Merge branch 'master' into steering-unwrap

This commit is contained in:
Tianyi Cui
2026-07-20 17:02:18 +08:00
committed by GitHub
175 changed files with 8626 additions and 852 deletions

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@@ -62,9 +62,7 @@ Left open, for the phase that needs them: whether network restriction arrives as
The launcher is a ~300-line C program (plain C11 over the raw Landlock UAPI — no libraries beyond a statically linked musl, so the audit surface is that one file plus the kernel's stable syscall contract): `--ro <path>` / `--rw <path>` grants, `--`, the wrapped argv; it installs the ruleset on itself and `exec`s (rulesets are inherited across `execve`, and it sets `no_new_privs` before restricting); `--probe` enforces a maximal ruleset in a short-lived child and exits 0 only when the kernel actually enforces; launcher failures exit 125 without exec'ing.
The Landlock launcher ships through [`node-addon-landlock-run`](https://www.npmjs.com/package/node-addon-landlock-run), with platform binaries selected by npm. That package owns path resolution, probing, and CLI flags; the harness maps sandbox modes to grants. Versioning the entry point with its binaries keeps probe parsing and launch syntax aligned.
FIXME: Revisit the separate-repository boundary and try to maintain the launcher source and its platform package family inside this monorepo, so the native release surface and harness contract evolve together.
The Landlock launcher source and package workspace live at `native/landlock-run`, next to the harness consumers. The standalone [`node-addon-landlock-run`](https://github.com/deepseek-harness/node-addon-landlock-run) repository is the release mirror used to pack and publish the npm package family; `native/README.md` owns the export procedure. Platform binaries are selected by npm, and the entry package owns path resolution, probing, and CLI flags while the harness maps sandbox modes to grants. Versioning the entry point with its binaries keeps probe parsing and launch syntax aligned.
Backend profiles share the mode contract but differ in necessary host grants. Landlock and Seatbelt allow only `/dev/null` in read-only mode; workspace-write also permits their required host temp roots. Each wrap carries backend-specific denial signatures. Landlock reports partial enforcement on older ABIs that cannot govern every operation, while successful bwrap and Seatbelt profiles report full enforcement.
@@ -98,7 +96,7 @@ The default is composition config (`cordis.yml`) — operator-owned, process-wid
```ts
interface SessionEventMap {
'bash/sandbox-mode': { mode: 'read-only' | 'workspace-write' | 'danger-full-access' }
'sandbox/mode': { mode: 'read-only' | 'workspace-write' | 'danger-full-access' }
'approval/policy': { policy: 'ask' | 'never' }
}
```
@@ -113,9 +111,7 @@ Sandbox mode is not narrated in the prompt; denial results report the mode when
#### In-process tools
fs/web/todo execute in-process, so their sandbox semantics are policy at their seams: the fs intent gates deciding by the shared mode vocabulary (§ Deferred phases, cross-family) make `read-only` a real boundary instead of a bash-only approximation — until then the contract says so honestly. No generic per-tool sandbox runtime: a host-mediated tool leaves the process only by returning declarative effects the host validates, which is a rewrite, not a wrapper.
FIXME: Revisit this tool-local boundary. The follow-up design needs to determine whether sandboxing becomes a global harness capability that applies uniformly to every tool, instead of expressing in-process enforcement independently at each tool seam.
fs/web/todo execute in-process, so their sandbox semantics are policy at their seams. The fs seam now enforces the shared mode vocabulary through a sandboxed provider (`dsh-fs-sandbox` fences write/edit by mode; see [the cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md)), so `read-only`/`workspace-write` are real boundaries for the filesystem tools, not a bash-only approximation. web/todo remain unfenced (web's only effect is network, outside the file-effect mode vocabulary). No generic per-tool sandbox runtime: a host-mediated tool leaves the process only by returning declarative effects the host validates, which is a rewrite, not a wrapper — the follow-up settled on one shared policy home (`ctx.sandboxPolicy`) with per-seam enforcement, not a uniform wrapper.
### Testing
@@ -128,8 +124,7 @@ FIXME: Revisit this tool-local boundary. The follow-up design needs to determine
Each phase gets its full design when picked up, validated against the code at that time, and lands with unit, real-API e2e, and snapshot coverage at the tiers it touches.
- **Per-session workspace root** — the executor's write boundary stays config-fixed for its lifetime while each ACP session has its own cwd; a per-session root rides the same per-call policy carrier once designed.
- **Cross-family boundary** — the fs intent gates decide by the shared mode, making `read-only`/`workspace-write` real boundaries beyond bash.
- **Per-session workspace root** — the executor's write boundary stays config-fixed for its lifetime while each ACP session has its own cwd; a per-session root rides the same per-call policy carrier once designed. Centralizing the root on `ctx.sandboxPolicy` (the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md)) is the groundwork.
- **Second consumer** — `subagent-acp` optionally confines child agents (per-call policy; unconfined default — a child agent must write its own persistence).
- **More environments** — an environment-coherent capability group example (e.g. bash+fs against one container).
- **Windows chain** — `PLATFORM_CHAINS.win32` is reserved and empty (fail-closed); filling it means a confinement runner from the AppContainer/restricted-token family, shipped from its own repository on the `node-addon-landlock-run` template, plus its profile dialect and denial/runner-failure signatures.
@@ -173,7 +168,7 @@ What shipped pins — the tiers in Testing hold each:
Costs and accepted limits:
- **The one-wrapper illusion is given up knowingly.** A `tools/pre-execute` wrapper plus prompt conventions does not solve sandbox approval — the correct design costs structured denials, native runner probes, per-call policy carriage, and consistent cross-family enforcement, and this design pays it.
- **`read-only` is not yet a cross-family boundary.** Until the fs intent gates decide by the shared mode, the claim holds for bash only; the contract says so honestly (§ In-process tools).
- **`read-only` became a cross-family boundary through a follow-up.** This RFC shipped bash-only enforcement; the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md) extends the same mode vocabulary to the filesystem tools through a sandboxed `ctx.fs` provider and relocates the mode/root config and the `sandbox/mode` override to `ctx.sandboxPolicy` (§ In-process tools).
- **Windows has no backend.** Its chain slot is reserved empty — fail-closed, never a fallthrough; filling it is a deferred phase.
- **The Seatbelt rung leans on Apple's deprecated-but-shipped `sandbox-exec` CLI.** As darwin's sole candidate it is selected without probing, so a future removal surfaces at execution as the runner-failure classification — re-thrown `SANDBOX_UNAVAILABLE`, the command never runs; fail closed, never open.
- **Landlock confinement is only as complete as the running kernel's ABI.** Reported as `enforcement: 'partial'` rather than refused — the deliberate trade that keeps the fallback available on older-kernel hosts.
