JSONie

JSONie is a data serialization format inspired by JSON, designed to improve human readability and configurability while remaining compatible with common JSON data structures. It preserves the core JSON elements of objects, arrays, strings, numbers, booleans, and null, but adds optional human-friendly features that are commonly requested in configuration files and lightweight data exchange.

Key features include support for inline comments, trailing commas, and a simple metadata layer implemented with reserved keys that begin with an at symbol, such as @schema and @version. JSONie documents are still valid JSON if the optional features are omitted, enabling gradual adoption.

The schema mechanism allows a top-level @schema entry to describe expected structures, types, and defaults. Tools can perform validation against this schema while parsers may ignore metadata for plain data flows. This makes JSONie suitable for configuration files that benefit from self-describing formats.

Adoption and tooling for JSONie are experimental and concentrated in open-source projects and educational contexts. Many JSON parsers can be extended to support the extended syntax, but compatibility with systems that require strict JSON varies.

Limitations include fragmentation, lack of a formal standard, and potential interoperability problems when exchanging data with strict JSON processors. Users should consider whether the extended features are necessary, and document the exact subset in use.

See also: JSON, YAML, TOML.