ABcsv

ABcsv is a CSV-based data exchange format that extends standard comma-separated values with optional metadata and lightweight type hints, while aiming to remain compatible with existing CSV tooling. The design prioritizes readability and simplicity, making it suitable for small datasets and quick data validation tasks.

In ABcsv, data rows follow the conventional CSV layout. Optional metadata may be placed at the top of the file and is typically indicated by a distinctive prefix (for example, lines starting with a comment marker). This metadata can declare column names and, optionally, simple type hints or constraints. Because the core data remains valid CSV, standard CSV parsers can read the data portion without modification.

ABcsv readers operate in two modes. A CSV mode ignores metadata, while an ABcsv-aware mode reads the metadata to enforce data types and constraints. There are libraries and small utilities that can validate ABcsv files and convert them to other formats such as JSON or SQL, and vice versa.

ABcsv is used in educational settings and in lightweight data pipelines where schema guidance is helpful but more formal schema languages would be unnecessarily heavy. It remains informal and community-driven, with implementations varying by project and no widely adopted standard.

See also CSV, JSON, data interchange formats.