{"schema":"hoh-person-v1","site":"https://humansofhistory.com","slug":"amaury-sechet","fullName":"Amaury Séchet","honorific":null,"altNames":[],"shortDescription":"Historical figure","birthYear":null,"birthDateLabel":null,"birthPlace":null,"deathYear":null,"deathDateLabel":null,"deathPlace":null,"nationality":null,"occupations":[],"era":null,"wikidataQid":null,"infobox":null,"article":{"version":1,"summary":"Amaury Séchet is a French software developer best known as the founder of Bitcoin ABC, the software project whose client launched Bitcoin Cash in August 2017. A former Facebook engineer with a background in compiler design, he became one of the most recognizable and most debated figures of the cryptocurrency scaling wars. After leading Bitcoin Cash through two contentious chain splits, he went on to create eCash (XEC), a redenominated continuation of his original project. His career offers a rare view into how open source governance, economics, and personality collide in decentralized systems.","sections":[{"heading":"Early Life and Background","markdown":"Little verified information is public about the childhood of Amaury Séchet, and he has generally kept personal details out of view even while maintaining a loud presence in technical debates. He is French, and before entering the cryptocurrency world he built a reputation as a systems programmer with a strong interest in language design and compiler engineering [1].\n\nWithin the **D programming language** community he became known under the handle **deadalnix**, contributing to discussions on language semantics and starting his own compiler project, the Snazzy D Compiler, usually shortened to SDC [1]. That work gave him credibility among low level programmers well before Bitcoin made him a public figure, and it shaped the blunt, engineering first style he later brought to cryptocurrency development.\n\nAnyone researching an Amaury Séchet biography quickly notices this gap between his private and public lives: his birth date, family background, and education are not reliably documented in mainstream sources, while his software output and public statements from 2017 onward are extensively recorded [2]."},{"heading":"Path to Prominence","markdown":"Séchet worked as a software engineer at **Facebook**, where he was involved in infrastructure level engineering during the period when the company invested heavily in high performance PHP tooling [2]. He has said in interviews and public talks that he left the company to work on Bitcoin full time as the block size debate intensified [2].\n\nThat debate defined the era he entered. Between roughly 2015 and 2017, the Bitcoin community argued bitterly over whether the network should raise its one megabyte block size limit to allow more transactions per block, or keep blocks small and scale through second layer systems. Séchet sided firmly with the large block camp, arguing that Bitcoin should function as inexpensive peer to peer electronic cash rather than primarily as a settlement layer [3].\n\nFor readers asking who was Amaury Séchet in this period, the answer is a relatively unknown engineer who chose an unusually direct route into the argument: instead of lobbying existing developers, he wrote his own full node implementation. In June 2017 he presented **Bitcoin ABC** (Adjustable Blocksize Cap) at the Future of Bitcoin conference in Arnhem, in the Netherlands, announcing software that would reject the SegWit upgrade and accept larger blocks [3]."},{"heading":"Bitcoin ABC and the Creation of Bitcoin Cash","markdown":"On 1 August 2017, nodes running Bitcoin ABC split from the Bitcoin network, creating a new chain with an eight megabyte block size limit. The result was **Bitcoin Cash** (BCH), which instantly became one of the largest cryptocurrencies by market value because every holder of Bitcoin received an equal balance on the new chain [4]. The event was covered by major financial press as the most significant fork in Bitcoin's history to that point [4].\n\nSéchet served as the lead developer of Bitcoin ABC, which functioned as the reference implementation for Bitcoin Cash. In that role he coordinated the network's scheduled protocol upgrades, which the project ran twice a year, and he pushed through technical changes including a new difficulty adjustment algorithm and the reintroduction of expanded script capabilities [5].\n\nAmong Amaury Séchet achievements, the launch itself remains the most consequential: few individual engineers have initiated a chain split of that scale. Supporters credited him with giving the large block movement working software rather than endless argument. Critics, including many Bitcoin Core supporters, viewed the fork as an unnecessary fracture of the network. Séchet never showed much interest in softening either reaction, and his combative posts became a fixture of cryptocurrency social media [2]."},{"heading":"The Hash War and Governance Battles","markdown":"In November 2018 Bitcoin Cash itself split. A faction led by **Craig Wright** and the mining firm CoinGeek backed a rival client called Bitcoin SV, opposing changes that Bitcoin ABC had scheduled, including canonical transaction ordering. The confrontation became known as the hash war, as each side directed mining power at its preferred chain [6]. The ABC side, supported by figures such as Roger Ver and the mining company Bitmain, retained the Bitcoin Cash name and ticker, while Bitcoin SV continued separately [6].\n\nThe episode confirmed Séchet's position at the center of Bitcoin Cash decision making, and that centrality soon became its own controversy. In 2020 he backed a proposal known as the **Infrastructure Funding Plan**, which would have redirected eight percent of newly mined coins to fund protocol development, primarily Bitcoin ABC [7]. Much of the Bitcoin Cash community rejected the idea as a developer tax that contradicted the currency's ideals.\n\nThe disagreement produced a second split on 15 November 2020. The majority of the ecosystem followed a new client, Bitcoin Cash Node, and kept the BCH name. The minority chain running Séchet's software continued under the ticker BCHA [7]. It was a costly outcome for him in influence and reputation, yet he kept building on the smaller chain rather than conceding."