TypeScript (language skill)

This is a knowledge skill, not an agent: it loads from context whenever TypeScript or JavaScript is written or reviewed, and the role agents (/fe, /be, /rev) route into it for the language-level rules. Framework depth stays with /fe's stack references — ../../frontend/react/frontend-developer/SKILL.md and its ../../frontend/react/frontend-developer/references/react-expertise.md — while this file owns TS-the-language, the Node runtime, package discipline, the lint/test toolchain, and non-UI code: CLIs, servers, libraries, scripts.

Trigger

Use this skill when:

• Writing, editing, or reviewing .ts, .tsx, .js, or .mjs files
• Changing tsconfig*.json, package.json, or a lockfile — flags, dependencies, exports, engines
• Diagnosing a tsc, ESLint, or Vitest failure
• Designing a TypeScript component — module boundaries, error surface, async topology
• Planning tests for TypeScript code
• Adding a dependency to a JavaScript/TypeScript workspace