Adds microsandbox (https://microsandbox.dev) as a terminal backend alongside
docker/singularity/modal/daytona/ssh. Commands run inside a libkrun microVM
with its own kernel — meaningfully stronger isolation than the shared-kernel
container backends, without a cloud dependency or a daemon.
Backend shape is a thin wrapper around the msb CLI: one long-lived sandbox
per environment (msb create), command execution via msb exec, teardown via
msb stop + msb remove. Env-var filtering mirrors the Docker backend —
explicit docker-style microsandbox_forward_env / microsandbox_env lists,
skill passthroughs still filtered through _HERMES_PROVIDER_ENV_BLOCKLIST.
Files:
- tools/environments/microsandbox.py — new MicrosandboxEnvironment backend
- tools/terminal_tool.py — dispatch, container_config keys, image resolution
- hermes_cli/config.py — default microsandbox_* entries + env var sync
- cli-config.yaml.example — 'Option 7' documented config block
- tests/integration/test_microsandbox_terminal.py — skip-if-no-KVM
integration tests for basic exec, filesystem, isolation, and the
secret-leak regression
Host requirements: Linux with /dev/kvm readable (or macOS on Apple Silicon)
and msb on PATH or at MSB_PATH. Install: curl -fsSL https://install.microsandbox.dev | sh
Follow-up PR will wire this into the hermes_cli/setup.py wizard.
