Federal Rules of Procedure API: FRCP, FRE, FRAP, FRCrP, FRBP and Supreme Court Rules

The federal rules of procedure are available as a queryable corpus at corpusType=FEDERAL_RULES, holding 589 sections across six rule sets: the Federal Rules of Civil Procedure, Criminal Procedure, Evidence, Appellate Procedure, and Bankruptcy Procedure, plus the Rules of the Supreme Court of the United States. The Supplemental Rules for Admiralty or Maritime Claims and for Social Security Actions are in there too. Each set is filterable by a source code, so you can scope a query to evidence law without dragging in bankruptcy timing rules. It is the smallest federal corpus we serve and one of the most requested, because litigation software touches these rules on almost every screen.

Disclosure: we build Vaquill AI, a US primary law API. Corpus numbers below were measured on 2026-08-30 and the coverage endpoint that reports them is free, so nothing here has to be taken on trust.

TL;DR

• 589 sections, corpusType=FEDERAL_RULES, refreshed monthly. Small corpus, heavy usage, because deadline math and evidentiary objections run through it constantly.
• Six source codes: frcp, frcrp, fre, frap, frbp, sct. The Supplemental Admiralty and Social Security Rules are included.
• Amendments arrive on a fixed calendar. Under the Rules Enabling Act, an approved amendment is transmitted to Congress by May 1 and takes effect the following December 1 unless Congress acts. Nothing else in federal law is this predictable.
• That calendar is why monthly is the right cadence, not a weak one. A daily poll against an annually-changing corpus spends requests to learn nothing.
• Committee notes are load-bearing. Courts read them to decide what a rule means. Each API result carries the official publisher's source URL so you can pull the note from the authoritative copy.
• Local district rules and standing orders are not here. Neither are judges' individual practices. That is a real gap and it is stated rather than papered over.

Another installment in our US primary law corpus series, which covers the corpus one source at a time.

The state-level counterpart is State Court Rules API: 46 Jurisdictions, and an Honest Map of the Six Gaps. For the other two small federal corpora that carry outsized weight in litigation, see US Sentencing Guidelines API: Querying the Manual That Sets Federal Exposure and State Constitutions API: 51 Jurisdictions With Article and Section Structure.

A tiny corpus with an outsized blast radius

589 sections is nothing next to 219,114 sections of CFR or 60,170 of US Code. It is also the corpus a litigation product hits on nearly every workflow.

Compute a response deadline, and you are in Rule 6 of the FRCP. Flag an objection in a deposition transcript, and you are in the FRE. Check whether an appeal is timely, and you are in the FRAP. Decide whether a claim survives a motion, and you are in Rule 12. None of that reaches for a statute.

The mismatch between size and usage is the reason to treat it as its own corpus with its own filter, rather than a folder inside a general federal blob. A 589-section corpus that you can scope precisely beats a 600,000-section one you have to sift.

The six rule sets and their source codes

The Supplemental Rules for Certain Admiralty or Maritime Claims and Asset Forfeiture Actions, and the Supplemental Rules for Social Security Actions, ride along with the civil rules and are included in the corpus.

The amendment mechanism, which is the useful part

If you build on this corpus, the single most valuable thing to understand is how these rules change. It is nothing like how statutes change.

Federal rules are amended through the Rules Enabling Act process, 28 U.S.C. 2071 through 2077. The path is fixed:

Each rule set has its own advisory committee. A proposed amendment is published for public comment, revised, and passed up to the Standing Committee, then to the Judicial Conference, then to the Supreme Court. If the Court approves, it transmits the amendment to Congress by May 1 under 28 U.S.C. 2074. The amendment takes effect on the following December 1 unless Congress passes a law to say otherwise.

One carve-out matters if you work with evidence rules. An amendment to the Federal Rules of Evidence that creates, abolishes, or modifies an evidentiary privilege does not take effect on the default timetable. It requires affirmative approval by Act of Congress. That is the exception people forget, and it is written into the same section.

Why December 1 makes this corpus predictable

Statutes change whenever a legislature feels like it. Fifty state legislatures on fifty calendars, plus Congress, plus emergency sessions. There is no date you can point to.

Federal rules have one. The change surface for frcp, frcrp, fre, frap, and frbp collapses to a single annual turnover on December 1, with the content of that turnover public and readable from the previous May. Between December 2 and the following May 1, the national rules are almost certainly identical to what you cached.

