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US court opinions in Duaer

In Duaer: CourtListener: US federal and state court opinions by words, court, and filing date, with citations and a snippet. One successful search uses 1 credit.

What you get

Duaer US court opinions searches the full text of US federal and state court opinions on CourtListener. Filter by court and filing date, and sort by relevance or newest first.

Pick Duaer Data → US court opinions in the node creator, or open the data market. Related: US Congress bills, US Federal Register.

When to use it

  • Find recent Supreme Court opinions that mention privacy.
  • Collect Ninth Circuit copyright opinions filed since 2025.

When not to use it

Search on the canvas

  1. Open the node creator and pick Duaer Data → US court opinions.
  2. Fill Words (such as fourth amendment cell phone). Optional: Court (scotus, ca9), Filed After (2020-01-01), Sort (newest).
  3. Limit defaults to 10, max 20. Execute.

A search uses 1 credit only when it returns rows. No rows, wrong input, or an upstream failure uses 0.

Call the API

  • GET https://api.duaer.com/v1/data/court-opinions?words=fourth%20amendment%20cell%20phone
  • Authorization: Bearer <Duaer key>

The call skill below matches Copy skill in the Duaer data market, with parameters, examples, and result fields.

Call skill

Same text as Copy skill.

---
name: duaer-court-opinions
description: >-
  Duaer US court opinions. CourtListener: US federal and state court opinions by words, court, and filing date, with citations and a snippet.
  One successful search uses 1 Duaer credit.
---

# Duaer US court opinions

Duaer US court opinions searches the full text of US federal and state court opinions on CourtListener. Filter by court and filing date, and sort by relevance or newest first.

## When to use

- Find recent Supreme Court opinions that mention privacy.
- Collect Ninth Circuit copyright opinions filed since 2025.

## When not to use

- Bills and laws in Congress. Use https://skills.duaer.com/congress-bills.md.
- Federal agency rules. Use https://skills.duaer.com/regulations.md.

## Call

`GET https://api.duaer.com/v1/data/court-opinions?words=fourth%20amendment%20cell%20phone`

Header: `Authorization: Bearer <Duaer key>`

Use an account key or a model API key.

Get a Duaer key: https://skills.duaer.com/keys.md

## Parameters

Provide `words` or `court`.

- `words` — Words to search in opinions, such as fourth amendment cell phone.
- `court` — Optional. CourtListener court ids such as `scotus`, `ca9`, or `cadc`, separated by spaces.
- `filedAfter` — Optional. Earliest filing date as YYYY-MM-DD.
- `sort` — Optional. `relevance` or `newest`. Default `relevance`.
- `limit` — Optional. Rows to return, from 1 to 20. Default 10.

## Examples

- `GET https://api.duaer.com/v1/data/court-opinions?words=privacy&court=scotus&sort=newest` — the newest Supreme Court opinions about privacy.
- `GET https://api.duaer.com/v1/data/court-opinions?words=copyright&court=ca9&filedAfter=2025-01-01` — Ninth Circuit copyright opinions since 2025.

## Result

The response is `{ "items": [...] }`. Each item has `source`, `title`, `url`, and `summary`, plus:

- `caseName`, `court`, `courtId` — case and court.
- `dateFiled`, `docketNumber`, `citations` — filing date, docket, and reporter citations.
- `citedBy`, `status`, `judge` — how often other opinions cite it, publication status, and judge.
- `snippet` — the start of the opinion text.

Fields without a value are left out.

## Credits

A search that returns at least one row uses 1 credit.
An empty search, a search that finds nothing, or a failed search uses 0.
Wrong input returns 400 with a message and uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.

## Related

- https://skills.duaer.com/congress-bills.md — Duaer US Congress bills
- https://skills.duaer.com/federal-register.md — Duaer US Federal Register

Questions

How many credits does a US court opinions search use in Duaer?

One credit when Duaer returns rows. A search with no rows or an error uses 0.

Which court ids does Duaer US court opinions accept?

CourtListener court ids: scotus for the Supreme Court, ca9 for the Ninth Circuit, cadc for the D.C. Circuit. Separate several courts with spaces.

In this section

Get started

US Congress bills in Duaer

In Duaer: Congress.gov: US bills, resolutions, and public laws with their sponsor chamber and latest action. One successful search uses 1 credit.

Get started

US Federal Register in Duaer

In Duaer: US federal rules, proposed rules, notices, and presidential documents, newest first, with agencies, abstract, and PDF. One successful search uses 1 credit.