json-schema-library

json-schema-library is a customizable, hackable, and highly compliant JSON Schema validator and utility library for JavaScript/TypeScript, fully supporting JSON Schema drafts 04, 06, 07, 2019-09, and 2020-12. Version 11.5.0 is current (released 2024), with frequent updates. Unlike faster or more minimal validators, it prioritizes extensibility: you can customize drafts, add keyword extensions, and traverse schemas via SchemaNode. It's the most compliant validator per Bowtie reports, runs in Node and browser, and ships TypeScript types. Designed for developers building custom tools around JSON Schema, not just validation.