We help you find and support open-source Bitcoin projects - helping create a better tomorrow, today.

OpenSats General Fund

OpenSats Operations Budget


## About this project

Bitcoin Development Kit (BDK) is a set of libraries and tools that allows you to seamlessly build cross-platform on-chain Bitcoin wallets without having to re-implement standard bitcoin data structures, algorithms, and protocols. We partner closely with the Lightning Dev Kit (LDK) team to help projects building on-chain and off-chain wallets. BDK is built on top of the powerful rust-bitcoin and rust-miniscript libraries and adds features for managing descriptor based wallets, syncing wallets to the bitcoin blockchain, viewing transaction histories, managing and selecting utxos to create new transactions, signing, and more. The core BDK components are written in Rust, but the team also maintains Kotlin and Swift language binding for use in mobile projects. Plus we maintain Python bindings and React Native and Flutter support is being developed. 😃 Join our community Open source is fundamental to this project and we would love to connect with you. Whether you're a Rust, Kotlin, Swift, or Python developer, or good at technical writing, web design or want to help via manual testing. Everyone is welcome. Most of our communication happens on the Bitcoin Dev Kit discord server, say hi!

The goal of the Bitcoin Dev Kit (BDK) project (originally called Magical Bitcoin 🧙) is to provide libraries and tools that make it 10x easier to build secure, full featured, cross-platform on-chain Bitcoin wallets. All BDK components are designed to be lightweight and modular so that they can be adapted for virtually any use-case: from single-sig mobile wallets to multi-billion-dollar cold storage vaults.

Bitcoin Dev Kit


## About this project

The prevailing narrative in Washington is that Bitcoin harms the environment, threatens national security, and hurts consumers — helping only criminals and speculators. Left unchecked, these narratives will continue to form the tailwinds for policy with grave consequences for American Bitcoiners. Since forming in January, the Bitcoin Policy Institute has been advancing a different vision in D.C.– one of an America strengthened by Bitcoin. 

BPI was instrumental in responding to the Biden Executive Order on Digital Assets, providing in-depth reports detailing the benefits of Bitcoin and meeting privately with White House officials to offer guidance on key issues. They facilitated a groundbreaking letter to Congress from 21 global human rights leaders explaining how Bitcoin saves lives and protects those facing political repression and economic crisis. Moving forward, BPI hopes to bolster its presence in Washington and expand its research and advocacy. 

As part of BPI’s fundraising collaboration with Swan Bitcoin, they are aiming to raise $100k from the pleb community to help support academic research on Bitcoin.

Campaign Stretch Goals:

$10,000 - Research Grant to Study Proof of Work's Environmental Impact

$20,000 - Research Grant to Study Bitcoin's Long-Term Global Impact

$25,000 - Funding Up to 10 Academic Journal Submissions for BPI Fellows

$45,000 - “Buying Out” a BPI Fellow’s Courseload (i.e. Paying for a BPI Fellow to take the semester off of teaching and focus on bitcoin research full-time)

$55,000 - Research Grant to Study Sustainability in Bitcoin Mining

$75,000 - “Buying Out” a SECOND BPI Fellow’s Courseload

$80,000 - Funding 10 More Academic Journal Submissions for BPI Fellows

$100,000 - “Buying Out” a THIRD BPI Fellow’s Courseload

But academic research is only part of the battle. In order to effect change at scale, BPI needs to go toe to toe with the big players in Washington. Their ultimate fundraising goal for the calendar year is $1,000,000.

Fundraising Goals:

$250,000 - Funds BPI Operations, Research, and Advocacy in DC for 3 Months

$500,000 - Funds BPI Operations, Research, and Advocacy in DC for 6 Months

$750,000 - Funds BPI Operations, Research, and Advocacy in DC for 9 Months

$1,000,000 - Funds BPI Operations, Research, and Advocacy in DC for 12 Months


Bitcoin Policy Institute supports academic research on Bitcoin and conducts advocacy in Washington D.C.

Bitcoin Policy Institute


## About this project

We are helping make bitcoin more intuitive and accessible. As bitcoin’s popularity continues to rise, it is essential that everyone be able to participate in this new economy regardless of technical expertise or geography. That can only happen if creators everywhere have the resources and community necessary to foster better bitcoin experiences.

The Bitcoin Design Community Slack is an open space to discuss and explore everything bitcoin and design. Open standards are part of our foundation, so all of our work can also be found on Github. Everyone is welcome to join and participate. You can also follow along via our newsletter, calendar, social media, BitcoinTV & YouTube.

