The layers of m101-demo and its doors
A host row with the sbx CLI, the sandboxd daemon, the keychain, and the forward proxy on gateway.docker.internal:3128. Below a dashed hypervisor line sits the guest: the Linux 7.0.14 aarch64 kernel with 16384-byte pages on Ubuntu 26.04.1, containerd v2.3.5, a private Docker Engine 29.8.1, the agent container running as uid 1000 with sudo and docker groups, and the workspace mounted through virtiofs at the same path. A right column names five doors through the boundary: network, secret, MCP, SSH agent, and bind mount, each with the guest line that opens it.
HOST · MACOS 26.2 ARM64 · SBX 0.47.0
sbx
CLI
sandboxd
sandboxd.sock
keychain
secret store
forward proxy :3128
gateway.docker.internal
hypervisor · kern.hv_support is 1
GUEST · M101-DEMO
kernel Linux 7.0.14 aarch64
Ubuntu 26.04.1 LTS · getconf PAGESIZE 16384
containerd v2.3.5
runc 1.5.1 · erofs root · overlay /
Docker Engine 29.8.1, private
images and containers stay in the VM
agent container
uid=1000(agent) groups sudo, docker
$CAPTURE/fixtures/repo
virtiofs rw at the same path
/etc/resolv.conf: virtiofs ro bind
DOORS
network
HTTPS_PROXY :3128
secret
proxy-managed sentinel
MCP
MCP_GATEWAY_URL
SSH agent
/run/ssh-agent.sock
bind mount
host path, rw