That is why monthly is the correct refresh cadence rather than a compromise. Consider the three options:

The Supreme Court Rules (sct) are the one set that does not follow the Rules Enabling Act track. The Court amends its own rules by order on its own schedule, which is another argument for a monthly floor rather than an annual one.

You can audit the cadence instead of trusting it. GET /boards carries no charge and enumerates the watchable sources, each with its declared cadence, its retrievalStatus, and a lastRetrievedAt timestamp. If a board claims monthly and has not been retrieved since spring, that is visible before it becomes a support ticket.

Committee notes, and why they decide arguments

Every federal rule ships with Advisory Committee Notes, written by the committee that drafted the amendment. They explain what problem the change was meant to fix, what the drafters intended a phrase to mean, and often what they deliberately chose not to do.

Federal courts read them. When a rule's text is ambiguous, the committee note is the first place a judge looks, and briefs cite notes routinely. They are not binding the way the rule text is binding, but they are the closest thing the rules have to legislative history, and they are far better organized than most legislative history.

For a developer, that has one practical consequence: rule text alone can be misleading. A rule that reads as a bright line often has a note explaining the exception the committee assumed everyone understood. Every result this API returns carries the official publisher's own source URL for that rule, so when a note matters, pull it from the authoritative copy rather than inferring intent from the text.

Worked queries

Base URL is https://api.vaquill.ai/api/v1. Auth is Authorization: Bearer vq_key_.... Search costs 4 credits. Coverage and boards are free. Failed calls are not charged.

1. Pull FRCP 26 by citation

The discovery rule is probably the single most-hit rule in civil litigation software. Start from the citation, not from an id you guessed.

curl -X POST https://api.vaquill.ai/api/v1/us/statutes/search \
  -H "Authorization: Bearer $VAQUILL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "Fed. R. Civ. P. 26 duty to disclose scope of discovery",
    "corpusType": "FEDERAL_RULES",
    "source": "frcp",
    "limit": 5
  }'

Take the actId off the top hit, then fetch the full text:

curl "https://api.vaquill.ai/api/v1/us/statutes/section/{actId}/body" \
  -H "Authorization: Bearer $VAQUILL_API_KEY"

/section/{actId} returns the section with its metadata and the publisher source URL. /section/{actId}/body returns the text. There is also a citation-resolve endpoint if you are starting from a properly formatted cite string rather than a natural-language query.

2. Phrase-match a defined term in the Rules of Evidence

Evidence work is exact-wording work. matchType: "phrase" is the setting you want.

curl -X POST https://api.vaquill.ai/api/v1/us/statutes/search \
  -H "Authorization: Bearer $VAQUILL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "excited utterance",
    "corpusType": "FEDERAL_RULES",
    "source": "fre",
    "matchType": "phrase",
    "limit": 10
  }'

That returns the hearsay exception in Rule 803 plus every other rule that uses the phrase, and nothing from bankruptcy or appellate procedure. matchType takes any, all, or phrase. Search is hybrid, so semantic and keyword signals both contribute and phrase tightens the keyword side.

3. Scope to the Supreme Court Rules

curl -X POST https://api.vaquill.ai/api/v1/us/statutes/search \
  -H "Authorization: Bearer $VAQUILL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "considerations governing review on certiorari",
    "corpusType": "FEDERAL_RULES",
    "source": "sct",
    "limit": 10
  }'

Supreme Court Rule 10 is the certworthiness rule and Rule 13 sets the time to petition, and both are questions an appellate product gets asked constantly. Scoping to source=sct keeps a certiorari question out of the district-court rules.

Paging is cut from a single ranking, so results never repeat or go missing between pages and a later page costs no more than the first. limit maxes at 50 and offset at 70, per the pagination rules.

What is not in this corpus

Three gaps.

Local district rules are not here. Each federal district court issues its own local rules under Rule 83 of the FRCP, and those govern page limits, meet-and-confer requirements, chambers copies, and much of what actually gets a filing rejected. They are not in FEDERAL_RULES.

Standing orders and individual judges' practices are not here either. Many judges publish their own requirements on top of the local rules. These are the least standardized documents in federal practice and they are not part of this corpus.

State court rules are a separate corpus. They live under corpusType=STATE_RULES, covering 46 jurisdictions (44 states plus DC and Puerto Rico) across roughly 47,600 sections. Six jurisdictions have no court rules coverage, each for its own stated reason: Arkansas and Vermont publish only an amendment stream rather than consolidated government text, Colorado's last government compilation is from 2023 and serving it would present superseded procedure as current, Oklahoma and South Dakota codify their rules into the statute book so they are already served under corpusType=STATE, and Missouri's judiciary publishes a policy against automated access that we honor. State Court Rules API: 46 Jurisdictions, and an Honest Map of the Six Gaps has the full breakdown.

