US laws for your AI agents
Vaquill AI is the open API for US primary law, with a source link on every section.
Free credits for personal projects, student work, and academic research.
- 5.4M+
- primary-law sections
- 56
- US jurisdictions
- 3
- access paths: REST, MCP and SQL
Accounts from 150+ organizations
Constellate
Readiness Systems
- Brent Resh Law, PLLC
- The New Firm, Ltd.
In their words
“Vaquill is the piece that made statutes verifiable rather than merely findable.”
Every US jurisdiction, in one consistent format.
A session law shows what changed and when: signing and effective dates, and the text as passed, struck words included. In 11 jurisdictions it also lists the code sections it changed. Not held: Indiana and Tennessee. Partial: Delaware, Oklahoma and Colorado.
How session laws workFederal agency guidance
How agencies read their own rules. Not binding law, so it is stored apart and filterable by source.
See all 53 sources
- Revenue Procedures
- Revenue Rulings
- Notices
- Announcements
- Internal Revenue Manual (procedure, not law)
- Written Determinations (PLR, TAM, CCA - not precedent)
- Medicare Internet-Only Manuals (procedure, not law)
- Justice Manual
- Antitrust Division Business Review Letters
- Antitrust Division Leniency Policy
- DOJ & FTC Merger Guidelines
- Advisory Opinions
- Policy Statements
- Circulars
- Compendium of Copyright Office Practices (Third)
- Opinion, Ruling and Administrator Interpretation Letters
- Field Operations Handbook
- Enforcement and Policy Guidance, incl. Compliance Manual
- Sanctions FAQs, with prior versions
- Administrative Rulings
- Guidance (alerts, advisories, notices)
- Beneficial Ownership Information FAQs
- BOI Rulemaking Q&As
- Small Entity Compliance Guide
- AML Act of 2020 implementation material
- Consumer Financial Protection Circulars
- Supervisory Guidance
- Rulings
- Manual of Patent Examining Procedure (MPEP)
- Trademark Manual of Examining Procedure (TMEP)
- Policy Manual
- General Counsel Memoranda
- Division of Advice Memoranda
- Staff Letters (no-action, exemptive, interpretative)
- Supervision & Regulation (SR) and Consumer Affairs (CA) Letters
- Bulletins
- Interpretive Letters
- Financial Institution Letters (FILs)
- HIPAA Guidance
- HIPAA FAQs
- Resolution Agreements & Civil Money Penalties
- Office of General Counsel Advisory Opinions
- Small Entity Compliance Guides
- Advisory Opinions (Export Administration Regulations)
- Commodity Jurisdiction Determinations
- Policy Guidance
- DFARS Procedures, Guidance and Information (PGI)
- Declaratory Rulings
- Policy Statements
- Appliance Standards Guidance and FAQs
Federal administrative adjudications
Decisions as issued. No publisher marks when a later decision overrules one, so check each as you would any decision.
- FTC Part 3 administrative filings
- SEC Commission opinions and adjudicatory orders
- Merit Systems Protection Board (MSPB)
- Board of Immigration Appeals and Attorney General (I&N Dec.)
- NLRB Board decisions
- DOJ Office of Legal Counsel opinions
- CFPB enforcement actions
Federal courts' own rules
Each from the court's own site, apart from the national Federal Rules of Procedure, which are also held.
- 13
- courts of appeals
- 32
- district courts
- 6
- national courts, such as the Tax Court and the Court of Federal Claims
- 1
- set of federal habeas rules
Refresh: CFR daily, US Code weekly, state regulations monthly. Every source comes from its jurisdiction's own official publisher.
Four ways to reach the corpus.
REST
The hosted API.
Your product looks up law a section at a time.
MCP
The same corpus inside an agent.
You want Claude or Cursor to look it up. No code.
SQL over the object store
Query the corpus as a database.
You would rather hold the data and query it.
Vector index
Skip rebuilding retrieval.
You are building AI search and do not want to index it yourself.
- Citation in, section out
- Bluebook, or the form a state’s own courts print. 42 U.S.C. § 1983 and MCR 3.709 both resolve to one exact provision.
- Point-in-time
- Pass asOf to read a section as it stood on a past date. Each answer says if it is a published edition or a reconstruction.
