Express HMAC Authentication Middleware

HMAC Auth Express provides middleware for Express applications to implement HMAC (Hash-based Message Authentication Code) authentication. It is currently at version 9.0.0 and demonstrates an active development cadence with regular updates. Key differentiators include zero runtime dependencies (only Express as a peer dependency), timing-safe comparisons, 100% code coverage, support for all standard hash algorithms, and built-in replay attack prevention. The library also features flexible secret management, allowing for static secrets or dynamic resolution via an async function. It ships with full TypeScript type definitions, enhancing developer experience and ensuring type safety in modern JavaScript projects.