For AI agents: read the machine-readable documentation index at /llms.txt or the single-file full reference at /llms-full.txt.
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Comparison · checked November 1, 2026

Where to look up US law: legal code databases compared

City codes, state statutes and federal law live on different sites, run by different people, under different rules. This page sets out what each major source covers, what it costs and how a program or an AI agent can reach it.

Corpus is one of the options, so every line about another provider links the page it came from, and each provider gets a line on where it is the better choice.

The short answer

If you needUse
The official text of one city’s codeThe publisher the city’s own website links to, usually Municode or ICC Code Solutions.
The official US CodeThe Office of the Law Revision Counsel, at uscode.house.gov.
One state’s statutesThe state legislature’s own site, or Justia or FindLaw for a free copy.
Case lawCourtListener (free), or Westlaw or Lexis with a subscription.
One search across many cities and states, or an API or MCP server for an AI agentCorpus, within the jurisdictions it lists. For a city Corpus lacks, Open Legal Codes, one city at a time.

City and county code publishers

Most US cities pay a codifier to keep their code of ordinances up to date and host it online. Two groups now host most of those codes. When a city’s own website links to one of them, that copy is the one the city stands behind.

Municode (CivicPlus)

  • City and county codes. CivicPlus says it serves 4,300+ local governments with Municode. source
  • CivicPlus acquired Municode in August 2021. source
  • Free to read in a browser at library.municode.com, with no account. source
  • CivicPlus also sells MuniPRO, a research product with search, organization and tracking tools; the page we read gives no price. source
  • The CivicPlus Municode page we read mentions no public API or MCP server. source
  • The better choice for: The code a city itself publishes, updated as each supplement is adopted, for every government on Municode.

ICC Code Solutions (American Legal Code Library, eCode360)

  • Since July 2026 General Code (eCode360) and American Legal Publishing operate together as ICC Code Solutions, part of the International Code Council. Its announcement says more than 7,000 communities. source
  • American Legal’s Code Library is free to read in a browser, organized by state and then city. source
  • eCode360 is free to browse; search across many codes is part of a $195-a-year Professional Subscription. source
  • The eCode360 API is available to General Code client cities for their own code, licensed per municipality. source
  • The better choice for: The official copy of any client city’s code, with archived versions and, on eCode360, a paid search across many codes.

Free statute and regulation websites

A free copy of state statutes or federal law is easy to find. What differs is who stands behind the text, how current it is, and whether a program may reuse it. Each state legislature publishes its own state’s statutes on its own site, in its own format.

The official publishers (US Code, eCFR, state legislatures)

  • On November 1, 2026 the House’s Office of the Law Revision Counsel showed the US Code current through Public Law 119-136, with the whole Code downloadable. source
  • The eCFR is updated continuously and says it is not an official legal edition of the CFR. source
  • Free, with no account, and the Office of the Law Revision Counsel offers downloads of the Code. source
  • The better choice for: The text with the strongest legal standing and the newest amendments, and bulk downloads of federal law.

Justia

  • Free copies of the US Code and state codes, kept as dated editions: its URLs carry the year, as in /codes/california/2025/. source
  • Its robots.txt disallows none of the AI crawlers we tested. Justia’s pages showed us a security check on November 1, 2026, so this row rests on its URLs and robots.txt rather than a fresh reading. source
  • The better choice for: Free reading of a state code by edition year, next to case law.

Cornell Legal Information Institute (LII)

  • A readable copy of the US Code. On November 1, 2026 it was current through Public Law 119-124, behind the official 119-136. source
  • Free, no account; its state pages are organized one state at a time. source
  • The better choice for: Federal law with cross-references and plain-language legal explainers.

FindLaw

  • A free source of state laws, the US Code and court opinions, with one search across all its codes. source
  • Thomson Reuters announced the sale of FindLaw to Internet Brands on December 2, 2024. source
  • The Internet Brands terms of use prohibit scraping. source
  • The better choice for: A free state statute next to plain-English legal articles and a lawyer directory.

APIs, datasets and MCP servers

These are for programs and AI agents rather than readers. What matters is coverage, price, whether a key is needed, and whether one search spans many jurisdictions.