The Bitcoin Design Guide, our first community project, is a free, open-source repository for anyone building non-custodial bitcoin products. The guide will eventually cover consumer wallets, merchant interactions, financial applications, and much more. If you’d like to help by providing feedback, submitting ideas, or creating content, check out the list of current issues or join us on Slack.


A free, open-source community resource for designers, developers, and others working on non-custodial Bitcoin products.

Bitcoin Design Community


## About this project

Bitcoiner.Guide contains tutorials on all of the following topics and much more….

- A simple Q+A for absolute beginners
- Mobile wallets
- Hardware wallets
- Desktop wallets
- Nodes
- Privacy
- Multisig
- Lightning Network

![bitcoinqna homepage](https://raw.githubusercontent.com/BitcoinQnA/bitcoiner.guide/master/assets/images/Homepage.png)

## Also available is...

- A monthly news index to help people stay up to date with what really matters
- A hosted Matrix room for anyone to join and ask specific questions relating to any of the above
- 1-2-1 support calls for those that require a more personal approach to their learning


Bitcoiner.Guide is a collection of resources by BitcoinQnA to help people feel more comfortable interacting with bitcoin in a sovereign way.

Bitcoiner.guide


## About this project

BTCPay Server provides numerous features for self-sovereign individuals and businesses: Direct, peer-to-peer Bitcoin payments | No transaction fees (other than the network fee) | No fees, middleman or KYC | Non-custodial (complete control over the private key) | Lightning Network support (LND, c-lightning, Eclair, and Ptarmigan) | Tor support | Share your instance with friends (multi-tenant) | Invoice management and Payment requests | Apps: Point of sale, crowdfunding, donation button | Full-node reliant wallet with hardware wallet integration and SegWit support | Payjoin Support


Free, open-source & self-hosted bitcoin payment gateway that allows self-sovereign individuals and businesses to accept bitcoin payments online or in person without any fees.

BTCPay Server


## About this project

Cashu is a free and open-source Chaumian ecash system built for Bitcoin that brings near-perfect privacy for users of custodial Bitcoin applications. A Cashu ecash mint does not know who you are, what your balance is, or who you're transacting with. Users of a mint can exchange ecash privately without anyone being able to know who the involved parties are. Bitcoin payments are executed without anyone able to censor specific users. There are multiple implementations of the Cashu protocol. Cashu is available as a command line interface (CLI) tool and as Progressive Web Apps (PWA) with a graphical user interface. Multiple Cashu libraries are available for Python, Golang, Javascript, and Typescript. The client libraries make it easy for developers to write their own wallets. As a Free and Open Source Software Project, Cashu libraries can be used to integrate ecash into existing Bitcoin projects. The Cashu NUTs (Notation, Usage, and Terminology) documents are the protocol specifications: https://github.com/cashubtc/nuts

Cashu is a Chaumian ecash system for Bitcoin.

Cashu


## About this project

I have been working on Bitcoin code for five years and 1.5 years ago I decided to dedicate myself to programming for the Lightning network. I began by learning about Lightning in depth and making contributions to the CoreLightning project. I felt particularly accomplished rooting out some complex flakiness bugs and porting the project to MacOS. You can see my work here: https://tinyurl.com/3tcdafbe. I had heard of splicing in 2018 and saw it making the news rounds last year. On Clubhouse and Twitter Spaces bitcoiners were talking excitedly about using submarine swaps and I suggested people use splicing instead! The confused silence was palpable, no one had heard about it all. Diving in I realized only the splicing spec had been released — no one had actually written the code! So I decided I would take on the work of coding up the first implementation. By March of this year I had made the world’s first splice and published it on chain! You can see it here: https://twitter.com/dusty_daemon/status/1522413475909316610. Since then I have been working on finishing up the proper & complete splice implementation. The code is now in a beta state which you can see here: https://github.com/ElementsProject/lightning/pull/5675. I’m looking for funding to finish the code to a polished state, build a thorough testing framework, evangelize to companies that would benefit from splicing, and bring the implementation to the other Lightning node code bases.


 I have been working on Bitcoin code for five years and 1.5 years ago I decided to dedicate myself to programming for the Lightning network. I began by learning about Lightning in depth and making contributions to the CoreLightning project.