@@ -193,9 +188,9 @@ Costs and accepted limits:
- **What happens on a platform with no backend — Windows today?** `confine()` throws the fail-closed `SANDBOX_UNAVAILABLE` and the command never spawns; `win32` is a reserved EMPTY chain, pinned by test to fail closed identically until a Windows runner fills it (§ Deferred phases).
- **`bwrap` is installed on my host but unusable (disabled unprivileged userns, an LSM denying `mount`) — what happens?** The chain probe is functional — it builds and enforces a real profile rather than checking `--version` — so a present-but-unusable `bwrap` fails its probe, selection falls to the registry-installed Landlock launcher, and the verdict is cached for the provider's lifetime.
- **Does the sandbox restrict network or process visibility?** No — `SandboxMode` claims FILE effects only; the bwrap profile deliberately does not unshare pid, and no backend claims network. Whether network restriction becomes its own knob is left open in § The seam.
- **Which tools actually run confined?** OS subprocesses through `ctx.bash` — the bash tools, and hook commands transitively. fs/web/todo execute in-process, where an `execve` wrapper is mechanically meaningless; their `read-only` semantics arrive with the cross-family deferred phase, and until then the contract says bash-only honestly.
- **Which tools actually run confined?** OS subprocesses through `ctx.bash` — the bash tools, and hook commands transitively — plus the filesystem tools (`read`/`write`/`edit`) through the sandboxed `ctx.fs` provider (the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md)): bash confines via the OS runner, fs via an in-process path fence, both keying off the same `ctx.sandboxPolicy` mode. web/todo stay in-process and unfenced (web's only effect is network, outside the file-effect mode vocabulary).
- **Does a granted escalation persist?** No. The grant is consumed by the exact foreground or background call that asked; every neighboring call keeps its own effective mode. A later background denial surfaces through `task_output` and may ground a new exact-command retry.
- **When does an editor's mode switch take effect?** Mid-turn: appended immediately, honored by the very next call's stamp. Idle: held on the bridge's session record, anchored at the next turn's `agent/prompt-submit`, with N flips coalescing to at most one event (none if net-zero); a crash before anchoring reverts it and `session/load` reports the truth. The model is not told — its next command simply behaves under the new mode.
- **When does an editor's mode switch take effect?** Mid-turn: appended immediately, honored by the very next call's stamp. Idle: held on the bridge's session record, anchored at the next `agent/prompt-submit` inside its open turn, with N flips coalescing to at most one event (none if net-zero); a crash before anchoring reverts it and `session/load` reports the truth. The model is not told — its next command simply behaves under the new mode.
- **What survives a restart — and what if the operator changed the config default while the process was down?** Overrides replay from the session log (`effective = fold ?? config`), so a resumed session keeps its modes with zero catch-up machinery; a default that drifted offline changes behavior the same way a switch does (the approval policy, being stated, is additionally narrated with operator/config attribution).
- **What does `enforcement: 'partial'` on a result mean?** The selected backend enforces the subset its kernel ABI governs — e.g. Landlock before ABI v3 does not govern path truncate — and says so structurally instead of refusing the host; the probe's report line distinguishes the cases. The bwrap and Seatbelt profiles govern every promised file effect by construction, so they always report `full`.

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@@ -10,13 +10,13 @@ Search output also has two distinct budgets. The tool needs enough raw `rg` outp
## Decision
`glob` and `grep` are model-facing tools in `@deepseek-ai/dsh-tool-fs-search`, backed by the bash seam, not by new `ctx.fs` provider methods. The package registers model-facing filesystem discovery tools, but execution uses `ctx.bash.resolve(request)` followed by `ctx.bash.run(spec)` with fixed `rg` command templates assembled by the tool. The tool layer owns schemas, argument validation, shell quoting, result parsing, result formatting, retention, formatted-result spill handoff, and timeout declaration. The bash executor owns request defaulting/capping, subprocess execution, process-group termination, environment scrubbing, raw output capture, and backend substitution across local, sandboxed, or remote bash implementations.
`glob` and `grep` are conditional model-facing tools in `@deepseek-ai/dsh-tool-fs-search`, backed by the bash seam, not by new `ctx.fs` provider methods. At plugin load, the package checks `command -v rg >/dev/null 2>&1` through `ctx.bash.resolve(request)` followed by `ctx.bash.run(spec)`; if the command exits nonzero, the package logs a warning and registers neither tools nor prompt sections. A probe that cannot start, times out, aborts, is killed, or produces no exit code fails plugin load loudly because that is a broken bash executor rather than an absent optional binary. When registered, execution uses the same `ctx.bash.resolve(request)` followed by `ctx.bash.run(spec)` flow with fixed `rg` command templates assembled by the tool. The tool layer owns schemas, argument validation, shell quoting, result parsing, result formatting, retention, formatted-result spill handoff, and timeout declaration. The bash executor owns request defaulting/capping, subprocess execution, process-group termination, environment scrubbing, raw output capture, and backend substitution across local, sandboxed, or remote bash implementations.
The tools do not use `ctx.bash.start()` and do not create model-visible background tasks. They run as ordinary foreground tools from the agent loop's perspective: the tool call returns only after the `rg` command exits, times out, is aborted, or fails. `defineTool({ timeoutMs })` declares the cooperative tool-call budget, `@deepseek-ai/dsh-timeout-policy` enforces it through `exec.signal`, and the tool forwards that signal into the bash request before `resolve()` / `run()`. The bash backend's own timeout remains a second safety cap; whichever aborts first wins.
The tools align `path` with Claude Code's search tools while binding resolution to the bash workdir, not to `ctx.fs`. The tool derives the bash request workdir from `exec.agent?.session.header.cwd`, mirroring `dsh-tool-bash` and `dsh-tool-fs`; when no session cwd exists, it omits `request.workdir` so the bash implementation applies its configured cwd or process cwd through `resolve()`. For `grep`, `path` is an optional ripgrep target and may be a file or directory; omitted means the resolved bash workdir. For `glob`, `path` is an optional directory search root; omitted means the resolved bash workdir. Relative `path` values resolve against that workdir. Returned paths are displayed relative to the resolved bash workdir when possible and are intended to be follow-up-readable only in co-located deployments where the bash workdir and filesystem `read` root are the same workspace. v1 documents that deployment requirement but does not perform runtime cross-service validation. Remote or virtual filesystem search is deferred until there is a shared workspace/root contract or a provider-specific search backend.
The package does not inject `fs`. It injects `tools`, `systemPrompt`, and `bash`; it deliberately reads `spillStore` with `ctx.get('spillStore')` instead of static inject because formatted-result spill is optional. Existing `@deepseek-ai/dsh-tool-fs` deployments that only want `read` / `write` / `edit` do not need to load bash.
The package does not inject `fs`. It injects `tools`, `systemPrompt`, and `bash`; it deliberately reads `spillStore` with `ctx.get('spillStore')` instead of static inject because formatted-result spill is optional. Existing `@deepseek-ai/dsh-tool-fs` deployments that only want `read` / `write` / `edit` do not need to load bash. Deployments that load search need `rg` available in the bash executor environment for the tools to enter the model-visible schema.
### Package shape
@@ -79,9 +79,9 @@ The `path` field follows the same split as Claude Code: `grep.path` is a file-or
Raw `rg` stdout is an internal transport detail. The tool requests `stdoutMaxBytes: rawOutputMaxBytes` through `ctx.bash.resolve()` and parses `stdout.text` only when the executor returns untruncated stdout within that cap. If stdout is larger than `rawOutputMaxBytes`, or the executor still returns `stdout.truncated`, the tool fails with a clear search error telling the model to narrow `pattern`, `path`, or `include`. The tool never exposes raw `rg` output or bash raw spill paths to the model.
Only stdout is a parse source. Stderr is diagnostic text for invalid patterns, missing `rg`, and search failures; if bash truncates stderr, the tool uses the retained stderr tail with a truncation note and does not read `stderr.spillPath`.
Only stdout is a parse source. Stderr is diagnostic text for invalid patterns, runtime `rg` disappearance after registration, and search failures; if bash truncates stderr, the tool uses the retained stderr tail with a truncation note and does not read `stderr.spillPath`.
If `ctx.bash.run()` reports `aborted` because the tool timeout or caller cancellation fired, the tool returns a structured failure rather than pretending there were no matches. If bash reports its own timeout first, the tool likewise fails with a clear timeout message. Nonzero ripgrep exit semantics are tool-owned: exit 0 is success with matches, exit 1 is success with no matches, invalid pattern / missing `rg` / inaccessible search workdir are failures.
If `ctx.bash.run()` reports `aborted` because the tool timeout or caller cancellation fired, the tool returns a structured failure rather than pretending there were no matches. If bash reports its own timeout first, the tool likewise fails with a clear timeout message. Nonzero ripgrep exit semantics are tool-owned: exit 0 is success with matches, exit 1 is success with no matches, invalid pattern / runtime `rg` disappearance / inaccessible search workdir are failures.
Search failures use a package-owned `HarnessError` subclass with `SEARCH_*` codes, not `FsErrorCode`, because these tools are not `ctx.fs` provider operations. The v1 vocabulary is `SEARCH_INVALID_PATTERN`, `SEARCH_FAILED`, `SEARCH_RAW_OUTPUT_OVERFLOW`, and `SEARCH_ABORTED`. Model argument validation failures such as missing required fields, blank strings, or unsupported negated/list `include` values remain ordinary tool argument errors.
@@ -116,7 +116,7 @@ Line 12: ...
(Full grep result stored at: /.../session-abc123/9f8e7d-grep-results.txt. Use read with offset/limit, or grep this path to search within it.)
```
If the complete logical result fits under the inline cap, no formatted spill artifact is created. If the complete logical result is too large but formatted spill is unavailable, the footer says that the result was capped and the complete result could not be saved. The `truncated` / omitted count is a budget fact, not an incomplete-search fact; timeout, invalid regex, missing `rg`, inaccessible workdirs, raw-output overflow, binary skips, and parse failures stay in tool-domain error or incomplete fields.
If the complete logical result fits under the inline cap, no formatted spill artifact is created. If the complete logical result is too large but formatted spill is unavailable, the footer says that the result was capped and the complete result could not be saved. The `truncated` / omitted count is a budget fact, not an incomplete-search fact; timeout, invalid regex, runtime `rg` disappearance, inaccessible workdirs, raw-output overflow, binary skips, and parse failures stay in tool-domain error or incomplete fields.
## Alternatives considered
@@ -138,22 +138,24 @@ If the complete logical result fits under the inline cap, no formatted spill art
**Expand the bash seam with a raw-output reader first.** Rejected: a portable `readRawOutput(ref, maxBytes)` API would add reference lifetime, permission, and backend storage semantics. A per-run `stdoutMaxBytes` request is the narrower seam: search either receives complete stdout within `rawOutputMaxBytes` or fails clearly.
**Always register and report missing `rg` only at execution time.** Rejected: a model-visible tool schema is a promise that the deployment can attempt that capability. If the bash executor cannot find ripgrep at load, the safer surface is no `glob` / `grep` tools or prompt guidance. Execution-time missing-`rg` classification remains as a defensive fallback for environments that change after registration.
## Testing
- Tests prove an aborted `exec.signal` reaches the bash backend (same-reference spec assertion plus the `SEARCH_ABORTED` result), and cover command construction/quoting (malicious patterns, paths with spaces, leading-dash values, quotes, newlines, glob metacharacters — unit assertions plus a real `bash -c` round-trip for every hostile value), `grep.path` as file and directory targets, `glob.path` as a directory search root, invalid pattern handling, no matches, malformed `rg --json` output, matched-line preview truncation, raw-output overflow, timeout/abort, formatted spill success/failure, the package-owned `SEARCH_*` error codes, and the no-background-task invariant.
- Tests cover registration-time `rg` probing (probe success registers both tools and prompt sections, nonzero probe skips both tools and prompt sections with a warning, infrastructure probe failures reject plugin load), prove an aborted `exec.signal` reaches the bash backend (same-reference spec assertion plus the `SEARCH_ABORTED` result), and cover command construction/quoting (malicious patterns, paths with spaces, leading-dash values, quotes, newlines, glob metacharacters — unit assertions plus a real `bash -c` round-trip for every hostile value), `grep.path` as file and directory targets, `glob.path` as a directory search root, invalid pattern handling, no matches, malformed `rg --json` output, matched-line preview truncation, raw-output overflow, timeout/abort, formatted spill success/failure, the package-owned `SEARCH_*` error codes, and the no-background-task invariant.
- The first-party tool-owned spill precedent is covered directly: spill backend present, spill backend absent, `saveText()` failure, and missing spill owner.
- The package has real Loader-path coverage for the namespace plugin export shape (`name`, `inject`, `Config`, and `apply`, with no default export).
- A real-executor integration suite (`dsh-bash-local` + a real `rg`) verifies the world: hostile patterns stay inert, per-session cwd resolution, VCS-metadata exclusion, modification-time ordering, and real ripgrep stderr classification. It self-skips where `rg` is not on PATH (a CI accommodation mirroring the keyless e2e skip); the fake-executor suite alone carries the per-file 100% coverage gate.
- A real-executor integration suite (`dsh-bash-local` + a real `rg`) verifies the world: hostile patterns stay inert, per-session cwd resolution, VCS-metadata exclusion, modification-time ordering, and real ripgrep stderr classification. It self-skips where `rg` is not on the test process PATH (a CI accommodation mirroring the keyless e2e skip); the fake-executor suite carries registration and execution coverage for missing `rg`, plus the per-file 100% coverage gate.
