kingwl
669771097d
Per-session policy overrides (sandbox/mode, approval/policy) never crossed the delegation boundary: a spawn child of a read-only-switched parent ran under the wider deployment default, and a fork child missed any switch made after its seed boundary — delegation was a bypass channel for a user's tightening. The in-process driver now snapshots the delegating parent's override chain and stamps it onto the child through the canonical write paths (SandboxPolicyService.inheritOverride / ApprovalService.inheritOverride), anchored inside the child's first turn via a one-shot agent/prompt-submit listener: turn-enclosed (durable), ahead of the first request (an inherited 'never' reaches the child's first system prompt), and positioned after any stale fork-seed switch so the ordinary last-event-wins fold resolves it. Only overrides are copied — an unswitched parent stamps nothing and the child follows the live deployment default; both services are consumed opportunistically, so compositions without them delegate unchanged. Nesting composes by construction (each stamp folds the already-stamped parent log). Evidence: inheritance.spec.ts drives scripted-model children into the real dsh-fs-sandbox fence through the real write tool (disk-state + denial-marker assertions; spawn, stale-seed fork, grandchild, escalation fail-closed, and no-stamp guards), inheritOverride contract tests in both service suites, and the recorded subagent-sandbox-inheritance ACP snapshot (read-only preset → delegate → child denied, replayed keylessly). See .agents/notes/implemented/feature/2026-07-25-subagent-policy-inheritance.md.
sandbox/ — process-sandbox capability family
The confinement half of the capability-seam split: an abstract provider interface, platform backends, and the shared policy home. Consumers hand ctx.sandbox the exact argv they are about to spawn and spawn the returned (wrapped) argv instead; a complete SandboxExecutionPolicy (mode + workspace root) rides each capability call, and its confined subset becomes the provider's SandboxPolicy. Different sessions and consumers can therefore confine under different policies at the same instant. All product packages.
| Package | Role | ctx key |
|---|---|---|
sandbox/ |
Abstract process-sandbox seam (the SandboxProvider contract + the mode/enforcement/policy vocabulary) plus the shared ESCALATION kit (approveEscalation, the strictly-wider ladder, the denial/hint markers) and the writableRoots derivation every enforcement dialect shares |
ctx.sandbox |
sandbox-local/ |
Local backends by platform chain: Linux bwrap else the landlock-run launcher (the npm-distributed node-addon-landlock-run family, built and released from its own repository), darwin sandbox-exec/Seatbelt — multi-candidate chains functionally probed, sole candidates selected directly, verdict cached, fail-closed |
(registers ctx.sandbox) |
sandbox-policy/ |
The policy resolver: deployment fallbacks plus each session's durable mode and immutable cwd root. Both enforcing families consume its complete per-call result, so bash and fs cannot confine to different roots | ctx.sandboxPolicy |
The seam confines SAME-WORLD subprocesses only (shared filesystem and kernel). Containers, microVMs, and remote executors are NOT backends here — they replace whole capability implementations (ctx.bash, ctx.fs) as environment-coherent groups; the boundary is recorded in the sandbox Agent Note.
Consumers today: bash/bash-sandbox (wraps ['bash', '-c', command] through ctx.sandbox) and fs/fs-sandbox (an in-process path fence, not an argv wrapper — reads ctx.sandboxPolicy and enforces the shared mode on write/edit). The cross-family boundary is the sandbox Agent Note's cross-family fs sandbox phase; the shared vocabulary lets both families teach the model one denial marker and one escalation flow.