pi-safety-net

A PreToolUse hook that intercepts and blocks destructive git and filesystem commands before AI coding agents run them. CC Safety Net parses command semantics — so flag reordering, shell wrappers, and interpreter one-liners can't bypass it.

[!NOTE] Full documentation → — installation, configuration, reference, guides, and the security model live on the docs site.

Why this exists

We learned the hard way that instructions aren't enough to keep AI agents in check. After an agent silently wiped hours of progress with a single rm -rf ~/ or git checkout --, it became clear that soft rules in a CLAUDE.md or AGENTS.md file cannot replace hard technical constraints. CC Safety Net is that constraint: it intercepts every Bash tool call and blocks destructive commands before they reach the shell. See What Is CC Safety Net for the full background.

Supported agents

CC Safety Net works across seven coding agent CLIs: Claude Code, Codex, Gemini CLI, GitHub Copilot CLI, Kimi Code, OpenCode, and Pi. Each integration is documented at Architecture.

Supported platforms

CC Safety Net runs on Windows, macOS, and Linux. It detects the host OS to apply correct behavior — case-insensitive path comparison on Windows, both / and \ path separators, and cmd.exe/PowerShell command resolution via COMSPEC/PATHEXT.

Prerequisites

• Node.js 18 or higher.

Quick start

Codex Installation

1. Enable Codex plugin hooks in ~/.codex/config.toml:

[features]
plugin_hooks = true

2. Add the marketplace:

codex plugin marketplace add kenryu42/cc-marketplace

3. Start Codex.
4. In the TUI, run /plugins.
5. Use arrow keys to select [cc-marketplace].
6. Press Enter to install the plugin.
7. run /hooks and select the safety-net PreToolUse hook and press t to trust it.

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Claude Code Installation

/plugin marketplace add kenryu42/cc-marketplace
/plugin install safety-net@cc-marketplace
/reload-plugins

Claude Code Auto-Update

1. Run /plugin → Select Marketplaces → Choose cc-marketplace → Enable auto-update

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Gemini CLI Installation

gemini extensions install https://github.com/kenryu42/gemini-safety-net

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GitHub Copilot CLI Installation

/plugin install kenryu42/copilot-safety-net

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Kimi Code Installation

Install CC Safety Net into your Kimi Code config:

npx -y cc-safety-net hook install --kimi-code

Optional: run npx skill add kenryu42/cc-safety-net to add the /cc-safety-net skill for configuring custom rules.

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OpenCode Installation

Install CC Safety Net with OpenCode's native plugin command:

opencode plugin -g cc-safety-net

[!NOTE] OpenCode can sometimes keep using a stale cached plugin version. See anomalyco/opencode#25293 for the current tracking issue.

To force OpenCode to reinstall cc-safety-net, remove its cached package and install the version you want:

rm -rf ~/.cache/opencode/packages/cc-safety-net@latest
opencode plugin -g -f cc-safety-net@latest

If you prefer pinning a specific version:

rm -rf ~/.cache/opencode/packages/cc-safety-net@latest
opencode plugin -g -f cc-safety-net@<version>

Restart OpenCode after updating so the plugin is loaded from the refreshed cache.

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Pi Installation

Install CC Safety Net with Pi's package installer:

pi install npm:cc-safety-net

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What it does

Capability	What it catches
Semantic command analysis	rm -rf on destructive targets, git reset --hard, git checkout --, git push --force, git stash clear, git clean -f, find -delete, dd/mkfs/shred — by intent, not string pattern. git checkout -b feature (safe) is allowed while git checkout -- file (destructive) is blocked.
Shell wrapper detection	Destructive commands hidden in bash -c, sh -c, and similar wrappers, recursively analyzed up to 10 levels deep.
Interpreter one-liners	Destructive code in python -c, node -e, ruby -e, perl -e one-liners (e.g. os.system("rm -rf /")).
Fail-closed by default	Malformed hook input, unparseable commands (in strict mode), invalid config, and broken rulebooks block rather than allow.
Custom rules via rulebooks	Add your own blocking rules at user or project scope, pinned by SHA-256 digest when fetched from GitHub.
Audit logging	Every blocked command logged to ~/.cc-safety-net/logs/<session_id>.jsonl with secrets auto-redacted.

Full blocked/allowed command lists: Blocked Commands · Allowed Commands.

Why not just use a sandbox?

A workspace-writable sandbox still permits git reset --hard, git push --force, and rm -rf . inside the project directory, because the OS only sees writes to an allowed path. Sandboxing contains blast radius; CC Safety Net catches the destructive operations sandboxing permits — use both for defense-in-depth. See vs Sandboxing.

Modes

CC Safety Net has opt-in modes toggled by CC_SAFETY_NET_* environment variables (legacy SAFETY_NET_* names also accepted):

Mode	Flag	Effect
Strict	CC_SAFETY_NET_STRICT=1	Fail closed on unparseable commands, not just malformed input.
Paranoid	CC_SAFETY_NET_PARANOID=1	Stricter checks; or use CC_SAFETY_NET_PARANOID_RM=1 (block rm -rf even within cwd) and CC_SAFETY_NET_PARANOID_INTERPRETERS=1 (block interpreter one-liners).
Worktree	CC_SAFETY_NET_WORKTREE=1	Relax local git discards inside verified linked worktrees.

See Modes and Environment.

Diagnostics and tracing

# Verify your installation and run a self-test
npx cc-safety-net doctor
# Trace how a command is analyzed step-by-step
npx cc-safety-net explain "git reset --hard"

Both support --json for machine-readable output. Full reference: CLI Commands · Explain Trace.

Upgrading from an older version

[!WARNING] If you previously defined custom rules in a legacy inline config (.safety-net.json or ~/.cc-safety-net/config.json), those files are no longer loaded at runtime. Commands now fail closed (stay blocked) until you migrate. Run npx -y cc-safety-net rule migrate to convert them to the rulebook layout. See the migration guide.

Full documentation

All details live on the docs site at ccsafetynet.com/docs:

Area	Pages
Get started	Introduction · Installation · Quickstart
Configuration	Modes · Environment · Custom Rules · Status Line
Reference	Blocked Commands · Allowed Commands · Audit Log · CLI Commands · Explain Trace · Glossary
Guides	How It Works · Architecture · Analysis Engine · Design Principles · Security Model · vs Sandboxing · Known Limitations · Troubleshooting
Project	Contributing · Security Policy

Development

See CONTRIBUTING.md for details on how to contribute to this project.

License

MIT

Fork: Fail-Open Default

This is a fail-open fork of kenryu42/cc-safety-net.

The upstream package defaults to fail-closed: when the rule config is missing, legacy, or unparseable, it blocks every command (bricking the shell/agent). This fork flips the default to fail-open — a broken rulebook runs with no custom rules so commands are allowed through, instead of bricking the agent.

Mode	Trigger	Behavior
fail-open (default)	policy errors / legacy config / analysis exception	allow commands through, no custom rules applied
fail-closed (CC_SAFETY_NET_STRICT=1)	same triggers	block every command except repair (rule sync / rule migrate)

Set CC_SAFETY_NET_STRICT=1 to restore the upstream fail-closed behavior.

Install (pi)

// settings.json
{
  "packages": ["pi-safety-net"]
}

Attribution

This package is a fork of kenryu42/cc-safety-net.

Forked and maintained by buihongduc132.