- Snapshot gap note for the transcript-visible spill notice: this landed with the gap note, not a snapshot. The snapshot tier replays the acp-agent tree, and adding the search plugin there changes the assembled system prompt — every expected output would need re-recording with a real key, which the implementing environment did not hold. The spill notice's exact transcript text is pinned by unit tests (`formatGlobOutput`/`formatGrepOutput` and the through-the-registry spill tests); wiring the plugin into the acp-agent tree plus a `test:snapshot:record` pass is the follow-up for the next key-holding session.
## Consequences
- `glob` and `grep` are model-facing tools in `@deepseek-ai/dsh-tool-fs-search`, not `ctx.fs` provider methods and not part of the existing `@deepseek-ai/dsh-tool-fs` root plugin. The package injects `tools`, `systemPrompt`, and `bash`; it does not inject `fs`, and `ctx.spillStore` stays optional via `ctx.get('spillStore')`.
- `glob` and `grep` are conditional model-facing tools in `@deepseek-ai/dsh-tool-fs-search`, not `ctx.fs` provider methods and not part of the existing `@deepseek-ai/dsh-tool-fs` root plugin. They register only when the bash executor can find `rg`; the package injects `tools`, `systemPrompt`, and `bash`, does not inject `fs`, and keeps `ctx.spillStore` optional via `ctx.get('spillStore')`.
- The schemas are exactly `glob(pattern, path?)` and `grep(pattern, path?, include?)`; search caps and timeout are defaulted, validated Config fields (`globMaxResults`, `grepMaxMatches`, `grepMaxLineBytes`, `rawOutputMaxBytes`, `timeoutMs`).
- The tools execute through `ctx.bash.resolve(request)``ctx.bash.run(spec)`, forward `exec.signal`, never call `ctx.bash.start()`, and never expose a bash task id. The bash request workdir comes from `exec.agent?.session.header.cwd` when available; the resolved `spec.workdir` drives execution and relative-path display.
- The tools request `stdoutMaxBytes: rawOutputMaxBytes` from the bash seam, parse only untruncated stdout within that cap, and treat over-cap or still-truncated raw output as a clear search failure; raw `rg` output is never exposed to the model.
- Oversized complete formatted results are saved through `ctx.spillStore.saveText()` when available while inline results stay bounded; spill failure, a missing backend, or a missing owner preserves the inline result and reports the unsaved remainder — never an `isError`.
- The package README, the generated config catalog, and exported JSDoc document the Config fields and `SEARCH_*` codes; the repl-agent example ships the tools (the acp-agent tree waits on the snapshot re-record above); the fs group README records the co-located bash/filesystem deployment requirement.
- The package README, the generated config catalog, and exported JSDoc document the Config fields and `SEARCH_*` codes; the repl-agent example ships the conditional tool plugin (the acp-agent tree waits on the snapshot re-record above); the fs group README records the `rg` availability and co-located bash/filesystem deployment requirements.
## Risks

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@@ -0,0 +1,6 @@
# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
# side as of the last confirmed-consistent state. Both languages carry equal authority;
# after editing either side, bring the other along and re-record with:
# pnpm run verify-translation-pairing --write
2026-07-14-cross-family-fs-sandbox.md: 9b6312e5994469606bd1645902fc798f70258580
2026-07-14-cross-family-fs-sandbox.zh.md: d4816e03d94bdf12b2db875d71dccb7db3a2c0d7

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@@ -0,0 +1,94 @@
# Agent Note: Cross-family file sandbox — one policy home, a sandboxed fs provider, and fs escalation parity
Status: implemented
English | [中文](2026-07-14-cross-family-fs-sandbox.zh.md)
## Problem
`SandboxMode` claims file effects, but originally only `ctx.bash` enforced it. The fs tools (`write`/`edit`) mutate the host filesystem in-process through `ctx.fs`, where an OS argv wrapper is mechanically meaningless — [the sandbox Agent Note](2026-07-06-sandbox.md) § In-process tools records this and left cross-family enforcement as a deferred phase with an open question: whether in-process enforcement stays per-seam or becomes a uniform harness capability. This Agent Note is that phase, and answers it: one shared policy home, per-seam enforcement at each family's correct altitude.
The gap was not read-only-shaped. A confined coding agent's product mode is `workspace-write`: bash may already write under the workspace root while everything outside is denied, so an fs enforcement that could only deny-all would be strictly worse than disabling the fs tools — the model would attempt an in-workspace `write`, be denied, and learn to detour through `bash` heredocs. Cross-family enforcement therefore speaks the full mode ladder, including the path-containment judgment `workspace-write` requires (canonical targets; `..`/symlink/absolute-path escapes) and the same escalation lever bash carries.
A second enforcing family also exposed an ownership problem in the original layout. The deployment default (`mode` + `workspaceRoot`) was configured on `dsh-bash-sandbox`, and the per-session override event was `bash/sandbox-mode`, folded and written by `dsh-bash`'s session-mode kit. With fs enforcing the same policy, either fs reads bash's config and events (a capability family depending on a sibling's plugin config) or each family carries its own copy — and two copies of `workspaceRoot` drift into exactly the split world the sandbox RFC warns about: bash confined to one root while fs fences another.
## Decision
Three coordinated pieces, all composed from the leaf `cordis.yml`, none touching `agent-loop`.
### `ctx.sandboxPolicy` — one home for mode and workspace root
`packages/sandbox/sandbox-policy/` (`@deepseek-ai/dsh-sandbox-policy`) registers `ctx.sandboxPolicy`, the single owner of the deployment's sandbox policy:
- `Config`: `mode` (the closed `SandboxMode` union, default `read-only`) and `workspaceRoot` (default the process cwd, resolved absolute). Misconfiguration fails loud at load.
- The per-session override event `sandbox/mode`, with its pure fold (`effectiveSandboxMode(events)`), its write path (`setSandboxMode(session, mode)`), and `SANDBOX_MODES`. The event is policy state — consumed by two families — so it lives here, not in either capability's seam. Its shape and log-only semantics match the `approval/*` precedent.
- `defaultMode` / `workspaceRoot` accessors the enforcing implementations read for their resolve fallback and boundary.
`dsh-bash-sandbox` carries no sandbox config of its own — it injects `sandboxPolicy` and reads the default from it; its `resolve()` precedence is unchanged (escalation grant > per-call stamp > default). `dsh-tool-bash` and `dsh-tool-fs` fold the session's `sandbox/mode` with `effectiveSandboxMode` to stamp each call; `dsh-permission` presets and the ACP bridge write through the relocated setter. The seam that owns bash execution no longer depends on `dsh-session` at all — the session dependency moved to the policy package with the fold.
### `dsh-fs-sandbox` — enforcement inside the provider
`packages/fs/fs-sandbox/` (`@deepseek-ai/dsh-fs-sandbox`) mirrors the `bash-local`/`bash-sandbox` split: `SandboxedFileSystem extends LocalFileSystem`, registered as `ctx.fs`, injecting `sandboxPolicy`. Reads (`resolve`/`stat`/`readText`/`streamText`/`listDir`) pass through untouched — every mode permits reading. The two mutations enforce by mode before delegating to the inherited atomic write:
- `read-only` denies `writeText`/`editText` outright.
