| name | courtlistener-api |
| title | CourtListener API Guide |
| description | Legal case law database with PACER data and judge profiles |
| author | wentorai |
| author_url | https://github.com/wentorai/research-plugins/tree/main/skills/domains/law/courtlistener-api |
| license | MIT |
| version | 0.1.0 |
| execution_mode | open |
| jurisdiction | us |
| practice | litigation |
| language | en |
CourtListener API Guide
Overview
CourtListener is a free legal research platform operated by Free Law Project, a non-profit organization dedicated to making legal data freely accessible. The platform hosts one of the largest open collections of U.S. case law, containing millions of court opinions, docket entries, oral arguments, and judge profiles sourced from PACER (Public Access to Court Electronic Records), state court websites, and historical digitization efforts.
The CourtListener REST API provides programmatic access to this extensive legal database, enabling searches across court opinions, dockets, judge biographical data, and court information. The API covers federal courts (Supreme Court, Circuit Courts, District Courts, Bankruptcy Courts) and many state courts, with records spanning from the founding of the republic to the present day.
Legal scholars, law students, practicing attorneys, journalists, policy researchers, and civic technologists use the CourtListener API to conduct legal research, perform empirical legal studies, build litigation analytics tools, track judicial behavior, monitor active litigation, and analyze trends in case law. It serves as a critical resource for computational legal studies and access-to-justice initiatives.
Authentication
No authentication is required for basic API access. The CourtListener API is publicly accessible for read operations. However, creating an account and using an API token provides higher rate limits and access to additional features. Authentication is recommended for production applications.
To obtain an API token:
- Create a free account at https://www.courtlistener.com/
- Navigate to your profile settings
- Generate an API token
- Include it in the
Authorization header
curl "https://www.courtlistener.com/api/rest/v4/opinions/?q=first+amendment"
curl -H "Authorization: Token YOUR_TOKEN" \
"https://www.courtlistener.com/api/rest/v4/opinions/?q=first+amendment"
Core Endpoints
opinions: Search Court Opinions
Search and retrieve the full text of court opinions (judicial decisions) across all indexed courts.
- URL:
GET https://www.courtlistener.com/api/rest/v4/opinions/
- Parameters: