A new Go API for JSON - The Go Programming Language

The new packages reject invalid UTF-8 and duplicate object member names, closing silent-corruption and security gaps such as CVE-2017-12635, and change nil slices and maps to marshal as empty arrays and objects rather than JSON null. The release follows an experimental API introduced last year and refined through user feedback, and it matters because JSON is the most widely used data format on the internet and is read and written by Go programs across the ecosystem. Watch for migration guidance and compatibility tooling for existing `encoding/json` users, plus adoption in downstream libraries that depend on the legacy behavior.