> ## 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. # Resolve and verify a statute citation > Take a statute or regulation citation string, resolve it to the governing section, and check a whole document's citations in one batch call **What this gets you:** a way to catch a fabricated or wrong citation before it ships, whether it came from an LLM, a user, or your own database - one call tells you if a citation is real, and hands you the verified text if it is. Given a Bluebook citation string like `42 U.S.C. § 1983`, `16 C.F.R. § 444.1`, or `Del. Code Ann. tit. 13, § 1301`, resolve it to the exact section and get back the section metadata with an official source link. One route does the whole job: `/us/statutes/resolve` parses the citation server-side and tells you whether it is real. Use the `GET` form for a single citation and the `POST` form for up to 50 at once, which is what you want when you are checking the citations in a document rather than looking one up. Bluebook-formatted citations resolve most precisely. These all resolve, on either form of `/us/statutes/resolve`: * Federal statute: `42 U.S.C. § 1983` (annotated `42 U.S.C.A. § 1983` / `42 U.S.C.S. § 1983` and `Title 42 U.S.C. § 1983` also resolve) * Federal regulation: `16 C.F.R. § 444.1` * State statute: `Del. Code Ann. tit. 13, § 1301` * US Constitution: `U.S. Const. art. I, § 8`, `U.S. Const. amend. XIV, § 1` * State constitution: `Cal. Const. art. I, § 7` * Federal court rule: `Fed. R. Civ. P. 12`, `Fed. R. Evid. 702` * Federal Acquisition Regulation / DFARS: `FAR 52.219-14`, `DFARS 252.225-7001` (with or without periods, and with a pinpoint like `FAR 52.219-14(b)`), resolving straight into the existing CFR Title 48 records, no separate corpus The form a state's own courts print resolves too, not just the Bluebook form: `O.C.G.A. § 51-1-6`, `RCW 59.18.060`, `R.C. 2305.10`, `§ 292.290, RSMo`. The safest string to send is the `citation` value we returned to you. Agency guidance resolves as well, and it has no Bluebook form at all. Send its citation exactly as we printed it: `NY Insurance Circular Letter No. 4 (2022)`, `TDI Commissioner's Bulletin B-0004-22`, `IL Company Bulletin 2021-03`. This covers `STATE_AGENCY_GUIDANCE` (state insurance bulletins and circular letters) and `AGENCY_GUIDANCE` (IRS Notices, OCC Bulletins, CFTC staff letters and the rest). Because these are matched on the published string rather than parsed, the `citation` we returned is not merely the safest input here, it is the only one guaranteed to work. Scope `corpusType` (and `state`) when the citation names the corpus, so a same-numbered section in another corpus cannot rank first. Scope is a **constraint, not a hint**: a citation naming a different jurisdiction returns `resolved: false` rather than being forced into the scope, so leave the scope off unless you are disambiguating. See [Citation Formats](/docs/api-guide/concepts/citation-formats) for every form that resolves, the shared acronyms refused on purpose, and how `state` unlocks them. This recipe covers **statutes and regulations only** (USC, CFR, state codes, state regulations, constitutions, court rules, and other statute-corpus types). It is not for case law citations. Case law is not part of the Vaquill Developer API. **Endpoints used:** `GET /us/statutes/resolve` for one citation, `POST /us/statutes/resolve` for up to 50 at a time. ## Resolve in one call `GET /us/statutes/resolve` does the whole thing for you: it parses the Bluebook citation, resolves it to the exact section, and returns the section metadata with an official source link. The `resolved` flag tells you whether the citation is real, which is exactly the signal you want when verifying a citation an LLM produced. ```bash cURL theme={"theme":"github-dark"} curl -G https://api.vaquill.ai/api/v1/us/statutes/resolve \ -H "Authorization: Bearer vq_key_..." \ --data-urlencode "cite=42 U.S.C. § 1983" ``` ```python Python theme={"theme":"github-dark"} import requests resp = requests.get( "https://api.vaquill.ai/api/v1/us/statutes/resolve", headers={"Authorization": "Bearer vq_key_..."}, params={"cite": "42 U.S.C. § 1983"}, ) data = resp.json() if data["resolved"]: sec = data["section"] print(sec["citation"], "->", sec["actId"]) else: print("Unverified citation:", data["inputCitation"]) ``` ```javascript JavaScript theme={"theme":"github-dark"} const url = new URL("https://api.vaquill.ai/api/v1/us/statutes/resolve"); url.searchParams.set("cite", "42 U.S.C. § 1983"); const data = await ( await fetch(url, { headers: { Authorization: "Bearer vq_key_..." } }) ).json(); if (data.resolved) { console.log(data.section.citation, "->", data.section.actId); } else { console.warn("Unverified citation:", data.inputCitation); } ``` A resolved response carries the full section (the same shape as `/us/statutes/section/{actId}`), plus `subsection` when the citation had a pinpoint like `42 U.S.C. § 1983(b)(2)`. When `resolved` is `false`, treat the citation as **unverified**, not current. `/us/statutes/resolve` is charged whether or not the citation resolves, because a confident "this does not resolve" is the answer you want when checking an LLM's output. Only server errors are refunded. **A guidance citation can be ambiguous, and we would rather answer nothing than guess.