Typescript Core

A solid baseline for modern TypeScript projects that leans hard into strict mode and runtime validation with Zod. The skill pushes you toward 2025 best practices like noUncheckedIndexedAccess and using unknown instead of any, which will catch real bugs but requires discipline. It's opinionated about config (strict mode, declaration files for libraries) and API patterns (Zod schemas at boundaries, satisfies for type narrowing). The graduated approach for existing projects is smart: start with strict false, progressively fix issues. If you're starting fresh or modernizing a TypeScript codebase and want guard rails that actually prevent runtime errors, this gives you a reasonable starting point without having to research every tsconfig flag yourself.

skills.sh installs: 487
GitHub stars: 79
last updated: Aug 21, 2026

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Install

$ npx -y skills add bobmatnyc/claude-mpm-skills --skill typescript-core --agent claude-code

Installs into .claude/skills of the current project.

Files

TypeScript Core Patterns

Modern TypeScript development patterns for type safety, runtime validation, and optimal configuration.

Quick Start

New Project: Use 2025 tsconfig → Enable strict + noUncheckedIndexedAccess → Choose Zod for validation

Existing Project: Enable strict: false initially → Fix any with unknown → Add noUncheckedIndexedAccess

API Development: Zod schemas at boundaries → z.infer<typeof Schema> for types → satisfies for routes

Library Development: Enable declaration: true → Use const type parameters → See advanced-patterns-2025.md

Quick Reference

tsconfig.json 2025 Baseline

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "strict": true,
    "noUncheckedIndexedAccess": true,
    "exactOptionalPropertyTypes": true,
    "verbatimModuleSyntax": true,
    "isolatedModules": true,
    "skipLibCheck": true,
    "declaration": true,
    "declarationMap": true
  }
}