npm ERR! code EINTEGRITY -- corrupted package cache

npm install fails with EINTEGRITY: sha512 integrity check failed. Package hash does not match expected value. Happens after network issues or switching registries.

Clear npm cache: npm cache clean --force. Then delete node_modules and package-lock.json, and reinstall: rm -rf node_modules package-lock.json && npm install. If using a proxy or private registry: check that the registry is serving correct packages. If happening in CI: ensure CI cache is not stale.

npm verifies package integrity using SHA-512 hashes stored in package-lock.json. A corrupted cache, network interruption during download, or registry proxy can cause hash mismatches.