Blackletter raised US$6 million in Seed funding led by Lerer Hippeau. The New York law firm combines senior lawyers with a proprietary AI platform. It serves clients through fixed fees rather than billable hours.
Investor group
Seven Stars, Maple VC, Garage Capital, and Ripple Ventures also joined the round. Several AI founders participated, including Aidan Gomez, Ivan Zhang, and Nick Frosst of Cohere. Jae Lee of Twelve Labs and Sara Hooker of Adaption Labs also invested.
Leadership and clients
Co-founders Jonathan Rosenbluth and David Stewart previously held product and engineering leadership roles at Cohere. Co-founder Avi Brudner was COO of Blue J. Since June 2026, the firm has built a client list of more than 75 early-stage and growth-stage companies and investors.
What the platform does
Lawyers work inside BlackletterOS, the firm's custom legal operating system. The system manages legal matters and stores each client's business context. Blackletter reports that its lawyers complete tasks in less than half the time they would take at a legacy firm.
The new capital will support further development of BlackletterOS. The firm also plans to grow its team of lawyers and engineers. These plans follow its June 2026 exit from stealth.