Merge remote-tracking branch 'origin/master' into worktree/web-multimodal-image-input

2026-07-30 15:57:36 +08:00
parent fc8e059a2f 09c217eba7
commit 981ef5bfa0
84 changed files with 4353 additions and 442 deletions
--- a/packages/client/ui-trajectory/src/client/TrajectoryTable.module.css
+++ b/packages/client/ui-trajectory/src/client/TrajectoryTable.module.css
@@ -103,6 +103,11 @@
  border-bottom: 0;
 }

+.table tbody tr[data-request-only='true']:last-child td {
+  /* Retain the lower half of the 16px boundary marker at the table's end. */
+  height: 9px;
+}
+
 .table tbody tr[data-request-only='true'] .turnRail {
  top: -15px;
  bottom: 0;
--- a/packages/client/ui-trajectory/src/client/TrajectoryTimeline.module.css
+++ b/packages/client/ui-trajectory/src/client/TrajectoryTimeline.module.css
@@ -1,4 +1,7 @@
 .root {
+  position: relative;
+  z-index: 0;
+  isolation: isolate;
  flex: none;
  border-bottom: 1px solid var(--dsw-alias-border-l2);
  user-select: none;
--- a/packages/client/ui-trajectory/src/client/views.module.css
+++ b/packages/client/ui-trajectory/src/client/views.module.css
@@ -13,11 +13,17 @@
  background: var(--dsw-alias-bg-layer-1);
 }

-/* Under the active conversation column (`[data-conversation-scroll]`) the
- * parent owns overflow so the sticky composer stays in the same scrollport. */
-:global([data-conversation-scroll]) .root {
-  overflow: visible;
-  height: auto;
+/* Trajectory keeps the ledger and details panel inside the remaining
+ * conversation height. Only the ledger pane scrolls; the composer remains
+ * the fixed flex sibling below this view. */
+:global([data-conversation-scroll]):has(.root) {
+  overflow: hidden;
+}
+
+:global([data-conversation-scroll]):has(.root) > :first-child {
+  flex: 1 1 0;
+  min-height: 0;
+  overflow: hidden;
 }

 .ledger {
--- a/packages/core/system-prompt/README.i18n.yaml
+++ b/packages/core/system-prompt/README.i18n.yaml
@@ -2,5 +2,5 @@
 # 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 packages/core/system-prompt/README.md
-README.md: 79badba0b84b27c01f25e9c31b5df78c556411ea
-README.zh.md: fb3ed08bc9ea546033acac3b577980f500ce243d
+README.md: 23bc0e8177ad2a778df9522e254bfd5e03a9871f
+README.zh.md: 1fd4febc1c15acda19e7abfca94079b9585c1972
--- a/packages/core/system-prompt/README.md
+++ b/packages/core/system-prompt/README.md
@@ -8,6 +8,7 @@ System prompt assembly registry. Plugins contribute ordered sections, tool schem

 | Key | Default | Meaning |
 |---|---|---|
+| `includeHarnessIdentity` | `true` | Include the fixed `You are an AI agent powered by the DeepSeek Harness SDK.` order-−100 opener. Set false only when a compatibility deployment owns the complete system prompt. |
 | `persona` | `''` | The global deployment-persona default: the ONE config-authored prompt fragment, rendered as the order-0 `deployment:persona` section unless an agent-scoped contribution shadows it. A template — complete `{{…}}` groups are interpreted strictly against the registered variables (the shipped loop registers `{{model}}`/`{{cwd}}`), with no escape syntax for literal braces yet. Empty ⇒ the section is dropped at render. |
 | `toolOrder` | — | Explicit model-facing tool order, as a list of `ToolSchema.name`s with one `'<unlisted-tools>'` rest entry (`TOOL_ORDER_REST`): listed tools take their listed position, unlisted tools land at the rest entry in lexicographic name order. Absent ⇒ plain lexicographic name order. Applied to the collected tools BEFORE the `system-prompt/assemble` waterfall — like the sections' `order` sort, it canonicalizes what the registry contributed (registration order is a plugin-load artifact), and a waterfall listener that mutates the list owns the determinism of what it emits. Misconfiguration fails loud: a list without exactly one rest entry, or with duplicates, throws at load; a listed name with no registered tool rejects every `assemble()`; a tool provider returning the reserved rest-entry name also rejects. Under the shipped loop the turn fails before any model request. Why a central list and not per-plugin weights: [Explicit model-facing tool order](../../../.agents/notes/implemented/feature/2026-07-06-explicit-tool-order.md). |

@@ -48,7 +49,7 @@ Design rationale: [the prompt-variables Agent Note](../../../.agents/notes/imple

 #### What the model sees

-Every assembly starts with the harness identity below, then the configured persona and ordered plugin sections after strict variable interpolation. Empty sections disappear; scoped sections and variables can shadow globals for one agent. The final `system-prompt/assemble` waterfall result is authoritative, so an expert listener's changes determine the delivered prompt and tool schemas.
+By default every assembly starts with the harness identity below, then the configured persona and ordered plugin sections after strict variable interpolation. `includeHarnessIdentity: false` omits only that fixed opener for a deployment that owns the complete compatibility persona. Empty sections disappear; scoped sections and variables can shadow globals for one agent. The final `system-prompt/assemble` waterfall result is authoritative, so an expert listener's changes determine the delivered prompt and tool schemas.

