A subagent child's recursion depth lived only in runtime AgentOptions,
so a persisted child came back from resume counted as top-level and
maxDepth stopped binding after every restart. Add
SessionHeader.delegationDepth, round-trip it through the JSONL and
SQLite backends (SQLite schema v5), restore it on agent-loop resume,
and write it when the in-process backends create a child. The seam now
owns the shared depth vocabulary (delegationDepthOf): the persisted
header is authoritative and monotone — runtime options may deepen it
but never lower it.
Semantic resolutions beyond line merges:
- The bash seam keeps resolveMode + the bash/resolve-mode waterfall on
master's task-free BashExecutor (run/start/resolve only; BashProcess
handles); tool-bash consults it at its stamping site and escalation
baseline on master's render/background split, with a waterfall test on
the recording executor.
- dsh-mode's BASH_FAMILY narrows to ['bash']: bash_output/bash_kill are
replaced by the kind-generic task_output/task_kill, which span every
task kind and only observe or stop work, so the access cap withholds
only the starter it can reason about.
- The plan-mode snapshot suite adopts master's pin grammar (tool-schema
sidecars; the expectedHeaderSnapshots extension is gone — the exit
transition deltas, and entering-before-turn-1 needs no second
snapshot); modes-advertise joins the plan header class (no-model, so
membership is vacuous). Fixtures re-recorded on the acp-demo bin;
the replay overlay gains the passthrough sandbox runner.
- examples/plan-acp-agent rewires to @deepseek-ai/dsh-acp-demo and drops
its tool-bash entry (the spine bundle now composes it); dsh-stdio (the
renamed stdio-chat home) keeps its /mode command and gains the dsh-mode
peer edge; the acp bridge keeps the modes surface beside master's
permission presets.
- mode README gains the Model Experience / Known Limitations sections the
new README gates require; AGENTS.md ceiling 1370 → 1440 for the kept
mode/ layout line and Agent efficiency section.
Extend SandboxMode enforcement from bash to the filesystem tools, the sandbox
RFC's deferred cross-family phase.
- dsh-sandbox-policy (new, ctx.sandboxPolicy): the single home for the
deployment default mode + workspaceRoot and the per-session override event,
renamed bash/sandbox-mode -> sandbox/mode and moved here with its fold/setter.
Decouples the bash seam from dsh-session.
- dsh-fs-sandbox (new): SandboxedFileSystem extends LocalFileSystem and fences
write/edit by the per-call mode (read-only denies, workspace-write contains to
the workspace + temp roots via the shared writableRoots, danger passes
through); reads pass through. Structured FS_SANDBOX_DENIED; in-lock parent
re-canonicalization. A policy fence in trusted code, not a kernel boundary.
- dsh-sandbox: the shared escalation kit (writableRoots, the strictly-wider
ladder, denial/hint markers, approveEscalation) both tool families use;
approveEscalation takes a structural approver so dsh-sandbox gains no
approval/agent dependency, and both tools stay duplication-free.
- tool-fs: write/edit advertise sandbox_permissions/justification under a
confining ctx.fs, map FS_SANDBOX_DENIED to the shared [sandbox: ...] marker,
and resolve the same one-approved-wider retry.
- examples/acp-agent: composes sandbox-policy + fs-sandbox, drops the gating
that disabled the fs stack under confined modes.
RFC docs/rfc/implemented/feature/2026-07-14-cross-family-fs-sandbox.md; the old
sandbox RFC's In-process/deferred/FAQ sections updated to shipped fact.
Conflict resolution beyond line merges: the ACP bridge's mode/set
re-notify moved inside master's new containment finally (a throwing
presenter must not desync the picker), and session/new keeps the modes
advertisement beside master's plain object return. dsh-mode's boundary
flush moved off the session/event feed onto the loop's interception
seams (agent/prompt-submit / agent/turn-continuation): master's scoped
dispatch made post-commit session observers observe-only — an append
from one re-enters the publishing append — while the two waterfalls
fire outside any log emit and bracket the same boundaries; mode.spec's
boundary helper now dispatches those seams via agentEvents, and the
containment tests stub only the mode/set append. Catalogs, doc graphs,
and the module graph regenerated.