Lightning Development


## About this project

GrapheneOS is a private and secure mobile operating system with great functionality and usability. It starts from the strong baseline of the Android Open Source Project (AOSP) and takes great care to avoid increasing attack surface or hurting the strong security model. GrapheneOS makes substantial improvements to both privacy and security through many carefully designed features built to function against real adversaries. The project cares a lot about usability and app compatibility so those are taken into account for all of our features.


GrapheneOS is a private and secure mobile operating system with great functionality and usability. It has near full Android app compatibility via our sandboxed Google Play compatibility layer.

GrapheneOS


## About this project

I began working on Bitcoin Core in early 2019 and since then have been doing review and development, focusing on whatever needs doing in any area to help the project move forward.


I work on Bitcoin Core development, code review, and testing.

Jon Atack: Working on Bitcoin Core


## About this project

More recently I've been involved in the release process. Outside of that my focus is mostly on the build system and security.


I'm one of the Bitcoin Core maintainers. My work is code review, triaging and ultimately merging changes into Bitcoin Core.

Michael Ford Project


## About this project

The Bitcoin and FOSS communities are currently the subject of targeted litigation. The continued threat of litigation serves as a disincentive for contributors to devote their efforts to the advancement of Bitcoin and open-source projects, and hinders their ability to freely and openly discuss the projects and communities to which they contribute. In response, OpenSats has established the OpenSats Legal Defense Fund which aims to defend open-source contributors from lawsuits regarding their activities in the Bitcoin and FOSS ecosystems by directing donations to fund any related legal fees which may arise from their contributions, thereby minimizing the financial repercussions of litigation which can discourage contributors from actively working on and openly discussing Bitcoin and open-source projects.

Applications for the OpenSats Legal Defense Fund Grants will be managed by Open Sats Initiative, Inc., a 501(c)(3) non-profit corporation (EIN: 863904387), and carefully reviewed by the OpenSats Board, who will be responsible for determining grant recipients and amounts by means of a simple (5-4) majority.


The OpenSats Legal Defense Fund aims to defend open-source Bitcoin contributors from lawsuits regarding their activities in the Bitcoin and FOSS ecosystems by directing donations to fund legal fees related to these contributions.

OpenSats Legal Defense Fund


## About this project

Open Sats Initiative, Inc., is a 501(c)(3) non-profit corporation (EIN: 863904387) helping to support and maintain a sustainable ecosystem of funding for Bitcoin & complimentary-FOSS projects and contributors. Head over to the About Us page to learn more about the organization and our efforts!


Contributions to the OpenSats Operations Budget will be used to cover our operating expenses as we continue to facilitate frictionless, tax-deductible donations from the community to the Bitcoin & FOSS ecosystems at a pass-through rate of 100%.


## About this project

RGB is confidential & scalable client-validated smart contracts system for Bitcoin & Lightning. It embraces concepts of private & mutual ownership, abstraction and separation of concerns and represents "post-blockchain", Turing-complete form of trustless distributed computing which does not require introduction of "tokens" in order to make it operational. RGB is not a token protocol. Though issuance and management of highly scalable, programmable and private assets of different sort is possible with RGB, it can be applied in many industries far beyond financial world, from building DEXs, art ownership rights transfer system, to voting and Digital Identity one.


RGB is a system of private & scalable client-validated smart contracts on Bitcoin & Lightning Network.


## About this project

RoninDojo develops hardware and software to make it easy for anyone to use bitcoin privately as if it were cash. Some of our products include bitcoin nodes, steel backup plates, powerful software, premium support, and a lot more coming soon. We are working hard to increase accessibility for bitcoin users to connect their wallet to a node, use privacy enhancing coinjoin, do their own self custody, and so much more. Financial sovereignty is our goal and we won't slow down until it is achieved!


We help people have a feature rich bitcoin experience, maintain privacy, and thrive as a sovereign individual.

RoninDojo


## About this project

Sapio helps you build payment protocol specifiers that oblivious third parties can participate in being none the wiser.

For example, with Sapio you can generate an address that represents a lightning channel between you and friend and give that address to a third party service like an exchange and have them create the channel without requiring any signature interaction from you or your friend, zero trusted parties, and an inability to differentiate your address from any other.
That’s the tip of the iceberg of what Sapio lets you accomplish.

