fix(sandbox): resolve workspace roots per session

packages/bash/tool-bash/src/index.ts

@@ -18,9 +18,9 @@ import type {} from '@deepseek-ai/dsh-session-persistence'
 import type {} from '@deepseek-ai/dsh-system-prompt'
 import type {} from '@deepseek-ai/dsh-tasks'
 import type {} from '@deepseek-ai/dsh-user-approval'
-import type { SandboxMode } from '@deepseek-ai/dsh-sandbox'
+import type { SandboxExecutionPolicy, SandboxMode } from '@deepseek-ai/dsh-sandbox'
 import { ESCALATION_TARGETS, approveEscalation, validateEscalationArgs } from '@deepseek-ai/dsh-sandbox'
-import { effectiveSandboxMode } from '@deepseek-ai/dsh-sandbox-policy'
+import type { SandboxPolicyService } from '@deepseek-ai/dsh-sandbox-policy'
 import { DSH_ENV_PREFIX } from '@deepseek-ai/dsh-bash'
 import type { DshEnvironment, DshEnvironmentKey } from '@deepseek-ai/dsh-bash'
 import { DSH_HOME_ENV, resolveDshHome } from '@deepseek-ai/dsh-home'
@@ -330,9 +330,14 @@ export function apply(ctx: Context, config: Config = {}): void {
   const backgroundEnabled = config.enableRunInBackground ?? true
   const defaultMode = ctx.bash.sandboxMode
   const escalationModes: readonly SandboxMode[] = defaultMode === undefined ? [] : ESCALATION_TARGETS
+  const sandboxPolicy: SandboxPolicyService | undefined = defaultMode === undefined ? undefined : ctx.get('sandboxPolicy')
+  if (defaultMode !== undefined && sandboxPolicy === undefined) {
+    throw new Error('tool-bash: the mounted bash executor confines but ctx.sandboxPolicy is missing')
+  }
 
-  const sessionOverride = (exec: ToolExecution): SandboxMode | undefined =>
-    defaultMode === undefined || exec.agent === undefined ? undefined : effectiveSandboxMode(exec.agent.session.events)
+  /** Resolve the complete standing policy for this call when a confining executor is mounted. */
+  const resolveSandboxPolicy = (exec: ToolExecution): SandboxExecutionPolicy | undefined =>
+    sandboxPolicy?.resolve(exec.agent === undefined ? {} : { session: exec.agent.session })
 
   /**
    * Resolve a sandbox-escalation request through `ctx.approval` BEFORE
@@ -342,14 +347,19 @@ export function apply(ctx: Context, config: Config = {}): void {
    * guard (the fields are unadvertised without a sandboxing executor, yet
    * schema validation checks advertised keys only, so an unadvertised
    * `sandbox_permissions` still reaches execute) and the approval ingredients
-   * — the seam is consumed opportunistically (`ctx.get`) so a deployment
-   * without it degrades per call.
+   * The shared policy resolver is required whenever the executor advertises
+   * confinement, so a split composition fails at tool-plugin load.
    */
-  const approveBashEscalation = (mode: string, justification: string, exec: ToolExecution): Promise<SandboxMode> => {
+  const approveBashEscalation = (
+    mode: string,
+    justification: string,
+    exec: ToolExecution,
+    standingPolicy: SandboxExecutionPolicy | undefined,
+  ): Promise<SandboxMode> => {
     if (escalationModes.length === 0) {
       throw new Error('sandbox_permissions is not available in this composition (no sandboxing executor to escalate)')
     }
-    const effectiveMode = (sessionOverride(exec) ?? defaultMode) as SandboxMode
+    const effectiveMode = (standingPolicy as SandboxExecutionPolicy).mode
     return approveEscalation(
       { requestedMode: mode, justification, effectiveMode, subject: 'command' },
       {
@@ -401,9 +411,13 @@ export function apply(ctx: Context, config: Config = {}): void {
     async execute(args: BashToolArgs, exec) {
       validateBashArgs(args)
       // Description is display metadata; workdir defaults to the caller's session.
-      const sandboxMode = args.sandbox_permissions !== undefined && args.justification !== undefined
-        ? await approveBashEscalation(args.sandbox_permissions, args.justification, exec)
-        : sessionOverride(exec)
+      const standingPolicy = resolveSandboxPolicy(exec)
+      const approvedMode = args.sandbox_permissions !== undefined && args.justification !== undefined
+        ? await approveBashEscalation(args.sandbox_permissions, args.justification, exec, standingPolicy)
+        : undefined
+      const policy = approvedMode === undefined
+        ? standingPolicy
+        : { ...(standingPolicy as SandboxExecutionPolicy), mode: approvedMode }
       const workdir = resolveWorkdir(args.workdir, exec)
       const dshEnv = bashEnv.collect(exec)
       const request = {
@@ -411,7 +425,7 @@ export function apply(ctx: Context, config: Config = {}): void {
         ...workdir !== undefined ? { workdir } : {},
         ...args.timeoutMs !== undefined ? { timeoutMs: args.timeoutMs } : {},
         dshEnv,
-        ...sandboxMode !== undefined ? { sandboxMode } : {},
+        ...policy !== undefined ? { sandboxPolicy: policy } : {},
       }
       if (args.run_in_background === true) {
         // Undeclared keys are allowed, so schema omission also needs enforcement.

