Typescript Strict Patterns

Q: What is a Claude Code skill and how does the Typescript Strict Patterns skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Typescript Strict Patterns is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Engineering · Sub-category: languages · Last updated: 2026-05-21

lang:typescript type:review

Use when writing or reviewing any TypeScript code. Covers discriminated unions, branded types, Zod at boundaries, const arrays over enums, and safe access patterns.

About this skill (catalog notes)

Typescript Strict Patterns includes 5 code blocks for direct copy-paste. The SKILL.md runs to about 710 words, in the catalog's typical mid-range.

License: MIT
Original author: sindresorhus
Indexed lastmod: 2026-05-21
Catalog position: Engineering · languages
Indexed related skills: 10

How Typescript Strict Patterns fits the catalog

Typescript Strict Patterns sits in the Engineering category under the languages sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

What this skill does

Typescript Strict Patterns is a community-contributed Claude Code skill in the languages sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/typescript-strict-patterns/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when writing or reviewing any TypeScript code. Covers discriminated unions, branded types, Zod at boundaries, const arrays over enums, and safe access patterns.

Who uses this skill

The Typescript Strict Patterns Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 120,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/typescript-strict-patterns
curl -L https://claudskills.com/skills/typescript-strict-patterns/SKILL.md \
  -o ~/.claude/skills/typescript-strict-patterns/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/typescript-strict-patterns/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/typescript-strict-patterns/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\typescript-strict-patterns\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Typescript Strict Patterns Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/typescript-strict-patterns/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Typescript Strict Patterns skill do?

Use when writing or reviewing any TypeScript code. Covers discriminated unions, branded types, Zod at boundaries, const arrays over enums, and safe access patterns.

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Typescript Strict Patterns skill?

Use Typescript Strict Patterns when your Claude Code task falls under the Engineering category — specifically in the languages area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Typescript Strict Patterns" or describe the task and let Claude pick). Browse related skills at /category/engineering/.

What is a Claude Code skill and how does the Typescript Strict Patterns skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Typescript Strict Patterns is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/sindresorhus/type-fest
License: MIT
Author: sindresorhus

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

sindresorhus. (2026). Typescript Strict Patterns [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/typescript-strict-patterns/

BibTeX

@misc{typescript-strict-patterns-2026,
  author    = {sindresorhus},
  title     = {Typescript Strict Patterns [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/typescript-strict-patterns/}
}

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