What is claude-code-typescript-hooks CLAUDE.md?

Project instructions for Claude Code hooks that check TypeScript and JavaScript files after they are edited. The checks use TypeScript, ESLint, Prettier, and project-specific rules, with optional automatic fixes.

They help configure and maintain post-edit checks for React apps and VS Code extensions, including TypeScript compilation, ESLint fixes, Prettier fixes, and blocking failed quality checks.

They provide immediate feedback on type errors, lint problems, formatting issues, and custom rule violations while files are being changed.

How bartolli/claude-code-typescript-hooks configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to bartolli/claude-code-typescript-hooks. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/bartolli/claude-code-typescript-hooks/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/bartolli/claude-code-typescript-hooks

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/bartolli/claude-code-typescript-hooks/claude-md/github.svg)](https://agentmods.dev/instructions/bartolli/claude-code-typescript-hooks/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/bartolli/claude-code-typescript-hooks/claude-md"><img src="https://agentmods.dev/badge/instructions/bartolli/claude-code-typescript-hooks/claude-md/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/bartolli/claude-code-typescript-hooks/claude-md"><img src="https://agentmods.dev/badge/instructions/bartolli/claude-code-typescript-hooks/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,034 This file is loaded in full into every session.

When invoked 1,034 The same file — it is already loaded in full.

Security scan B 1 finding. 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.

Model	Per session	Once invoked
Fable 5.1	$0.01034	$0.01034
Opus 5.5	$0.00414	$0.00414
Sonnet 5.5	$0.00207	$0.00207
Haiku 4.5	$0.00103	$0.00103

Measured 2mo ago against content hash 0c0829ca9e80, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

claude-code-typescript-hooks CLAUDE.md scanned grade B with 1 finding 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 2mo 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

cat .claude/hooks/react-app/hook-config.json

CLAUDE.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

This repository contains quality check hooks for Claude Code that automatically validate and fix code when files are edited. The hooks integrate with Claude Code's PostToolUse event system to provide real-time feedback on TypeScript, ESLint, and Prettier issues.

Key Architecture

Hook System

Hooks are triggered after Write/Edit/MultiEdit operations on TypeScript/JavaScript files
Each project type (react-app, vscode-extension) has its own quality check implementation
Exit code 0 = success (silent), exit code 2 = quality issues found (blocking)

Core Components

settings.local.json: Configures which hooks run and when
quality-check.js: Main validation logic for each project type
hook-config.json: Defines rules, severity levels, and allowed patterns
tsconfig-cache.json: Auto-generated cache mapping project paths to TypeScript configs

Quality Checks Performed

TypeScript compilation checks (using project's tsconfig.json)
ESLint with auto-fix capability
Prettier formatting with auto-fix
Custom rule validation (console usage, 'as any', debugger, TODOs)

Development Commands

Since this is a hooks collection without a traditional build system:

# Test a hook manually
node .claude/hooks/react-app/quality-check.js /path/to/file.tsx

# View hook configuration
cat .claude/hooks/react-app/hook-config.json

# Clear TypeScript cache if needed
rm .claude/hooks/*/tsconfig-cache.json

Working with Hooks

Adding New Project Types

Create a new directory under .claude/hooks/
Copy quality-check.js and hook-config.json from an existing hook
Modify rules and configuration for the new project type
Update settings.local.json to include the new hook

Modifying Rules

Edit hook-config.json to:

Change rule severity (info/warning/error)
Add allowed patterns for specific rules
Adjust TypeScript/ESLint/Prettier behavior

Read the full file on GitHub · 161 lines

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.

2mo ago First seen · 161 lines · 1,034 tokens per session scan B 0c0829ca9e80

Subscribe to this mod's changes

claude-code-typescript-hooks CLAUDE.md is an instructions file published in the GitHub repository bartolli/claude-code-typescript-hooks (180 stars, last pushed 1y ago), licensed MIT. It adds 1,034 tokens to every session, about $0.0041 per session on Opus 5.5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

claude-code-typescript-hooks CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
claude-code-typescript-hooks CLAUDE.mdbartolli/claude-code-typescript-hooks	Instructions file	180	1y ago	MIT	B	1,034	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

claude-code-typescript-hooks: Instructions file for Claude Code