- `workspace-write` fences the canonicalized target against the writable-root set — `writableRoots(policy)` in `dsh-sandbox`: the workspace root plus the platform temp areas (`/tmp`, `os.tmpdir()`), each realpathed — the SAME set the Seatbelt profile grants, so the fs fence is the fourth dialect of one mode meaning alongside the bwrap/Landlock/Seatbelt profiles, and "the write tool cannot write `/tmp` but bash can" asymmetries cannot arise. Containment is prefix-inclusion on real paths; the target is re-canonicalized (`resolve` realpaths the deepest existing ancestor) immediately before delegating, so an ancestor symlink swapped since the tool resolved it is caught.
- `danger-full-access` delegates unfenced.
A denial is the structured `FS_SANDBOX_DENIED` carrying the effective mode — distinct from `FS_PERMISSION_DENIED` (a host EACCES is the world refusing; this is policy refusing). No text inference: an in-process fence knows exactly what it denied. The per-call carrier is a trailing optional `sandboxMode` on `writeText`/`editText` (the filesystem twin of `BashExecRequest.sandboxMode`); the seam stays session-free (the caller stamps, exactly as `resolve` takes a cwd), and the bare local backend carries-and-ignores it. `FileSystem.sandboxMode` is the capability fact (`undefined` on the base and `fs-local`, the default on `SandboxedFileSystem`), so the tool layer advertises escalation from composition truth.
The threat model is stated in the package README: a policy fence in trusted code over model-controlled paths, not a kernel boundary — the operations are the seam's own, only the target path is untrusted, so canonicalize-then-contain is the complete answer to this surface (the `code-runtime` "containment, not a security boundary" precedent). Kernel-grade isolation of untrusted CODE stays `ctx.bash`'s job. The residual resolve-to-syscall race is narrowed by the in-place re-canonicalization and eliminated only by platform primitives (`openat2` `RESOLVE_BENEATH`) not worth their portability cost here.
### Tool parity — one denial marker, one escalation flow
`dsh-tool-fs` stamps the effective mode onto each mutation and maps `FS_SANDBOX_DENIED` to the marker the model already knows from bash: `[sandbox: file access denied under <mode> mode]`. When `ctx.fs.sandboxMode` reports a confining mode at registration, `write` and `edit` advertise the same `sandbox_permissions` + `justification` fields, teach the same same-turn retry, and resolve the same `ctx.approval` request before executing — the four outcomes and their verbatim fail-closed texts carried over from [the sandbox Agent Note](2026-07-06-sandbox.md) § Escalation (strict widening checked at execution against the call's effective mode; a grant consumed by the one call that asked; no new session events).
The shared pieces live in `dsh-sandbox`, which owns the mode types: `WIDER_MODES`, the escalation-target enum, the argument-pairing validation, the denial/hint marker builders, and `approveEscalation` — the ordered fail-closed choreography. `approveEscalation` takes a minimal STRUCTURAL approver (`EscalationApprover`, generic over the agent and call-id types), not the approval service type, so `dsh-sandbox` gains no dependency on the approval or agent packages: each tool passes its own `ctx.approval`, agent, call id, and tool name as ingredients. `dsh-tool-bash` and `dsh-tool-fs` both use these; the cross-file duplication gate holds the single-sourcing honest.
The [`examples/acp-agent`](../../../../examples/acp-agent/cordis.yml) composition loads `dsh-sandbox-policy` and `dsh-fs-sandbox`, moves the `mode`/`workspaceRoot` config to the policy entry, and drops the old gating that disabled the fs stack under confined modes; `fs-policy` (read-before-edit) composes orthogonally on top. The system prompt still states no sandbox mode — the marker teaches the boundary at the moment it matters, per the sandbox Agent Note's live evidence.
### The enforcement point: provider, not intent gate
The sandbox Agent Note's original cross-family sketch put fs enforcement on the `fs/write-intent`/`fs/edit-intent` events. This Agent Note enforces in the provider instead, on two mechanical facts: the intent slots are single-decision first-wins (occupied by `dsh-fs-policy`, whose contract names a second decider a misconfiguration), and the intent events are dispatched only by `dsh-tool-fs` — a direct `ctx.fs` caller (a cordis-mounted plugin, a custom tool) bypasses them, where provider-level enforcement covers every caller by construction. The sandbox Agent Note's deferred-phase wording is updated to match in the same change.
### Out of scope
- **Network policy for `ctx.web`** — `SandboxMode` claims file effects only; a web-only network knob while bash `curl` runs free would be a false boundary. Revisit when a bash backend enforces network (bwrap `--unshare-net`, Landlock ABI v4+).
- **The `subagent-acp` consumer** and **per-session workspace root** — unchanged deferred phases of the sandbox RFC; centralizing the root in `ctx.sandboxPolicy` is groundwork for the latter, not its design.
- **A uniform per-tool sandbox runtime** — remains rejected for the reasons in the sandbox RFC.
## Alternatives considered
- **Enforce on the `fs/*` intent events (the sandbox Agent Note's original sketch)** — rejected on the two mechanical facts in § The enforcement point: single-slot first-wins already occupied, and a bypass for direct `ctx.fs` callers. Provider-level enforcement covers every caller and mirrors bash's swap-the-implementation shape.
- **Enforce in `tools/pre-execute`** — rejected: the listener sees the model's raw path string before `resolve()`, so it would re-implement cwd defaulting and symlink canonicalization and still race the real resolve. Disqualifying for `workspace-write`, a judgment over canonical paths.
- **Inline checks in `dsh-tool-fs`** — rejected: covers only the tool path (same bypass as the intent events) and duplicates resolve knowledge one layer above where the canonical target already exists.
- **A `mode` flag on `dsh-fs-local` instead of a sibling backend** — rejected: the capability fact must be composition truth the way `dsh-bash-local` vs `dsh-bash-sandbox` is; a config flag makes the tool's advertisement conditional on configuration, and the bash family already establishes the sibling-package shape.
- **Kernel-enforced fs mutations via a confined helper subprocess** — rejected: a process per write; `editText`'s read-match-write critical section would have to move wholesale into the child to stay atomic; and the threat surface (trusted operations, untrusted path argument) does not need a kernel — the fence in trusted code is the complete answer, while untrusted-code isolation stays on `ctx.bash`.
- **Per-family policy config with a load-time consistency check** — rejected: two homes for one fact, patched by a check that must enumerate every future enforcing family; the policy service makes drift inexpressible instead of detected.
- **Keep the override event in `dsh-bash` as `bash/sandbox-mode`** — rejected: the event is policy state consumed by two families; leaving it bash-named forces `dsh-fs-sandbox` to depend on bash vocabulary. Pre-release, the rename is a same-change move with snapshot re-records, no shims.
