Twitter/X

Calderwood & Harkness is a synthetic law firm built by EngramLab in collaboration…

Brief

Calderwood & Harkness is a synthetic law-firm dataset and agent environment (over 100M tokens, 250 client cases) created by EngramLab with Harvey to model how lawyers accumulate firm-specific knowledge. The goal is to enable agents to reuse memory and experience across tasks—reflecting realistic legal workflows—rather than treating each task as an isolated benchmark run.

Why it matters

Calderwood & Harkness is a synthetic law firm built by EngramLab in collaboration with Harvey containing over 100 million tokens of documents and 250 client cases.

Key details

  • The environment is designed to let legal agents accumulate memory and experience across tasks (mirroring real law practice) rather than starting each task from scratch as current agent benchmarks do.
  • EngramLab announced the project on 2026-03-11 (last updated 2026-04-04) and co-developed the open-source LAB expansion with Harvey’s research team, including contributors Julio Pereyra, niko grupen, and gabe pereyra; results will be published soon.
Cleaned source text

In collaboration with @harvey, we’re excited to build a new kind of agent environment to reflect realistic knowledge work: an entire synthetic law firm, Calderwood & Harkness, with over 100M (!) tokens of documents and 250 client cases. 💼

Today’s AI models know a lot about the law, but don’t understand how the law is practiced, because this information remains proprietary within firms. Unlike how agents are benchmarked today – starting each task from scratch with a new set of context — lawyers accumulate knowledge over time, building on years of experience.

Calderwood & Harkness makes it possible for agents to do the same. Legal agents do many tasks in the same environment, making it possible to leverage memory and experience to do better work over time.

We’ve had a great time co-developing this benchmark with Harvey’s research team, partnering @ItsJulioPereyra @nikogrupen @gabepereyra. We’ll share more results on this soon.

Julio Pereyra (@ItsJulioPereyra)

Article

LAB: Law Firm Knowledge

We are open-sourcing our next LAB expansion: a synthetic law firm, Calderwood & Harkness (“C&H” or “the firm”). Built in collaboration with @engramlab, the firm contains work product from more than

— https://nitter.net/ItsJulioPereyra/status/2085772997944803682#m