cc-safe-setup

cc-safe-setup

🚀 Launching on Product Hunt — April 21! Follow us and upvote to support open source safety for AI coding agents.

One command to make Claude Code safe for autonomous operation. 701 example hooks · 9,200+ tests · 30K+ total installs · 日本語

npx cc-safe-setup

Installs 8 safety hooks in ~10 seconds. Blocks rm -rf /, prevents pushes to main, catches secret leaks, validates syntax after every edit. Zero npm dependencies. Hooks use jq at runtime (brew install jq / apt install jq).

What's a hook? A checkpoint that runs before Claude executes a command. Like airport security — it inspects what's about to happen and blocks anything dangerous before it reaches the gate.

Getting Started · Incident Tracker · Hook Selector · Token Checkup · Cache Health · Version Check · CLAUDE.md Analyzer · All Tools · Recipes · Validate your settings.json · Check your score (npx cc-health-check) · Safety Audit

  cc-safe-setup
  Make Claude Code safe for autonomous operation

  Prevents real incidents (from GitHub Issues):
  ✗ rm -rf permanently destroyed ~50 GB / 1,500 files (#49129) ← April 2026
  ✗ Auto mode approved ~/.ssh deletion — all SSH keys gone (#49554)
  ✗ ~/.git-credentials PATs deleted without confirmation (#49539)
  ✗ rm -rf deleted 3,467 files (~7 GB) without confirmation (#46058)
  ✗ rm -rf deleted entire user directory via NTFS junction (#36339)
  ✗ Remove-Item -Recurse -Force destroyed unpushed source (#37331)
  ✗ Entire Mac filesystem deleted during cleanup (#36233)
  ✗ Untested code pushed to main at 3am
  ✗ Force-push rewrote shared branch history
  ✗ API keys committed to public repos via git add .
  ✗ Syntax errors cascading through 30+ files
  ✗ Sessions losing all context with no warning
  ✗ CLAUDE.md rules silently ignored after context compaction
  ✗ Claude ran destructive DDL on production database (#46684)
  ✗ AI executed delete/kill operations on production environment (#46650)
  ✗ Subagents ignoring all CLAUDE.md rules since v2.1.84 (#40459)

  Hooks to install:

  ● Destructive Command Blocker
  ● Branch Push Protector
  ● Post-Edit Syntax Validator
  ● Context Window Monitor
  ● Bash Comment Stripper
  ● cd+git Auto-Approver
  ● Secret Leak Prevention

  Install all 8 safety hooks? [Y/n] Y

  ✓ Done. 8 safety hooks installed.

Why This Exists

A user lost 3,467 files (~7 GB) when Claude ran rm -rf on their data directory without confirmation. Another lost their entire C:\Users directory when rm -rf followed NTFS junctions. Another lost all source code when Claude ran Remove-Item -Recurse -Force * on a repo. One user's Claude ran destructive DDL on a production database when asked only to investigate. Another had Claude execute delete and kill operations on production systems. Others had untested code pushed to main at 3am. API keys got committed via git add .. Syntax errors cascaded through 30+ files before anyone noticed. And CLAUDE.md rules get silently dropped after context compaction — your instructions vanish mid-session.

One user analyzed 6,852 sessions and found the Read:Edit ratio dropped from 6.6 to 2.0 — Claude editing files it never read jumped from 6% to 34%. That issue has over 2,100 reactions. The read-before-edit example hook catches this pattern before damage happens.

In April 2026, $1,446 was transferred without authorization when Claude moved funds between exchange accounts. A user lost $367 and got their account suspended from a Claude-generated script. Physical coordinates were uploaded to a public website despite 17 sessions of "no PII" in CLAUDE.md. And deny rules can be bypassed with 50+ subcommands.

Claude Code ships with no safety hooks by default. This tool fixes that. (Standalone guard script for quick setup | Database protection hooks | Credential protection hooks | Fabrication detection hook | Security vulnerability hooks)

Works with Auto Mode. Claude Code's Auto Mode sandboxing provides container-level isolation. cc-safe-setup adds process-level hooks as defense-in-depth — catching destructive commands even outside sandboxed environments.

Works with subagents. Since v2.1.84, subagents and teammates don't receive CLAUDE.md — your project rules are silently skipped. Hooks operate at the process level, but subagent tool calls may bypass PreToolUse hooks in some configurations. As defense-in-depth, cc-safe-setup installs hooks at the user level (~/.claude/settings.json). The subagent-claudemd-inject example hook re-injects critical rules into subagent prompts.

