Move creator Blackshear leaves Mysten Labs for Anthropic, 2021 co-founder

Sam Blackshear, who co-founded Mysten Labs in 2021 and created the Move smart-contract language, is leaving the Sui blockchain developer to join Anthropic's defensive security research team.

"When I reflect on my career, I have been happiest doing hands-on technical work while exploring new problem domains," Blackshear said. "This is an opportunity to do both, and I'm motivated to work on security at a time when the balance of power between attackers and defenders is shifting."

Blackshear, who served as chief technology officer, will hand the technical reins to co-founder and chief executive Evan Cheng, who will set Mysten's technical vision going forward. Blackshear said he will remain an advisor to Mysten, stay engaged with developers building on Sui, and support the upcoming Move Foundation, which advances the Move programming language.

The departure lands as AI reshapes blockchain security. Blackshear said a turning point came when he used Anthropic's Claude model to port a static analysis tool he built at Facebook from OCaml-Java to Move and flag potential vulnerabilities. "It just did it," he said, describing triage that was previously manual and would have taken far longer. In April he hosted a panel on how AI coding agents are reshaping smart-contract security, warning the AI arms race is "getting scary."

The move raises questions about Sui's long-term technical direction. Blackshear was the architect behind Move, the language originally developed for Meta's Libra/Diem project, and helped build Sui's layer-1 infrastructure along with related projects such as Walrus. His departure removes a foundational technical figure from day-to-day development at a time when AI is increasingly used to identify software vulnerabilities, automate phishing campaigns, and accelerate attacks on blockchain infrastructure.

Crypto firms have been seeking access to frontier AI models to harden their code, with many models at Anthropic restricted to a small group of companies. Solana Foundation chief information security officer Michael Coates said guardrails for advanced models make sense, but verification programs need streamlining to put the best models in defenders' hands "because attackers will have something capable enough."

For Sui, the immediate question is whether Cheng and the remaining team can sustain the technical momentum Blackshear drove. Investors reassessing leadership stability could weigh on the SUI token in the near term, though Blackshear's continued advisory role and the Move Foundation's launch provide some continuity. The network's next major upgrade and developer activity will be watched as signs of whether the transition holds.

This article is for informational purposes only and does not constitute investment advice.