packages/bash/tool-bash/tests/tools.spec.ts

@@ -17,6 +17,7 @@ import * as ToolTasks from '@deepseek-ai/dsh-tool-tasks'
 import ApprovalService from '@deepseek-ai/dsh-user-approval'
 import type { ApprovalOutcome } from '@deepseek-ai/dsh-user-approval'
 import { LocalBashExecutor } from '@deepseek-ai/dsh-bash-local'
+import SandboxPolicyService from '@deepseek-ai/dsh-sandbox-policy'
 import * as ToolBash from '@deepseek-ai/dsh-tool-bash'
 import { processOutcome } from '../src/background.ts'
 import { renderProcessRead, renderResult } from '../src/render.ts'
@@ -105,12 +106,12 @@ class RecordingSandboxExecutor extends BashExecutor {
       stdoutMaxBytes: request.stdoutMaxBytes ?? 64_000,
       timeoutMs: request.timeoutMs ?? 1000,
       ...request.signal ? { signal: request.signal } : {},
-      sandboxMode: request.sandboxMode ?? 'read-only',
+      sandboxPolicy: request.sandboxPolicy ?? { mode: 'read-only', workspaceRoot: process.cwd() },
     }
   }
 
   run(spec: BashExecSpec): Promise<BashRunResult> {
-    this.modes.push(spec.sandboxMode)
+    this.modes.push(spec.sandboxPolicy?.mode)
     return Promise.resolve({
       exitCode: 0,
       signal: null,
@@ -119,18 +120,18 @@ class RecordingSandboxExecutor extends BashExecutor {
       timeoutMs: spec.timeoutMs,
       stdout: { text: 'ok', truncated: false },
       stderr: { text: '', truncated: false },
-      sandbox: { mode: spec.sandboxMode ?? 'read-only', denied: false },
+      sandbox: { mode: spec.sandboxPolicy?.mode ?? 'read-only', denied: false },
     })
   }
 
   start(spec: BashExecSpec): BashProcess {
-    this.modes.push(spec.sandboxMode)
+    this.modes.push(spec.sandboxPolicy?.mode)
     return {
       status: 'completed',
       exitCode: 0,
       signal: null,
       done: Promise.resolve(),
-      sandbox: { mode: spec.sandboxMode ?? 'read-only', denied: false },
+      sandbox: { mode: spec.sandboxPolicy?.mode ?? 'read-only', denied: false },
       readOutput: () => ({ delta: '', lossy: false }),
       kill: () => false,
     }
@@ -147,7 +148,7 @@ class CountingStartExecutor extends BashExecutor {
       workdir: request.workdir ?? '/x',
       timeoutMs: request.timeoutMs ?? 0,
       stdoutMaxBytes: request.stdoutMaxBytes ?? 64_000,
-      sandboxMode: request.sandboxMode,
+      sandboxPolicy: request.sandboxPolicy,
     }
   }
 
@@ -173,6 +174,7 @@ async function setupSandboxed(withApproval = false) {
   await ctx.plugin(AgentRegistry)
   await ctx.plugin(TaskService)
   await ctx.plugin(ToolTasks)
+  await ctx.plugin(SandboxPolicyService, {})
   await ctx.plugin(RecordingSandboxExecutor)
   if (withApproval) await ctx.plugin(ApprovalService)
   await ctx.plugin(ToolBash)
@@ -524,6 +526,14 @@ describe('sandbox escalation through the generic task producer', () => {
     justification: 'the command needs workspace writes',
   }
 
+  it('fails load when a confining executor has no shared sandbox-policy resolver', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SystemPrompt)
+    await ctx.plugin(ToolRegistry)
+    await ctx.plugin(RecordingSandboxExecutor)
+    await expect(ctx.plugin(ToolBash)).rejects.toThrow('tool-bash: the mounted bash executor confines but ctx.sandboxPolicy is missing')
+  })
+
   it('advertises the sandbox fields and validates their pairing', async () => {
     const { ctx } = await setupSandboxed()
     const schema = ctx.tools.schemas().find(item => item.name === 'bash')!
@@ -962,7 +972,7 @@ describe('the model-facing bash tool builds its request from named args only (no
         ...request.stdin !== undefined ? { stdin: request.stdin } : {},
         ...request.env !== undefined ? { env: request.env } : {},
         ...request.dshEnv !== undefined ? { dshEnv: request.dshEnv } : {},
-        sandboxMode: request.sandboxMode,
+        sandboxPolicy: request.sandboxPolicy,
       }
     }
     run(): Promise<BashRunResult> {