# Vaquill > Vaquill is a legal AI suite for in-house counsel, plus a US statutes and regulations Developer API. The API lets you search and retrieve the US Code, the Code of Federal Regulations, nearly all 50 state statutory codes plus DC and Puerto Rico, state and US constitutions, court rules, executive orders, Federal Register agency rules, federal agency guidance, session laws, and 13,000+ state Department of Insurance bulletins and circular letters across 49 jurisdictions. Every result carries 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 products. Base URL: https://api.vaquill.ai. All paths are prefixed with /api/v1. Authenticate every request with an API key: `Authorization: Bearer vq_key_...`. The API serves US statutes and regulations only (case law and India are not part of the Developer API). ## API: Get Started - [API Overview](https://www.vaquill.ai/docs/api-guide/overview): What the API covers, every public endpoint, and what you can build. - [Quickstart](https://www.vaquill.ai/docs/api-guide/quickstart): Make your first search, fetch a section and its full text, and discover coverage. - [Authentication](https://www.vaquill.ai/docs/api-guide/authentication): API keys, the Authorization header, and key rotation. ## API: Core Concepts - [Corpus Types](https://www.vaquill.ai/docs/api-guide/concepts/corpus-types): The 19 corpusType tokens (USC, CFR, CFR_ANNUAL, STATE, CONSTITUTION, FEDERAL_RULES, STATE_CONSTITUTION, STATE_RULES, EXECUTIVE_ACTION, REGULATION, FEDERAL_REGISTER, FEDERAL_REGISTER_NOTICE, AGENCY_GUIDANCE, AGENCY_ADJUDICATION, STATE_AGENCY_GUIDANCE, SESSION_LAW, STATUTE_COMPILATION, SENTENCING_GUIDELINES, US_TAX_TREATY), federal vs state scope, and how to filter a search. - [Jurisdictions and State Codes](https://www.vaquill.ai/docs/api-guide/concepts/jurisdictions): The 52 jurisdictions, 2-letter state codes, and discovering what is queryable via /statutes/coverage. - [Section Identifiers](https://www.vaquill.ai/docs/api-guide/concepts/section-ids): The actId format and the search then section then body workflow. - [Response Formats](https://www.vaquill.ai/docs/api-guide/concepts/formats): HTML, PDF, XML, plain text, DOCX, and official government source links. - [Status and Currency](https://www.vaquill.ai/docs/api-guide/concepts/status-and-currency): The actStatus vocabulary, the derived goodLawStatus verdict (good_law, not_good_law, not_operative, unknown), how to filter on each, and the move pointers. - [Response Fields](https://www.vaquill.ai/docs/api-guide/concepts/response-fields): Which fields a section carries, which corpus each belongs to, and how to tell 'not applicable' from 'we do not hold it'. - [Amendment History](https://www.vaquill.ai/docs/api-guide/concepts/amendment-history): amendmentYears, lastAmendedYear, amendmentsCount and amendmentHistory, taken from the publisher's own credit line. - [Citation Formats](https://www.vaquill.ai/docs/api-guide/concepts/citation-formats): Which citation strings resolve, which are refused on purpose, and batch resolution. - [Section Intelligence](https://www.vaquill.ai/docs/api-guide/concepts/section-intelligence): What cites a section, what its defined terms mean, how other states word it, and what has changed. ## API: Working with the API - [Pagination](https://www.vaquill.ai/docs/api-guide/pagination): The limit and offset parameters and the hasMore flag on search. - [Rate Limits](https://www.vaquill.ai/docs/api-guide/rate-limits): Per-key, per-plan limits, 429 handling, and backoff. - [Errors](https://www.vaquill.ai/docs/api-guide/errors): Status codes and how to recover from each. - [Best Practices](https://www.vaquill.ai/docs/api-guide/best-practices): Scoping, caching coverage, retries, and using discovery before search. - [Point-in-time law](https://www.vaquill.ai/docs/api-guide/point-in-time): Read a section as it stood on a past date with asOf, and the provenance block (source, existed, isBounded, coverage) that says how far the answer can be trusted. - [Law Change Alerts](https://www.vaquill.ai/docs/api-guide/alerts): Board watches, webhook and email delivery, HMAC signature verification, scoping, and cursor paging with sinceId and beforeId. - [Data and Privacy](https://www.vaquill.ai/docs/api-guide/data-privacy): What the API stores about your requests, and for how long. ## API: Coverage and Data - [Coverage](https://www.vaquill.ai/docs/api-guide/coverage): The jurisdiction-by-jurisdiction matrix of what is ingested. - [Federal coverage](https://www.vaquill.ai/docs/api-guide/coverage/federal): Every federal