},{"heading":"eCash and Later Work","markdown":"In July 2021 Séchet rebranded the BCHA chain as **eCash**, with the ticker XEC, redenominating the currency so that one old coin became one million new units [8]. He framed the project as a return to the original goal of electronic cash, borrowing its name from the digital money concept associated with cryptographer David Chaum decades earlier [8].\n\nTechnically, eCash under Séchet's direction pursued an unusual hybrid design: it kept Bitcoin style proof of work while layering **Avalanche** consensus on top for fast finality and improved coordination between nodes. The Avalanche post consensus system went live on the eCash network in 2022 [9]. The roadmap he published also included staking rewards for Avalanche participants, which were activated in a later upgrade [9].\n\nSéchet remains a working programmer rather than a figurehead. His commits, technical writing, and long form posts continue to appear under the deadalnix name, and he still argues publicly, often abrasively, with critics of his design choices [2]. As a living person whose main record is code and public commentary, the basic Amaury Séchet facts are best checked against the project's own documentation and contemporaneous press coverage rather than secondhand summaries."},{"heading":"Legacy and Assessment","markdown":"Séchet's place in cryptocurrency history is secure even though its interpretation is contested. He demonstrated that a determined engineer with a working client could split the largest blockchain in the world, a precedent that reshaped how the industry thinks about protocol governance, miner signaling, and the power of reference implementations [4]. Bitcoin Cash, whatever its later fortunes, forced exchanges, wallets, and businesses worldwide to build processes for handling chain splits.\n\nHis career also illustrates the limits of that power. Twice, communities he helped build moved against him: first the Bitcoin SV faction in 2018, then the Bitcoin Cash majority in 2020. Each rupture shrank the network he led while leaving him free to pursue his own technical vision with fewer constraints [7].\n\nAmong developers he is respected for genuine engineering depth, from compiler internals to consensus design, and criticized for a governance style that concentrated decisions in his own hands. Journalists covering the scaling wars regularly described him as one of the era's most consequential and most polarizing figures [2]. Whether eCash ultimately succeeds or not, any honest account of how Bitcoin fractured and evolved between 2017 and the early 2020s has to reckon with his work."}],"faqs":[{"answer":"Amaury Séchet is a French software developer who founded Bitcoin ABC, the node software that created Bitcoin Cash in August 2017. He later founded eCash (XEC) after a 2020 split in the Bitcoin Cash community. He previously worked as a software engineer at Facebook.","question":"Who is Amaury Séchet?"},{"answer":"He is best known for leading the hard fork that split Bitcoin Cash from Bitcoin on 1 August 2017, making him the lead developer of one of the largest cryptocurrencies of that period. He is also known for the 2021 launch of eCash and for integrating Avalanche consensus into a proof of work chain.","question":"What is Amaury Séchet famous for?"},{"answer":"His exact birth date is not reliably documented in public sources. He is French and was active as a professional software engineer, including at Facebook, before turning to full time cryptocurrency development around 2017.","question":"When was Amaury Séchet born?"},{"answer":"After the Bitcoin Cash community split in November 2020 over his Infrastructure Funding Plan, the chain running his Bitcoin ABC software continued under the ticker BCHA. In July 2021 he rebranded it as eCash (XEC), and he remains its lead developer.","question":"What is Amaury Séchet's connection to eCash?"},{"answer":"Deadalnix is the online name Séchet has used for years in programming communities. Under that handle he contributed to the D programming language ecosystem, wrote the SDC compiler project, and continues to publish code and commentary related to eCash.","question":"What was the deadalnix handle?"},{"answer":"He created Bitcoin ABC, the software client whose activation on 1 August 2017 produced the Bitcoin Cash chain, so he is widely described as the founder of Bitcoin Cash. The large block movement behind the fork, however, included many other developers, miners, and businesses.","question":"Did Amaury Séchet invent Bitcoin Cash?"}]},"references":[{"marker":1,"title":"SDC: The Snazzy D Compiler (project repository by deadalnix)","author":"Amaury Séchet","publisher":"GitHub","url":"https://github.com/snazzy-d/sdc","publicationDate":null,"type":"PRIMARY"},{"marker":2,"title":"The Bitcoin Cash Schism Is a Battle for BCH's Soul","author":"CoinDesk staff","publisher":"CoinDesk","url":null,"publicationDate":"2020","type":"NEWS"},{"marker":3,"title":"Bitcoin ABC presentation, The Future of Bitcoin conference, Arnhem","author":"Amaury Séchet","publisher":"Future of Bitcoin Conference","url":null,"publicationDate":"2017-06-30","type":"PRIMARY"},{"marker":4,"title":"Bitcoin 'clone' sees a slow start following split","author":"Reuters staff","publisher":"Reuters","url":null,"publicationDate":"2017-08-02","type":"NEWS"},{"marker":5,"title":"Bitcoin ABC official website and upgrade documentation","author":"Bitcoin ABC developers","publisher":"Bitcoin ABC","url":"https://www.bitcoinabc.org","publicationDate":null,"type":"WEBSITE"},{"marker":6,"title":"Bitcoin Cash Hard Forks in Dispute Over Network's Future","author":"CoinDesk staff","publisher":"CoinDesk","url":null,"publicationDate":"2018-11-15","type":"NEWS"},{"marker":7,"title":"Bitcoin Cash Undergoes Contentious Hard Fork, Splitting in Two","author":"CoinDesk staff","publisher":"CoinDesk","url":null,"publicationDate":"2020-11-15","type":"NEWS"},{"marker":8,"title":"eCash official website and project roadmap","author":"eCash developers","publisher":"eCash","url":"https://e.cash","publicationDate":null,"type":"WEBSITE"},{"marker":9,"title":"Avalanche on eCash: post-consensus launch documentation","author":"Bitcoin ABC developers","publisher":"eCash / Bitcoin ABC","url":"https://avalanche.cash","publicationDate":null,"type":"WEBSITE"}],"image":{"arweaveTxId":null,"originalUrl":null,"attribution":null},"archivedAt":"2026-09-10T00:48:55.031Z"}