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Seventeenth Wave of Bitcoin Grants
OpenSats is pleased to announce the seventeenth wave of grants from our General Fund, awarding three first-time grants and six grant renewals to open-source projects across the Bitcoin ecosystem.
This round supports projects that bring transparency and direct access to three distinct layers of the Bitcoin experience, spanning transaction construction, on-chain privacy, and open-hardware self-custody. Six renewed grants will continue to sustain work on education, payments, and developer training across the ecosystem.
The three first-time grants in this wave go to:
The six grant renewals have been awarded to:
- Bitcoin Dev Launchpad (Mar. 2025)
- Bitcoin Jungle (Sep. 2024)
- Bitcoin Safe (Mar. 2025)
- Bitshala (Mar. 2025)
- Odudex for Kern (Jul. 2024)
- Payjoin (Jul. 2023)
These grants are made possible by donations to our General Fund. If you'd like to see free and open-source Bitcoin development continue to flourish, 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.
JoinMarket NG
JoinMarket NG is a reimplementation of the JoinMarket protocol, a decentralized system that gives bitcoin users on-chain privacy. The system works by combining inputs from multiple participants into a single transaction with equal-value outputs, making it difficult for bad actors to identify and target individual users. The protocol uses a peer-to-peer model so transactions flow directly between users. JoinMarket NG is compatible with the original implementation, enabling users on either codebase to find and transact with each other. The project runs on a tested codebase with a built-in Neutrino based light client option, allowing people to participate without running a full bitcoin node.
With support from this grant, the project will undergo an external security audit to improve the code based on the findings. The project will add nostr relay support for offer broadcasting to improve censorship resistance, patch known privacy vulnerabilities, and make it easier for liquidity providers to establish a verifiable reputation on the network. The project will also research CoinJoinXT, Lightning integration, and ecash as a complementary privacy layer. The grant will additionally fund tutorials, videos, and onboarding materials for new users, alongside ongoing maintenance and compatibility with the broader network.
Repository: joinmarket-ng/joinmarket-ng
License: MIT
rawBit
rawBit is a visual editor that helps people see how bitcoin transactions are built. It presents transactions as connected blocks on a canvas so users can link together the pieces that make up a payment and see the underlying data update as they work. The interface shows the raw transaction, transaction ID, and fees in real time. A script view walks through each step that the Bitcoin network checks before accepting a transaction. rawBit currently offers fourteen guided lessons that cover patterns such as simple payments, multisig, timelocks, OP_RETURN anchors, payment channels, SegWit formats, and Taproot key-path and script-path spends. Each example can be broadcast to Bitcoin testnet for independent verification. This gives developers, educators, and curious learners a hands-on way to explore how Bitcoin transactions are structured and validated at the byte and script level.
With support from this grant, rawBit will grow its library of guided content for Bitcoin's transaction layer. The project plans to expand to twenty or more guided lessons and add flows that cover Lightning channel and HTLC patterns, privacy-focused payment patterns such as CoinJoin, PSBT workflows, and early covenant experiments. Each new lesson will pair an interactive canvas flow with clear written explanations and short video walkthroughs. This grant will also support ongoing maintenance, testing, and interface improvements so the tool remains a stable visual workspace for teaching, reviewing, and discussing bitcoin transactions in classrooms, workshops, and independent study.
Repository: rawBit-io/rawbit
License: MIT
Specter DIY
Specter DIY is an open-source hardware signing device that users can assemble from off-the-shelf components and verify from the ground up. The project publishes everything from firmware to schematics to give individuals, researchers, and developers full visibility into how their signing device works. Its firmware is written in MicroPython, making the code accessible to audit and modify, and uses the secp256k1 library from Bitcoin Core for cryptographic operations and the LVGL library for its graphical interface. Specter DIY also maintains embit, a lightweight Bitcoin library for MicroPython and Python 3 that has become a shared foundation for other open-hardware projects including Krux and SeedSigner, reducing duplicated effort across the ecosystem. A secure bootloader with multisig firmware signing adds a layer of upgrade verification, and optional smart-card support provides additional key storage options.
With support from this grant, the project will update the foundational software it builds on by migrating to LVGL v9 and MicroPython v1.26, and introducing reproducible builds for compilation and firmware signing. The project will also build out automated testing and continuous integration pipelines. Additional milestones include expanded documentation and contributor onboarding guides, a redesigned user interface informed by community feedback, and a modular firmware architecture that supports independently developed apps for features such as the Liquid Network and BIP-85 derived seeds.
Repository: cryptoadvance/specter-diy
License: MIT
Transaction literacy, on-chain privacy, and key security reinforce each other. The projects in this wave address all three.
rawBit opens up the transaction layer for education and prototyping. For privacy, JoinMarket NG offers CoinJoin infrastructure that operates without central coordination. And Specter DIY gives users a signing device they can build, inspect, and reproduce on their own.
OpenSats has issued more than 390 grants to date, underscoring both the scale of our program and the ongoing need to support open-source contributors building across the ecosystem.
Our ability to fund work like this depends on the generosity of our donors. Please consider supporting the Bitcoin ecosystem by setting up a recurring donation.
If you are building free and open-source Bitcoin software, we encourage you to apply for funding.