Bitcoin Development Grants: Who Funds Open-Source Bitcoin Work?

How Bitcoin Development Gets Funded

Bitcoin has no foundation, no protocol treasury, and no block reward allocation for developers. Unlike Ethereum, Solana, or Polkadot, where foundations or on-chain treasuries distribute millions to ecosystem builders, every satoshi of Bitcoin development funding comes from voluntary donations by individuals, companies, and nonprofit organizations. This makes Bitcoin's funding model unique in all of crypto: the people maintaining a $1.7 trillion network depend entirely on external grants.

The ecosystem has responded by building a patchwork of grant programs, fellowships, and corporate sponsorships. Organizations like OpenSats, Brink, and Spiral now fund dozens of full-time developers working on Bitcoin Core, the Lightning Network, privacy protocols, and second-layer scaling solutions. This directory catalogs every major funding source available to aspiring and established Bitcoin developers.

Major Grant Programs Compared

The following table summarizes the primary organizations funding open-source Bitcoin development. Grant amounts, focus areas, and application processes vary significantly between programs.

OpenSats

OpenSats is the largest single funder of open-source Bitcoin development by volume. The 501(c)(3) nonprofit distributes approximately $1 million per month to over 150 active grantees across more than 40 countries. Since its founding, OpenSats has allocated over $27 million to 319 grantees in 32+ countries.

OpenSats announces grants in numbered "waves," each funding a batch of individual developers and projects. Recent waves have focused on Bitcoin Core maintainability, safety, and privacy improvements. The organization funds work across the full stack: protocol development, wallet infrastructure, Lightning tooling, educational efforts, and ecash implementations like Fedimint.

Applications are open year-round at opensats.org/apply. OpenSats is funded by donations from companies and individuals, including significant contributions from the Reynolds Foundation ($2M), Tether ($250K), and StarkWare ($400K).

Brink

Brink is a nonprofit focused specifically on Bitcoin protocol development. It operates two distinct programs: a grants program for established developers and a fellowship program for engineers new to Bitcoin Core.

The grants program awards year-long funding to experienced protocol developers who work full-time on open-source Bitcoin projects. The primary focus is security and stability of the base protocol, though grants also cover research into extending functionality, scalability, and usability of Bitcoin and related projects including Lightning and other layer-2 technologies.

The fellowship is an intensive one-year program based in Brink's London office. Fellows work alongside senior engineers, learning consensus, peer-to-peer networking, wallets, and cryptography. In 2025, Brink's eight funded engineers collectively left over 6,000 review comments on other developers' pull requests. Brink received $5 million from Jack Dorsey's #startsmall fund and a $150,000 grant from Kraken.

Spiral (Block)

Spiral is Block's (formerly Square) independent Bitcoin development arm, established in 2019 as Square Crypto and rebranded in 2022. Spiral pays grants in BTC to developers working on the broader Bitcoin ecosystem, including Lightning, wallets, payments, and swaps.

Spiral has funded over 100 open-source projects and supports more than 30 developers, designers, and product managers working full-time on Bitcoin tooling. Its most significant contributions are the Lightning Development Kit (LDK) and the Bitcoin Development Kit (BDK): open-source libraries that abstract low-level complexity for developers building wallets and Lightning applications. For a deeper look at these developer tools, see the Bitcoin development tools landscape.

Applications are open year-round. Spiral prioritizes projects that improve Bitcoin's privacy, security, scalability, and user experience.

Human Rights Foundation Bitcoin Development Fund

The HRF Bitcoin Development Fund was launched in 2020 with a unique mandate: funding Bitcoin projects that advance financial freedom for the 6.2 billion people living under authoritarian regimes. Since launch, the fund has granted $9.6 million in BTC to 319 projects across 62 countries.

HRF distributes grants quarterly, denominated in satoshis. Recent quarterly distributions have ranged from 800 million to 1.5 billion satoshis per round. Focus areas include open-source development, censorship-resistant communications, mining decentralization, and privacy tools. Applications are accepted year-round, with grantee announcements at the end of each quarter.

