Little Snitch Rules

Opinionated Little Snitch 6 remote rule groups for tightening outbound network control on macOS.

The repository is built around a simple model:

• start with a deny-first rule group for high-risk executables
• layer on narrow allow-rule groups for workflows you explicitly trust
• keep exceptions separated so you can subscribe only to what you need

These rule groups are intended for people who want a stricter outbound posture on developer machines, where shells, interpreters, and download tools are often the easiest path to unwanted network activity.

Rule Groups

File	Purpose	Typical use
high-risk-executables-deny.lsrules	Baseline deny rules for shells, interpreters, and common CLI tools	Subscribe first
dev-safe-exceptions.lsrules	Narrow developer exceptions for GitHub, PyPI, npm, and Homebrew metadata	Add when you need common package and source control workflows
openai-ai-tools-exceptions.lsrules	Narrow exceptions for OpenAI and ChatGPT connectivity	Add only if local tools or scripts need OpenAI access

Quick Start

1. Subscribe to high-risk-executables-deny.lsrules.
2. Add dev-safe-exceptions.lsrules if you want common developer traffic to work without creating your own rules first.
3. Add openai-ai-tools-exceptions.lsrules only if you want local scripts, shells, or automation to reach OpenAI or ChatGPT services.
4. Watch what gets blocked and add destination-specific allow-rules instead of weakening the baseline deny policy.

Little Snitch applies the most specific matching rule, so narrow destination-specific allow-rules can coexist with broad deny rules for the same process.

Subscribe in Little Snitch

In Little Snitch Configuration:

1. Open Rule Groups.
2. Click +.
3. Choose Remote Rule Group....
4. Paste one of the raw URLs below.
5. Click Add.
6. Repeat for the other rule groups you want.

Rule group	Raw URL
High-risk deny	https://raw.githubusercontent.com/HendrikReh/little_snitch/main/high-risk-executables-deny.lsrules
Dev-safe exceptions	https://raw.githubusercontent.com/HendrikReh/little_snitch/main/dev-safe-exceptions.lsrules
OpenAI AI tools exceptions	https://raw.githubusercontent.com/HendrikReh/little_snitch/main/openai-ai-tools-exceptions.lsrules

What Gets Blocked

high-risk-executables-deny.lsrules

This is the baseline ruleset. It denies outbound internet access for these processes:

• /bin/sh
• /bin/bash
• /bin/zsh
• /usr/bin/osascript
• /usr/bin/python3
• /usr/bin/perl
• /usr/bin/ruby
• /usr/bin/curl
• /usr/bin/ssh

It also includes these Apple Silicon Homebrew paths as disabled rules:

• /opt/homebrew/bin/curl
• /opt/homebrew/bin/wget
• /opt/homebrew/bin/python3

Included Exceptions

dev-safe-exceptions.lsrules

This group keeps the baseline deny rules in place and adds narrow exceptions for common development workflows.

Process	Allowed destinations
/usr/bin/ssh	github.com
/usr/bin/curl, /opt/homebrew/bin/curl	github.com, api.github.com, raw.githubusercontent.com, objects.githubusercontent.com, codeload.github.com
/usr/bin/curl, /opt/homebrew/bin/curl	formulae.brew.sh
/usr/bin/python3, /opt/homebrew/bin/python3	pypi.org, files.pythonhosted.org
/bin/sh, /bin/bash, /bin/zsh	registry.npmjs.org

openai-ai-tools-exceptions.lsrules

This group is meant for workflows that use OpenAI or ChatGPT from local tools, scripts, or automation while keeping the baseline deny rules active.

Process	Allowed destinations
/usr/bin/python3, /opt/homebrew/bin/python3	openai.com, chatgpt.com, auth.openai.com, oaistatic.com, oaiusercontent.com
/usr/bin/curl, /opt/homebrew/bin/curl	openai.com, chatgpt.com, auth.openai.com, oaistatic.com, oaiusercontent.com
/bin/sh, /bin/bash, /bin/zsh	openai.com, chatgpt.com
/usr/bin/osascript	openai.com, chatgpt.com

Recommended Combinations

Goal	Subscribe to
Strict baseline only	high-risk-executables-deny.lsrules
Safer developer machine	high-risk-executables-deny.lsrules + dev-safe-exceptions.lsrules
Developer machine with OpenAI tooling	high-risk-executables-deny.lsrules + dev-safe-exceptions.lsrules + openai-ai-tools-exceptions.lsrules

Customization Notes

• Keep the deny rules broad and the allow-rules narrow.
• Prefer host or domain specific exceptions over remote: any.
• If you use Intel Homebrew, adjust paths under /usr/local/bin/...; the bundled Homebrew rules target Apple Silicon paths under /opt/homebrew/bin/....
• The disabled Homebrew deny rules are present so you can enable or duplicate them instead of starting from scratch.
• Domain requirements can change over time, especially for cloud and AI tooling, so review exceptions periodically.

Operational Notes

Changing a .lsrules file in this repository and pushing a commit updates the remote file that subscribed Macs fetch on their next refresh cycle, based on the update interval configured in Little Snitch.

This ruleset can break normal workflows, including:

• ssh connections
• shell scripts that download dependencies
• Python scripts calling external APIs
• curl-based install or update flows
• AppleScript automations that reach internet services

Start with the baseline deny group, add the smallest exception groups you need, then observe denied connections before creating any new allows.

File Format

Little Snitch remote rule groups are JSON files with top-level fields such as:

• name
• description
• rules

Rules can define attributes such as:

• process
• action
• remote
• remote-domains
• remote-hosts
• remote-addresses
• disabled

For official product and rule-group documentation, see Objective Development's Little Snitch site.

License

MIT