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.
Review round 2 (tianyicui inline comments):
- dsh-system-prompt itself registers the harness:identity (-100) and
deployment:persona (0) sections — they must survive a swapped loop
plugin, so they leave dsh-agent-loop; the persona text is the plugin's
own validated 'persona' config. The model/cwd variables STAY on the
loop: runtime facts of the agents it drives.
- AgentOptions.systemPrompt is deleted with all its forwarding plumbing:
the app configs' systemPrompt keys become 'persona' routed through
dsh-agent-core (schema = z.intersect of the owners'), the ACP bridge
and tool-subagent stop carrying persona configuration, and subagent
children now render the deployment persona like every other agent.
- Example personas drop transport/interface trivia (ACP, CLI) — facts
irrelevant to the model.
- Root CONTEXT.md removed (not idiomatic); its persona definition was
wrong under the new ownership anyway.
- Docs, READMEs, the prompt-variables RFC, and generated catalogs
updated; new loop test pins the assemble-waterfall escape valve
(an emptied assembly sends NO system field).
A Codex review pass on the draft caught four real gaps and two solid
suggestions; all addressed except one pushed back on the merits:
- hooks-claude/hooks-codex: stderrSummaryMaxChars was the one new knob
with NO range validation — a negative/NaN cap would silently
misbehave inside slice(). Both bridges now assert a positive integer
at the TOP of apply() (before the config-file parse's early return,
so a bad value fails the load loudly), with rejection tests.
- tool-fs: the read caps count lines/chars/bytes, so positive-FINITE
was too loose (a fractional readLimit would flow into windowing
arithmetic and the schema description). All four now require a
positive integer, matching tool-web's cap.
- Doc drift the gates cannot catch: tool-web's README tools table
still named WEB_SEARCH_MAX_RESULTS as the mechanism; compact-basic's
README/module doc and the compaction-capability-seam RFC still
described estimation as fixed char/4 rather than the charsPerToken
default.
- subagent-acp: the dispose graces were tested only at the
startAcpRun level, so a regression that stopped threading plugin
config into AcpRunSpec would have survived. A provider-path test now
drives the trap-escalation scenario through ctx.subagents.start with
small config graces and bounds dispose at 4s.
Pushed back on: converting compact-basic's charsPerToken to a
schemastery field. The package's whole config is deliberately
hand-rolled (resolveConfig, every threshold REQUIRED with no default —
a documented design posture); one schemastery field beside it would be
incoherent. The knob is cordis.yml-reachable, defaulted, and validated,
which is what the convention requires; migrating the package to
schemastery wholesale is pre-existing config-surface hygiene out of
this change's scope.
The audit swept every packages/*/* plugin for the new AGENTS.md
convention (no hardcoded tunables in plugins) and exposes each finding
as a defaulted, validated Config field. Defaults are the previously
hardcoded values throughout, so no deployment or golden changes.
- tool-fs (had NO Config): readLimit, readMaxLineLength, readMaxBytes,
readStreamMinSize. The caps thread through ReadToolCaps/ReadWindow —
read-render already documented that the consumer applies the caps, so
they become explicit per-request fields.
- tool-web: searchMaxResults (WEB_SEARCH_MAX_RESULTS stays as the
schemastery default). Also fixes the stale GREP_LIMIT references in
search.ts and the web-capability-seam RFC (no such constant exists).
- bash-local: graceMs (SIGTERM->SIGKILL escalation grace). The
RunInternals.graceMs test seam is gone: graceMs is now a required
SpawnSpec field filled from config, so tests exercise the real
config path and the defaults live in exactly one place.
- subagent-acp: disposeEofGraceMs / disposeGraceMs. The AcpRunSpec
fields become required for the same one-defaulting-layer reason.
- session-persistence-sqlite: journalMode ('wal' default; the
rollback-journal modes serve filesystems where WAL's shared-memory
files do not work, e.g. network mounts).
- hooks-claude + hooks-codex: stderrSummaryMaxChars for the persisted
hook/result stderr summary. The duplicated summarize() helpers merge
into hook-protocol's summarizeStderr(stderr, maxChars), beside the
HookResultRecord field it feeds, with the bound parameterized the
same way runHook's defaultTimeoutMs already is.
- compact-basic: charsPerToken for the token estimator (default 4, the
English-text heuristic; CJK-heavy deployments need ~1-2 or compaction
fires far too late). Also corrects the BasicCompactService class doc,
which claimed defaults the required-field config never had.
- fs-local: deletes the dead STREAM_MIN_SIZE constant and the dead
FsIoInternals.streamMinSize seam — the read-routing bound lives in
the consumer (tool-fs), where it is now config. This is item 1 of
the proposed prune-write-only-fs-surface RFC, annotated accordingly.
Every new field gets range validation (following the existing
assertPositiveFinite pattern), a README row, and tests covering the
configured behavior, the schema default, and load-time rejection.
The fs seam split left four pieces of pre-split surface populated on
every call and read by nobody:
- STREAM_MIN_SIZE + FsIoInternals.streamMinSize in dsh-fs-local: the
backend has no read routing (readWholeText/streamWholeText are
separate primitives the caller picks), and the real 10 MiB routing
constant lives in dsh-tool-fs's read tool. Delete the dead mirror and
the knob whose JSDoc claimed an override that did not exist; the
remaining FsIoInternals knobs stay (the atomic-write tests use them).
- FsTarget.inputPath: a "diagnostics only" field every backend and test
fake had to fabricate, with zero production readers (policy and error
messages use targetKey/displayPath). listDir gave children the bare
entry name, which was nobody's input.
- FsEditOutcome.replacements/.replaceAll: replacements had no reader
(the single-match policy is enforced by the FS_AMBIGUOUS_EDIT /
FS_EDIT_NOT_FOUND throws, whose message keeps the internal count);
replaceAll only echoed the replace_all argument back to
formatEditOutput, which now takes it from the parsed args. The
outcome shrinks to { version, before, after }, parallel to
FsWriteOutcome's backend-discovered fields. Emitted text is unchanged
for both branches (no snapshot churn).
- FileReadOutcome.limit/.version: formatReadOutput renders
offset/lines/totalLines/truncatedByBytes only, and the fs/observed
emit uses info.version directly.
Backends shed four fabrication obligations and gain none. Doc pastes
(core-data-structures/filesystem.md), the dsh-fs README resolve row,
and the test fakes shrink with the types. RFC moved to
implemented/simplification and amended to the shipped shape
(FsEditSpec -> FsEditRequest name fix; manifest rows needed no change).
A Write CREATE rendered its completed tool_call_update as the model-facing
result TEXT (`<path>…</path>…Created file`), which — because an ACP
tool_call_update.content REPLACES the call's content — clobbered the
new-file diff the pending call installed. So Zed showed the diff, then
replaced it with raw XML-ish text; only overwrite/edit looked right
(their result re-sends a diff).
write's presentResult now ALWAYS returns a diff card for a successful
write: the applied contextual hunk from `meta` when there is one
(overwrite), else an args-derived whole-file diff (`oldText: null`) for a
create or an unchanged-content overwrite. This matches claude-agent-acp,
where the create diff rides on the update and no result text replaces it.
An error still falls through to generic rendering so its message shows.
edit is unchanged (it always has a hunk; no whole-file fallback).
Re-recorded fs-write / fs-write-overwrite goldens; the create's completed
update is now a {type:'diff'} block, not the XML result text.
Tianyi Cui
kingwl
Yichen Jiang
Dudu-0223