🚨 Opus 4.7 Crisis (April 2026)

Opus 4.7 broke auto mode's safety classifier — it was hardcoded to Opus 4.6. If you use auto mode with Opus 4.7, dangerous commands run without the built-in safety check. In 3 days: 50 GB permanently deleted, ~/.ssh wiped, git credentials destroyed, shell configs truncated to 0 bytes. Users report 4x token consumption from silent model switches.

One command to fix it:

npx cc-safe-setup --opus47

Installs 4 hooks targeting known Opus 4.7 regressions. Full details → · Emergency Defense Kit (Gist) · Safety Scanner

What Gets Installed

Hook	Prevents	Related Issues
Destructive Guard	rm -rf /, git reset --hard, git clean -fd, git checkout --force, sudo + destructive, PowerShell Remove-Item -Recurse -Force, rd /s /q, NFS mount detection	#46058 #36339 #36640 #37331
Branch Guard	Pushes to main/master + force-push (--force) on all branches
Secret Guard	git add .env, credential files, git add . with .env present	#6527
Syntax Check	Python, Shell, JSON, YAML, JS errors after edits
Context Monitor	Session state loss from context window overflow (40%→25%→20%→15% warnings)
Comment Stripper	Bash comments breaking permission allowlists	#29582
cd+git Auto-Approver	Permission prompt spam for cd /path && git log	#32985 #16561
API Error Alert	Silent session death from rate limits or API errors — desktop notification + log

Each hook exists because a real incident happened without it.

Free diagnostic tools

Tool	What it does
Token Checkup	5 questions → find where your tokens are going (30 seconds)
Security Checkup	6 questions based on real incidents ($1,800+ in losses)
Version Check	Is your CC version affected by cache inflation?

Go deeper

Resource	What you get	Price
Token Book	Cut token consumption in half. CLAUDE.md templates, hook configs, context management, 32 failure patterns with fixes. 44,000+ words from 800+ hours of real operation data.	¥2,500 (~$17). Ch.1 free
Safety Guide	End-to-end Claude Code safety setup. From first install to overnight autonomous runs.	¥800 (~$5). Ch.3 free

Why pay? A Max plan costs $200/month. One token waste incident burns 50–80% of your weekly quota in hours (#46727). One rm -rf incident costs days of recovery. The Token Book costs less than 2 hours of Max subscription time — and the CLAUDE.md templates alone can reduce consumption by 40%.

v2.1.85: if Field Support

Hooks now support an if field for conditional execution. The hook process only spawns when the command matches the pattern — ls won't trigger a git-only hook.

{
  "type": "command",
  "if": "Bash(git push *)",
  "command": "~/.claude/hooks/test-before-push.sh"
}

All example hooks include if field documentation in their headers.

PermissionRequest Hooks (NEW)

Override Claude Code's built-in confirmation prompts. These run after the built-in safety checks, so they can auto-approve prompts that permissions.allow cannot suppress.

Hook	What It Solves	Issue
quoted-flag-approver	"Quoted characters in flag names" prompt on git commit -m "msg"	#27957
bash-heuristic-approver	Safety heuristic prompts for $(), backticks, ANSI-C quoting	#30435
edit-always-allow	Edit prompts in .claude/skills/ despite bypassPermissions	#36192
allow-git-hooks-dir	Edit prompts in .git/hooks/ for pre-commit/pre-push setup
allow-protected-dirs	All protected directory prompts (CI/Docker environments)	#36168
git-show-flag-sanitizer	Strips invalid --no-stat from git show (wastes context on error)	#13071
compact-blocker	Blocks auto-compaction via PreCompact (preserves full context)	#6689
webfetch-domain-allow	Auto-approves WebFetch by domain (fixes broken domain:* wildcard)	#9329

Install any of these: npx cc-safe-setup --install-example <name>

Session Protection Hooks

Guards against issues that corrupt sessions or waste tokens silently.

