Laurent Sifre is a co-founder of H Company, the Paris agentic AI start-up announced in 2024 with a seed round of about $220 million. The company was founded by five people.
In August 2024 three of them, Karl Tuyls, Daan Wierstra and Julien Perolat, left. That left Charles Kantor as chief executive and Laurent Sifre as chief technology officer.
In November 2024 H launched Runner H, an agent platform for computer-use and web tasks. In June 2025 Gautier Cloix, formerly head of Palantir France, replaced Charles Kantor as CEO.
In May 2026 Laurent Sifre stepped down as CTO to head the scientific council.