fp-ts Skills for AI Agents

Practical functional programming for TypeScript. No jargon, just patterns that work.

Quick Install

# List available skills
npx skills add whatiskadudoing/fp-ts-skills --list

# Install all skills
npx skills add whatiskadudoing/fp-ts-skills --all

# Install specific skill
npx skills add whatiskadudoing/fp-ts-skills --skill fp-react

Works with Claude Code, Cursor, GitHub Copilot, Gemini CLI, and any agent supporting the SKILL.md format.

Skill Tiers

Tier	Lines	Tokens	When Loaded
quick-ref	50-100	~400	Always cheap - use freely
core	300-600	~2,500	On invocation
advanced	600-1500	~6,000	Opt-in for deep dives

Quick References (Always Cheap)

Skill	Lines	Use For
fp-types-ref	75	"Which type should I use?"
fp-pipe-ref	70	pipe() and flow() patterns
fp-option-ref	70	Handling nullable values
fp-either-ref	75	Error handling basics
fp-taskeither-ref	85	Async error handling

Core Patterns

Skill	Lines	Use For
fp-pragmatic	598	80/20 of FP, when NOT to use it
fp-errors	857	Error handling patterns
fp-async	964	Async operations
fp-react	790	React state, forms, fetching
fp-compose	837	Function composition
fp-validation	912	Form/API validation

Advanced (Opt-in)

Skill	Lines	Use For
fp-data-transforms	1516	Complex data manipulation
fp-backend	1335	Service layer, DI
fp-refactor	1781	Migration from imperative
fp-algebraic-types	1445	Semigroup, Monoid, etc.
fp-side-effects	2042	Effect management

Bundles

Install multiple related skills at once:

# Essentials - quick refs only (375 lines)
npx skills add whatiskadudoing/fp-ts-skills --skill fp-types-ref
npx skills add whatiskadudoing/fp-ts-skills --skill fp-pipe-ref
npx skills add whatiskadudoing/fp-ts-skills --skill fp-option-ref
npx skills add whatiskadudoing/fp-ts-skills --skill fp-either-ref
npx skills add whatiskadudoing/fp-ts-skills --skill fp-taskeither-ref

# React Developer
npx skills add whatiskadudoing/fp-ts-skills --skill fp-react

# Backend Developer
npx skills add whatiskadudoing/fp-ts-skills --skill fp-async
npx skills add whatiskadudoing/fp-ts-skills --skill fp-backend

Philosophy

• Token-efficient: Small focused skills that compose well
• No jargon: "chain operations" not "monadic bind"
• When NOT to use FP: We tell you when a for loop is clearer
• Pragmatic: The 80/20 of functional programming

Writing Good Descriptions

Claude uses LLM reasoning (not keywords) to decide when to invoke skills. Write descriptions that cover:

---
name: fp-validation
description: Form and API validation with error accumulation. Use when validating user input, handling multiple errors, or building type-safe validators.
---

Resources & Sources

These skills were created by studying and synthesizing patterns from:

Core Libraries

• fp-ts - The functional programming library for TypeScript
• Effect - Next-generation FP in TypeScript

Books & Guides

• Functional-Light JavaScript - Kyle Simpson's pragmatic approach to FP
• Mostly Adequate Guide to FP - Professor Frisby's FP fundamentals
• Functional Programming Guide - Enrico Polanski's comprehensive guide

Articles

• Level Up React: Functional Programming in React - 56kode
• Fundamentals of Functional Programming in React - LogRocket
• Hooked on React: React 19's Function Component Superpowers - Dev.to
• Functional Programming in React - Saeloun

License

MIT

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Keywords: functional programming, typescript, fp-ts, claude code, ai skills, option type, either type, taskeither, react hooks, node.js, error handling, validation, pipe, composition