Hook	What It Solves	Issue
cch-cache-guard	Blocks reads of Claude session/billing files that poison prompt cache via cch= substitution	#40652
image-file-validator	Blocks Read of fake image files (text in .png) that permanently corrupt sessions	#24387
terminal-state-restore	Restores Kitty keyboard protocol, cursor, bracketed paste on exit	#39096 #39272
large-read-guard	Warns before reading large files via cat/less that waste context tokens	#41617
prompt-usage-logger	Logs every prompt with timestamps to track token consumption patterns	#41249
compact-alert-notification	Alerts when auto-compaction fires (tracks compact-rebuild cycles that burn tokens)	#41788
token-budget-guard	Blocks tool calls when estimated session cost exceeds a configurable threshold	#38335
session-index-repair	Rebuilds sessions-index.json on exit so claude --resume finds all sessions	#25032
session-backup-on-start	Backs up session JSONL files on start (protects against silent deletion)	#41874
working-directory-fence	Blocks Read/Edit/Write outside CWD (prevents operating on wrong project copy)	#41850
mcp-warmup-wait	Waits for MCP servers to initialize on session start (fixes first-turn tool errors)	#41778
pre-compact-transcript-backup	Full JSONL backup before compaction (protects against rate-limit data loss)	#40352
conversation-history-guard	Blocks access to session JSONL files (prevents 20x cache poisoning)	#40524
read-before-edit	Warns when Edit targets a file not recently Read (Read:Edit ratio dropped 70% — #42796)	#42796
replace-all-guard	Warns/blocks Edit replace_all:true (prevents bulk data corruption)	#41681
ripgrep-permission-fix	Auto-fixes vendored ripgrep +x permission on start (fixes broken commands/skills)	#41933

All 49 Commands

Command	What It Does
npx cc-safe-setup	Install 8 safety hooks
--create "desc"	Generate hook from plain English
--audit [--fix|--json|--badge]	Safety score 0-100
--lint	Static analysis of config
--diff <file>	Compare settings
--compare <a> <b>	Side-by-side hook comparison
--migrate	Detect hooks from other projects
--generate-ci	Create GitHub Actions workflow
--share	Generate shareable URL
--benchmark	Measure hook speed
--dashboard	Real-time terminal UI
--issues	GitHub Issues each hook addresses
--doctor	Diagnose hook problems
--watch	Live blocked command feed
--stats	Block history analytics
--learn [--apply]	Pattern learning
--scan [--apply]	Tech stack detection
--export / --import	Team config sharing
--verify	Test each hook
--install-example <name>	Install from 701 examples
--examples [filter]	Browse examples by keyword
--full	All-in-one setup
--status	Check installed hooks
--dry-run	Preview changes
--uninstall	Remove all hooks
--shield	Maximum safety in one command
--guard "rule"	Instantly enforce a rule from English
--suggest	Predict risks from project analysis
--from-claudemd	Convert CLAUDE.md rules to hooks
--team	Project-level hooks for git sharing
--profile [level]	Switch safety profiles
--save-profile <name>	Save current hooks as profile
--analyze	Session analysis dashboard
--health	Hook health table
--quickfix	Auto-fix common problems
--replay	Visual blocked commands timeline
--why <hook>	Show real incident behind hook
--migrate-from <tool>	Migrate from other hook tools
--diff-hooks [path]	Compare hook configurations
--init-project	Full project setup (hooks + CLAUDE.md + CI)
--score	CI-friendly safety score (exit 1 if below threshold)
--test-hook <name>	Test a specific hook with sample input
--simulate "cmd"	Preview how all hooks react to a command
--protect <path>	Block edits to a file or directory
--rules [file]	Compile YAML rules into hooks
--validate	Validate all hook scripts (syntax + structure)
--safe-mode	Maximum protection: all safety hooks + strict config
--changelog	Show what changed in each version
--report	Generate safety report
--help	Show help