** Some regulators reuse one citation across several documents: Delaware reissues `DE Domestic/Foreign Bulletin No. 113` five times, Vermont twice, and Massachusetts has three separate documents citing `MA Bulletin 1991-01`. Where the publisher's own citation does not identify a single document, `resolved` is `false` rather than one of the candidates picked arbitrarily. Reach those documents by `actId`, or with a `corpusType=STATE_AGENCY_GUIDANCE` search scoped to the state. ## Resolve a whole document's citations at once A brief, a memo, or a model's output typically carries dozens of citations, and checking them one at a time is dozens of round trips. `POST /us/statutes/resolve` takes up to 50 citations in one call and returns the same verdict per citation. ```bash cURL theme={"theme":"github-dark"} curl -X POST https://api.vaquill.ai/api/v1/us/statutes/resolve \ -H "Authorization: Bearer vq_key_..." \ -H "Content-Type: application/json" \ -d '{"citations": ["42 U.S.C. 1983", "16 C.F.R. 444.1", "Cal. Civ. Code 1950.5"]}' ``` ```python Python theme={"theme":"github-dark"} import requests resp = requests.post( "https://api.vaquill.ai/api/v1/us/statutes/resolve", headers={ "Authorization": "Bearer vq_key_...", "Content-Type": "application/json", }, json={ "citations": [ "42 U.S.C. 1983", "16 C.F.R. 444.1", "Cal. Civ. Code 1950.5", ] }, ) resp.raise_for_status() data = resp.json() print(f"{data['resolvedCount']}/{data['count']} resolved, " f"{data['creditsConsumed']} credits") for item in data["results"]: if item["resolved"]: print("OK ", item["inputCitation"], "->", item["section"]["actId"]) else: print("FLAG", item["inputCitation"]) ``` ```javascript JavaScript theme={"theme":"github-dark"} const resp = await fetch( "https://api.vaquill.ai/api/v1/us/statutes/resolve", { method: "POST", headers: { Authorization: "Bearer vq_key_...", "Content-Type": "application/json", }, body: JSON.stringify({ citations: ["42 U.S.C. 1983", "16 C.F.R. 444.1", "Cal. Civ. Code 1950.5"], }), }, ); if (!resp.ok) throw new Error(`resolve failed: ${resp.status}`); const data = await resp.json(); for (const item of data.results) { console.log(item.resolved ? "OK" : "FLAG", item.inputCitation); } ``` A trimmed response: ```json theme={"theme":"github-dark"} { "results": [ { "resolved": true, "inputCitation": "42 U.S.C. 1983", "section": { "actId": "USC_T42_C21_S1983", "citation": "42 U.S.C. § 1983", "title": "Civil action for deprivation of rights" }, "subsection": null }, { "resolved": false, "inputCitation": "42 U.S.C. 19833", "section": null, "subsection": null } ], "resolvedCount": 1, "count": 2, "creditsConsumed": 4 } ``` Four things about the batch route are worth knowing before you build on it. * **Every input gets an entry.** An unresolved citation comes back with `resolved: false`, never as an omission, so you can tell WHICH of thirty citations failed. The `results` array lines up with your de-duplicated input, in order. * **Duplicates are collapsed** before pricing and before the response is built, so the same citation sent twice costs once and returns one entry. * **Cost is per citation**, the same as resolving them one at a time. Batching buys a round trip and latency, not a discount. Read `creditsConsumed` rather than multiplying: citations we failed to process because of a backend error are refunded. * **Scope the whole batch** with `state` or `corpusType` when every citation belongs to one jurisdiction or corpus. `22 CCR 76227` is California and `8 CCR 1206-2` is Colorado, and the acronym alone cannot say which. Omit both for a batch that spans jurisdictions and let each citation name its own. `POST /us/statutes/resolve` accepts at most 50 citations, and rejects an empty list or a longer one with `422`. Chunk a longer document into batches of 50. ## If you need your own match tolerance Both resolve routes run the server-side citation parser, which knows every form in [Citation Formats](/docs/api-guide/concepts/citation-formats), including the ones a state's own courts print and the agency-guidance strings that have no Bluebook form at all. You only need to build your own matcher if you want tolerance the parser does not offer, for example accepting a citation whose section number is off by a digit and reporting it as a near miss. In that case, send the citation as the `query` on `POST /us/statutes/search`, compare the top result's `citation` and `citationShort` against your input under your own rules, and call `GET /us/statutes/section/{actId}/body` when you are satisfied. Do the arithmetic before you commit to it. That path bills a search plus a body where `/resolve` bills one cheaper call, and a substring comparison is a weaker matcher than the parser you just skipped. It is the right call only when the tolerance itself is the point. ## Flagging what you cannot resolve `resolved: false` means **unverified**, not "not current". Do not fall through to a loosely related section, and do not present a near match as the answer. If you are checking a citation an LLM produced, an unresolved flag is exactly the signal that the model may have fabricated it. The corpus token is usually right there in the citation. `... CFR ...` means `corpusType: "CFR"`; `... U.S.C. ...` means `"USC"`; a state code section means `"STATE"` with the two-letter `state`. Scope is a **constraint, not a hint**: a citation naming a different jurisdiction returns `resolved: false` rather than being forced into the scope, so leave the scope off unless you are disambiguating. `FAR`/`DFARS` citations live in CFR Title 48, so they are `corpusType: "CFR"`; add `source: "far"` or `source: "dfars"` to exclude every other CFR title from the ranking. A citation can resolve while its full text is not yet ingested. In that case `GET /us/statutes/section/{actId}/body` responds with `available: false` and `creditsConsumed: 0`. Treat it as resolved-without-text: you have a confirmed `actId`, citation and source link, but nothing you can quote yet. A resolved section carries several optional source URL fields and any of them may be null. Use the canonical preference order in [Text Formats and Source URLs](/docs/api-guide/concepts/formats#picking-the-best-available-format) rather than writing your own, so every surface in your product links the same reader to the same official page. ## Related Use verified citations as grounding sources for an LLM answer. Go from a plain-language obligation to the governing sections. Why citation verification belongs in every legal AI pipeline. A conversational front end over the same lookups. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.