Bill Commons
Bill Commons is a public, open-source legislative search platform covering the
current session/biennium for all 50 U.S. states plus DC. It provides a web
search UI, a REST API, an MCP (Model Context Protocol) server, and a public
status/coverage page. Public infrastructure first: no paywall on ordinary
search or reasonable API use — anonymous callers get a generous daily cap
(2,000 requests/day per IP, 5,000/day per /24 subnet); a free API key raises
that further, and only high-volume/bulk use is paid. See
/docs/bulk for API keys and
full-corpus snapshots.
See docs/architecture/ARCHITECTURE.md
for the locked architecture and data model.
Production
Hosted on Railway (project billcommons: api, mcp, worker services +
managed Postgres) and Vercel (project billcommons-web). See
docs/operations/deployment-runbook.md
for the full deploy/rollback procedure.
Use with Claude (or any MCP client)
The hosted MCP server gives AI assistants direct access to all 209k+ bills —
no API key, no setup beyond one command:
Claude Desktop: Settings → Connectors → Add custom connector with URL
https://mcp.billcommons.org/mcp. Cursor and other clients: add the same URL
as a Streamable HTTP server in mcp.json.
Ten tools including search_legislation, get_bill_record,
compare_bill_versions, and trace_legislative_history. Full walkthrough
(including REST recipes for agents without MCP):
https://billcommons.org/docs/agents
Architecture at a glance
packages/schema (SQLAlchemy models + Alembic) is the single source of
truth every other package/app imports from — no service owns its own copy
of the data model.
Monorepo layout
Local development setup
Prerequisites
- Python 3.12
- PostgreSQL 16 (with
pg_trgm, unaccent, pgcrypto extensions available)
- Node.js 20+ (for
apps/web)
Python environment
This installs packages/schema and packages/shared as editable installs
(single source of truth for the data model + shared utils), plus the
worker package: .venv/bin/pip install -e workers/ingest. Install the API
package too if you're working on it: .venv/bin/pip install -e apps/api.
Database
Set DATABASE_URL in your environment (or in ~/.config/billcommons/.env,
which is read as a fallback and is never committed):
Requires Postgres 16 with the pg_trgm and unaccent extensions available
(created by migration 0001). Run migrations:
Seeding data locally
Running the apps locally
Tests
Running the stack locally with Docker
This brings up Postgres, the API, the ingestion worker, and the MCP server.
The web app (apps/web) is run separately via npm run dev during local
development (see infra/docker/docker-compose.yml for the placeholder
service definition).
Documentation
License
Apache-2.0. See LICENSE and NOTICE for data attribution
(Open States / Plural Policy, public-domain legislative data).
Contributing
See CONTRIBUTING.md. This project follows the
Contributor Covenant.
Security
See SECURITY.md for responsible disclosure.