CAP Citation Pipeline

Extract case law citation data for U.S. Code sections from CourtListener — no authentication required.

What it does

1. Queries CourtListener's public search API for each USC section
2. Retrieves case metadata (name, court, date, URL)
3. Generates YAML annotation sidecars for us-code-tracker
4. Annotations power the "Case Law" section on statute pages

Quick start

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

# Test with 10 sample sections
python extract.py --sample 10

# Process all sections in a specific title
python extract.py --repo /path/to/us-code --title 18

# Process all sections (slow, ~8 hours for 60K sections)
python extract.py --repo /path/to/us-code --full

Output format

# annotations/title-18/section-111.yaml
targetSection: "18 U.S.C. § 111"
lastSyncedET: "2026-03-31T03:28:58+00:00"
totalCases: 1298
cases:
  - caseName: "United States v. Mobley"
    citation: "344 F. Supp. 3d 1089"
    court: "District"
    date: "2018-10-01"
    sourceUrl: "https://www.courtlistener.com/opinion/7332965/..."
    impact: "interpretation"

Data source

CourtListener — public search API, no authentication required. Rate-limited at 0.5s between requests.

Top cited sections from our analysis:

Section	Cases
42 U.S.C. § 1983	88,031
42 U.S.C. § 2000e	32,717
28 U.S.C. § 1332	26,106
18 U.S.C. § 922	15,800

License

Apache 2.0 (code) / CC0 (data)