- **Escalation choreography imported from the approval/agent packages into `dsh-sandbox`** — rejected: it would invert the layering (a base vocabulary package depending on UI/agent packages). The structural approver keeps the logic single-sourced in `dsh-sandbox` while the dependencies stay in the tool layer that already holds them.
- **A consolidated mutation-options object on the fs seam** (the shape first sketched for the per-call carrier) — rejected on friction: it churns every `writeText`/`editText` caller and splits `signal` across an options bag for mutations while reads keep it positional. A trailing optional `sandboxMode` matches bash's carry-and-ignore pattern and keeps `signal` symmetric across the seam.
- **Extra writable-root grants on `SandboxPolicy` now** — deferred unchanged: `writableRoots()` derives from the mode meaning today; ad-hoc grants are an escalation-scope question the sandbox RFC left open.
## Consequences
What shipped — the tiers in § Testing hold each:
- Under `read-only`, `write`/`edit` return the `[sandbox: file access denied under read-only mode]` marker and the disk is untouched; `read`/`listDir` behave identically to `dsh-fs-local`.
- Under `workspace-write`, mutations land under the workspace root and the temp areas and are denied outside; the containment matrix — `..` traversal, absolute paths outside, a pre-existing symlinked directory inside pointing out, and a new file created under such a symlink — denies every escape on real disks.
- A denied fs mutation retried once with `sandbox_permissions` + `justification` prompts through the composed approval chain; a grant runs exactly that call under the wider mode and the write lands; rejected/cancelled/unavailable each produce their verbatim fail-closed text and mutate nothing.
- One `permission` preset switch governs both families: after a session switches modes, the next bash call and the next fs mutation both honor the new mode from the same `sandbox/mode` fold.
- A direct `ctx.fs.writeText` with no per-call stamp is confined at the deployment default.
- The escalation fields on `write`/`edit` exist exactly when the mounted `ctx.fs` confines, absent under `dsh-fs-local`.
- `agent-loop` is untouched — everything rides `ctx.sandboxPolicy`, the `ctx.fs` seam, `SessionEventMap` merging, and the tool-execution pipeline.
Costs and accepted limits:
- **The fs fence is a policy boundary, not a kernel one.** Its threat surface is model-chosen paths, not adversarial host processes; the residual resolve-to-syscall TOCTOU is narrowed, not eliminated, and the README says so. Kernel boundaries remain bash's.
- **`dsh-bash-sandbox` gains a hard dependency on `ctx.sandboxPolicy`.** Every sandboxed composition adds one `cordis.yml` entry or fails loud at load — the intended pre-release foundation move; the examples update in the same change.
- **Fence-vs-runner parity is derived, not asserted.** The fs fence and the Seatbelt profile both take their writable set from `writableRoots`, and a parity unit test pins the sets; a runner profile changing its writable set without that function would drift.
- **The marker and escalation teaching now serve two families.** A wording change is a coordinated edit behind one builder in `dsh-sandbox`; the duplication gate and pinned snapshots hold it single-sourced, at the cost that fs and bash cannot deliberately diverge in phrasing without splitting the builder.
## Testing
- Unit: `dsh-sandbox` pins the escalation ladder, the marker builders, the argument-pairing validation, and `approveEscalation`'s ordered fail-closed sequence (non-widening, no-approval, no-agent, each outcome), plus `writableRoots`/`canonicalPath`. `dsh-sandbox-policy` pins the default accessors, the fold/setter, the load-time mode rejection, and HMR safety. `dsh-fs-sandbox` pins the per-mode fence and the containment matrix (inside, temp area, absolute-outside, `..`, symlinked-out directory, new file under one, path-equals-root, root-ending-in-separator) on a real filesystem, plus the per-call override and HMR safety. `dsh-tool-fs` pins advertisement gating, the mode stamp, the fold, denial-marker mapping, and the full escalation matrix (grant, reject, no-service, no-agent, pairing, non-confining guard). `dsh-tool-bash`, `dsh-bash-sandbox`, and `dsh-permission` migrate to the relocated policy/kit.
