JWX is a library for handling JSON data and more. It is implemented in the SPARK programming language and has been proven to contain no runtime errors. As a result, JWX is particularly suited for processing untrusted information. In version 0.5.0 of JWX, parsing of Base64 (RFC 4648) data, JSON (RFC 8259) documents, JSON Web Keys (JWK, RFC 7517) and limited support for JSON Web Signatures (JWS, RFC 7515) and JSON Web Tokens (JWT, RFC 7519) is implemented. In the future, JSON Web Encryption (JWE, RFC 7516) and potentially JSON Schema is anticipated.