Data quality & freshness

Legal reference data goes stale quietly: a new interest rate is published, a court moves, a law merges two cantons. This page explains how the package keeps up, and how far you can trust each dataset.

Where each dataset comes from

Dataset	Source	How it's built	Changes when	Review every
Judicial areas, arrondissements	Judicial Code, annex art. 4–5	By hand	A law redraws the judicial map (rare; last in 2014)	24 months
Cantons	Judicial Code, annex art. 1 (nl + fr)	Generated: pnpm build:cantons	A law changes the annex; municipalities merge	12 months
Municipalities	Statbel open data	Generated: pnpm build:cantons	Municipalities merge (2019, 2025)	12 months
Courts	Court websites, just.fgov.be	By hand	A court moves or changes phone, e-mail, bank account	12 months
Interest rates	FOD Financiën, Belgisch Staatsblad	By hand	Every year (legal) and every semester (commercial)	6 months

Generated datasets are never edited by hand: the script parses the official text and refuses to write anything unless the Dutch and French versions agree and every municipality is covered.

Automatic checks

On every change (CI)

• Schema validation: every data file matches its JSON Schema.
• Integrity: ids are unique and well-formed; every reference (arrondissement, canton, municipality) points at a record that exists; every municipality is in exactly one canton or split over several; every canton stays within its arrondissement's provinces; the justices of the peace of East and West Flanders cover every canton there.
• Interest rates: periods are sorted, never overlap and leave no gaps; the legal rate runs per calendar year and the commercial rate per semester; the 2013–2015 contract-date rate only appears in that window.
• Contact data: every IBAN passes its ISO 13616 checksum, phone numbers are E.164 Belgian numbers, e-mail addresses are lowercase, and opening hours parse as opening_hours.
• Code: strict TypeScript (including unchecked index access and exact optional properties), ESLint with type-aware rules, Prettier, and 100 % test coverage of src/.
• Packaging: the built package loads with import and with require(), from every entry point, on Node 22.12, 22, 24 and 26; publint and arethetypeswrong check the exports and type declarations.

Every week (scheduled)

The freshness workflow runs every Monday and opens an issue labelled data-freshness when it finds something:

• Missing rates: no legal or commercial rate for today, or no commercial rate for the next two weeks (FOD Financiën publishes it before the semester starts).
• Overdue reviews: a dataset's lastReviewed date in datapackage.json is older than its reviewEveryMonths.
• Dead sources: an official source URL no longer responds.
• Changed law or municipalities: it re-runs pnpm build:cantons against the live Judicial Code and Statbel, and reports any difference with the committed data.

Run them yourself with pnpm test:freshness (add FRESHNESS_ONLINE=1 to check the URLs).

How to read a value

• Absent is not zero. getInterestRate returns null for a day without a rate on file, rather than guessing; getJusticeOfThePeace returns undefined for a court not yet in the data. Handle both.
• Contact data is the least stable. Phone numbers, e-mail addresses and opening hours change without notice. Courts will get a per-record source URL and check date (#5).
• Legal text wins. For split municipalities, the canton's territory is the law's own text, verbatim. When a summary and the text disagree, the text is right.

Reporting a mistake

Open a data correction with the record id and a link to the official source. Corrections are released as patch versions.