Overview

Updated Nov 4, 2026

Fairspec Cardealer provides libraries for TypeScript, Python and Rust. Each one extends the matching Fairspec base library, so a cardealer dataset is also a valid Fairspec dataset, and all three pass the same conformance suite.

Libraries

All three are released together under one version, the same version as the standard.

What they export

The same names in every language:

• Dataset - a whole cardealer dataset: its $schema and its dealer, facility and car resources
• DealerResource, FacilityResource, CarResource and their union CardealerResource
• Dealer, Facility, Car - a single table row
• Category, Color, Door, FacilityType, Fuel, Gearbox - the enumerations
• VERSION - the standard version the library implements

What they check

A library accepts a dataset only when:

• $schema is the dataset profile URL of the library's own VERSION, and every resource's tableSchema is the matching table schema URL
• there is at least one resource, a dealer resource holds exactly one row, and every other resource at least one
• every row has its required columns, enumerated columns hold a listed value, and numbers are in range (price and mileage not negative, year from 1900, month from 1 to 12)

They are deliberately strict about types: no value is coerced ("45990" is not a number), an integer column accepts 2023 or 2023.0 but not 2023.5, and an optional column may be left out but not set to null.

Two things are left to a Fairspec validator: format (that email and url look like an email and a URL) and the rules between rows, such as a car's facilityId pointing to an existing facility id. Validate against the published profile and schemas when you need the full check.

Versions

A library validates datasets of its own version only, so pin it to the standard version your datasets declare. Build $schema and tableSchema from VERSION rather than writing the number by hand, and upgrading the library upgrades the URLs with it.