> ## Documentation Index
> Fetch the complete documentation index at: https://vaquill.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# API Overview

> The deepest US statutes and regulations API, built for grounding AI and compliance

The Vaquill Developer API is the deepest US statutes and regulations API. Search and retrieve the US Code, the Code of Federal Regulations, all 50 state statutory codes plus DC and Puerto Rico, state and US constitutions, court rules, executive orders, Federal Register agency rules, and agency guidance.

Every section comes back with a citation, full text in multiple formats, and a link to the official government source. It is built for grounding AI (RAG and agents), compliance and RegTech, and embedding authoritative legal text into your product.

## Capabilities

Every path is prefixed with `/api/v1`. Every result carries a citation, status and currency signals, and a link to the official government source.

| Capability | Endpoint |
| - | - |
| Hybrid **semantic + keyword** search, scoped by corpus, jurisdiction, and code | `POST /us/statutes/search` |
| Resolve a **Bluebook citation** to its exact section | `GET /us/statutes/resolve` |
| **Browse the hierarchy** (titles to chapters or parts to sections) in statutory order | `GET /us/statutes/divisions` |
| Section **metadata**, **full text**, and **neighboring sections** | `GET /us/statutes/section/{actId}`, `.../body`, `.../related` |
| **Defined terms** resolved from the chapter's definitions section | `GET /us/statutes/section/{actId}/definitions` |
| The **same subject in other states**, for a 50-state survey | `GET /us/statutes/section/{actId}/cross-state` |
| Sections that **cite this one**, and **observed changes** to it | `GET /us/statutes/section/{actId}/cited-by`, `.../changes` |
| **Batch** metadata for up to 50 sections in one call | `POST /us/statutes/sections` |
| Discover live **coverage**: which jurisdictions hold which corpora | `GET /us/statutes/coverage` |
| **State session laws** as enacted: list by state and date, **search the text**, fetch by id or citation, read the text | `GET /us/session-laws/list`, `POST /us/session-laws/search`, `GET /us/session-laws/{sessionLawId}`, `.../body` |
| **Subscribe** to a jurisdiction or corpus and get a webhook or email when it changes, section by section, with before/after text on amendments | `GET /boards`, `POST /watches`, `GET /watches/{id}/changes`, `.../diff` |

### Search with `includeBody`

`POST /us/statutes/search` accepts `includeBody: true`, which attaches each hit's full text on the result's `body` instead of making you call `/section/{actId}/body` once per hit.
A row whose text cannot be resolved comes back with `body: null` and is not charged.
It buys you round trips, not a discount.

<Note>
  `GET /api-credits/pricing` returns the live per-endpoint credit matrix, needs
  no authentication and costs nothing. `creditsConsumed` on every response
  reports what was actually billed, which can be less on a partial or refunded
  result (for example, a `404` on `/us/statutes/section/{actId}` is not
  charged). Between them they are the only correct way to know what a call
  costs.
</Note>

### Corpora

**Federal:** US Code (`USC`), Code of Federal Regulations (`CFR`), the CFR annual editions 1996 to 2026 (`CFR_ANNUAL`), Federal Register agency rules (`FEDERAL_REGISTER`), a curated slice of Federal Register notices (`FEDERAL_REGISTER_NOTICE`), agency guidance (`AGENCY_GUIDANCE`), executive orders (`EXECUTIVE_ACTION`), Federal Rules of Procedure (`FEDERAL_RULES`), the local rules of 52 federal courts (`FEDERAL_LOCAL_RULES`), the US Constitution (`CONSTITUTION`), session laws as enacted (`SESSION_LAW`), statute compilations as amended (`STATUTE_COMPILATION`), US Sentencing Guidelines (`SENTENCING_GUIDELINES`), administrative adjudications (`AGENCY_ADJUDICATION`), and US tax treaties plus the full Senate treaty record, including resolutions of advice and consent (`US_TAX_TREATY`).

**State, across 56 jurisdictions:** statutory codes (`STATE`), administrative regulations (`REGULATION`), constitutions (`STATE_CONSTITUTION`), court rules (`STATE_RULES`), state register notices (`STATE_REGISTER`, not codified law), and state regulator guidance (`STATE_AGENCY_GUIDANCE`).

**State session laws:** 20,604 acts from the 2025 sessions across 50 jurisdictions, served by `/us/session-laws` rather than a `corpusType`. See [State Session Laws](/docs/api-guide/session-laws).

`STATE_AGENCY_GUIDANCE` is worth calling out because it is the newest and least
expected: **13,000+ state Department of Insurance bulletins and circular letters
across 49 jurisdictions**, going back to 1924. A bulletin interprets the law
rather than being the law, which is why it is a separate token from
`REGULATION`. It is the corpus to reach for on an insurance compliance or
50-state survey question.

Scope any search with the `corpusType` token. See [Corpus Types](/docs/api-guide/concepts/corpus-types) for what each holds.

<Note>
  Coverage expands weekly. Call `/us/statutes/coverage` at runtime to see exactly what is queryable rather than hardcoding jurisdiction counts.
</Note>

## What you can build

<CardGroup cols={2}>
  <Card title="Use cases" icon="lightbulb" href="/docs/api-guide/use-cases">
    Grounding AI, compliance mapping, legal research tools, and more.
  </Card>

  <Card title="Resolve a citation" icon="quote-right" href="/docs/api-guide/recipes/citation-lookup">
    Turn a Bluebook citation into the exact section, verified, with full text and an official link.
  </Card>

  <Card title="RAG grounding" icon="robot" href="/docs/api-guide/recipes/rag-grounding">
    Feed authoritative statute text to an LLM in your stack, with citations and source links.
  </Card>

  <Card title="Compliance mapping" icon="shield-check" href="/docs/api-guide/recipes/compliance-mapping">
    Map obligations to the statutes and regulations that govern them.
  </Card>

  <Card title="Statute chatbot" icon="comments" href="/docs/api-guide/recipes/statute-chatbot">
    Answer statute questions in your product, grounded in official text.
  </Card>

  <Card title="Law Change Alerts" icon="bell" href="/docs/api-guide/alerts">
    Get a webhook or email the moment a jurisdiction or corpus changes, with the exact sections and a before/after diff.
  </Card>
</CardGroup>

## Get started

<CardGroup cols={2}>
  <Card title="Quickstart" icon="bolt" href="/docs/api-guide/quickstart">
    Make your first search and fetch a section in a few minutes.
  </Card>

  <Card title="Authentication" icon="key" href="/docs/api-guide/authentication">
    Create an API key and authenticate every request.
  </Card>

  <Card title="Data & Privacy" icon="shield-halved" href="/docs/api-guide/data-privacy">
    What the API stores about your requests, and for how long.
  </Card>
</CardGroup>

## Related

<CardGroup cols={2}>
  <Card title="Coverage" icon="table" href="/docs/api-guide/coverage">
    The jurisdiction matrix in human-readable form.
  </Card>
</CardGroup>


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