agentcage 0.4.1

Defense-in-depth proxy sandbox for AI agents

agentcage

Defense-in-depth proxy sandbox for AI agents.

Because "the agent would never do that" is not a security policy.

:warning: Warning: This is an experimental project. It has not been audited by security professionals. Use it at your own risk. See Security & Threat Model for details and known limitations.

Setting up OpenClaw? See the OpenClaw guide.

Setting up NanoClaw? See the NanoClaw guide -- includes nested container support (podman-in-podman).

What is it?

agentcage is a CLI that generates hardened, sandboxed environments for AI agents. Your agent runs on an internal-only network with no internet gateway; the only way out is through an inspecting proxy that scans every HTTP request before forwarding it.

Most agent deployments hand the agent a lethal trifecta: internet access, real secrets, and arbitrary code execution. Combined, they create an exfiltration risk that most setups have zero defense against. agentcage breaks that combination. See Security & Threat Model for the full breakdown.

• Network isolation -- agent on internal-only network, no internet gateway
• Inspecting proxy -- pluggable inspector chain on every HTTP request, WebSocket frame, and DNS query
• Secret injection -- agent gets placeholders, proxy swaps in real values outbound and redacts inbound
• Secret & payload scanning -- regex secret detection, Shannon entropy, content-type mismatch, base64 blob scanning
• DNS filtering -- allowlist-based dnsmasq sidecar, placeholder IPs for unauthorized domains
• Fail-closed by default -- all hardening on out of the box; component failure stops traffic

Both container mode (rootless Podman) and Firecracker mode (KVM microVM) are supported -- see Security & Threat Model for the comparison. For the full container topology and inspector chain, see Architecture.

Quick Start

# Install
curl -fsSL https://raw.githubusercontent.com/agentcage/agentcage/master/install.sh | sh

# Scaffold a config (or use --scaffold openclaw)
agentcage init myapp --image node:22-slim

# Store secrets
agentcage secret set myapp ANTHROPIC_API_KEY

# Create and start the cage
agentcage cage create -c cage.yaml

# Verify it's healthy
agentcage cage verify myapp

Run agentcage init --list-scaffolds to see available scaffolds. See CLI Reference for the full command set.

Install

One-line installer (installs agentcage + prerequisites):

curl -fsSL https://raw.githubusercontent.com/agentcage/agentcage/master/install.sh | sh

For Firecracker mode, add --with-firecracker:

curl -fsSL https://raw.githubusercontent.com/agentcage/agentcage/master/install.sh | sh -s -- --with-firecracker

Manual install -- prerequisites: Podman (rootless), Python 3.12+, uv.

OS	Command
Arch Linux	sudo pacman -S podman python uv
Debian / Ubuntu 24.04+	sudo apt install podman python3 && curl -LsSf https://astral.sh/uv/install.sh | sh
Fedora	sudo dnf install podman python3 uv
macOS	brew install podman python uv && podman machine init && podman machine start

Then install agentcage:

uv tool install agentcage                                            # from PyPI
uv tool install git+https://github.com/agentcage/agentcage.git      # from GitHub

For development:

git clone https://github.com/agentcage/agentcage.git
cd agentcage
uv run agentcage --help

Firecracker mode requires Linux with /dev/kvm. See Firecracker setup for details. macOS is not supported for Firecracker mode.

Usage

# View logs
agentcage cage logs myapp             # agent logs
agentcage cage logs myapp -s proxy    # proxy inspection logs

# Audit inspection decisions
agentcage cage audit myapp --summary --since 24h

# Rotate a secret (auto-reloads the cage)
agentcage secret set myapp ANTHROPIC_API_KEY

# Update after code/config changes
agentcage cage update myapp -c cage.yaml

# Restart without rebuild
agentcage cage restart myapp

# Backup and restore
agentcage cage backup myapp --include-secrets -o backup.tar.gz
agentcage cage restore backup.tar.gz --name myapp-clone

# Tear it all down
agentcage cage destroy myapp

Command / Group	Commands
init	(top-level) -- scaffold a config file
cage	create, update, edit, list, destroy, verify, restart, logs, exec, audit, har, backup, restore (aliases: ls/ps/status → list, rm → destroy, reload → restart)
secret	set, list, rm (alias: ls → list)
domain	list, add, rm (alias: ls → list)
build	nested-base -- build base images for nested container support
firecracker	setup
completions	(top-level) -- print shell completion script (bash/zsh/fish)

See CLI Reference for full documentation of all commands and options.

Configuration

See the Configuration Reference for all settings, defaults, and examples. Example configs: basic/cage.yaml. Deployment state is tracked per-cage in ~/.config/agentcage/deployments/<name>/.

Security

The agent has no internet gateway -- all traffic must pass through the proxy, which applies domain filtering, secret detection, payload inspection, and custom inspectors. For workloads requiring hardware-level isolation, Firecracker mode adds a dedicated guest kernel per cage, eliminating container escape as an attack vector. See Security & Threat Model for the full threat model, defense layers, and known limitations.

License

MIT