Self-review findings, all prose/metadata (no behavior change): the
package description still claimed hard (execution) enforcement; the RFC
Problem framing still defined plan mode as a read-only tool policy;
integration/mode/snapshot-suite comments still referenced the removed
sandbox clamp and cap; the header-fallback explanation said
'front-of-list insertion' where the actual mechanism is a non-tail
insertion the append-only tools delta cannot express (exit_plan_mode
sits mid-list alphabetically); AGENTS.md's layout line and the RFC's
'policy state/listener' phrasing move to collaboration-state wording.
Review follow-up (tianyicui): plan mode and the sandbox are orthogonal
AXES, not just orthogonal state — entering plan must not change what the
sandbox enforces, matching Codex's separation of Plan/Default
collaboration presets from sandbox and approval settings.
ModeDefinition.access, the bash/resolve-mode clamp, and both cap-derived
guards are removed; a ModeDefinition is exactly { section }, and a mode
now carries only its guidance section plus the exit_plan_mode review.
The bash seam's resolveMode + waterfall go with their only listener:
dsh-bash and dsh-tool-bash revert to master byte-for-byte, and the
dsh-mode → dsh-bash dependency edge is gone. A deployment that wants
kernel-enforced read-only planning pairs the mode picker with the
independent sandbox-mode option, in either order.
The RFC archives this as the second removed enforcement shape (after
the interim allowlist) with the same restart trigger — effects
self-declaration; the orthogonality FAQ now answers with the two-axis
rule. The plan example demonstrates the axes side by side, and the
re-recorded fixtures pin the guidance-only section.
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).
Review finding, valid: under the registry's Code Mode the assembly's
only wire tool is run_code, which the plan allowlist filtered out —
leaving the model with NO tools at all, the exit review included. The
composition exists today (the acp-agent example ships a code-mode
overlay), so plan mode bricked it outright.
run_code is a transport, not a capability: every bridged sub-call is
serialized back through ToolRegistry.execute() carrying the same agent,
so tools/pre-execute judges each capability individually — exactly like
native calls. Both layers now exempt it by name: the filter keeps it
visible (tests pin plan-mode Code Mode assembly = ['run_code']) and the
gate passes the wrapper while the same run's write sub-call still
denies with the plan-mode reason.
Documented residual, same class as the prepend-after-load one: the SDK
section renders from the registry's store, so a plan-mode program may
be offered bindings whose dispatch the gate then denies — nothing runs
that a native call could not.
Plan mode's stage 2 (RFC 2026-07-07-plan-mode). The exit tool: one
required plan argument (the durable log artifact), execute re-checks the
folded mode, then conducts the review over the user-interaction seam —
one single-select question (Approve / Keep planning) with free text open
— so an approval appends mode/set back to default in-turn and every
other outcome (keep-planning feedback verbatim, aborted, no provider)
returns the corrective isError with the mode unchanged. presentCall is a
generic card titled by the plan's first heading carrying the plan
markdown; over ACP the review rides the ask_user elicitation flow, in
the terminal the stdio prompt queue — no approval-seam dependency.
The ACP bridge maps the picker 1:1 onto ctx.modes (opportunistic, a
type-only peer edge): session/new + session/load advertise
availableModes/currentModeId, session/set_mode validates through set()
and echoes an optimistic current_mode_update (the pending mode IS the
selection; the logged mode/set lands at the boundary and, matching, is
not re-sent), and a session/event listener re-notifies on each logged
flip that differs from the last sent — the tool-driven exit updates the
picker. The feature matrix rows move from 'not modeled' to the
picker-to-modes / knobs-to-config-options division, with the ACP v2
removal direction recorded as a mechanical-migration risk.
The snapshot harness gains the setMode/setModeExpectError ops and a
scripted elicitationAnswers FIFO (cancel on exhaustion; a stray choice
string reaches the agent verbatim as a non-consenting custom answer, so
a scenario bug fails safe). The suite factory's header-pin requirement
now applies only to model-turn scenarios — a protocol-only suite has no
header content to anchor. examples/plan-acp-agent is the live
composition; its keyless modes-advertise scenario pins the wire surface
(advertisement, both set_mode round-trips, unknown-id rejection). The
recorded plan-mode approve/reject arc awaits a with-key recording
session; its texts are pinned at the unit tier meanwhile.
examples/AGENTS.md ceiling 653 → 680: the new example's required smoke
row does not fit the old budget.
Plan mode's stage 1 (RFC 2026-07-07-plan-mode): a new packages/mode/ group
with one product package owning the mode/set SessionEventMap vocabulary
(log-only, non-surface, whole-value replace), the pure foldMode, and the
ctx.modes service (list/get/set). User flips are pending intents flushed
at turn/start / step/end — turn enclosure makes an idle append illegal —
with one coalesced context/message notice when the flushed mode differs
from what the last logged request header told the model; a folded mode
the config no longer defines reads as default plus one boundary notice.
Enforcement is two covering layers: a system-prompt/assemble wrapper
filters the RETURNED assembly's tools to the mode's allowlist (and shows
exit_plan_mode IFF the folded mode is plan) beside the mode:policy
section at order 50, and a tools/pre-execute gate denies deny-by-default
against the same allowlist, judging by the logged mode only. The default
mode is the absence of policy — assemblies stay byte-identical to a
no-dsh-mode deployment.
AgentOptions.mode (declaration-merged) seeds a child's initial mode
through the same flush on agent/created; the stdio app gains /mode
(print/switch, never sent to the model) over an opportunistic
ctx.get('modes'). Config is an explicit resolve step: the built-in plan
definition (read-only allowlist; bash/subagent excluded until the
sandbox family lands) merges unless overridden, 'default' as a key
throws at load, unknown names throw at set() time.
