mk:typescript

mk:typescript is a skill for Claude Code from ngocsangyem/MeowKit. It costs 43 tokens per session (1,390 once invoked), scanned A, original, MIT.

A TypeScript coding guide for writing safer code, fixing type errors, and configuring strict type checking. TypeScript adds checks to JavaScript so many mistakes are found before the program runs.

In plain words
What is it for?
Use it when adding types, handling null values, using utility types, resolving ESLint or compiler errors, or checking a project with tsc.
Why use it?
It reduces unclear or unsafe handling of values and helps projects keep type-checking and linting consistent.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Good fit Use it when adding types, handling null values, using utility types, resolving ESLint or compiler errors, or checking a project with tsc.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ngocsangyem/meowkit/typescript
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ngocsangyem/MeowKit --skill typescript
Clone the repo
git clone --depth 1 https://github.com/ngocsangyem/MeowKit

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for mk:typescript

README.md
[![agentmods](https://agentmods.dev/badge/skills/ngocsangyem/meowkit/typescript/github.svg)](https://agentmods.dev/skills/ngocsangyem/meowkit/typescript)
Your own site
<a href="https://agentmods.dev/skills/ngocsangyem/meowkit/typescript"><img src="https://agentmods.dev/badge/skills/ngocsangyem/meowkit/typescript/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for mk:typescript

Your own site · 80×15
<a href="https://agentmods.dev/skills/ngocsangyem/meowkit/typescript"><img src="https://agentmods.dev/badge/skills/ngocsangyem/meowkit/typescript.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,390 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00043 $0.01390
Opus 5 $0.00022 $0.00695
Sonnet 5 $0.00009 $0.00278
Haiku 4.5 $0.00004 $0.00139

Measured 5d ago against content hash 020d812c7e10, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

mk:typescript scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/typescript/SKILL.md · 113 lines

How it starts

The opening of the file, as written. The whole thing — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.

TypeScript Expert

Strict TypeScript patterns for type safety, null handling, and modern best practices.

When to Use

Auto-activate on: .ts, .tsx, .js, .jsx files, type errors, ESLint issues, "fix types", "add types", "TypeScript help"

Explicit: /mk:typescript [concern]

Do NOT invoke for: Vue-specific patterns (use mk:vue), visual design (use mk:frontend-design)

Workflow Integration

Operates in Phase 3 (Build GREEN). Output supports the developer agent.

Process

  1. Detect concern — type error? new code? refactor? ESLint config?
  2. Load relevant reference — strict-null, type-safety, utility-types, or eslint
  3. Apply patterns — implement using strict TS patterns from references
  4. Verifynpx tsc --noEmit must pass with zero errors

Core Rules (always apply)

  • NEVER use any — use unknown + type guards (security-rules.md)
  • NEVER use type assertion — use unknown + type guards (security-rules.md)
  • NEVER use implicit truthiness for null checks — use explicit === null || === undefined
  • ALWAYS use strict TypeScript config: strict: true, noUncheckedIndexedAccess: true
  • ALWAYS use type imports: import type { X } from 'y'
  • PREFER named exports over default exports
  • PREFER discriminated unions over type assertions

Anti-Patterns

Don't Do Instead
as any or as unknown as X Proper type narrowing with guards
if (value) for null check if (value !== null && value !== undefined)
export default export const X / export function X
Object type Record<string, unknown>
Implicit return types Explicit return type annotations
enum (runtime overhead) as const satisfies or union types

Read the full file on GitHub · 113 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 113 lines · 43 tokens per session scan A 020d812c7e10

Subscribe to this mod's changes

mk:typescript is a skill published in the GitHub repository ngocsangyem/MeowKit (14 stars, last pushed 1mo ago), licensed MIT. It adds 43 tokens to every session and 1,390 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.