OpenLaws

  • Statutes and regulations for 53 US jurisdictions: federal, the states, DC and Puerto Rico. Its pricing page does not mention city codes. source
  • Law Data API from $2,500 a month, with no free tier; an evaluation key is available on request. The pricing page does not mention an MCP server. source
  • The better choice for: A contracted production feed of state and federal statutes, with bulk exports.

Vaquill (API, MCP server and the Open US Law dataset)

  • Federal law plus statutes and regulations for 56 US jurisdictions. Its coverage page lists no city codes. source
  • API key or OAuth. Plans are sold in API credits (20,000 or 200,000 a month); dollar prices are shown after sign-up. source
  • The open dataset, Open US Law, is licensed CC BY-NC 4.0, which rules out commercial use without a license. source
  • The better choice for: Statutes and regulations for every state and territory through one API or MCP server.

CourtListener (Free Law Project)

  • Case law: millions of federal and state court decisions, plus PACER data, oral argument transcripts and judge data. source
  • Free account required. The default API limit is 5 requests a minute and 125 a day, higher with a paid membership. source
  • Available inside Claude as an MCP connector since May 12, 2026. source
  • The better choice for: Case law. Corpus has none.

Which AI crawlers each site turns away

We fetched each site’s robots.txt on November 1, 2026 and tested it against the training crawlers (GPTBot (OpenAI), ClaudeBot (Anthropic), Google-Extended (Google), CCBot (Common Crawl)) and the crawlers that fetch pages for AI search and for a user’s question (OAI-SearchBot, ChatGPT-User, Claude-User, PerplexityBot). robots.txt states a policy; it does not show whether a site’s bot protection lets a given request through.

SiteDisallows
Municode LibraryGPTBot, ClaudeBot, anthropic-ai, Google-Extended, CCBot Also declares “search=yes, ai-train=no”.
American Legal Code LibraryGPTBot, ClaudeBot, anthropic-ai, Google-Extended, CCBot Also declares “search=yes, ai-train=no”.
eCode360GPTBot, ClaudeBot, anthropic-ai, Google-Extended, CCBot, Bingbot Also declares “search=yes, ai-train=no”.
JustiaNone of those tested
Cornell LIINone of those tested
FindLawNone of those tested
US Code (OLRC)None of those tested
eCFRNone of those tested
UpCodesGPTBot, ClaudeBot, Google-Extended, CCBot, OAI-SearchBot, ChatGPT-User, Claude-User, PerplexityBot Disallows every crawler not named in an allow list, AI assistants included.
CorpusNone of those tested

Corpus

  • 2,473,703 provisions: federal law (the US Code and the CFR), statutes for 48 states and DC and the codes of 95 cities.
  • Partial for now: Georgia, Ohio and Tennessee.
  • Not yet covered: Arkansas and Hawaii.
  • Text is collected ahead of time and indexed, so one search covers every listed jurisdiction at once, by meaning or by keyword.
  • Free to search on the website. The API and MCP server take 250 searches a month with no key and 1,000 with a free key, then $0.005 a search.
  • Each section page names the source its text was taken from, and links it where one exists.

The full list, with counts per jurisdiction, is on the coverage page. To connect an assistant, see the MCP server or the API.

Where Corpus is the weaker choice

  • No case law. Use CourtListener, or a professional platform.
  • Corpus is not an official publisher. For a filing or a court, rely on the publisher’s copy each section links to.
  • Far fewer cities than the code publishers host, which serve thousands of governments.
  • No annotations, case notes or citator such as KeyCite or Shepard’s.

Check it yourself

These are the pages each line above was read from. Read them rather than trusting our summary of them.

Also compared: AI legal research and code tools, compared.

Try it

Search federal, state and city law at once

Each result cites its section and links the source it was taken from.

Search the lawConnect your AI assistant

Products, coverage and prices change. This page records what each source said on November 1, 2026; check the source before relying on a line.

Corpus appears in this comparison and is not affiliated with any other provider named. Corpus is not a law firm and does not provide legal advice.