Sam Blackshear, Co-founder and CTO of Mysten Labs and the creator of the Move programming language, announced on Thursday that he will be leaving Mysten Labs to join Anthropic, where he will work in defensive security research.
The move marks a notable leadership transition at Mysten Labs, the company tied to the Layer 1 blockchain Sui, while bringing one of the Move ecosystem’s key engineers to AI security. On Anthropic’s side, Blackshear’s transition to defensive security research comes as the company expands its AI security efforts—an increasingly critical domain as AI models are more widely used in software development and testing.
Sam Blackshear Confirms Move to Anthropic
Blackshear confirmed his transition to Anthropic in a brief post on X, stating that he will work on defensive security research. He has not released further details regarding his official title, team, or starting date for the new role.
I am leaving Mysten Labs and joining Anthropic to work on defensive security research.
— Sam Blackshear (@b1ackd0g) August 5, 2026
Blackshear is one of the most prominent technical figures associated with the Sui ecosystem. Before co-founding Mysten Labs, he worked at Meta on the Diem project, where he created Move—a programming language designed for digital assets and smart contracts.
At Mysten, Blackshear served as Co-founder and CTO, and was one of five founding members alongside Evan Cheng, Adeniyi Abiodun, Kostas Chalkias, and George Danezis. His move to Anthropic is therefore not just an individual career change, but also a shift for a key technical figure deeply tied to the Move and Sui story from the early days.
Evan Cheng Steps Back Into CTO Role
Shortly after Blackshear’s announcement, Evan Cheng stated he would be “returning to my roots” by leading engineering teams and the research-to-engineering-to-product pipeline. Cheng added that, as CTO and CEO, he will be closer to the technical work and directly involved in operations.
This is a notable detail for the Sui community as it helps narrow the information gap following the departure of a founding CTO. Cheng is not only CEO of Mysten Labs but also a veteran engineer who previously served as Director of R&D at Meta’s Novi Financial and earlier worked at Apple, where he contributed to the LLVM compiler infrastructure.
Cheng stepping into the dual role of CTO helps Mysten maintain continuity in technical leadership, at least during the transition period. Instead of appointing a new technical leader from the outside, Mysten currently has Cheng directly overseeing both corporate operations and technical direction.
Mysten’s Founders Signal Continuity
Responses from Mysten’s founding team signal a desire to maintain stability following Blackshear’s announcement. Adeniyi Abiodun, Co-founder and CPO of Mysten Labs, congratulated Blackshear and expressed happiness for his colleague’s next chapter.
Abiodun also noted that he will continue collaborating with Evan Cheng as Cheng steps into the CTO role, while referencing Kostas Chalkias and George Danezis within the team driving the company’s next phase. For Mysten, this emphasizes that the remainder of the founding team remains actively involved in the transition.
Can’t say enough nice things about @b1ackd0g. Great friend, great colleague, and genuinely happy for his next chapter.
Super pumped to partner with @EvanWeb3 again as he steps in as CTO. He, @kostascrypto, @GDanezis and I are already executing hand in hand on what comes next for…
— Adeniyi.sui (@EmanAbio) August 6, 2026
Why the Departure Matters for Sui
Blackshear’s role is particularly significant for Sui because Move is a core element of the network’s technical architecture. Sui mainnet launched on May 3, 2023; the SUI token is used for gas fees, staking, and network governance, with a total supply capped at 10 billion tokens.
According to DeFiLlama, Sui currently holds approximately $408 million in total value locked in DeFi, a stablecoin market cap of around $436.4 million, 174,927 active addresses, and 13.31 million transactions in 24 hours. CoinGecko recorded SUI trading around $0.68 on the same day, with a market cap of approximately $2.8 billion and 24-hour volume of around $167 million.
Given Sui’s current scale, the departure of a technical figure tied to Move from the early days is notable news. However, Blackshear’s exit does not imply immediate protocol changes: Move has evolved beyond a single individual, while Sui continues to operate with independent engineering teams, validators, and on-chain applications. Mysten has not yet announced a timeline for Cheng’s tenure as CTO, nor any changes to technical priorities such as Move, Walrus, or DeepBook.
Anthropic Deepens Its AI Security Push
On Anthropic’s side, Blackshear joining defensive security research coincides with the company’s expansion of products and initiatives related to cybersecurity. On April 30, 2026, Anthropic launched Claude Security in public beta for Claude Enterprise customers, enabling code scanning for vulnerabilities and patch recommendations powered by Claude models.
The company is also rolling out Project Glasswing, an initiative using frontier AI to safeguard critical software. In a May 22 update, Anthropic stated that Project Glasswing and around 50 partners had identified over 10,000 high- or critical-severity vulnerabilities; by June 2, the program expanded to approximately 150 organizations across more than 15 countries.
With his background in Move and smart contract security, Blackshear brings to Anthropic experience from an environment where code is typically public, assets hold real-world value, and logic flaws can lead to immediate loss. This contrast makes the transition from blockchain infrastructure to AI security particularly intriguing, rather than a routine personnel change between two tech companies.
