Agents in the Wild

Allen & Overy rolled out Harvey to 3,500 lawyers after a 40,000-query trial

Law firm Allen & Overy (now A&O Shearman) trialled the legal AI assistant Harvey for three months, then rolled it out firm-wide across 43 offices.

Organization
A&O Shearman (Allen & Overy)
Industry
Legal
When
Feb 2023
Evidence
Company reported
Agents and tools
HarveyOpenAI GPT-4

Reported outcome

About 3,500 lawyers asked around 40,000 questions during the trial, followed by a firm-wide rollout across 43 offices.

  • ~3,500
    Lawyers
  • ~40,000
    Trial queries
  • 43
    Offices

Caveats

Stated by the company that uses the agent (blog, earnings call, interview). Not independently audited.

  • Query counts come from the firm's own announcement.
  • The firm stated that every output needs careful review by a lawyer.
  • Usage counts do not tell you about accuracy or time saved.

What the agent does

Lawyers use Harvey to draft documents, summarize contracts, and research legal questions in many languages. A lawyer reviews every output before it reaches a client.

How the rollout worked

The firm ran a beta from November 2022 through its Markets Innovation Group, a mixed team of lawyers and developers. After the trial it made Harvey available firm-wide. A Harvey founder said about a quarter of the firm used it daily and 80% monthly.

What to copy

  • Run a time-boxed trial with a named owner team before a full rollout.
  • Write the human-review rule down and make it part of the workflow.
  • Track daily and monthly active users, not just licenses.

Starter prompt

Written by us. Not legal advice.

You are assisting a qualified lawyer. Draft, do not decide.

Task: summarize the attached {contract type} for {client role}.
Output:
1. Parties, term, and governing law.
2. Obligations of {client role}, as a numbered list with clause numbers.
3. Unusual or one-sided clauses, each with the clause number and why.
4. Questions the lawyer should ask the client.

Quote clause text exactly when you rely on it. If something is unclear,
say "unclear" instead of guessing.

Sources

  1. A&O announces exclusive launch partnership with Harvey — A&O Shearman, Feb 2023
  2. As Allen & Overy deploys GPT-based legal app Harvey firmwide — LawSites, Feb 2023

Added Oct 16, 2026. Spotted an error? Send a correction.

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