“ACS Infra: free access to large base models for LLM psychology research” by Martin Vaněk, Jan_Kulveit, Ondřej Havlíček, Ivar Frisch, Veronika_H, vgel, Raymond Douglas, Charlie Amis, Faw Ali

LessWrong (30+ Karma) · Oct 20, 2026 · 7m

TL;DR: We're opening a platform serving large open base models to researchers and tinkerers working on LLM psychology and adjacent areas. It's free and comes with logprobs, activation harvesting and steering, a browser workbench, and a loom. Read here what research we’d like to see and apply for access at https://infra.acsresearch.org/signup.

Much of what we want to understand about LLMs (e.g. where their beliefs, propensities and characters come from) is split between pre-training and post-training. If you want to claim that post-training instilled certain psychological properties, such as a…