typescript-core

typescript-core is a skill for Claude Code from bobmatnyc/claude-mpm-skills. It costs 14 tokens per session (2,535 once invoked), scanned A, original, MIT.

A guide to advanced TypeScript features and safer project configuration. TypeScript adds checking to JavaScript so many incorrect data uses can be found before the program runs.

In plain words
What is it for?
Use it to configure TypeScript projects, improve type safety, model APIs, validate external input, remove unsafe any values, and publish typed libraries.
Why use it?
It helps teams use strict checks, validate data at application boundaries, and keep types consistent as a codebase grows. It also covers different practices for applications and reusable libraries.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter.

not rated 75repo +1 1mo ago A scan Socket: passSnyk: passSkillSpector: pass 14 tokens original MIT

Good fit Use it to configure TypeScript projects, improve type safety, model APIs, validate external input, remove unsafe any values, and publish typed libraries.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bobmatnyc/claude-mpm-skills/typescript-core
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 bobmatnyc/claude-mpm-skills --skill typescript-core
Clone the repo
git clone --depth 1 https://github.com/bobmatnyc/claude-mpm-skills

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 typescript-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/typescript-core/github.svg)](https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/typescript-core)
Your own site
<a href="https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/typescript-core"><img src="https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/typescript-core/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 typescript-core

Your own site · 80×15
<a href="https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/typescript-core"><img src="https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/typescript-core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 14 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,535 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. Third-party audits
  • Socket pass 23 Apr 2026
  • Snyk pass 23 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00014 $0.02535
Opus 5 $0.00007 $0.01267
Sonnet 5 $0.00003 $0.00507
Haiku 4.5 $0.00001 $0.00253

Measured 9d ago against content hash 9e46f70afd79, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

typescript-core 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 9d 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.

toolchains/typescript/typescript-core/SKILL.md · 290 lines

How it starts

The opening of the file, as written. The whole thing — 290 lines — stays where its author put it; the contents beside it link to each section on GitHub.

TypeScript Core Patterns

Modern TypeScript development patterns for type safety, runtime validation, and optimal configuration.

Quick Start

New Project: Use 2025 tsconfig → Enable strict + noUncheckedIndexedAccess → Choose Zod for validation

Existing Project: Enable strict: false initially → Fix any with unknown → Add noUncheckedIndexedAccess

API Development: Zod schemas at boundaries → z.infer<typeof Schema> for types → satisfies for routes

Library Development: Enable declaration: true → Use const type parameters → See advanced-patterns-2025.md

Quick Reference

tsconfig.json 2025 Baseline

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "strict": true,
    "noUncheckedIndexedAccess": true,
    "exactOptionalPropertyTypes": true,
    "verbatimModuleSyntax": true,
    "isolatedModules": true,
    "skipLibCheck": true,
    "declaration": true,
    "declarationMap": true
  }
}

Key Compiler Options

Option Purpose When to Enable
noUncheckedIndexedAccess Forces null checks on array/object access Always for safety
exactOptionalPropertyTypes Distinguishes undefined from missing APIs with optional fields
verbatimModuleSyntax Enforces explicit type-only imports ESM projects
erasableSyntaxOnly Node.js 22+ native TS support Type stripping environments

Local Baselines

See references/configuration.md for repo-specific tsconfig patterns (CommonJS CLI, NodeNext strict, Next.js bundler).

Core Type Patterns

Const Type Parameters

Preserve literal types through generic functions:

function createConfig<const T extends Record<string, unknown>>(config: T): T {
  return config;
}

const config = createConfig({ 
  apiUrl: "https://api.example.com", 
  timeout: 5000 
});
// Type: { readonly apiUrl: "https://api.example.com"; readonly timeout: 5000 }

Read the full file on GitHub · 290 lines

Files

What ships with it

8 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. 9d ago First seen · 290 lines · 14 tokens per session scan A 9e46f70afd79

Subscribe to this mod's changes

typescript-core is a skill published in the GitHub repository bobmatnyc/claude-mpm-skills (75 stars, last pushed 1mo ago), licensed MIT. It adds 14 tokens to every session and 2,535 once invoked, about $0.0001 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.

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