Change detection, and the honest limit

For monitoring, the corpus exposes change events captured at each refresh, per-section diffs on watched boards, and watch subscriptions with delivery logs. GET /boards lists what is watchable. Watches can be created, updated, listed, tested, and deleted, and you can pull a diff for a specific change, all covered in the alerts guide.

What does not exist is point-in-time retrieval. Each citation resolves to a single stored text: the one in force. There is amendment history, a lastAmendedYear per section, a yearFrom and yearTo currency filter, and change events, but no as_of=2019-12-01 parameter that returns the rule as it read before a given amendment cycle. Amendment History and Point-in-Time Law: What a Legal API Can and Cannot Tell You is the longer treatment.

For a rules corpus that has a sharp edge worth naming. If your product needs to show a litigator the version of Rule 26 that governed a case filed in 2018, size that requirement early, and make any provider demonstrate it live on a rule you picked rather than on their example.

Where this sits in the wider corpus

FEDERAL_RULES is one of ten federal corpora in a US primary law corpus totaling 4,150,839 distinct sections, indexed as 12,003,716 retrieval passages, across 53 jurisdictions. The federal side runs from the CFR at 219,114 sections and the Federal Register at 202,526 down through the US Code at 60,170, the Sentencing Guidelines at 302, and the US Constitution at 74.

The collection layer is published at github.com/Vaquill-AI/open-us-law, including bulk-source parsers, scrapers, and the JSONL schema. The same API surface is also published as an MCP server at mcp.vaquill.ai, so an agent can query the rules directly. Our MCP guide covers that path.

FAQ

What are the Federal Rules of Procedure?

They are the national rules that govern how federal cases are conducted: the Federal Rules of Civil Procedure, Criminal Procedure, Evidence, Appellate Procedure, and Bankruptcy Procedure. They are primary law, adopted through the Rules Enabling Act process rather than passed as ordinary statutes. The Rules of the Supreme Court sit alongside them and govern practice before that Court.

How do the federal rules get amended?

An advisory committee drafts a change, publishes it for public comment, and sends it to the Standing Committee on Rules of Practice and Procedure, then to the Judicial Conference, then to the Supreme Court. If the Court approves, it transmits the amendment to Congress by May 1 under 28 U.S.C. 2074. It takes effect the following December 1 unless Congress acts.

When do federal rule changes take effect?

December 1 of the year the amendment was transmitted, unless Congress rejects, modifies, or defers it by statute. The one significant exception is an amendment to the Federal Rules of Evidence that creates, abolishes, or modifies a privilege, which needs affirmative approval by Act of Congress.

Are Advisory Committee Notes binding?

No. The rule text is what binds. The notes are the drafting committee's explanation of what an amendment was meant to do, and courts cite them heavily when a rule's meaning is contested. Treat them the way you would treat well-organized legislative history: persuasive, frequently decisive, never the rule itself.

Does this API include local district court rules?

No. Local rules issued by each district court under FRCP 83, along with standing orders and individual judges' practices, are outside this corpus. If your workflow depends on local page limits or chambers requirements, plan for a separate source.

How do I filter to just the Federal Rules of Evidence?

Set corpusType to FEDERAL_RULES and source to fre on a search call. The other codes are frcp, frcrp, frap, frbp, and sct. An invalid code returns a 422 whose message lists every valid value.

Can I get a rule as it read before a past amendment?

Versioning here runs off the amendment record rather than a date parameter. One stored text per citation, the one in force, plus amendment history, a currency filter, and change events per refresh. There is no historical as_of=DATE retrieval.

Why refresh a rules corpus monthly instead of daily?

Because the change surface is annual and dated. National rule amendments land on December 1 and are public from the previous May, so a daily crawl learns nothing on almost every day of the year. Monthly catches the turnover well inside any window where a user would act on it, and still picks up an off-cycle Supreme Court Rules order within weeks.

What does a federal rules search cost?

A search call is 4 credits. Coverage and boards are free. Failed calls are not charged, and paging is cut from one ranking, so a later page costs the same as the first.

Priyansh Khodiyar

Co-Founder & CTO

Priyansh leads engineering and AI at Vaquill, from the matter workbench to drafting, document comparison, document matrix, and citation-verified research.