Court opinions
Federal and state court opinions with case metadata, from the LAW.co corpus. The legacy corpus follows the Caselaw Access Project structure; newer opinions come from CourtListener plain text.
How the corpus is built
LAW.co bulk-loaded the Caselaw Access Project corpus and ingests newer opinions daily from CourtListener, accepting only plain-text or Harvard XML opinion bodies through a copyright gate.
Coverage is uneven by year and court, and the same case can appear under more than one id. Text is not official or certified and may contain OCR and pagination errors.
Counts and dates
LAW.co's own documentation reports a corpus size, but Data.co has not verified it, so we do not publish a record count or date range yet. They will appear on the dataset page once confirmed with the provider.
What a court opinion is
A court opinion is the written explanation a judge or panel gives for deciding a case: the facts the court relied on, the legal question, the reasoning and the outcome. Appellate courts often issue a majority opinion along with concurrences and dissents; the dataset's opinion_type field records which one a body of text is.
Opinions written by judges in their official capacity are not protected by copyright under the government-edicts doctrine. That is why the opinion text and case facts carry a public-domain license id, while anything a publisher or LAW.co adds on top is handled separately.
Fields you can rely on
Case name and short name, decision date, docket number, reporter citations with their type, court and jurisdiction objects, opinion text, opinion type and author, judges and parties. The provenance object records the upstream source (CAP or CourtListener), when Data.co retrieved the record and the license.
Head matter from the Caselaw Access Project is excluded by default because it may contain reporter-written headnotes or syllabi whose rights are unconfirmed. Stored CAP PDF links are dead upstream and are not returned as source URLs.
Known quality issues
Legacy text came from scanned reporters, so expect OCR errors, broken hyphenation and lost page breaks. The same decision can exist under two ids when it was imported from two sources. Decision dates are stored as text upstream and occasionally need normalizing. Treat the corpus as research material and check anything you rely on against the court's own record.
Reading an opinion record
Start with the court, date and citation to place the decision, then read the majority opinion before any concurrence or dissent. Use authorities to find the cases it relied on and cited-by to find later cases that discuss it, keeping in mind both lists may be capped.
Provenance on every record
Whatever the topic, each legal record carries the same provenance fields, so you can tell source text from derived work and cite it correctly.
- provider / sourceId
- Who served the record and its id at that provider.
- upstreamSource
- Where the provider got it (for example CAP or CourtListener), or null if not stated.
- canonicalUrl
- Public URL for the record, when one exists.
- licenseId
- The license that applies, such as public domain for court-authored text.
- isDerived
- false for original text and facts; true for AI or editorial layers.
- retrievedAt
- When Data.co fetched it from the provider.
Access today
Individual cases can be read now on LAW.co's own public case pages. REST API and MCP access through Data.co are live for court opinions, case summaries and the citation graph. Previews on this site are synthetic samples titled [DEMO] that are never billed; the API returns live records. Bulk downloads stay closed until the provider confirms redistribution rights.
Each dataset page shows its status channel by channel, with the reason for anything that is not open, so you can plan an integration without guessing.
Court Opinions: common questions
Which courts are included?
Federal and state courts, per the provider catalog. Per-court coverage and date spans have not been verified, so we do not list them yet.
Do records include dissents and concurrences?
Where the source separated them, each opinion carries an opinion_type such as majority, dissent or concurrence, and an author when recorded.
How fresh is the data?
LAW.co ingests new opinions from CourtListener daily. Data.co reads at request time, so live records reflect what LAW.co holds when you call.
Can I search by citation?
You can filter search results by a citation string. Resolving a citation directly to one record needs a resolver endpoint LAW.co has not built yet, so the citation-resolve endpoint returns unsupported_operation.
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