A preset names a bundle of the two mechanism knobs — request =
workspace-write + ask, yolo = danger-full-access + never — so the editor
shows ONE 'Permissions' select where the sandbox-mode and approval-policy
tiers stay orthogonal capabilities (the Codex /approvals shape: presets over
two dials). ctx.permission (dsh-permission) owns the config-defined table,
validates the default preset's bundle against the composed knob defaults at
load (fails loud), and writes a switch THROUGH: one log-only
permission/preset event (the audit fact reverse-mapping cannot recover —
the planned 'agent' preset shares request's knob values and differs only in
composed policy) plus each knob event via its own setter, deduped — a
net-zero switch appends nothing. Every knob consumer keeps reading its own
fold, untouched.
The current preset DERIVES from the effective knob values — the fold breaks
bundle ties, a knob state outside the table is the reserved 'custom' value
(a state, not an error: shown while it holds, switchable FROM, never a
target), and defaultPreset disappears (zero-event state reverse-maps from
the composition defaults).
The ACP bridge drops the two per-knob selects for the one preset select
(advertised only when ctx.permission is composed); pending/anchor/no-op
semantics carry over unchanged, with the no-op echo acknowledged before
vocabulary validation so a client re-pushing a derived 'custom' current
never errors. The sandbox variant example composes the
service with a workspace-write default; the permission-switching,
escalation-approved and escalation-rejected scenarios are re-recorded under
it (escalations now target an outside-workspace /tmp path under
danger-full-access, self-cleaning) and config-options is re-authored on the
single-select wire.
A ModeDefinition is now exactly { section, access? }; unknown keys (a
tools list included) fail loud at load. What plan mode still does: the
guidance section, the exit_plan_mode visibility rule (plan only, both
soft surfaces), the access cap's bash/resolve-mode clamp, and the two
cap-derived pre-execute guards (the bash trio is withheld when no
confining executor can honor the cap; sandbox escalation is denied
while it holds). The general deny-by-default gate and the assemble
allowlist filter are gone: which tools a mode admits is an effects
question, and a hand-maintained name list mislabels it — it must track
every composed tool and rots silently as tools arrive. The dimension
returns as a consumer of effects self-declaration on tool definitions
(MCP ToolAnnotations as the template) — rationale and restart trigger
archived in the RFC's Alternatives/Deferred; the interim guidance-only
non-shell restraint is priced in Consequences.
Exiting plan is now a pure removal (the exit tool + section), which the
delta encoding CAN express: the re-recorded plan-mode fixture pins one
plan-shaped initial header snapshot plus one header-delta instead of
two snapshots.
A ModeDefinition may declare access: the widest sandbox access shell
commands run under while the mode holds, on the SANDBOX_MODES ladder.
The bash seam gains the resolution point to hang it on: BashExecutor.
resolveMode(session) folds override ?? default and dispatches the new
bash/resolve-mode waterfall; dsh-tool-bash consults it at both the
stamping site and the escalation baseline; dsh-mode's clamp listener
takes the ladder minimum per call. Two independent log folds compose at
read time — the mode never writes the sandbox knob, so the two switch
in any order and the knob re-emerges intact on exit.
The built-in plan definition ships access: read-only with the bash trio
allowlisted CONDITIONALLY: both policy layers admit bash/bash_output/
bash_kill only while a confining executor is mounted (an unconfinable
shell cannot honor the cap), and a bash call carrying sandbox_permissions
under a cap is denied at the gate — no widening mid-mode; the widened
step belongs in the plan.
examples/plan-acp-agent swaps bash-local for sandbox-local +
bash-sandbox (workspace-write default, clamped read-only inside plan)
plus the approval seam; the re-recorded plan-mode arc runs a real cat
inside plan under the clamped sandbox, and modes-advertise now pins the
sandbox-mode and approval config options. RFC amended to the landed
shape (access cap section, orthogonality FAQ, deferred item resolved
into effects self-declaration).