Quick Start by Scenario

I want to...	Command
Make Claude Code safe right now	npx cc-safe-setup --shield
Stop permission prompt spam	npx cc-safe-setup --install-example auto-approve-readonly
Enforce a rule instantly	npx cc-safe-setup --guard "never delete production data"
See what risks my project has	npx cc-safe-setup --suggest
Convert CLAUDE.md rules to hooks	npx cc-safe-setup --from-claudemd
Share hooks with my team	npx cc-safe-setup --team && git add .claude/
Choose a safety level	npx cc-safe-setup --profile strict
See what Claude blocked today	npx cc-safe-setup --replay
Know why a hook exists	npx cc-safe-setup --why destructive-guard
Block silent memory file edits	npx cc-safe-setup --install-example memory-write-guard
Stop built-in skills editing opaquely	npx cc-safe-setup --install-example skill-gate
Diagnose why hooks aren't working	npx cc-safe-setup --doctor
Preview how hooks react to a command	npx cc-safe-setup --simulate "git push origin main"
Protect a specific file from edits	npx cc-safe-setup --protect .env
Stop .git/ write prompts	npx cc-safe-setup --install-example allow-git-hooks-dir
Auto-approve compound git commands	npx cc-safe-setup --install-example auto-approve-compound-git
Detect prompt injection patterns	npx cc-safe-setup --install-example prompt-injection-detector
Define rules in YAML, compile to hooks	npx cc-safe-setup --rules rules.yaml
Validate all hook scripts are correct	npx cc-safe-setup --validate
Maximum protection mode	npx cc-safe-setup --safe-mode
Migrate from Cursor/Windsurf	Migration Guide

Plugin Marketplace

Install safety hooks as Claude Code plugins — no npm required:

/plugin marketplace add yurukusa/cc-safe-setup
/plugin install safety-essentials@cc-safe-setup

Plugin	What it blocks
safety-essentials	rm -rf, force-push, hard-reset, .env overwrite, npm publish
git-protection	Force-push, main/master push, git clean, branch -D
credential-guard	.env write/edit, API keys in commands, service account files

Also listed on claudemarketplaces.com.

Common Pain Points (from GitHub Issues)

Problem	Issue	Fix
Claude uses cat/grep/sed instead of built-in Read/Edit/Grep	#19649 (48👍)	npx cc-safe-setup --install-example prefer-builtin-tools
cd /path && cmd bypasses permission allowlist	#28240 (88👍)	npx cc-safe-setup --install-example compound-command-approver
Multiline commands skip pattern matching	#11932 (47👍)	Use hooks instead of allowlist patterns for complex commands
No notification when Claude asks a question	#13024 (52👍)	npx cc-safe-setup --install-example notify-waiting
allow overrides ask in permissions	#6527 (17👍)	Use hooks to block dangerous commands instead of ask rules
Plans stored in ~/.claude/ with random names	#12619 (163👍)	npx cc-safe-setup --install-example plan-repo-sync

How It Works

• Writes hook scripts to ~/.claude/hooks/
• Updates ~/.claude/settings.json to register the hooks
• Restart Claude Code — hooks are active

Safe to run multiple times. Existing settings are preserved. A backup is created if settings.json can't be parsed.

Maximum safety: npx cc-safe-setup --shield — one command: fix environment, install hooks, detect stack, configure settings, generate CLAUDE.md.

Instant rule: npx cc-safe-setup --guard "never touch the database" — generates, installs, activates a hook instantly from plain English.

Team setup: npx cc-safe-setup --team — copy hooks to .claude/hooks/ with relative paths, commit to repo for team sharing.

Preview first: npx cc-safe-setup --dry-run

Check status: npx cc-safe-setup --status — see which hooks are installed (exit code 1 if missing).

Verify hooks work: npx cc-safe-setup --verify — sends test inputs to each hook and confirms they block/allow correctly.

Troubleshoot: npx cc-safe-setup --doctor — diagnoses why hooks aren't working (jq, permissions, paths, shebang).

Live monitor: npx cc-safe-setup --watch — real-time dashboard of blocked commands during autonomous sessions.

Uninstall: npx cc-safe-setup --uninstall — removes all hooks and cleans settings.json.

Requires: jq for JSON parsing (brew install jq / apt install jq).

Note: Hooks are skipped when Claude Code runs with --bare or --dangerously-skip-permissions. These modes bypass all safety hooks by design.

Known limitations:

• In headless mode (-p / --print), hook exit code 2 may not block tool execution (#36071). For CI pipelines, use interactive mode with hooks rather than -p mode.
• FileChanged notifications inject file contents into model context before hooks can intervene. If a sensitive file (.env, credentials.json) is modified externally during a session, its contents may appear in the conversation transcript regardless of hooks (#44909). Mitigation: use dotenv-watch to get alerted, and avoid editing sensitive files while Claude Code is running.

