Skip to content

Case law

This page is for attorneys who research case law for a matter. It covers how to have the AI find cases, how to keep the ones you want on the matter, how to read and highlight an opinion, and how saved cases reach the matter's AI chat. If you have not worked in a matter's case file before, read Matters first. The chat itself is described in AI chat.

Before you start

You need the Research permission to search case law from a chat, to see a matter's saved cases and to open them. Ask your administrator. Your firm must also have connected CourtListener, which the person who runs your server does once (see AI providers and research). Without it, saved case law does not appear at all. Having the AI find cases also needs an AI provider (see AI).

The cases come from CourtListener, a free database of court opinions run by the Free Law Project. Where a matter's saved cases are depends on whether your firm uses AI:

  • With AI, they are on the matter's AI tab: click Case, then AI, then Case Law at the right of the toolbar. Conversations beside it takes you back to the chats.
  • Without AI, they have a Case Law tab of their own on the Case side. You add cases by citation, read them and highlight them as described below. There is no AI column and no summary, and the sections of this page about the AI do not apply.

Without the Research permission neither is shown.

Find cases with the AI

Research happens in an Agentic conversation on the matter's AI tab (see AI chat). Ask your question as you would put it to a colleague, with the procedural setting: "If I move to compel and the other side then supplements its responses, can I still recover fees?" With the Research permission, the AI can search CourtListener, look up a citation, read whole opinions and search inside them for a phrase, and the steps it takes are shown as it works. It also reads the cases already saved on the matter.

Good to know:

  • The search starts from the state in the matter's Jurisdiction field. Tell the AI if you want another state, federal courts as well, or only decisions after a date.
  • Each case citation in the reply is checked against the opinion and gets a badge (see Check sources and citations).

Save cases to the matter

Saved cases belong to the matter and are shared by everyone who works on it. There are two ways to add one.

  • From a chat. In an Agentic conversation, ask the AI to save the cases: "Save these cases." The reply shows "Saved to case law:" and each case. What the case was cited for goes into its notes. A case that is already saved keeps its place and gets the new point added.
  • By citation. In Case Law, click the + button. Look Up Case Law opens. Enter a reporter citation such as 410 U.S. 113, or a case name, in Citation and click Look Up. Check the preview and click Add to Matter.

When AI is set up, Kosmos writes a short summary of each saved case (about 200 words) a few moments after it is added.

Work with saved cases

In Case Law, type in Search cases... to match case names and citations. Click a case name for View Case, View on CourtListener and Delete. Delete removes the case from the matter, with any highlights made in it. Use the flag column to set a case's importance, from Highest to Lowest. Tick cases to set AI (when AI is set up) or Labels for several at once, or to delete them.

View Case opens the opinion in a new tab. Select a passage and click the highlighter button to save it as a highlight. Highlights made in opinions are listed on the matter's Highlights tab with the others.

Use saved cases in AI chat

Saved cases are available to the matter's AI chat. The AI column sets how: Auto lets the chat decide when a case is relevant, Always includes it every time, and Never keeps it out.

What leaves your firm

The searches and citations go to CourtListener, and the opinions the AI reads come from CourtListener. Your question and what the AI reads are sent to the provider of the chat's model, as for any other question (see What leaves the firm). The opinion text of each saved case is sent to the AI provider (Google Gemini when it is connected, otherwise Anthropic) to write its summary. Whatever you type into the question is sent as written, so leave out names and details it does not need. For the full list, see AI providers and research.

What to check yourself

The searches, the reading of each opinion and the answer are the work of an AI model. Read the opinions before you rely on any of them.

  • Quotations. A quotation in a reply may not match the opinion word for word. The citation badge checks the case, not every quotation.
  • Coverage. The AI reads only the cases it finds. CourtListener does not have every decision, and a case that uses none of the search terms is not found.
  • Good law. Nothing in Kosmos checks whether a later court overruled or limited a case. Check the treatment yourself before you rely on it.
  • New law. A case with no reporter citation yet (a slip opinion), or one nobody has cited, is not settled law.