feat(bash): generalize managed shell environment

packages/bash/bash/README.md

@@ -30,8 +30,8 @@ Implementations subclass `BashExecutor`, implement the abstract methods, and cal
 
 ## Vocabulary
 
-`BashExecRequest` (command, workdir?, timeoutMs?, signal?, stdin?, env?, owner?, sandboxMode?) resolves to `BashExecSpec` (command, workdir, timeoutMs, signal?, stdin?, env?, owner, sandboxMode) before execution; `owner` and `sandboxMode` are optional on the request and **required-but-nullable** on the resolved spec, so a forgotten one is a visible `undefined` rather than a silently-absent property. `sandboxMode` is the explicit per-call sandbox-policy input: an escalation grant a human just issued ([the sandbox RFC § Escalation](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md), which outranks) or the session's standing override ([the sandbox RFC § Per-session mode switching](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md)); a sandboxing executor's `resolve()` stamps its configured default when the request carries none, and a non-sandboxing executor carries the field verbatim and confines nothing.
+`BashExecRequest` (command, workdir?, timeoutMs?, signal?, stdin?, env?, dshEnv?, owner?, sandboxMode?) resolves to `BashExecSpec` (command, workdir, timeoutMs, signal?, stdin?, env?, dshEnv?, owner, sandboxMode) before execution; `owner` and `sandboxMode` are optional on the request and **required-but-nullable** on the resolved spec, so a forgotten one is a visible `undefined` rather than a silently-absent property. `sandboxMode` is the explicit per-call sandbox-policy input: an escalation grant a human just issued ([the sandbox RFC § Escalation](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md), which outranks) or the session's standing override ([the sandbox RFC § Per-session mode switching](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md)); a sandboxing executor's `resolve()` stamps its configured default when the request carries none, and a non-sandboxing executor carries the field verbatim and confines nothing.
 
 The seam also owns the per-session mode override vocabulary (the sandbox RFC § Per-session mode switching): the log-only `'bash/sandbox-mode'` session event, the pure fold `effectiveSandboxMode(events)` (last event wins; `undefined` means "apply the executor default"), and THE write path `setSandboxMode(session, mode)` — the session log is the store, so an override survives restart by replay and two sessions can never see each other's mode. Writers must respect turn-enclosure: the ACP bridge anchors an idle switch at the next turn rather than appending between turns. The task id (`BashTaskId`) and the `owner` token (`OwnerToken`) are [branded](../../util/brand) — `OwnerToken` is a DISTINCT brand from `SessionId` (the seam never imports `dsh-session`; the `dsh-tool-bash` consumer is the single boundary that casts its `SessionId` into one). `run()` returns `BashRunResult` (exitCode, signal, timedOut, aborted, timeoutMs, stdout/stderr as `CollectedOutput`) and `start()`/`readOutput()` use `BashTask`/`BashTaskRead` for the background side. A sandboxing executor additionally stamps `sandbox` result facts on results and settled tasks (`BashSandboxInfo`: the mode it executed under, the conservative `denied` classification, and — for confined modes — the backend's `enforcement` completeness); the mode/enforcement vocabulary is owned by the [`dsh-sandbox`](../../sandbox/sandbox/) seam, and the facts are documented in [core-data-structures/bash.md](../../../docs/core-data-structures/bash.md). See `src/types.ts` for the full contracts.
 
-`stdin` and `env` are set by in-process plugins (the hooks bridges, native plugins) to feed a hook command its JSON payload on stdin and its `CLAUDE_PROJECT_DIR`/`CLAUDE_PLUGIN_ROOT` env. The model-facing `dsh-tool-bash` tool does not expose them as parameters — a model already has equivalent power through shell syntax (`FOO=bar cmd`, a heredoc), so they would be redundant tool params. This is not a security boundary: the implementation's credential scrub (not these fields) is what keeps the harness's ambient secrets out of a spawned command. They are plain optionals on the resolved spec (unlike `owner`'s required-but-nullable): a missing one means "none", the safe default. See [the bash-stdin-env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md).
+`stdin` and ordinary `env` are set by in-process plugins (the hooks bridges, native plugins) to feed a hook command its JSON payload and `CLAUDE_PROJECT_DIR`/`CLAUDE_PLUGIN_ROOT` values. `dshEnv` is a separate trusted overlay restricted by type to `DSH_*` keys; model bash uses it for the current snapshot collected by `ctx.bashEnv`. Implementations remove inherited `DSH_*`, reject those names in ordinary `env`, then merge `dshEnv`, so an omitted current fact cannot fall back to stale ambient state. The model-facing tool exposes none of these as parameters. All three remain optional on the resolved spec; absent means no input/overlay. See [the bash-stdin-env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md) and [the session environment RFC](../../../docs/rfc/implemented/feature/2026-07-10-agent-session-identity-and-log-location.md).