Before / After

Run npx cc-health-check to see the difference:

	Before	After
Safety Guards	25%	75%
Overall Score	50/100	95/100
Destructive commands	Unprotected	Blocked
Force push	Allowed	Blocked
.env in git	Possible	Blocked
Context warnings	None	4-stage alerts

Configuration

Variable	Hook	Default
CC_ALLOW_DESTRUCTIVE=1	destructive-guard	0 (protection on)
CC_SAFE_DELETE_DIRS	destructive-guard	node_modules:dist:build:.cache:__pycache__:coverage
CC_PROTECT_BRANCHES	branch-guard	main:master
CC_ALLOW_FORCE_PUSH=1	branch-guard	0 (protection on)
CC_SECRET_PATTERNS	secret-guard	.env:.env.local:credentials:*.pem:*.key
CC_CONTEXT_MISSION_FILE	context-monitor	$HOME/mission.md

After Installing

Verify your setup:

npx cc-health-check

Full Kit

cc-safe-setup gives you 8 essential hooks. Want to know what else your setup needs?

Run npx cc-health-check (free, 20 checks) to see your current score. If it's below 80, the Claude Code Ops Kit fills the gaps — 6 hooks + 5 templates + 9 scripts + install.sh. Pay What You Want ($0+).

Starter Kit: Want hooks + settings + templates in one download? The Claude Code Safety Kit bundles 5 safety hooks, a pre-configured settings.json, CLAUDE.md templates, and 800-hour operation tips. Name your price ($0+).

Or browse the free hooks: claude-code-hooks

Examples

Safety Audit

Try it in your browser — paste your settings.json, get a score instantly. Nothing leaves your browser.

Or from the CLI:

npx cc-safe-setup --audit

Analyzes 9 safety dimensions and gives you a score (0-100) with one-command fixes for each risk.

CI Integration (GitHub Action)

# .github/workflows/safety.yml
- uses: yurukusa/cc-safe-setup@main
  with:
    threshold: 70  # CI fails if score drops below this

Project Scanner

npx cc-safe-setup --scan         # detect tech stack, recommend hooks
npx cc-safe-setup --scan --apply # auto-create CLAUDE.md with project rules

Create Hooks from Plain English

npx cc-safe-setup --create "block npm publish without tests"
npx cc-safe-setup --create "auto approve test commands"
npx cc-safe-setup --create "block curl pipe to bash"
npx cc-safe-setup --create "block DROP TABLE and TRUNCATE"

9 built-in templates + generic fallback. Creates the script, registers it, and runs a smoke test.

Self-Learning Safety

npx cc-safe-setup --learn        # analyze your block history for patterns
npx cc-safe-setup --learn --apply # auto-generate custom hooks from patterns

Examples

Need custom hooks beyond the 8 built-in ones? Install any example with one command:

npx cc-safe-setup --install-example block-database-wipe

Or browse all available examples in examples/:

