ruby-jwt is a Ruby implementation of the RFC 7519 OAuth JSON Web Token standard.
The tool addresses the need to create and verify JSON Web Tokens in Ruby applications. It handles token encoding and decoding with cryptographic signing and verification, protecting against algorithm substitution attacks by requiring developers to explicitly specify the algorithm during decoding rather than trusting the token header.
The gem natively supports HMAC, RSA, ECDSA, and RSASSA-PSS algorithms through the OpenSSL library, with EdDSA available through a separate extension gem. It suits any Ruby project requiring token-based authentication or secure token exchange. The tool can be extended with custom algorithm implementations by creating objects that implement the JWT::JWA::SigningAlgorithm module with the required signing or verification methods. The README emphasizes that hard-coding the algorithm during decode operations is strongly recommended to prevent vulnerability to algorithm-switching attacks.
The project maintains an active community discussion channel and provides detailed upgrade guidance between major versions. Development activity shows consistent attention to security practices and standards compliance, with documentation that prioritizes safe cryptographic usage patterns over convenience.
