Meta open-sources MIMESIS user simulator to boost agent training

Meta Superintelligence Labs released MIMESIS, an open-source user simulator trained on real human conversations with explicit reasoning supervision and 13 realistic user behavior modes. It outscored Claude Opus 5 in behavioral realism by 13.4 points, and agents trained with it beat GPT-5.5.

2026-10-09 ~ 2026-10-09 · 2 related posts

• Meta's MIMESIS: 9B user simulator beats GPT-5.5 for training interactive agents — facebook · 2026-10-09
• Meta's MIMESIS: A 9B User Simulator That Beats Claude Opus 5 on Behavioral Fidelity — dair_ai · 2026-10-09