• auto-approve-git-read.sh — Auto-approve git status, git log, even with -C flags
• auto-approve-ssh.sh — Auto-approve safe SSH commands (uptime, whoami, etc.)
• enforce-tests.sh — Warn when source files change without corresponding test files
• notify-waiting.sh — Desktop notification when Claude Code waits for input (macOS/Linux/WSL2)
• edit-guard.sh — Block Edit/Write to protected files (defense-in-depth for #37210)
• auto-approve-build.sh — Auto-approve npm/yarn/cargo/go/python build, test, and lint commands
• auto-approve-docker.sh — Auto-approve docker build, compose, ps, logs, and other safe commands
• block-database-wipe.sh — Block destructive database commands: Laravel migrate:fresh, Django flush, Rails db:drop, raw DROP DATABASE (#46684 #46650 #37405 #37439)
• auto-approve-python.sh — Auto-approve pytest, mypy, ruff, black, isort, flake8, pylint commands
• auto-snapshot.sh — Auto-save file snapshots before edits for rollback protection (#37386 #37457)
• allowlist.sh — Block everything not explicitly approved — inverse permission model (#37471)
• protect-dotfiles.sh — Block modifications to ~/.bashrc, ~/.aws/, ~/.ssh/ and chezmoi without diff (#37478)
• scope-guard.sh — Block file operations outside project directory — absolute paths, home, parent escapes (#36233)
• auto-checkpoint.sh — Auto-commit after every edit for rollback protection (#34674)
• git-config-guard.sh — Block git config --global modifications without consent (#37201)
• deploy-guard.sh — Block deploy commands when uncommitted changes exist (#37314)
• network-guard.sh — Warn on suspicious network commands sending file contents (#37420)
• test-before-push.sh — Block git push when tests haven't been run (#36970)
• large-file-guard.sh — Warn when Write tool creates files over 500KB
• commit-message-check.sh — Warn on non-conventional commit messages (feat:, fix:, docs:, etc.)
• env-var-check.sh — Block hardcoded API keys (sk-, ghp_, glpat-) in export commands
• timeout-guard.sh — Warn before long-running commands (npm start, rails s, docker-compose up)
• branch-name-check.sh — Warn on non-conventional branch names (feature/, fix/, etc.)
• todo-check.sh — Warn when committing files with TODO/FIXME/HACK markers
• path-traversal-guard.sh — Block Edit/Write with ../../ path traversal and system directories
• case-sensitive-guard.sh — Detect case-insensitive filesystems (exFAT, NTFS, HFS+) and block rm/mkdir that would collide due to case folding (#37875)
• compound-command-approver.sh — Auto-approve safe compound commands (cd && git log, cd && npm test) that the permission system can't match (#30519 #16561)
• tmp-cleanup.sh — Clean up accumulated /tmp/claude-*-cwd files on session end (#8856)
• session-checkpoint.sh — Save session state to mission file before context compaction (#37866)
• verify-before-commit.sh — Block git commit when lint/test commands haven't been run (#37818)
• hook-debug-wrapper.sh — Wrap any hook to log input/output/exit code/timing to ~/.claude/hook-debug.log
• loop-detector.sh — Detect and break command repetition loops (warn at 3, block at 5 repeats)
• commit-quality-gate.sh — Warn on vague commit messages ("update code"), long subjects, mega-commits
• session-handoff.sh — Auto-save git state and session info to ~/.claude/session-handoff.md on session end
• diff-size-guard.sh — Warn/block when committing too many files at once (default: warn at 10, block at 50)
• dependency-audit.sh — Warn when installing packages not in manifest (npm/pip/cargo supply chain awareness)
• env-source-guard.sh — Block sourcing .env files into shell environment (#401)
• symlink-guard.sh — Detect symlink/junction traversal in rm targets (#36339 #764)
• no-sudo-guard.sh — Block all sudo commands
• no-install-global.sh — Block npm -g and system-wide pip
• no-curl-upload.sh — Warn on curl POST/upload (data exfiltration)
• no-port-bind.sh — Warn on network port binding
• git-tag-guard.sh — Block pushing all tags at once
• npm-publish-guard.sh — Version check before npm publish
• max-file-count-guard.sh — Warn when 20+ new files created per session
• protect-claudemd.sh — Block edits to CLAUDE.md and settings files
• reinject-claudemd.sh — Re-inject CLAUDE.md rules after compaction (#6354)
• binary-file-guard.sh — Warn when Write targets binary file types (images, archives)
• stale-branch-guard.sh — Warn when working branch is far behind default
• cost-tracker.sh — Estimate session token cost and warn at thresholds ($1, $5)
• read-before-edit.sh — Warn when editing files not recently read (prevents old_string mismatches)

Safety Checklist

SAFETY_CHECKLIST.md — Copy-paste checklist for before/during/after autonomous sessions.

Windows Support

Works on Windows via WSL or Git Bash. Native PowerShell is not supported (hooks are bash scripts).

Common issue: If you see Permission denied or No such file errors after install, run:

npx cc-safe-setup --doctor

This detects Windows backslash paths (C:\Users\... → C:/Users/...) and missing execute permissions.

See Issue #1 for details.

Troubleshooting

TROUBLESHOOTING.md — "Hook doesn't work" → step-by-step diagnosis. Covers every common failure pattern.

settings.json Reference

SETTINGS_REFERENCE.md — Complete reference for permissions, hooks, modes, and common configurations. Includes known limitations and workarounds.

Migration Guide

MIGRATION.md — Step-by-step guide for moving from permissions-only to permissions + hooks. Keep your existing config, add safety layers on top.

