LuLu CLI

Manage LuLu macOS firewall rules from the command line. Use when connections are blocked, domains need allowing/blocking, or firewall rules need reviewing. Prevents data exfiltration while allowing essential services. Triggers include "connection blocked", "allow domain", "firewall rules", "check blocks", "lulu", "unblock".

LuLu Firewall CLI

CLI for managing LuLu macOS firewall rules. LuLu is a free, open-source macOS firewall that blocks unknown outgoing connections.

Requires: macOS 13+, LuLu installed, sudo for write operations.

When to Use This Skill

• A network request fails and you suspect it's being blocked by the firewall
• You need to allow a new domain or service through the firewall
• You want to audit what's currently allowed or blocked
• You need to clean up stale or unnecessary rules
• You're setting up a new machine and need to configure firewall rules

How LuLu Works

LuLu runs as a macOS system extension. When configured in passive mode with new connections defaulting to block, any unrecognized outbound connection is silently blocked and logged as a passive rule.

• Rules live in /Library/Objective-See/LuLu/rules.plist (NSKeyedArchiver binary format, owned by root)
• The CLI reads/writes this file directly using the same serialization format as LuLu
• The system extension only reads rules at startup, so reload (kill + auto-restart) is needed after changes
• New blocks from passive mode appear immediately in recent without needing a reload

Core Workflow

Most usage follows this pattern:

1. Diagnose -- check what's being blocked
2. Fix -- add allow rules for legitimate domains
3. Apply -- reload the extension

bash

# 1. Check recent blocks
lulu-cli recent 10

# 2. Allow the blocked domain
sudo lulu-cli add --key '*' --path '*' --action allow --addr api.example.com --port 443

# 3. Apply
sudo lulu-cli reload

Commands

list [filter]

List all firewall rules. Optionally filter by keyword (matches key or binary path).

bash

lulu-cli list              # all rules
lulu-cli list curl         # rules for curl
lulu-cli list node         # rules for node
lulu-cli list '*'          # global/wildcard rules only

No sudo required.

recent [N]

Show the N most recent block rules, sorted by creation date (newest first). Default: 20.

bash

lulu-cli recent            # last 20 blocks
lulu-cli recent 5          # last 5 blocks

No sudo required. This is the first command to run when diagnosing connection failures.

add

Add a new firewall rule. Requires sudo.

Flags:

• --key KEY -- signing identity (e.g. com.apple.curl) or * for global
• --path PATH -- binary path or * for global
• --action allow|block -- rule action
• --addr ADDR -- domain, IP, or regex pattern (default: *)
• --port PORT -- port number or * for any (default: *)
• --regex -- treat --addr as a regex pattern

bash

# Allow a domain globally (all apps)
sudo lulu-cli add --key '*' --path '*' --action allow --addr example.com --port 443

# Allow a domain and all subdomains (regex)
sudo lulu-cli add --key '*' --path '*' --action allow \
  --addr '^(.+\.)?example\.com$' --port '*' --regex

# Allow for a specific app only
sudo lulu-cli add --key "/usr/bin/curl" --path /usr/bin/curl \
  --action allow --addr example.com --port 443

# Block a domain
sudo lulu-cli add --key '*' --path '*' --action block --addr malicious.com --port '*'

delete

Delete rule(s) by key. Requires sudo.

Flags:

• --key KEY -- required
• --uuid UUID -- specific rule UUID. If omitted, deletes ALL rules for the key.

bash

# Delete a specific rule by UUID
sudo lulu-cli delete --key "com.apple.curl" --uuid "A1B2C3D4-..."

# Delete ALL rules for a key
sudo lulu-cli delete --key "com.apple.curl"

delete-match

Delete rules matching specific criteria. Requires sudo.

Flags:

• --key KEY -- required
• --action allow|block -- optional filter
• --addr ADDR -- optional filter
• --port PORT -- optional filter

bash

# Delete all block rules on port 53 for curl
sudo lulu-cli delete-match --key "com.apple.curl" --action block --port 53

enable / disable

Toggle a rule's enabled state. Requires sudo.

Flags:

• --key KEY -- required
• --uuid UUID -- required

bash

sudo lulu-cli enable --key '*' --uuid A1B2C3D4-...
sudo lulu-cli disable --key '*' --uuid A1B2C3D4-...

reload

Restart the LuLu system extension to apply rule changes. Requires sudo.

bash

sudo lulu-cli reload

Kills the extension process. macOS auto-restarts registered system extensions within ~8 seconds. There is a brief gap in filtering during the restart.

Always run reload after add, delete, enable, or disable.

help

Show usage information.

bash

lulu-cli help

Key Concepts

• key: Signing identity (e.g. com.apple.curl) or binary path for unsigned apps. Use * for global rules that apply to all apps.
• action: allow or block
• addr: Domain name, IP address, regex pattern, or * (any)
• port: Port number or * (any)
• type: default (system), apple, user (manually created), passive (auto-created from blocked connections)
• Global rules: key=* and path=* apply to all applications

Rule Policy: Allow-All vs Domain Allowlist

Not all processes should get unrestricted internet access. When using LuLu as a security boundary for AI agents:

Allow-all (addr=* port=*) -- Only for processes the agent cannot invoke:

• Apple system daemons (apsd, mDNSResponder, trustd, ocspd, etc.)
• User-only apps (Raycast, Zed, LuLu, Bitwarden CLI)
• Network infrastructure (Tailscale, ssh)

Domain allowlist only -- Any process an agent could use to reach the internet:

• node (Claude Code, OpenClaw runtime)
• python / uv (agent scripts)
• curl (command-line HTTP)
• git / gh (could push to arbitrary remotes)
• Browser helpers (agent browser automation)

When in doubt, leave a process restricted to the domain allowlist. It's easy to add an allow-all later; harder to notice data leaking through an over-permissive rule.

Troubleshooting

If a connection is failing:

1. Run lulu-cli recent to see if it was blocked
2. If yes, add an allow rule for the domain + port (usually 443 for HTTPS)
3. Run sudo lulu-cli reload to apply
4. Retry the connection

If the domain doesn't appear in recent, the problem is not the firewall.