- SandboxManager (tc-runtime): one container per agent, provisioned
lazily on first use, reused for the manager's lifetime, replaced
transparently if dead, destroyed on shutdown
- shell.exec tool: sh -lc inside the agent's sandbox; stdout/stderr/
exit_code return to the model as the step output. No external effects
declared — the sandbox boundary (uid 10001, no caps, seccomp
allowlist, read-only rootfs, zero egress) is the §15 control here,
not an approval gate
- RuntimeConfig.sandboxes (+ with_sandboxes builder); [sandbox] config
{image, enabled}; the server connects the Docker driver at boot and
tolerates an absent engine (shell.exec reports it per-call)
- Tests with the REAL DockerDriver: a scripted run executes two
commands — output proves uid 10001 from inside, and /home/agent state
written by the first call is read by the second (same sandbox); a
deployment without a sandbox runtime records honest error steps and
the run still completes
151 Rust tests + 27 Playwright journeys.
Co-Authored-By: Claude Fable 5 <[email protected]>