The stack rebases onto a moved master through its base branch. Beyond
mechanical unions (both branches' demo scripts, example rows, service
roles, tool lists, acp deps, doc budgets — each side fit alone, the
union needs the higher ceilings), three semantic reconciliations:
- The ACP bridge now carries BOTH per-session surfaces: the sandbox
stack's config options + approval answerer and this branch's session
modes; session/new and session/load advertise modes AND configOptions
side by side.
- The feature matrix supersedes the sandbox stance per the RFC's
second-lander rule: session/set_mode and current_mode_update flip to
shipped-by-dsh-mode, config-option rows stay as #169 wrote them, and
§6 records both landed features under the picker-to-modes /
knobs-to-config-options division.
- The snapshot pin grammar (#254: one header snapshot + declared deltas
+ a Markdown prompt golden) gains a symmetric declaration for what a
delta cannot express: expectedHeaderSnapshots — a plan-mode flip
resorts the canonical tool list, so its widening lands as a second
full snapshot, now its own Markdown section. The pin-less-class and
model-turn-only-pin amendments carry over; new fixtures cover the
extended writer paths, and the plan-acp-agent scenarios re-recorded
under the merged composition (the app now bundles the skill tool)
with the suite's refresh mode wired through.
Drain idle injection flushes before agent teardown, snapshot approval and subagent provider inputs, and gate subagent lifecycle events on real child readiness. Align the RFCs and generated contracts with the hardened behavior.
The three-entry cordis.yml (dsh-sandbox-local + dsh-bash-sandbox at a
read-only default + dsh-approval) served over ACP: the first live approval
composition. Recorded snapshot scenarios pin the wire end to end —
config-options advertisement, the mode-switching arc as the suite pinned
header (both switches, the prompt-section delta, one changed-by-the-user
notice per knob, a confined write landing under the switched mode), and
both escalation branches over scripted permissionAnswers (a grant runs
confined under workspace-write; a rejection executes nothing and pins the
fail-closed text). The with-key escalation e2e drives a real model +
real runner + the real bridge answerer, world-verified; ci.yml snapshot
lane and e2e.yml install bubblewrap so the confined replays actually
execute.
Both RFCs move to implemented/ (Decision/Consequences form, deferred
phases tracked in their own sections), with every cross-reference flipped.
effective(session) = findLast(the session own knob events)?.value ?? the
composition-config default. One log-only event per knob, owned by its
domain (bash/sandbox-mode in dsh-bash, approval/policy in dsh-approval),
each exporting the same three-piece kit: the event declaration, a pure
fold, and THE write path — a switch IS its event; no owner service, no
facts map. Restart immunity and multi-session isolation fall out of the
log replay by construction.
Execution follows the fold on both sides: the bash tool stamps
escalation grant > session override > executor default, and the approval
seam prepends the never-gate that auto-rejects before any interactive
answerer. Visibility is two layers per knob: a per-agent prompt section
states the effective value on every request (logged through
request/header*, so what-the-model-was-told replays from the log), and an
agent/pre-step narrator injects at most one coalesced delta notice with
positional attribution (user switch vs operator/config drift). The ACP
bridge advertises one capability-gated select per composable knob with
currentValue folded per session, validates set_config_option against the
closed vocabularies, and anchors idle switches at the next turn
prompt-submit under the turn-enclosure contract.
ctx.approval (dsh-approval): request() dispatches the approval/request
waterfall and always resolves a closed outcome — allowed-once / rejected /
cancelled / unavailable — never rejects; zero listeners fall through to
fail-closed unavailable; abort settles cancelled and discards late answers;
throwing or rogue answerers are contained as unavailable; every ask lands
the log-only approval/asked / approval/decided audit pair. dsh-tools routes
a pre-execute ask through the seam opportunistically (ctx.get) with three
distinct deny reasons, keeping the historical ask→deny degrade when the
seam is absent.
The per-session policy tier, the ACP bridge answerer, and the sandbox
escalation asker are staged follow-ups of the approval-seam RFC.
Yichen Jiang
Tianyi Cui
pku-xht
kingwl