packages/bash/bash/src/index.ts

@@ -30,6 +30,7 @@ export type {
   BashTaskRead,
   BashTaskStatus,
   CollectedOutput,
+  DshEnvironment,
 } from './types.ts'
 
 declare module 'cordis' {

packages/bash/bash/src/types.ts

@@ -12,6 +12,9 @@ import type { SandboxEnforcement, SandboxMode } from '@deepseek-ai/dsh-sandbox'
 /** Identifies one background task within an executor (generated `bash-N`). */
 export type BashTaskId = Branded<'BashTaskId'>
 
+/** Trusted DeepSeek Harness variables for one bash execution. */
+export type DshEnvironment = Readonly<Record<`DSH_${string}`, string>>
+
 /**
  * Brand a string as a {@link BashTaskId}.
  * @param id - the raw task-id string (the executor generates `bash-N`).
@@ -106,15 +109,19 @@ export interface BashExecRequest {
    */
   stdin?: string | undefined
   /**
-   * Extra environment entries for the command, merged AFTER the
-   * implementation's credential scrub (so an explicit entry here is honored even
-   * when its name matches the scrub pattern — the caller named a value it holds,
-   * not the harness's ambient secret). Set by in-process plugins (the hooks
-   * bridges set `CLAUDE_PROJECT_DIR`, `CLAUDE_PLUGIN_ROOT`, …); the model-facing
-   * bash tool does not expose it as a parameter (a model that needs an env var
-   * uses shell syntax like `FOO=bar cmd`).
+   * Ordinary environment entries for the command, merged after the credential
+   * scrub. `DSH_*` is reserved for {@link dshEnv} and implementations reject it
+   * here. Set by in-process plugins (the hooks bridges set
+   * `CLAUDE_PROJECT_DIR`, `CLAUDE_PLUGIN_ROOT`, …); the model-facing bash tool
+   * does not expose it as a parameter.
    */
   env?: Record<string, string> | undefined
+  /**
+   * Harness-owned `DSH_*` variables for this execution. Executors discard
+   * ambient `DSH_*` entries before merging this snapshot, so an unavailable
+   * current fact cannot inherit a stale value from the harness process.
+   */
+  dshEnv?: DshEnvironment | undefined
   /**
    * Opaque OWNER token for a background task — the consumer's isolation key
    * (the tool layer passes the owning agent's `session.header.id`). The
@@ -163,13 +170,14 @@ export interface BashExecSpec {
    */
   stdin?: string | undefined
   /**
-   * Extra environment entries, carried through verbatim from
-   * {@link BashExecRequest.env} and merged by the implementation AFTER its
-   * credential scrub (an explicit entry wins even when its name matches the
-   * scrub pattern). OPTIONAL on the spec for the same reason as `stdin` — no
-   * config default, absent means "no extra env".
+   * Ordinary environment entries carried through from
+   * {@link BashExecRequest.env}. `DSH_*` remains reserved for {@link dshEnv}.
+   * OPTIONAL on the spec for the same reason as `stdin`: absent means no
+   * ordinary extra environment.
    */
   env?: Record<string, string> | undefined
+  /** Trusted `DSH_*` snapshot carried through from {@link BashExecRequest.dshEnv}. */
+  dshEnv?: DshEnvironment | undefined
   /**
    * Opaque owner token, REQUIRED-but-nullable (mirrors `workdir`/`timeoutMs`
    * being required on the resolved spec): {@link BashExecutor.resolve} carries