- Snapshot: the acp-agent example composes `dsh-sandbox-policy` + `dsh-fs-sandbox`; the pinned header carries the fs escalation fields and the `sandbox/mode` event name, re-recorded once.

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# Agent Note: 跨家族文件沙箱——统一策略归属、沙箱化 fs 提供方、fs 升级对等
Status: implemented
[English](2026-07-14-cross-family-fs-sandbox.md) | 中文
## 问题
`SandboxMode` 声明的是文件效果,但最初只有 `ctx.bash` 执行它。fs 工具(`write`/`edit`)在进程内经由 `ctx.fs` 变更宿主文件系统,那里的 OS argv 包装在机制上毫无意义——[沙箱 RFC](2026-07-06-sandbox.md) § In-process tools 记录了这一点,并把跨家族执行留作一个延后阶段,附带一个未决问题:进程内执行是各 seam 各自表达,还是变成一个统一的 harness 能力。本 Agent Note 就是那个阶段,并给出答案:一个共享的策略归属,在每个家族各自正确的高度上做 per-seam 执行。
这个缺口不是 read-only 形状的。一个受限编码 agent 的产品模式是 `workspace-write`:bash 已经可以在工作区根目录下写入,而其外的一切都被拒绝,所以一个只能全部拒绝的 fs 执行会严格劣于禁用 fs 工具——模型会尝试在工作区内 `write`,被拒,然后学会绕道 `bash` heredoc。因此跨家族执行必须讲完整的模式阶梯,包括 `workspace-write` 要求的路径包含判定(规范化目标;`..`/符号链接/绝对路径逃逸),以及与 bash 相同的升级杠杆。
第二个执行家族还暴露了原布局中的一个归属问题。部署默认值(`mode` + `workspaceRoot`)配置在 `dsh-bash-sandbox` 上,而 per-session 覆盖事件是 `bash/sandbox-mode`,由 `dsh-bash` 的 session-mode 工具集折叠与写入。当 fs 执行同一套策略时,要么 fs 读取 bash 的配置与事件(一个能力家族依赖同级插件的配置),要么各家族各持一份副本——两份 `workspaceRoot` 会漂移进沙箱 RFC 警告过的那个割裂世界:bash 受限于一个根,而 fs 围栏另一个根。
## Decision
三个相互协调的部分,全部在叶子 `cordis.yml` 中组合,均不触及 `agent-loop`
### `ctx.sandboxPolicy`——mode 与工作区根的统一归属
`packages/sandbox/sandbox-policy/`(`@deepseek-ai/dsh-sandbox-policy`)注册 `ctx.sandboxPolicy`,即部署沙箱策略的唯一所有者:
- `Config`:`mode`(封闭的 `SandboxMode` 联合,默认 `read-only`)与 `workspaceRoot`(默认进程 cwd,解析为绝对路径)。配置错误在加载时高声失败。
- per-session 覆盖事件 `sandbox/mode`,连同它的纯折叠(`effectiveSandboxMode(events)`)、写入路径(`setSandboxMode(session, mode)`)与 `SANDBOX_MODES`。该事件是策略状态——被两个家族消费——所以它住在这里,而不在任一能力的 seam 里。它的形状与仅日志(log-only)语义遵循 `approval/*` 的先例。
- `defaultMode` / `workspaceRoot` 访问器,供执行实现读取其 resolve 回退值与边界。
`dsh-bash-sandbox` 自身不再携带任何沙箱配置——它注入 `sandboxPolicy` 并从中读取默认值;其 `resolve()` 优先级不变(升级授权 > per-call 盖章 > 默认)。`dsh-tool-bash``dsh-tool-fs``effectiveSandboxMode` 折叠会话的 `sandbox/mode` 以对每次调用盖章;`dsh-permission` 预设与 ACP bridge 经由迁移后的 setter 写入。拥有 bash 执行的那个 seam 不再依赖 `dsh-session`——会话依赖随折叠一起迁到了策略包。
### `dsh-fs-sandbox`——在提供方内部执行
`packages/fs/fs-sandbox/`(`@deepseek-ai/dsh-fs-sandbox`)镜像 `bash-local`/`bash-sandbox` 的拆分:`SandboxedFileSystem extends LocalFileSystem`,注册为 `ctx.fs`,注入 `sandboxPolicy`。读取(`resolve`/`stat`/`readText`/`streamText`/`listDir`)原样透传——每种模式都允许读。两个变更操作在委托给继承来的原子写之前按模式执行:
- `read-only` 直接拒绝 `writeText`/`editText`
- `workspace-write` 把规范化后的目标围栏于可写根集合——`dsh-sandbox` 中的 `writableRoots(policy)`:工作区根加上平台临时目录(`/tmp``os.tmpdir()`),各自 realpath——与 Seatbelt profile 授予的是同一个集合,所以 fs 围栏是这一个模式含义在 bwrap/Landlock/Seatbelt profile 之外的第四种方言,因此不会出现「write 工具不能写 `/tmp` 而 bash 能」的不对称。包含判定是对真实路径的前缀包含;目标在委托前被立即重新规范化(`resolve` 对最深的既有祖先做 realpath),因此自工具解析该目标以来被换出的祖先符号链接会被捕获。
- `danger-full-access` 不加围栏地委托。
拒绝是结构化的 `FS_SANDBOX_DENIED`,携带生效模式——区别于 `FS_PERMISSION_DENIED`(宿主 EACCES 是世界在拒绝;这里是策略在拒绝)。无文本推断:进程内围栏确切知道它拒绝了什么。per-call 载体是 `writeText`/`editText` 上一个末尾可选的 `sandboxMode`(文件系统侧对应 `BashExecRequest.sandboxMode`);该 seam 保持无会话依赖(由调用方盖章,正如 `resolve` 接收一个 cwd),而裸的本地后端携带并忽略它。`FileSystem.sandboxMode` 是能力事实(在基类与 `fs-local` 上为 `undefined`,在 `SandboxedFileSystem` 上为默认值),所以工具层按组合真相来宣告升级。
威胁模型写在包 README 里:一道位于可信代码中、针对模型可控路径的策略围栏,而非内核边界——操作是 seam 自身的,只有目标路径不可信,所以「先规范化再判包含」是对这个面的完整答案(`code-runtime` 的「containment, not a security boundary」先例)。对不可信代码的内核级隔离仍是 `ctx.bash` 的职责。resolve 到系统调用之间残留的竞态被就地重新规范化收窄,只有平台原语(`openat2` `RESOLVE_BENEATH`)能彻底消除它,而那在此不值其可移植性代价。
### 工具对等——一个拒绝标记、一条升级流程
`dsh-tool-fs` 把生效模式盖章到每次变更上,并将 `FS_SANDBOX_DENIED` 映射为模型已从 bash 认识的标记:`[sandbox: file access denied under <mode> mode]`。当 `ctx.fs.sandboxMode` 在注册时报告一个受限模式,`write``edit` 宣告相同的 `sandbox_permissions` + `justification` 字段,教授相同的同回合重试,并在执行前解析相同的 `ctx.approval` 请求——四种结果及其逐字的 fail-closed 文案沿用自[沙箱 RFC](2026-07-06-sandbox.md) § Escalation(严格加宽在执行时针对调用的生效模式检查;授权由发起它的那一次调用消费;无任何新会话事件)。
共享部分住在 `dsh-sandbox`,它拥有模式类型:`WIDER_MODES`、升级目标枚举、参数配对校验、拒绝/提示标记构造器,以及 `approveEscalation`——有序的 fail-closed 编排。`approveEscalation` 接收一个最小的结构化 approver(`EscalationApprover`,对 agent 与 call-id 类型泛型化),而非审批服务类型,所以 `dsh-sandbox` 不获得对 approval 或 agent 包的依赖:每个工具把自己的 `ctx.approval`、agent、call id 与工具名作为原料传入。`dsh-tool-bash``dsh-tool-fs` 都使用它们;跨文件重复检测门禁确保单一来源不走样。