Learn More

• Opus 4.7 Survival Guide — 61 known issues (76+ GitHub Issues + CVEs) with fixes: data loss, recursive spawn DoS, billing mismatch, subagent OOM, cache_read anomaly, allowedTools bypass, 1.7x token inflation, classifier failure, thinking summary bugs, 30-min stalls, enterprise hooks bypass, and more. npx cc-safe-setup --opus47
• Token Book (¥2,500) — Cut token consumption in half. CLAUDE.md optimization, hook-based guards, context management, workflow design. 44,000 words with copy-paste templates. Intro + Ch.1 free. Details
• Safety Guide (¥800) — Token consumption diagnosis, file loss prevention, autonomous operation safety. From 800+ hours of real incidents. Chapter 3 free
• 800 Hours Operation Record (¥800) — Non-engineer running Claude Code autonomously for 800 hours. Failures, recovery, revenue reality. Chapter 2 free
• Wiki Guides: Token FAQ · CLAUDE.md Best Practices · Token Optimization
• Cookbook — 26 practical recipes (block, approve, protect, monitor, diagnose)
• Official Hooks Reference — Claude Code hooks documentation
• Hooks Cookbook — 25 recipes from real GitHub Issues (interactive version)
• Skills Guide deep-dive (Qiita, 19K+ views) — Anthropic's official Skills PDF analyzed with 40% token reduction
• Japanese guide (Qiita) — この記事の日本語解説
• v2.1.85 if field guide (Qiita) — Reduce hook overhead with conditional execution
• Deny rules bypass vulnerability (Qiita) — 50+ subcommands disable all deny rules; hook-based defense
• Hook Test Runner — npx cc-hook-test <hook.sh> to auto-test any hook
• Hook Registry — npx cc-hook-registry search database (browse online)
• Hooks Cheat Sheet — printable A4 quick reference
• Ecosystem Comparison — all Claude Code hook projects compared
• The incident that inspired this tool — NTFS junction rm -rf
• How to prevent rm -rf disasters — real incidents and the hook that stops them
• How to prevent force-push to main — branch protection via hooks
• How to prevent secret leaks — stop git add . from committing .env

Free Gists

• settings.json Complete Template — copy-paste ready safety configuration
• First 3 Safety Steps — 5-minute safety setup from scratch
• CLAUDE.md Before/After — 40% token reduction through better writing patterns
• Token Savings Cheat Card — 5 techniques to cut consumption in half
• Token Consumption Checklist — 10-item diagnostic
• Outage Survival Kit — what to do when Claude Code is down
• CLAUDE.md Token Optimizer — 35-line template, 40% token reduction (800h tested)
• Worktree Safety Hooks — 3 hooks to protect against worktree deletion and cross-tree destruction
• Opus 4.7 Emergency Checklist — token burn diagnosis + immediate fixes
• Cache TTL Mitigation Guide — #46829 cache TTL change (1h→5m) impact and 4 mitigations
• Security Checkup Hooks — 4 hooks for financial, PII, deny bypass, and background task protection
• Cache Breakage Fix — 2 root causes of prompt cache invalidation (#47107 git status, #47098 session restart)
• CLAUDE.md Token Optimization Cheat Sheet — 5 CLAUDE.md patterns that reduce token consumption with before/after examples
• Token Troubleshooting Guide — fix quota drain, cache bugs, 1M context trap. Symptom-based diagnosis with latest issue references
• Token Optimization Guide (English) — 3 biggest token levers with hook code, practical walkthrough
• Token Book Sampler: 5 Techniques — free preview of the Token Book — 5 immediate techniques to reduce consumption
• Token Optimization Checklist — 10-step checklist to cut token consumption in half, with hook configs
• 3 Things That Actually Work — CLAUDE.md sizing, cache TTL, subagent control — based on 800h data
• Cache TTL Diagnostic — 3 patterns that break prompt cache + fixes
• Token Book Ch.1 Free Preview — Where are your Claude Code tokens going? The 4 layers of token consumption explained
• Deny Rules Break After 50 Subcommands — the hook that fixes Claude Code's deny rule bypass vulnerability
• Opus 4.7 Emergency Kit — 5 commands to protect your data from Opus 4.7 regressions (auto mode broken, 23+ data loss incidents)
• cache_read Billing Bug Guide — Opus 4.7 cache_read billed at full rate. Anthropic confirmed. Max plan users losing quota 3-6x faster
• Opus 4.7 Survival Guide Summary — 50 known issues with quick reference table, free diagnostic tools, and one-command fix
• Opus 4.7 Known Issues Quick Reference — 26 issues / 43+ GitHub bugs in one table. Severity ratings and direct issue links
• 4 New Critical Issues (April 18) — DoS via recursive spawn, subagent OOM, billing mismatch, UI/CLI model mismatch
• トークン消費を半分にする方法 — 800時間の実測データ＋設定テンプレート（日本語）
• How to Cut Token Usage in Half — 800h real data + config templates (English)
• Compaction Triple Threat — 3 compaction bugs active simultaneously (#50402 + #50467 + #50492)
• Sandbox Relative Path Bug (CRITICAL) — denyWrite/denyRead silently ignores relative paths (#50454)
• 27 Token Symptoms Quick Reference — all 27 known token failure modes with top 5 killers table and April 2026 new symptoms
• Token Saving Checklist (15 Items) — ordered by impact: critical (30-50%), important (10-20%), good practice (5-10%)
• Opus 4.7 Survival Cheatsheet — 46 known problems, quick fixes under 60 seconds, full reference table

