ssri is a Node.js library implementing Subresource Integrity (SRI) hash generation and verification according to the W3C specification. It facilitates secure delivery of static assets by generating cryptographic hashes, ensuring files haven't been tampered with. ssri supports various hashing algorithms (SHA-256, SHA-384, SHA-512) and provides utilities for parsing, serializing, and comparing SRI strings. This library is crucial for web security, safeguarding against malicious code injection and ensuring data integrity.