context/message previously defaulted to a <context source="…">…</context>
wrapper. No model is trained on a <context> tag either, and message
framing does not belong on the session surface: the surface projects the
durable log, and a caller that wants a frame formats its own content —
which the one heavy producer (workspace-context) already does with its own
<system-reminder> frame, opting out via 'raw'. The tag only added
machinery — ContextEnvelope plus an envelope field threaded through
InjectOptions, HookContext, the context/message event, and the agent-loop
inject/additionalContexts plumbing.
context/message now projects its content verbatim as a user-role message,
sharing one deriveEventMessage case with user/message and steering/message.
ContextEnvelope and every envelope field are removed; context/message.meta
still carries durable, model-hidden JSON state. Regenerated catalogs and
website API; refreshed the three affected keyless snapshots (envelope field
only; timestamps unchanged).
Broadens and renames the steering Agent Note to cover both envelope
removals as one decision.
Agent Note: .agents/notes/implemented/simplification/2026-07-20-unwrap-injected-content-envelopes.md
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.
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.
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.
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.
Tianyi Cui
Turtle
Yichen Jiang
pku-xht
kingwl