# fundamentals > TypeScript type system fundamentals and basic typing patterns - Author: pluginagentmarketplace - Repository: pluginagentmarketplace/custom-plugin-typescript - Version: 20260105115612 - Stars: 1 - Forks: 0 - Last Updated: 2026-02-06 - Source: https://github.com/pluginagentmarketplace/custom-plugin-typescript - Web: https://mule.run/skillshub/@@pluginagentmarketplace/custom-plugin-typescript~fundamentals:20260105115612 --- --- name: fundamentals description: TypeScript type system fundamentals and basic typing patterns sasmp_version: "1.3.0" bonded_agent: 01-typescript-fundamentals bond_type: PRIMARY_BOND --- # TypeScript Fundamentals Skill ## Overview Master TypeScript's type system fundamentals including basic types, interfaces, and type annotations. ## Topics Covered ### Basic Types - Primitive types (string, number, boolean) - Arrays and tuples - Enums - Any, unknown, never, void - Null and undefined handling ### Type Annotations - Variable annotations - Function parameters and returns - Object type annotations - Type inference - Type assertions ### Interfaces - Interface declaration - Optional properties - Readonly properties - Index signatures - Interface extension ### Type Aliases - Type alias syntax - Union types - Intersection types - Literal types - Type narrowing ### Functions - Function type expressions - Call signatures - Overloads - Generic functions - Rest parameters ## Prerequisites - JavaScript fundamentals - ES6+ features ## Learning Outcomes - Write type-safe code - Use interfaces effectively - Apply type narrowing - Understand type inference