Solidity Security

This one's for when you're writing or reviewing Solidity contracts and need to catch security issues before they become expensive mistakes. It covers the standard vulnerabilities like reentrancy, overflows, and access control problems, plus helps with gas optimization without sacrificing safety. The skill includes an implementation playbook with specific patterns and examples, which is helpful since security advice without concrete code can be pretty vague. It's positioned as prep work before professional audits rather than a replacement for them. If you're building anything that touches real money on-chain, the checklist approach here beats trying to remember every attack vector from scratch.