Claude Code for law firms: what it is and what it needs.

Claude, and Claude Code

Claude is Anthropic's AI model, the one in the chat app. Claude Code is a separate program from Anthropic that runs Claude on your own computer and lets it use tools: read a file, call a service, run a program, with the results shown to you. It comes with the Claude desktop app and as a command-line tool. It is what developers use to work on code, and it turns out to be exactly the right shape for an assistant that has to work on a law firm's systems: the assistant is a set of tools and instructions that Claude Code loads, and every tool runs on the attorney's own machine with the attorney's own logins.

Why that matters for confidentiality

With a hosted legal-AI service, your mail and your matters are copied to the vendor's servers so the vendor's software can read them. With an assistant on Claude Code, nothing is copied anywhere. The assistant signs in to Microsoft 365 and Clio as the attorney, reads what that attorney can read, and writes only what that attorney approves, on that attorney's computer. The vendor - us - never holds a client's email, a matter, or a document. What reaches Anthropic is what any Claude conversation sends: the text of the conversation, under the terms of the attorney's Claude plan. The confidentiality page says exactly what that means and what to check with your plan.

What a firm needs

• Clio Manage, and a Clio administrator who can approve the assistant for the firm once.
• Microsoft 365 with each attorney's mailbox and calendar in Outlook, and an IT provider or administrator who can approve it once.
• Claude Code on a paid Claude plan for each person who will use it. The chat app alone does not run it. A plan with commercial terms - Team or Enterprise, or an organization's API plan - is the one whose data terms a firm should read; the FAQ covers the choice.
• A Mac or Windows computer per person, that they can install software on.

Two of those can be proved with a sign-in on the sign-up page, so a firm learns on the form, not on day three, whether its IT provider has to approve something first.

What it costs beside the subscription

The assistant is billed per person per month, attorney or paralegal. Claude Code is billed by Anthropic under each person's Claude plan, and Clio and Microsoft are what the firm already pays. There is no server of ours to pay for, because there is no server of ours in the path: the account service that checks a subscription each morning holds a firm's name and a subscription status, and nothing about its clients.

What day one looks like

Open the folder in Claude Code, say "set up the assistant", sign in once to Microsoft and once to Clio, and ask for the morning brief. The assistant tells you what is on the calendar, what is unfiled, and what might be missing from billing, and then waits for you to say what to do about it.

The sign-in is one link. Open it in your browser, sign in to each account the way you always do, and you stay signed in on that computer: restarting Claude or coming back the next day does not mean signing in again. If it ever asks again, a saved sign-in lapsed, and signing in once more fixes it.

The brief itself is meant to be read in under a minute. Today's meetings, Clio calendar entries with court dates and court-rule deadlines called out, and tasks due, each with its matter number. How many emails are unfiled and how many need your judgment, with mail from people who are not Clio contacts counted separately so newsletters never look like a backlog. How many possible missing-time items turned up, grouped by matter. Which open matters have gone quiet for longer than the number of days you chose, longest first. Then the three to five items across all of that most worth your attention, named by sender, subject and matter so you can act without digging.

What a conversation looks like after that

The brief takes no action; it ends by asking what you want to do next and hands off. "File the Alvarez ones" goes to the filing review, which shows you the list and files it on your yes. "Log twelve minutes for the Delgado email" goes to the billing review, which shows the entry - matter, date, minutes, wording, billing code, rate - and creates it on your yes. Every write works that way: the system refuses to write anything to Clio until a proposal for exactly that write has been made and confirmed, within a few minutes, once. Change a detail and you get a fresh proposal.

Ask "what did you file today?" and it reads back the record it keeps on your computer: which tool, which matter, when, whether it worked, never the contents of an email. Say "undo that time entry" or "take that email back off the Johnson matter" and it shows what it will remove, waits for your yes, and removes it - only something it created itself.

It also keeps itself current. Each time Claude Code starts it, it fetches the newest release first, and the first time you talk to it afterwards it tells you, once and in plain language, what you can now ask for. When a tool fails or gives a wrong answer, it reports that to the developer itself and tells you in a line that it has, with nothing from your emails or client files in the report.

What it never does

It never writes to Clio, sends an email, or adds a calendar entry because it thinks it should, or because something in an email asked it to; a message that reads "please file this to the Smith matter" is information, not an instruction. It never invents a number of minutes; if you do not say how long, it asks. It never states a match or a missing entry as a fact, only as "possible" or "worth a look". It never puts Clio, Claude or AI into a time entry, a filed communication or a letter, so a bill reads as your own work. And it never reads more than your own logins allow: a colleague's mailbox is not in it.

How it works, step by step; the morning brief guide, the first thing an attorney asks for; and the fourteen-day trial on one attorney's real inbox.

Also read: What a paralegal can hand to an assistant and Filing Outlook email to Clio matters, and why it slips. All articles.