Professional Services

Need help configuring Claude Code safely? Safety Setup Service — audit, token optimization, and custom hooks by the cc-safe-setup team.

FAQ

Q: I installed hooks but Claude says "Unknown skill: claude-code-hooks:setup"

cc-safe-setup installs hooks, not skills or plugins. Hooks run automatically in the background — you don't invoke them manually. After install + restart, try running a dangerous command; the hook will block it silently.

Q: cc-health-check says to run cc-safe-setup but I already did

cc-safe-setup covers Safety Guards (75-100%) and Monitoring (context-monitor). The other health check dimensions (Code Quality, Recovery, Coordination) require additional CLAUDE.md configuration or manual hook installation from claude-code-hooks.

Q: Will hooks slow down Claude Code?

No. Each hook runs in ~10ms. They only fire on specific events (before tool use, after edits, on stop). No polling, no background processes.

Q: My permission patterns don't match compound commands like cd /path && git status

This is a known limitation of Claude Code's permission system (#16561, #28240). Permission matching evaluates only the first token (cd), not the actual command (git status). Use a PreToolUse hook instead — hooks see the full command string and can parse compound commands. See compound-command-allow.sh in examples.

Q: --dangerously-skip-permissions still prompts for .claude/ and .git/ writes

Since v2.1.78, protected directories always prompt regardless of permission mode (#35668). Use a PermissionRequest hook to auto-approve specific protected directory operations. See allow-protected-dirs.sh in examples.

Q: allow: ["Bash(*)"] overrides my ask rules

allow takes precedence over ask. If you allow all Bash, ask rules are ignored (#6527). Use PreToolUse hooks to block dangerous commands instead of relying on the ask/allow priority system.

Q: Hooks silently fail on macOS (Homebrew jq not found)

Claude Code runs hooks with a restricted PATH that excludes /opt/homebrew/bin (#46954). If jq is installed via Homebrew, hooks silently exit 0. Fix: add export PATH="/opt/homebrew/bin:$PATH" at the top of your hook script, or use absolute paths like /opt/homebrew/bin/jq. Inline hooks in settings.json may also be affected — add a PATH export prefix: export PATH="/opt/homebrew/bin:$PATH"; INPUT=$(cat); ...

Q: How is this different from claude-token-efficient?

Different goals. claude-token-efficient optimizes CLAUDE.md to make Claude's responses shorter and cheaper. cc-safe-setup prevents dangerous operations (file deletion, credential leaks, force-push). They work well together: use claude-token-efficient for cost reduction, cc-safe-setup for safety. For comprehensive token optimization beyond CLAUDE.md (hooks, context management, workflow design), see the Token Book.

Still stuck? See the full Permission Troubleshooting Flowchart for step-by-step diagnosis.

Contributing

Report a problem: Found a false positive or a bypass? Open an issue. Include the command that was incorrectly blocked/allowed and your OS.

Request a hook: Describe the problem you're trying to prevent (not the solution). We'll figure out the hook together.

Write a hook: Fork, add your .sh file to examples/, add tests to test.sh, and open a PR. Every hook needs:

• A comment header explaining what it blocks and why
• At least 7 test cases (block, allow, empty input, edge cases)
• bash -n syntax validation passing

Share your experience: Used cc-safe-setup and have feedback? Open a discussion or comment on any issue. We read everything.

If cc-safe-setup saved you from a disaster (or just saved you time), a ⭐ helps others find it too.

Also by yurukusa

• quiet life — Touch the dark. Something alive appears
• deep breath — Breathe with the light
• star moss — Drag to grow

License

MIT