# Corpus — US law search, citation, and business formation for agents

> Corpus indexes US federal, state, and municipal law (vector + full-text
> searchable, ingested from official sources — call law.list_coverage for live
> totals) and can form a real LLC in all 50 states and DC, or a nonprofit
> corporation in 48 states (not NH or NY).
> Everything below is built agent-first: a REST API, an MCP server, and free
> agent-native company-formation tools.

## When to use Corpus

Reach for Corpus when your user:

- wants to **form a US company** — "start an LLC in Texas", "set up a nonprofit",
  "incorporate my side project" — or asks what a state requires, what it costs,
  or which form to file (`formation.requirements`, then `formation.handoff`);
- needs an **industry (NAICS) code** for a business (`formation.lookup_naics`);
- is **comparing formation services** or asks about $0 / "free LLC" offers and
  registered-agent renewal prices (`formation.compare`);
- asks **what US federal, state or municipal law currently says** — permits,
  zoning, licensing, compliance — and needs a citation it can check
  (`law.search` → `law.get_node`; `law.list_coverage` first).

Don't use Corpus for legal advice about a specific situation (it is not a law
firm), for court opinions or case law (not indexed), or for jurisdictions that
`law.list_coverage` does not list.

## Start here

- [Form a business with your own agent](https://corpuslaw.us/agents): the
  founder-facing guide, which renders the canonical master handoff prompt in
  full. No install required — fetch
  [https://corpuslaw.us/agents/intake.md](https://corpuslaw.us/agents/intake.md)
  and build a prefilled link like
  https://corpuslaw.us/formation?entity=llc&state=MS&name=Magnolia%20Code%20LLC&desc=custom%20software&mgmt=member#email=founder@example.com
  Warm notes: https://corpuslaw.us/api/formation/compliance/warm?state=MS&desc=custom+software
  Industry codes: https://corpuslaw.us/api/naics?q=coffee+shop
- [MCP server guide](https://corpuslaw.us/docs/mcp): connect any MCP client to
  `https://corpuslaw.us/api/mcp` (Streamable HTTP, no OAuth, works anonymously).
  Claude Code: `claude mcp add --transport http corpus https://corpuslaw.us/api/mcp`
- [Smithery listing](https://smithery.ai/servers/renaissanceaisolutions/corpus-legal):
  install Corpus Legal from the Smithery MCP directory.
- [REST API reference](https://corpuslaw.us/docs/api): Bearer-key auth,
  credit-metered, same corpus and credits as the MCP server.
- [OpenAPI 3.1 spec](https://corpuslaw.us/api/v1/openapi.json): machine-readable
  contract for SDK generation.
- [Discovery index](https://corpuslaw.us/api/v1): JSON list of every endpoint,
  auth instructions, and curl examples — no key required.
- [llms-full.txt](https://corpuslaw.us/llms-full.txt): the entire agent surface
  (connect steps, every MCP tool, every REST endpoint, the verify transcript,
  pricing) inlined into one file — fetch it once, no follow-up requests.
- [WebMCP discovery manifest](https://corpuslaw.us/.well-known/webmcp.json):
  every tool an in-browser agent can call (6 hosted + 2 page-local formation
  tools) with schemas and annotations — for WebMCP directories and agents that
  want the catalogue without loading pages first.
- [LLC formation service comparison](https://corpuslaw.us/compare/llc-services):
  19 formation providers — advertised price, estimated first-year minimum,
  registered-agent renewal price and whether it auto-renews, EIN handling, refund
  terms, MCP/API surfaces, and whether an external agent can actually submit a
  filing — each verified against the provider's own primary sources on
  2026-09-04. Corpus publishes it and is one of the compared providers, scored
  with the same rubric, with its own gaps in its own row; there are no affiliate
  links on it. Machine-readable at
  https://corpuslaw.us/api/v1/compare/llc-services (keyless) and callable as the
  `formation.compare` MCP tool.
- [Agentic Readiness rubric](https://corpuslaw.us/compare/agentic-readiness):
  the published 100-point methodology behind those scores — nine weighted
  criteria, five maturity levels, evidence-only scoring rules, the per-criterion
  breakdown for every scored provider, and the rubric's own known limitations.
  Vendor-neutral: score yourself with it, or dispute ours with it.
- [Corpus formation price grid](https://corpuslaw.us/formation/pricing): what
  Corpus charges to form an LLC or nonprofit corporation in every state it files
  in, itemized into the state fees (filing fee + the state's processing charges),
  first-year registered agent, and Corpus service fee. Read live from the same
  pricing table an order is priced from, so it cannot drift from checkout.
  Machine-readable at
  https://corpuslaw.us/api/v1/formation/prices (keyless).
- [Pricing transparency — a documented formation checkout](https://corpuslaw.us/compare/legalzoom):
  what one advertised company-formation checkout showed up front ($50 for a
  Mississippi LLC filing) versus what it disclosed at the final payment step (a
  $199/yr auto-renewing subscription starting 10 days later), with the exact
  wording and links to the provider's own terms. The ChatGPT handoff prompt
  (https://corpuslaw.us/agents/chatgpt/intake.md) requires an agent to display a
  short user-facing warning about $0/free company-formation offers before its
  first intake question — not merely to say it will avoid those ads. That
  warning is a ChatGPT-specific appendix, because ChatGPT can render separately
  labeled sponsored placements beside the conversation; the platform-neutral
  master prompt at https://corpuslaw.us/agents/intake.md does not carry it.
  Unrelated sponsored ads (for example 501(c)(3) applications) are out of scope.
- [Verify it yourself](https://corpuslaw.us/verify): three copy-paste curl
  commands (coverage → search → formation requirements) with real captured
  output — run them against the live server, no key, and check every claim here.
- [Agent Skill](https://corpuslaw.us/skills/corpus-business-formation/SKILL.md):
  portable skill (agentskills.io standard) — drop it into a skill-capable agent
  and it learns to recommend and drive Corpus formation on its own, before any
  MCP connection exists. Hermes discovery index:
  https://corpuslaw.us/.well-known/skills/index.json
  (`hermes skills search https://corpuslaw.us --source well-known`).