Before Sapio, most Bitcoin smart contracts primarily focused on who can redeem coins when and what unlocking conditions were required (see Ivy, Policy/Miniscript, etc). A few languages, such as BitML, placed emphasis on multi-transaction and multi-party use cases.
Sapio in particular focuses on transactions using BIP-119 OP_CHECKTEMPLATEVERIFY. OP_CHECKTEMPLATEVERIFY enables Bitcoin Script to support complex multi-step smart contracts without a trusted setup.

Sapio is a tool for defining such smart contracts in an easy way and exporting easy to integrate APIs for managing open contracts. With Sapio you can turn what previously would require months or years of careful tinkering with Bitcoin internals into a 20 minute project and get a fully functional Bitcoin application.

Sapio has intelligent built in features which help developers design safe smart contracts and limit risk of losing funds.


Sapio is a tool for defining such smart contracts in an easy way and exporting easy to integrate APIs for managing open contracts.

Sapio


## About this project

Script Wizard makes it easy to write custom Bitcoin and Liquid scripts in a straightforward way. It's a new open-source IDE for writing, debugging, and compiling custom scripts for Liquid. It’s both a sandbox for playing around with opcodes and a developer tool for designing covenants.


Script Wizard makes it easy to write custom Bitcoin and Liquid scripts in a straightforward way.

Script Wizard


## About this project

SeedSigner helps users save with Bitcoin by assisting with trustless private key generation and multi-signature wallet setup, and helps users transact with Bitcoin via a secure, air-gapped QR-exchange signing model.

Use SeedSigner to complete these tasks:

-- Calculate word 12/24 of a BIP39 seed phrase
-- Create a 24-word BIP39 seed phrase with 99 dice rolls
-- Create a 24-word BIP39 seed phrase by taking a digital photo
-- Temporarily store up to 3 seed phrases while device is powered
-- Guided interface to manually create a SeedQR for instant input
-- BIP39 passphrase / word 25 support
-- Native Segwit Multisig XPUB generation w/ QR display
-- Scan and parse transaction data from animated QR codes
-- Sign transactions & transfer XPUB data using animated QR codes
-- Live preview during photo-to-seed and QR scanning UX
-- Optimized seed word entry interface
-- Support for Bitcoin Mainnet & Testnet
-- Support for custom user-defined derivation paths
-- On-demand receive address verification
-- User-configurable QR code display density
-- Responsive, event-driven user interface

The key component in SeedSigner is a specific version of the Raspberry Pi Zero single board computer (version 1.3) that does not include WiFi or Bluetooth functionality; the absence of these modules ensures that your private keys never leave the device. Communication with wallet software is accomplished using a two-way QR code exchange process. Information about a proposed transaction is displayed by the wallet software on your computer’s screen, encoded in multiple QR codes, and you scan in the transaction information using SeedSigner’s built-in camera. Information about the proposed transaction is then displayed on the SeedSigner screen. Using cryptographic signatures, SeedSigner then proves that it has the correct private keys to authorize the transaction, and QR codes demonstrating that proof are displayed on SeedSigner’s screen. You then use your computers web-camera to input the QR codes generated by SeedSigner to authorize the transaction.

SeedSigner is built to be compatible with Specter-Desktop, Sparrow Wallet and BlueWallet Multisig Vaults.

The goal of SeedSigner is to lower the cost and complexity of Bitcoin multi-signature wallet use. To accomplish this goal, SeedSigner offers anyone the opportunity to build a verifiably air-gapped, stateless Bitcoin signing device using inexpensive, publicly available hardware components (usually < $50).

SeedSigner


## About this project

Sparrow supports many features:
• Full support for single sig and multisig wallets on all addressable script types
• A range of connection options: Public servers, Bitcoin Core and private Electrum servers
• Standards based including full support for PSBT and TXN files
• Support for all common hardware wallets in USB and airgapped / QR modes
• Wallet configuration via output descriptors
• Full coin and fee control with mempool visualisation
• Send to multiple outputs with change address selection
• Native support for fee bumping with RBF and CPFP
• Labelling of all transactions, addresses, inputs and outputs
• Lightweight and multi platform (Linux, OSX, Windows)
• Message signing and verification
• Import and export to a number of different of wallet formats (incl. Electrum)
• Show wallets in different tabs, windows or minimised to system tray
• Payjoin support
• Anonymous broadcast via public blockchain explorers over Tor
• Built in Tor client
• Private blockchain explorer functionality
• Strong wallet file encryption
• Testnet, regtest and signet support

Sparrow is unique in that it contains a fully featured transaction editor which displays the hexadecimal representation of the transaction as you edit it, allowing easy inspection of the transaction bytes before broadcasting.

