Helmet is a middleware for Express and Connect applications that automatically sets HTTP security headers to protect against common web vulnerabilities. It configures headers like Content-Security-Policy, X-Frame-Options, Strict-Transport-Security, and others with secure defaults, reducing the effort needed to manually implement security best practices. Developers use Helmet to quickly harden their applications against attacks like clickjacking, cross-site scripting, and other header-based exploits without having to understand or configure each security header individually.

adam_baldwin, evanhahn