Maelstrom

Maelstrom, Arthur Hayes's family office, launched its Bitcoin grant program in 2024. Grants range from $50,000 to $150,000 per developer annually, issued as monthly payments in BTC, USDC, or USDT over 12-month periods. Developers can stack grants up to a $250,000 annual cap.

The program currently funds four full-time developers. Half of Maelstrom's grantees work on privacy-focused technologies, specifically Silent Payments and Payjoin. Jonathan Bier of Farside Investors serves as the grant program administrator, with Hayes on the review committee.

Chaincode Labs

Chaincode Labs is a New York-based Bitcoin research and development center that has trained a significant portion of today's active Bitcoin Core contributors since 2016. Rather than issuing grants directly, Chaincode operates as an educational pipeline.

The BOSS (Bitcoin Open-Source Software) Challenge is a structured three-month program: one guided month of coding exercises followed by two months of advanced mentorship. Graduates are connected with funding organizations like OpenSats, Spiral, Brink, and Maelstrom for full-time open-source work. Chaincode also publishes a freely available Bitcoin protocol development curriculum used by developer education programs worldwide.

Btrust

Btrust is a nonprofit founded by Jack Dorsey and Jay-Z focused on decentralizing Bitcoin development by cultivating talent in the Global South. In 2025, Btrust's active grantee count grew from 5 to 18 (a 260% increase), with its geographic footprint expanding across Nigeria, Kenya, Uganda, Morocco, and Egypt.

The organization offers starter grants for early contributors and long-term grants for developers ready to commit full-time. In 2025, Btrust allocated over $1 million in developer and event grants. The 2026 Btrust Builders program continues to scale, partnering with Chaincode Labs on the BOSS Challenge to create a pipeline from learning to contributing.

Other Funding Sources

Several additional organizations contribute to Bitcoin development funding:

• Vinteum: a Brazilian nonprofit funding open-source developers in Latin America, currently supporting three full-time developers working on Bitcoin Core, BDK, Fedimint, and Utreexo
• Blockstream: employs developers working on Liquid Network, Lightning (Core Lightning), and Bitcoin research. Their Lugano research center offers CHF 100,000 grants to startups building on Blockstream technology
• MIT Digital Currency Initiative: an academic research group at MIT Media Lab that has historically funded Bitcoin Core developers and published peer-reviewed Bitcoin research
• Summer of Bitcoin: a global internship program matching university students with open-source Bitcoin projects, funded by OpenSats and industry sponsors
• Corporate sponsors: companies like Coinbase, Gemini, BitMEX, and Paradigm have funded individual Core developers directly through salary sponsorships or one-time grants

Grant Focus Areas

Different organizations concentrate on different parts of the Bitcoin stack. The following table maps grant programs to their primary technical focus areas.

Many developers receive funding from multiple sources over their careers. A common path is: Chaincode BOSS Challenge or Summer of Bitcoin for initial onboarding, followed by a Brink fellowship or OpenSats grant for full-time work, with occasional supplementary grants from HRF or Maelstrom for privacy-specific projects.

Bitcoin vs. Ethereum: Two Models of Development Funding

Bitcoin and Ethereum represent opposite ends of the development funding spectrum. The Ethereum Foundation holds billions of dollars in ETH from the 2014 presale and distributes tens of millions annually through its Ecosystem Support Program (ESP). In Q1 2024 alone, the Foundation awarded $32.65 million in grants. The Foundation sets priorities through a wishlist and Requests for Proposals (RFPs), effectively directing the ecosystem's research agenda.

Bitcoin has no equivalent. There was no presale, no ICO, no foundation endowment, and no block subsidy earmarked for developers. Every dollar funding a Bitcoin Core contributor comes from a company, philanthropist, or nonprofit that chose to donate. This creates both a vulnerability and a strength: funding can be inconsistent, but no single entity can set the development agenda or threaten to cut off a developer who works on something unpopular.

The tradeoff is real. Bitcoin's consensus changes move slowly because there is no foundation to champion proposals. But that same decentralization means the protocol resists capture. Developers funded by Brink, Spiral, OpenSats, and HRF work on overlapping but independent agendas, and no funder controls commit access to the Bitcoin Core repository.

How to Apply for a Bitcoin Development Grant

Most grant programs share similar expectations. Here is a practical framework for applicants:

1. Build a public track record: contribute to Bitcoin Core, LDK, BDK, or another open-source Bitcoin project on GitHub. Review pull requests, fix bugs, or improve documentation. Grant committees evaluate demonstrated ability, not resumes.
2. Start with an educational program: Chaincode's BOSS Challenge, Summer of Bitcoin, or Btrust's starter grants provide structured onboarding with mentorship.
3. Write a clear proposal: describe what you will work on, why it matters for Bitcoin, and what deliverables you expect to produce over 12 months. Programs like OpenSats and Brink expect specific, scoped plans.
4. Apply to multiple programs: there is no exclusivity requirement. Many developers hold grants from two or more organizations simultaneously.
5. Engage the community: participate in Bitcoin Optech discussions, review others' code, and attend developer meetups. The Bitcoin development community is small enough that reputation matters.

For developers interested in building on Bitcoin's second layer, the Bitcoin development tools landscape provides a comprehensive guide to the SDKs and frameworks available, including tools like Spark for building on Bitcoin's Layer 2.

Frequently Asked Questions

How do Bitcoin Core developers get paid?

Bitcoin Core developers are funded through a mix of nonprofit grants (OpenSats, Brink, HRF), corporate sponsorships (Spiral/Block, Blockstream, Coinbase), and individual donations. There is no protocol treasury or foundation paying salaries. Some developers hold grants from multiple organizations simultaneously, while others contribute part-time alongside other employment.

How much do Bitcoin development grants pay?

Grant amounts vary by organization and developer experience. Maelstrom's grants range from $50,000 to $150,000 annually. Brink and OpenSats grants are typically structured as year-long stipends competitive with senior software engineering salaries. HRF grants are smaller and project-scoped, often ranging from $10,000 to $100,000 per quarter. Exact amounts are not always publicly disclosed.

Can I apply for a Bitcoin development grant as a beginner?

Yes, but through entry-level programs. Chaincode Labs' BOSS Challenge, Summer of Bitcoin, and Btrust's starter grants are designed for developers new to Bitcoin. These programs provide mentorship and structured learning before connecting graduates with full-time grant opportunities. Brink's fellowship specifically targets experienced software engineers who are new to Bitcoin protocol development.

Why does Bitcoin not have a development foundation like Ethereum?

Bitcoin launched in 2009 without a presale, ICO, or corporate entity. Satoshi Nakamoto did not create a foundation or reserve tokens for development. This was a deliberate design choice: avoiding any central point of control over the protocol. The tradeoff is that development funding requires continuous community effort, but no single organization can dictate Bitcoin's technical direction.

What areas of Bitcoin development need the most funding?

Code review is consistently cited as the biggest bottleneck. Bitcoin Core has a small number of active reviewers relative to the volume of proposed changes, and every change to consensus-critical code requires extensive scrutiny. Privacy improvements ( Silent Payments, Payjoin), Layer 2 protocol research ( scaling solutions), and testing infrastructure are also underfunded relative to their importance.

Are Bitcoin development grants paid in BTC or fiat?

It depends on the organization. Spiral pays grants in BTC. HRF denominates grants in satoshis and pays in BTC. Maelstrom offers a choice of BTC, USDC, or USDT. OpenSats and Brink typically pay in fiat (USD) or BTC depending on grantee preference. Tax implications vary by jurisdiction, so grantees should consult a tax professional.

How many full-time Bitcoin Core developers are there?

Estimates vary, but approximately 40 to 50 developers contribute to Bitcoin Core regularly, with a smaller subset working full-time. Brink funds eight engineers, Spiral supports over 30 across the ecosystem, and OpenSats has more than 150 active grantees (not all Core-focused). The actual number of developers with commit-level influence on consensus code is much smaller.

This directory is for informational purposes only and does not constitute financial or career advice. Grant amounts, application processes, and program availability change frequently. Always verify current details directly with each organization before applying.