Look up the safe idiom and known-risky API/library for a language or framework (Python, JS/TS/Node, Java, Go, C/C++, Ruby) before or while writing code — a design/build-time cheat-sheet, distinct from post-hoc scanning. Use when writing or reviewing code, scoping a PRD's tech stack, or advising an AI-assisted/vibe-coded change on which APIs and libraries to avoid up front.