corpus, with section counts, refresh cadence and per-corpus scope limits. - [State and territory coverage](https://www.vaquill.ai/docs/api-guide/coverage/states): Per-jurisdiction counts for statutes, regulations, constitutions and court rules across all 52 US jurisdictions. - [Agency guidance sources](https://www.vaquill.ai/docs/api-guide/coverage/agency-guidance): The 51 named federal sources behind corpusType=AGENCY_GUIDANCE, each independently filterable with source. ## API: Grounding AI - [Grounding LLMs with Vaquill](https://www.vaquill.ai/docs/api-guide/grounding-llms): Retrieve, cite, and verify so an LLM or agent answers only from authoritative law. ## API: Recipes - [Ground an LLM answer in statutes (RAG)](https://www.vaquill.ai/docs/api-guide/recipes/rag-grounding): Search, fetch section text, build a grounded and cited prompt. - [Build a statute lookup chatbot](https://www.vaquill.ai/docs/api-guide/recipes/statute-chatbot): A retrieve-then-ground Q&A loop for any chat surface. - [Resolve and verify a statute citation](https://www.vaquill.ai/docs/api-guide/recipes/citation-lookup): Turn a citation string into the section and its authoritative text. - [Map a compliance requirement to the governing law](https://www.vaquill.ai/docs/api-guide/recipes/compliance-mapping): Find the CFR, Federal Register, agency guidance, and state regulation sections that govern an obligation. - [Compare a rule across states](https://www.vaquill.ai/docs/api-guide/recipes/multi-state-comparison): Run one query across several states and assemble a comparison. - [Monitor corpus coverage and changes](https://www.vaquill.ai/docs/api-guide/recipes/coverage-monitoring): Snapshot and diff /statutes/coverage over time. - [Enrich a citation database with source text](https://www.vaquill.ai/docs/api-guide/recipes/citation-enrichment): Batch-attach citations, excerpts, and official source URLs. - [Add the corpus as an AI agent tool (MCP)](https://www.vaquill.ai/docs/api-guide/recipes/mcp-tool): Use the hosted MCP server or wrap the REST API as your own tool. ## API: Use Cases - [Use Cases](https://www.vaquill.ai/docs/api-guide/use-cases): Who builds with the API (legaltech, in-house, compliance, RegTech, GRC, investigations, research, publishing, AI labs) and the patterns they build. ## API Reference - [Search US statutes](https://www.vaquill.ai/docs/api-reference/us-statutes/search-us-statutes-constitutions-court-rules-and-executive-actions): POST /api/v1/us/statutes/search. - [Get statute section metadata](https://www.vaquill.ai/docs/api-reference/us-statutes/get-statute-section-metadata): GET /api/v1/us/statutes/section/{act_id}. - [Get statute full text](https://www.vaquill.ai/docs/api-reference/us-statutes/get-statute-full-text): GET /api/v1/us/statutes/section/{act_id}/body. - [Get metadata for many statute sections](https://www.vaquill.ai/docs/api-reference/us-statutes/get-metadata-for-many-statute-sections): POST /api/v1/us/statutes/sections. - [Resolve a citation to its section](https://www.vaquill.ai/docs/api-reference/us-statutes/resolve-a-citation-to-its-section): GET /api/v1/us/statutes/resolve. - [Get the sections around this one](https://www.vaquill.ai/docs/api-reference/us-statutes/get-the-sections-around-this-one): GET /api/v1/us/statutes/section/{act_id}/related. - [Coverage matrix by jurisdiction and corpusType](https://www.vaquill.ai/docs/api-reference/us-statutes/coverage-matrix-by-jurisdiction-and-corpustype): GET /api/v1/us/statutes/coverage. - [Browse the statutory hierarchy](https://www.vaquill.ai/docs/api-reference/us-statutes/browse-the-statutory-hierarchy): GET /api/v1/us/statutes/divisions. - [List watchable boards](https://www.vaquill.ai/docs/api-reference/board-watches/list-watchable-boards): GET /api/v1/boards, the entry point for the free law-change alert endpoints. - [Get API credit pricing](https://www.vaquill.ai/docs/api-reference/pricing/get-api-credit-pricing): GET /api/v1/api-credits/pricing, public and unauthenticated. - [OpenAPI schema](https://api.vaquill.ai/external/openapi.json): Machine-readable spec for all public endpoints. ## Optional - [Introduction](https://www.vaquill.ai/docs/introduction): The full Vaquill product, including the in-app legal AI suite. - [Changelog](https://www.vaquill.ai/docs/api-guide/changelog): API updates and additions. - [Roadmap](https://www.vaquill.ai/docs/api-guide/roadmap): Corpora being built next, and what is deliberately out of scope. - [Vaquill MCP](https://www.vaquill.ai/docs/integrations/mcp/vaquill): The hosted MCP server for AI agents.