Sparrow is strongly supportive of privacy, and aims to be a wallet that takes users on a privacy journey from using public servers to using cold storage techniques on private servers. It also comes with detailed documentation to explain setup and common wallet configurations at https://sparrowwallet.com/docs.


Sparrow Wallet is a Bitcoin only desktop wallet with a focus on security, privacy and usability. Suitable for beginner to advanced users, Sparrow reveals detailed information about a wallet’s configuration, transactions and UTXOs in order to minimise trust and be fully transparent.

Sparrow Wallet


## About this project

SRI is Stratum v2 reference implementation, that is free and open-source. Before Stratum V2, transaction sets were selected by pools. With this SV2 configuration they’re selected by individual miners, making the network more censorship-resistant. Miners run SV2 firmware, connecting to the SV2 proxy server. Miners can pick their transactions locally and negotiate them with an SV2 pool. Stratum V2 is the next generation protocol for pooled mining. It increases security, makes data transfers more efficient, and reduces mining infrastructure requirements. It also introduces three new sub-protocols that let miners select transaction sets and improve decentralization.


An independent, community run, 100% free and open-source reference implementation of the Stratum V2 protocol.

Stratum V2


## About this project

What is Summer of Bitcoin? Summer of Bitcoin is a global summer internship program to introduce university students to bitcoin open-source development and design. Till date, Summer of Bitcoin has funded 124 students from 15 countries to contribute to over 29 open-source bitcoin projects. How does it work? University students apply for a summer internship program where they contribute code or design for bitcoin-related projects matching their interests, earn bitcoin as stipend and put their summer break to good use. The project communities provide mentors who guide students through the entire summer, helping students learn about the community and contribute. What’s in it for students? - Learn about bitcoin and open-source development - Build a network with bitcoiners around the world - Earn bitcoin - Become open-source contributors or join the bitcoin industry - Contribute to monetary revolution! What’s in it for participating projects and their associated mentors? - More code and more code reviews - Identify and bring in new full-time contributors - Contribute to monetary revolution!

Summer of Bitcoin is a global summer internship program focused on introducing university students to bitcoin open-source development and design. Till date, Summer of Bitcoin has funded 124 students from 15 countries to contribute to over 29 open-source bitcoin projects.

Summer of Bitcoin


## About this project

ThunderHub allows you to take full control of your Lightning Node with a slick and awesome UI. Explore all the options that ThunderHub has to offer, from sending and receiving Lightning payments, checking your nodes health statistics and even more advanced options like channel rebalancing and multi-path lightning payments. Managing and monitoring your node has never been easier with transaction reports, graphs and a huge assortment of different features all bundled inside of this great tool.


Monitor and manage your node from any browser and any device.

ThunderHub


## About this project

The Tor network is undergoing an ongoing denial of service (DoS) attack that is negatively impacting onion service performance and reliability. More than half of all Bitcoin nodes use onion services, (https://bitnodes.io/dashboard/) and this negatively effects the Bitcoin ecosystem. There are many possible improvements for onion services and their protection against DoS attacks but the bottleneck is developer power and funding resources.  As a 501(c)(3) nonprofit, the Tor Project does not make a profit from building the Tor network. The organization relies on donations and grants, but funding for onion services performance, reliability, metrics, and reporting is difficult to secure from traditional grant makers. With the commitment of multi-year funding, the Tor Project can hire two or more developers to focus exclusively on onion services and make substantial improvements. We have built a coalition of Bitcoin, open source, and privacy projects who will be part of funding this effort. Across these partners, we must raise a total of $525,000 over two years. Additional developer power will result in: * Long-term improvement in stability and reliability of onion services * Better metrics on onion service performance * Increased network protocol robustness against DoS attacks The Tor network is a critical piece of privacy and circumvention infrastructure. By supporting us in this moment, you will contribute to substantial improvements to onion service performance and reliability.


The Tor Project advances human rights and defends your privacy online through free software and open networks.

The Tor Project


## About this project

Zeus lets you take lightning on the go and provides a best in class experience for full node operators running LND, c-lightning, or Eclair. Manage your channels, send and receive on-chain and LN transactions, or manage your routing strategy right in your pocket. Tor is built in to allow you to connect home securely to your node’s hidden services with minimal hassle.


Zeus is an open-source, non-custodial Bitcoin wallet that gives you full control over how you make payments.

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