caselaw-access-api

name	caselaw-access-api
title	Caselaw Access Project API
description	Query 360+ years of US case law via the Harvard Caselaw Access Project
author	wentorai
author_url	https://github.com/wentorai/research-plugins/tree/main/skills/domains/law/caselaw-access-api
license	MIT
version	0.1.0
execution_mode	open
jurisdiction	us
practice	litigation
language	en

Caselaw Access Project API

Overview

The Caselaw Access Project (CAP) by Harvard Law School provides free access to 6.9 million US court opinions spanning 360+ years. The REST API enables searching, filtering, and downloading full-text case opinions from all federal and state courts. No authentication required for metadata; API key (free registration) required for full text of post-1923 cases.

API Endpoints

Base URL

https://api.case.law/v1/

Cases

# Search cases by keyword
curl "https://api.case.law/v1/cases/?search=free+speech&decision_date_min=2020-01-01"

# Get a specific case by ID
curl "https://api.case.law/v1/cases/12345678/"

# Filter by jurisdiction and court
curl "https://api.case.law/v1/cases/?jurisdiction=us&court=us-sup-ct&search=miranda+rights"

# Filter by date range
curl "https://api.case.law/v1/cases/?decision_date_min=2015-01-01&decision_date_max=2025-12-31"

# Get full text (requires API key for post-1923)
curl -H "Authorization: Token YOUR_API_KEY" \
  "https://api.case.law/v1/cases/12345678/?full_case=true"

Query Parameters

Parameter	Description	Example
search	Full-text search	search=due+process
jurisdiction	Filter by jurisdiction slug	jurisdiction=cal (California)
court	Filter by court slug	court=us-sup-ct
decision_date_min	Earliest date	decision_date_min=2020-01-01
decision_date_max	Latest date	decision_date_max=2025-12-31
cite	Search by citation	cite=410+U.S.+113