Nicolas Dorier is a French software developer and the creator of BTCPay Server, the open-source, self-hosted Bitcoin payment processor. His decision to build BTCPay Server in response to BitPay's support for the controversial SegWit2x proposal has become one of Bitcoin's most celebrated origin stories -- a single developer, motivated by principle, building an alternative that would serve thousands of merchants worldwide.
Background
Dorier is a C# and .NET developer with deep expertise in Bitcoin protocol development. He is the author of NBitcoin, the most comprehensive Bitcoin library for the .NET platform, which provides cryptographic primitives, transaction construction, and full protocol support for C# developers. NBitcoin became the foundation on which BTCPay Server was built.
Before BTCPay Server, Dorier contributed to various Bitcoin-related open-source projects and wrote extensively about Bitcoin development. His technical proficiency and commitment to Bitcoin's principles positioned him to act decisively when the blocksize debate reached its peak.
The BTCPay Story
In August 2017, during the height of the Bitcoin block size debate, payment processor BitPay announced its support for SegWit2x -- a hard fork proposal that would have increased Bitcoin's block size and was opposed by much of the Bitcoin community. Dorier responded on Twitter with what became a rallying cry, declaring he would make BitPay obsolete.
Within months, Dorier had delivered on that promise, releasing the first version of BTCPay Server -- a free, open-source alternative to BitPay that required no account, no KYC, no fees, and no trust in a third party. Merchants could run their own payment processor, maintaining full custody of their funds. The story is documented in the broader context of Jonathan Bier's The Blocksize War.
Development Philosophy
Dorier's approach to software development reflects Bitcoin's core values: sovereignty, privacy, and trustlessness. BTCPay Server is designed so that merchants never need to trust anyone -- not the payment processor, not a third-party service, not even the BTCPay Server developers themselves. The code is open-source on GitHub, the server is self-hosted, and the keys never leave the merchant's control.
Under his continued leadership, BTCPay Server has grown to support Lightning Network payments (via LND, Core Lightning, and Eclair), point-of-sale interfaces, crowdfunding, invoicing, and multi-signature wallet integration. The project is funded through donations and grants from organizations including OpenSATS and the Human Rights Foundation.
Significance
Nicolas Dorier demonstrates the power of open-source development as principled resistance. His response to BitPay wasn't a petition, a boycott, or a tweet thread -- it was working code. BTCPay Server has grown from a one-person protest project into critical Bitcoin infrastructure used by thousands of merchants globally, funded by donations and grants rather than venture capital. His story exemplifies the Bitcoin ethos that individuals can build alternatives to institutions they disagree with.
External Links
- Nicolas Dorier on GitHub
- BTCPay Server Official Website
- BTCPay Server on GitHub
- NBitcoin on GitHub
- Nicolas Dorier on Twitter/X
References
- BTCPay Server -- the project he created
- The Blocksize War -- the context that motivated BTCPay Server
- Lightning Network -- integrated into BTCPay Server
- Bitcoin Core -- the software BTCPay Server depends on
- Gavin Andresen -- key figure in the blocksize debate
- Mapping Bitcoin -- directory of merchants many of which use BTCPay Server
- Adopting Bitcoin -- conference focused on practical Bitcoin adoption