mobile wallet for [Ark], a Layer 2 protocol, developed +by returning grantee [Hampus Sjöberg], creator of [Blixt Wallet]. Noah runs on +Android and iOS and uses Ark's virtual transaction outputs (VTXOs), so users see +a single balance that can send and receive over Lightning and on-chain. The +wallet connects to [Second's Ark client Bark] and removes channel setup, +liquidity management, and backup complexity while keeping users in control of +their keys. A working alpha already supports sending and receiving payments and +builds on years of experience operating Blixt as a non-custodial Lightning +wallet. + +With this grant, Hampus will work on reliable Ark round syncing using silent +push notifications, Lightning Address and future [BIP-353] support, expanded +LNURL features, and a seed-based encrypted backup system. He will also add +receive flows that let the app accept payments while it is offline. The roadmap +adds auxiliary Lightning and nostr integrations such as the LNURL protocol +suite, WebLN, Nostr Wallet Connect, payments via nostr profiles, and Tor support +for privacy. Alongside Noah, Blixt will shift toward a power-user wallet with +planned features including BOLT12 support tied to the upcoming `lnd` release, +offline receive, faster chain sync, desktop builds for Windows and Linux, +Lightning/on-chain swaps, LSP-spec support, and interface improvements. + +Repository: [BlixtWallet/noah] +License: MIT + +[Ark]: https://ark-protocol.org/ +[Hampus Sjöberg]: https://github.com/hsjoberg +[Blixt Wallet]: /blog/advancements-in-bitcoin-and-lightning-wallets#blixt-wallet +[Second's Ark client Bark]: https://docs.second.tech/getting-started/ +[BIP-353]: https://github.com/bitcoin/bips/blob/master/bip-0353.mediawiki +[BlixtWallet/noah]: https://github.com/BlixtWallet/noah + +### Rust-Bitcoin + +Through this grant, we [continue our support] for `rust-bitcoin` projects by +providing additional funding to developer [mpbagot] for his work on the library, +which provides Rust types and utilities for serializing, parsing, and executing +Bitcoin protocol messages, blocks, transactions, scripts, keys, addresses, and +PSBTs in Rust applications. The library sits at the center of the [rust-bitcoin +organization] together with crates such as `rust-secp256k1`, `bitcoin_hashes`, +`rust-miniscript`, and client libraries for Bitcoin Core, and it underpins +projects like Bitcoin Dev Kit, Lightning Dev Kit, electrs and Fedimint. + +This grant will support work on upcoming releases of the main bitcoin crate and +related primitives, bug fixes, expanded test coverage, documentation +improvements, and refactoring across the crate set. Bagot will continue his +existing cleanup patches and will take on larger tasks aimed at stable 1.0 +releases of key crates in the ecosystem. The goal is a well-tested, +well-documented, and CC0-licensed Rust Bitcoin stack with stable APIs for +downstream projects. + +Repository: [rust-bitcoin/rust-bitcoin] +License: CC0 1.0 + +[continue our support]: /blog/advancements-in-developer-libraries#rust-bitcoin +[mpbagot]: https://github.com/mpbagot +[rust-bitcoin organization]: https://github.com/rust-bitcoin +[rust-bitcoin/rust-bitcoin]: https://github.com/rust-bitcoin/rust-bitcoin + +### Stratum V2 + +Our [support for Stratum V2 continues] with a new grant to developer [Lucas +Balieiro] for his work on the Stratum V2 Reference Implementation (SRI), +focusing on stability, testing, and developer tooling. SRI is the Rust reference +implementation of the Stratum V2 mining protocol and provides core libraries and +pool and miner applications for encrypted, decentralized pooled mining. It +powers roles such as pool servers, miners, and job declaration clients and +serves as the main open-source codebase for adopters of Stratum V2 in production +mining setups. + +With this grant, Balieiro will improve SRI's testing infrastructure and adopter +experience. Planned work includes expanding the continuous testing tool for +long-running cross-implementation sessions, raising low-level crate test +coverage from roughly 25% toward 40%, and updating documentation alongside new +tests. He will build a unified command-line interface for launching SRI +applications, add Docker support and binary releases for easier deployment, and +streamline CI workflows to integrate the new testing tools. The roadmap also +covers compatibility testing with other Stratum V2 stacks and community work, +such as mentoring contributors and running educational sessions with the +Brazilian Bitcoin community. + +Repository: [stratum-mining/stratum] +License: Apache-2.0/MIT + +[support for Stratum V2 continues]: /projects/stratumv2 +[Lucas Balieiro]: https://github.com/lucasbalieiro +[stratum-mining/stratum]: https://github.com/stratum-mining/stratum + +--- + +The projects in this wave share a focus on practical Bitcoin infrastructure that +people can run and verify themselves. They move core libraries, wallet tooling, +ecash systems, and mining software toward greater security and usability for +both developers and end users. They strengthen self-custody, improve reliability +for operators, and expand pathways for new contributors. + +As with all OpenSats grants, funding decisions follow a [mission-aligned] review +process grounded in [clear criteria]. Our ability to fund this work depends on +donations to our [General Fund]. If you would like to help sustain these +projects and future grants, please consider setting up a recurring donation. + +
+ +
+ +If you are building free and open-source Bitcoin software, we encourage you to +[apply for funding]. + +[mission-aligned]: /mission +[clear criteria]: /apply#criteria +[General Fund]: /funds/general +[apply for funding]: /apply diff --git a/public/static/images/blog/99-sixteenth-wave-of-bitcoin-grants.jpg b/public/static/images/blog/99-sixteenth-wave-of-bitcoin-grants.jpg new file mode 100644 index 000000000..38b2cc300 Binary files /dev/null and b/public/static/images/blog/99-sixteenth-wave-of-bitcoin-grants.jpg differ