croissant

croissant

E.D. Gennatas, MBBS AICSM PhD Updated: 2026-10-27

croissant is an R package that reads, validates, and writes Croissant metadata, and reads the records that the metadata describes.

Croissant is a JSON-LD vocabulary, developed by MLCommons, for describing machine learning datasets. A Croissant document records a dataset’s descriptive metadata, the files it consists of, and the structure of its records.

Read and write

Read Croissant 1.0 and 1.1 documents into typed S7 objects, write them as JSON-LD, and create metadata for R tables.

Validate

Report every error and warning in a document in one table, with the checks of the reference implementation.

Load records

Read the records of a record set from CSV, JSON, JSON Lines, and Parquet files, local, downloaded, or archived.

The package also reads the Croissant metadata that the Hugging Face Hub generates for its datasets, and downloads and verifies the files that the metadata names.

Start with the Introduction for installation, an outline of the Croissant format, and a complete example.