Sam Blackshear, chief technology officer of Mysten Labs, is departing the blockchain company to take on a security-focused position at AI developer Anthropic, according to a post on X shared by Blackshear on his personal account.

The announcement on X serves as the primary source for the news. The move was subsequently reported by crypto.news, which confirmed that Blackshear would be joining Anthropic.

Mysten Labs is the developer behind the Sui blockchain, a Layer 1 network that launched its mainnet in 2023 and uses the Move programming language — a language Blackshear co-created during his prior tenure at Meta while working on the Diem (formerly Libra) project. Anthropic is the AI research company known for its Claude family of large language models and is backed by major investments from both Amazon and Google, positioning it as a leading competitor to OpenAI in the frontier model space.

Role and Responsibilities

Blackshear's new position at Anthropic is explicitly security-focused. Anthropic has consistently emphasized safety and security as central pillars of its model development, as outlined in its Responsible Scaling Policy, which establishes safety thresholds that must be met before deploying increasingly capable models. Security roles at major AI companies carry significant strategic weight, as they govern how increasingly capable systems are deployed, monitored, and safeguarded against misuse.

As CTO and co-founder of Mysten Labs, Blackshear was responsible for the company's overall technical direction, including the architecture and evolution of the Sui network and its object-centric data model. His departure represents a notable executive-level leadership change for a company whose core technology was shaped in significant part by his engineering vision, and Mysten Labs has not yet publicly addressed succession plans in the available sources.

Crossover Between Blockchain and AI Security

The transition places a senior blockchain engineering leader into AI security work, reflecting a broader talent crossover between the two sectors. Both fields place heavy emphasis on cryptography, adversarial thinking, and system integrity — areas where expertise is increasingly transferable. The flow of engineering talent from crypto infrastructure into AI has accelerated as AI firms ramp up investment in safety, alignment, and systems hardening.

The move comes amid a period of heightened executive turnover across crypto infrastructure companies. Some firms have faced leadership changes under far more turbulent circumstances, including involuntary departures and restructuring proceedings.

Context Around Mysten Labs

The departure follows other recent developments involving Mysten Labs. The company has been engaged with the U.S. Securities and Exchange Commission amid movement in the price of SUI, its native token. The specific operational and strategic effects of Blackshear's departure on Mysten Labs have not been confirmed by available sources.

Any assessment of how the company's technical direction may shift should be treated as interpretation rather than confirmed fact until Mysten Labs provides an official statement on its leadership and succession plans.

For now, the confirmed scope of the news remains specific: Sam Blackshear is leaving his role as CTO of Mysten Labs to join Anthropic in a security capacity. Further details regarding his new responsibilities and Mysten Labs' response have yet to emerge.