- Change alerts
- Watch a section or a corpus. Signed webhooks and email when the text moves, with old and new text attached.
- Formats per section
- Styled HTML, plain text, the publisher’s PDF and XML, and DOCX where the source offers one.
One call.
curl -G https://api.vaquill.ai/api/v1/us/statutes/resolve \
-H "Authorization: Bearer $VAQUILL_API_KEY" \
--data-urlencode "cite=42 U.S.C. 1983"# pip install vaquill
from vaquill import Vaquill
client = Vaquill() # reads VAQUILL_API_KEY
result = client.statutes.resolve("42 U.S.C. 1983")
if result.resolved and result.section:
print(result.section.citation, result.section.act_id)// npm install @vaquill-ai/sdk
import { Vaquill } from '@vaquill-ai/sdk'
const client = new Vaquill() // reads VAQUILL_API_KEY
const result = await client.statutes.resolve({ cite: '42 U.S.C. 1983' })
if (result.resolved && result.section) {
console.log(result.section.citation, result.section.actId)
}Title 42 › Chapter 21 › Subchapter I › § 1983
§ 1983. Civil action for deprivation of rights
42 U.S.C. § 1983 (2026)
US Code Federal Current through Sep 18, 2026 In force
Every person who, under color of any statute, ordinance, regulation, custom, or usage, of any State or Territory or the District of Columbia, subjects, or causes to be subjected, any citizen of the United States or other person within the jurisdiction thereof to the deprivation of any rights, privileges, or immunities secured by the Constitution and laws, shall be liable to the party injured in an action at law, suit in equity, or other proper proceeding for redress, except that in any action…
Last amended 1996 · 2 amendments · Pub. L. 104-317, Pub. L. 96-170
The Python and TypeScript SDKs wrap the same endpoint. A resolve call costs 2 credits, charged even when a citation does not resolve.
1. Get your key→2. Call the endpoint→3. Ship cited law
What comes with the API
Run live requests and see the real response before you write a line of code.
Learn moreKnow when the law you rely on changes, by webhook or email, down to the section.
Learn moreStatute search and section lookup as native tools in Claude, Cursor and VS Code.
Learn moreThe full corpus as Parquet, free for non-commercial use under CC BY-NC 4.0.
Learn more
API Playground
Run live requests and see the real response before you write a line of code.
Learn moreLaw Change Alerts
Know when the law you rely on changes, by webhook or email, down to the section.
Learn moreMCP Server
Statute search and section lookup as native tools in Claude, Cursor and VS Code.
Learn morePricing
Pro
Where most builds start.
- 20,000 API credits included every month
- Law change alerts by email
Bootstrapped, under 10 people?
Business at a reduced rate. Email contact@vaquill.ai and tell us about your team.
Who this is for
- ·Businesses testing us as their data backend
- ·Lawyers verifying answers in Claude or ChatGPT
- ·Developers evaluating coverage before they build
Business
For shipping our data inside your product.
- 200,000 API credits included every month
- Law change alerts by webhook Signed webhooks and up to 100 watches.
- Point-in-time state law Read a section as it stood on a past date, rebuilt from the changes we have tracked.
Who this is for
- ·Legal tech products serving their own users
- ·Compliance platforms tracking every US jurisdiction
- ·AI teams grounding agents at scale
Not building a business on it yet? Personal projects, student work, and academic research get free credits. Email contact@vaquill.ai with what you are building.
Sign up to see pricing.
What a license gives you
- Full corpus sync into your own database
- The source PDFs and text files we collect
- Train and fine-tune on all of it
- Redistribution and white-label terms in writing
- Volume pricing, custom SLA, and invoicing
Frequently asked questions
US primary law other than case law: statutes, regulations, constitutions, court rules, executive orders, agency guidance, and agency adjudications. Federal plus all 50 states, DC, Puerto Rico, Guam, the Northern Mariana Islands, the US Virgin Islands and American Samoa, about 5.4M+ sections. State session laws, the acts as each legislature passed them, are served alongside: 20,604 acts from the 2025 sessions across 50 jurisdictions, with signing and effective dates. The coverage section above breaks it down corpus by corpus, and GET /api/v1/us/statutes/coverage returns the live numbers.