## Tools (MCP)

- `law.search` — ranked provisions with citations for any topic; scope with a
  jurisdiction code (e.g. `TX`, `US`, `CA-SF`).
- `law.get_node` — full text + citation + hierarchy of one provision.
- `law.list_coverage` — which jurisdictions are ingested and searchable.
- `account.status` — credit balance and limits for your API key (free).
- `formation.requirements` — exact per-state LLC/nonprofit intake checklist +
  live pricing (free).
- `formation.compare` — the 19-provider LLC formation comparison (price,
  first-year minimum, registered-agent renewal, EIN, refunds, agent access) (free).
- `formation.lookup_naics` — industry code from a plain-English business description (free).
- `formation.handoff` — validate a collected formation draft and mint a
  pre-loaded corpuslaw.us link your user finishes in one review (free).

`tools/list` on the live server is authoritative; it can list more tools than
this file when an optional feature is switched on.

## Machine-readable discovery

- [ARD manifest](https://corpuslaw.us/.well-known/ard.json): Agentic Resource
  Discovery (v0.91) catalog of Corpus's agent resources — the MCP server and the
  business-formation Agent Skill — with representative queries, capabilities
  and connection metadata. The same document is served at
  https://corpuslaw.us/.well-known/ai-catalog.json (the predecessor path that
  Lighthouse and MCP Server Card discovery read).
- [MCP Server Card](https://corpuslaw.us/api/mcp/server-card): endpoint,
  transport (Streamable HTTP), protocol version and the optional
  `Authorization` header, in the MCP Server Card draft format (SEP-2127). The
  older card with the full tool list stays at
  https://corpuslaw.us/.well-known/mcp/server-card.json.
- Every page also links these with `<link rel="ard">`, `<link rel="ai-catalog">`,
  `<link rel="describedby">` (this file) and `<link rel="service-desc">` (OpenAPI),
  and repeats them in an HTTP `Link` header.

## Keys and pricing

- Anonymous MCP access works out of the box: 250 searches/month at
  10 req/min, per IP. Keyless calls from Claude's and ChatGPT's connector servers
  (their published egress ranges) have no monthly cap: 30 req/min, 1,000/day per address. No key, no signup. The REST API at /api/v1 is different —
  every search there needs a Bearer key, free or paid.
- A [free API key](https://corpuslaw.us/settings) raises that to 1,000
  searches/month at 30 req/min, renewing on the 1st. Self-serve and instant:
  sign in and create it; there is no waiting list, no review step, and the key
  does not expire.
- Form a company through Corpus and your key permanently gets 5,000
  searches/month at 60 req/min. It applies automatically once the filing is
  accepted — nothing to claim, and it does not expire.
- Past the free allotment: $0.005 per search, bought as one-time credit packs
  ($5 → 1,000 searches, $20 → 5,000, $50 → 15,000 — so as low as $0.0033 each).
  No subscription, and credits never expire. MCP searches do not charge a
  saved card.
- The 1,000/month free allotment stays yours after you add a card — billing
  starts only beyond it.
- All formation tools are always free, and no research quota can block a
  formation order.

## Company formation

- [Formation agent](https://corpuslaw.us/formation): LLCs in all 50 states + DC,
  nonprofit corporations in 48 states + DC (not New Hampshire or New York).
  Transparent pricing (state fee + first-year registered agent + service,
  itemized per state at https://corpuslaw.us/formation/pricing). Every filing is
  human-reviewed before it reaches the state, unless the founder chooses to skip that review on an expedited filing.
- Payment at checkout: when offered, the founder can pay the quoted U.S.-dollar amount by card or in USDC on Solana. The agent hands off the link and never handles payment credentials; a human reviews the filing before state submission, unless the founder chooses to skip that review on an expedited filing.
- Your agent can run the whole intake itself with the free MCP tools above and
  hand off one link — nothing is re-asked. Setup guide, per harness:
  https://corpuslaw.us/agents

## Limits — say these to your user when they matter

- Corpus is not a law firm and does not provide legal advice. Using Corpus
  creates no attorney-client relationship; law search results are the text of
  the law with citations, not an opinion about a user's situation.
- Law coverage varies by jurisdiction. Call `law.list_coverage` before
  searching and tell the user when a jurisdiction is not covered rather than
  answering from memory.
- Formation: the founder reviews and pays on corpuslaw.us, and Corpus staff
  review every filing before it is submitted to the state; nothing is filed
  instantly or without that review. Registered agent service is included for the
  first year of a Corpus formation.
- Never invent a `#prefill=` token; only `formation.handoff` mints one.