# Developer Check Types > Run the project's TypeScript type checker and fix or explain errors in plain language. Use when user says check types, typecheck, tsc, type errors. Use when this capability is needed. - Skill: `tomevault-io/developer-check-types` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/developer-check-types` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/developer-check-types/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/developer-check-types --- # Developer Check Types Run the project's type checker (e.g. `tsc --noEmit` or the script in package.json). Use after changing TypeScript code. Explain any errors in simple words; use [document-voice](.claude/skills/document-voice/SKILL.md) when talking to the user. ## When to use - After writing or changing TypeScript. - When the user reports type errors. - After formatting (Prettier), before linting (ESLint). Fix types first so lint rules see clean code. ## Process 1. Find how the project runs type checking (e.g. `npm run check:types`, `pnpm exec tsc --noEmit`, or `npx tsc --noEmit`). Run it from the right directory (package or repo root, per project). 2. If there are errors: read file and line, fix the type issue (use [developer-typescript](.claude/skills/developer-typescript/SKILL.md) for patterns). Re-run until clean. 3. When explaining to the user: use plain language, explain terms the first time, no jargon. ## Output - Success: types are valid; say so briefly. - Errors: list file and line, what’s wrong in plain language, and what you changed (or what the user should change). Fix one at a time if many; re-run after each fix. ## Reference [developer-typescript](.claude/skills/developer-typescript/SKILL.md) – type patterns. [document-voice](.claude/skills/document-voice/SKILL.md) – how to explain. --- > Source: [ryanallen/product-studio](https://github.com/ryanallen/product-studio) — distributed by [TomeVault](https://tomevault.io).