[`examples/acp-agent`](../../../../examples/acp-agent/cordis.yml) 组合加载 `dsh-sandbox-policy``dsh-fs-sandbox`,把 `mode`/`workspaceRoot` 配置移到策略条目,并去掉在受限模式下禁用整个 fs 栈的旧门控;`fs-policy`(read-before-edit)正交地叠加其上。系统提示仍然不陈述沙箱模式——标记会在真正重要的那一刻教会模型边界,依据沙箱 RFC 的线上证据。
### 执行点:提供方,而非 intent gate
沙箱 RFC 最初的跨家族草图把 fs 执行放在 `fs/write-intent`/`fs/edit-intent` 事件上。本 Agent Note 改为在提供方中执行,基于两个机制性事实:intent 槽是单决策、先到先得(已被 `dsh-fs-policy` 占据,其契约称第二个决策者为配置错误),且 intent 事件只由 `dsh-tool-fs` 派发——一个直连 `ctx.fs` 的调用方(一个 cordis 挂载插件、一个自定义工具)会绕过它们,而提供方级执行按构造覆盖每一个调用方。沙箱 RFC 的延后阶段措辞在同一变更中被更新以匹配。
### 范围之外
- **`ctx.web` 的网络策略**——`SandboxMode` 只声明文件效果;在 bash `curl` 畅通时给一个仅限 web 的网络旋钮会是一道假边界。待某个 bash 后端能执行网络(bwrap `--unshare-net`、Landlock ABI v4+)时再议。
- **`subagent-acp` 消费者** 与 **per-session 工作区根**——沙箱 RFC 未变的延后阶段;把根集中到 `ctx.sandboxPolicy` 是后者的铺垫,而非其设计。
- **统一的 per-tool 沙箱运行时**——因沙箱 RFC 中的理由继续否决。
## Alternatives considered
- **在 `fs/*` intent 事件上执行(沙箱 RFC 的原始草图)**——因 § 执行点 中的两个机制性事实被否决:单槽先到先得且已被占据,以及对直连 `ctx.fs` 调用方的绕过。提供方级执行覆盖每一个调用方,并镜像 bash 的换实现形态。
- **在 `tools/pre-execute` 中执行**——否决:监听器在 `resolve()` 之前看到模型的原始路径字符串,因此它会重新实现 cwd 默认化与符号链接规范化,并且仍与真正的 resolve 竞态。对 `workspace-write`(一个对规范路径的判定)而言是取消资格级的。
- **在 `dsh-tool-fs` 中做内联检查**——否决:只覆盖工具路径(与 intent 事件同样的绕过),并在规范目标已存在之上重复了一层 resolve 知识。
- **在 `dsh-fs-local` 上加一个 `mode` 标志而非同级后端**——否决:能力事实必须是组合真相,正如 `dsh-bash-local``dsh-bash-sandbox`;一个配置标志会让工具的宣告取决于配置,而 bash 家族已经确立了同级包形态。
- **经受限 helper 子进程做内核级 fs 变更**——否决:每次写一个进程;`editText` 的读-匹配-写临界区不得不整体搬进子进程才能保持原子;而威胁面(可信操作、不可信路径参数)不需要内核——可信代码中的围栏就是完整答案,而不可信代码隔离仍在 `ctx.bash`
- **带加载期一致性校验的 per-family 策略配置**——否决:一个事实两个归属,靠一个必须枚举每个未来执行家族的校验来打补丁;策略服务让漂移不可表达,而非被检测到。
- **把覆盖事件留在 `dsh-bash` 里作 `bash/sandbox-mode`**——否决:该事件是被两个家族消费的策略状态;保留 bash 命名会迫使 `dsh-fs-sandbox` 依赖 bash 词汇。预发布阶段,该改名是同一变更内的迁移,附带快照重录,无任何 shim。
- **把升级编排从 approval/agent 包导入 `dsh-sandbox`**——否决:那会倒置分层(一个基础词汇包依赖 UI/agent 包)。结构化 approver 让逻辑单一来源于 `dsh-sandbox`,而依赖留在本就持有它们的工具层。
- **fs seam 上一个合并的 mutation-options 对象**(per-call 载体最初草拟的形状)——因摩擦被否决:它会搅动每一个 `writeText`/`editText` 调用方,并把 `signal` 拆进变更专用的选项包,而读取仍保持位置参数。一个末尾可选的 `sandboxMode` 匹配 bash 的携带并忽略模式,并使 `signal` 在整个 seam 上保持对称。
- **现在就在 `SandboxPolicy` 上加额外的可写根授权**——照旧延后:`writableRoots()` 如今由模式含义推导;临时授权是沙箱 RFC 留下的升级作用域问题。
## Consequences
已交付的部分——§ Testing 的各层各自钉住:
-`read-only` 下,`write`/`edit` 返回 `[sandbox: file access denied under read-only mode]` 标记,磁盘不受触动;`read`/`listDir``dsh-fs-local` 行为一致。
-`workspace-write` 下,变更落在工作区根与临时目录下,其外被拒;包含矩阵——`..` 穿越、指向外部的绝对路径、一个既有的、指向外部的工作区内符号链接目录,以及在这样一个符号链接下新建的文件——在真实磁盘上拒绝每一种逃逸。
- 一个被拒的 fs 变更,携带 `sandbox_permissions` + `justification` 重试一次,会经组合的审批链提示;一次授权让恰好那一次调用在更宽的模式下运行且写入落盘;rejected/cancelled/unavailable 各自产生其逐字的 fail-closed 文案且不做任何变更。
- 一次 `permission` 预设切换同时管辖两个家族:会话切换模式后,下一次 bash 调用与下一次 fs 变更都从同一个 `sandbox/mode` 折叠遵循新模式。
- 一次无 per-call 盖章的直连 `ctx.fs.writeText` 会被围栏于部署默认值。
- `write`/`edit` 上的升级字段恰好在被挂载的 `ctx.fs` 受限时存在,在 `dsh-fs-local` 下不存在。
- `agent-loop` 未被触动——一切都骑在 `ctx.sandboxPolicy``ctx.fs` seam、`SessionEventMap` 合并,以及工具执行管线之上。
代价与接受的限制:
- **fs 围栏是策略边界,而非内核边界。** 它的威胁面是模型选定的路径,而非对抗性宿主进程;resolve 到系统调用之间残留的 TOCTOU 被收窄而非消除,README 已如实声明。内核边界仍属 bash。
- **`dsh-bash-sandbox` 获得对 `ctx.sandboxPolicy` 的硬依赖。** 每个沙箱化组合要么加一个 `cordis.yml` 条目,要么在加载时高声失败——这是有意的预发布奠基之举;示例在同一变更内更新。
- **围栏与 runner 的对等是推导出来的,而非断言的。** fs 围栏与 Seatbelt profile 都从 `writableRoots` 取其可写集合,一个对等单元测试钉住这些集合;一个 runner profile 若在不经该函数的情况下改变其可写集合便会漂移。
- **标记与升级教学如今服务于两个家族。** 措辞改动是 `dsh-sandbox` 中一个构造器背后的协调编辑;重复检测门禁与钉住的快照维持单一来源,代价是 fs 与 bash 无法在不拆分该构造器的情况下有意地在措辞上分道。
## Testing
- 单元:`dsh-sandbox` 钉住升级阶梯、标记构造器、参数配对校验,以及 `approveEscalation` 的有序 fail-closed 序列(非加宽、无 approval、无 agent、各结果),外加 `writableRoots`/`canonicalPath``dsh-sandbox-policy` 钉住默认访问器、折叠/setter、加载期模式拒绝,以及 HMR 安全。`dsh-fs-sandbox` 在真实文件系统上钉住 per-mode 围栏与包含矩阵(内部、临时目录、绝对路径-外部、`..`、指向外部的符号链接目录、其下的新建文件、路径等于根、以分隔符结尾的根),外加 per-call 覆盖与 HMR 安全。`dsh-tool-fs` 钉住宣告门控、模式盖章、折叠、拒绝标记映射,以及完整的升级矩阵(授权、拒绝、无服务、无 agent、配对、非受限守卫)。`dsh-tool-bash``dsh-bash-sandbox``dsh-permission` 迁移到迁移后的策略/工具集。
- 快照:acp-agent 示例组合 `dsh-sandbox-policy` + `dsh-fs-sandbox`;被钉住的 header 携带 fs 升级字段与 `sandbox/mode` 事件名,一次性重录。