type-fest

Provide 180+ TypeScript utility types for compile-time type transformations.

Updated Mar 8, 2026
One-click install
npx skills add https://github.com/xabierlameiro/price-tracker --skill type-fest
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: type-fest
Source: https://github.com/xabierlameiro/price-tracker/tree/main/.agents/skills/type-fest
Command: npx skills add https://github.com/xabierlameiro/price-tracker --skill type-fest

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill provides over 180 compile-time TypeScript utility types to perform complex type transformations, deep object manipulation, and ensure strict type safety, going beyond built-in TypeScript utilities.

Core Features & Use Cases

  • Strict Type Transformations: Deeply merge, pick, omit, and transform object types with compile-time safety.
  • Data Schema Safety: Ensure type correctness for API payloads, configurations, and state management, especially with JSON serialization and case conversions.
  • Use Case: When building a type-safe API client, use type-fest to automatically convert incoming snake_case JSON responses to camelCase TypeScript types, while also ensuring sensitive fields are omitted for public consumption.

Quick Start

Use the type-fest skill to create a type that recursively makes all properties of an interface optional.

Frequently Asked Questions about type-fest

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I convert snake_case JSON responses to camelCase TypeScript types?

You can convert snake_case JSON responses to camelCase TypeScript types using advanced utility types that perform compile-time case conversions. This ensures strict type safety for API payloads without runtime overhead.

What are advanced TypeScript utility types used for?

Advanced TypeScript utility types are used for compile-time transformations like deep object manipulation, strict type merges, and JSON-safe typing. They solve challenges in building type-safe APIs and configuration systems beyond built-in capabilities.

Can I deeply merge and omit object properties with compile-time type safety?

Yes, you can deeply merge, pick, and omit object properties with compile-time type safety using specialized utility types. This enables strict type transformations for complex state management and external data schemas.

Does type-fest work for building type-safe API clients?

Yes, type-fest works for building type-safe API clients by providing utility types that ensure type correctness for API payloads. It handles complex type-level programming and JSON serialization for external data schemas.

How do I recursively make all properties of a TypeScript interface optional?

To recursively make all properties of a TypeScript interface optional, you use deep partial utility types. These perform deep object manipulation to transform strict type operations at compile time.