 ##### Harness identity

@@ -58,7 +59,7 @@ You are an AI agent powered by the DeepSeek Harness SDK.

 #### Token effect

-Identity is a fixed per-request cost. Persona and plugin text are repeated per request and scale with their rendered content.
+Identity is a fixed per-request cost when enabled. Persona and plugin text are repeated per request and scale with their rendered content.

 #### KV Cache effect

--- a/packages/core/system-prompt/README.zh.md
+++ b/packages/core/system-prompt/README.zh.md
@@ -8,6 +8,7 @@

 | 键 | 默认值 | 含义 |
 |---|---|---|
+| `includeHarnessIdentity` | `true` | 是否包含固定的 `You are an AI agent powered by the DeepSeek Harness SDK.`、顺序为 −100 的开场白。仅当兼容部署拥有完整系统提示词时设为 false。 |
 | `persona` | `''` | 全局部署 persona 默认值：唯一由配置创作的提示词片段，渲染为顺序为 0 的 `deployment:persona` 段，除非 agent 作用域的贡献将其遮蔽。它是模板，完整的 `{{…}}` 组会严格按已注册变量解释（随附循环注册 `{{model}}`/`{{cwd}}`），目前没有表达字面量花括号的转义语法。为空 ⇒ 渲染时删除该段。 |
 | `toolOrder` | 无 | 显式的面向模型工具顺序：一个 `ToolSchema.name` 列表，包含一个 `'<unlisted-tools>'` 其余项（`TOOL_ORDER_REST`）。已列工具占据列出的位置；未列工具按名称字典序落在其余项位置。缺席 ⇒ 直接按名称字典序排列。在 `system-prompt/assemble` waterfall（瀑布式事件）之前应用于已收集工具；与段的 `order` 排序一样，它会规范化注册表贡献的内容（注册顺序是插件加载产物），而修改列表的 waterfall 监听器拥有其输出的确定性。配置错误会明确失败：列表没有恰好一个其余项或存在重复项，会在加载时抛出；已列名称没有对应已注册工具，会使每次 `assemble()` 被拒绝；工具提供方返回保留的其余项名称也会被拒绝。在随附循环下，轮次会在任何模型请求前失败。为何采用中心列表而非每插件权重，见[显式面向模型工具顺序](../../../.agents/notes/implemented/feature/2026-07-06-explicit-tool-order.md)。 |

@@ -48,7 +49,7 @@

 #### 模型看到的内容

-每次组装都从下方 harness 身份开始，然后在严格变量插值后追加已配置 persona 与有序插件段。空段会消失；带作用域的段和变量可以为一个 agent 遮蔽全局项。最终 `system-prompt/assemble` waterfall 结果是权威来源，因此专家监听器的变更决定交付的提示词与工具 schema。
+默认情况下，每次组装都从下方 harness 身份开始，然后在严格变量插值后追加已配置 persona 与有序插件段。`includeHarnessIdentity: false` 仅为拥有完整兼容 persona 的部署省略这个固定开场白。空段会消失；带作用域的段和变量可以为一个 agent 遮蔽全局项。最终 `system-prompt/assemble` waterfall 结果是权威来源，因此专家监听器的变更决定交付的提示词与工具 schema。

 ##### Harness 身份

@@ -58,7 +59,7 @@ You are an AI agent powered by the DeepSeek Harness SDK.

 #### Token 影响

-身份是每次请求的固定成本。Persona 与插件文本在每次请求中重复，成本随渲染内容增长。
+启用时，身份是每次请求的固定成本。Persona 与插件文本在每次请求中重复，成本随渲染内容增长。

 #### KV Cache 影响

--- a/packages/core/system-prompt/src/index.ts
+++ b/packages/core/system-prompt/src/index.ts
@@ -145,6 +145,8 @@ function compareToolNames(a: ToolSchema, b: ToolSchema): number {

 /** Plugin config: the deployment-authored fragment of the system prompt (see {@link Config.persona} for its contract). */
 export interface Config {
+  /** Include the fixed DeepSeek Harness identity before the deployment persona (default true). */
+  includeHarnessIdentity?: boolean
  /**
   * Deployment-wide order-0 persona template. A scoped section named
   * `deployment:persona` shadows it; `{{variable}}` references are strict.
@@ -245,6 +247,7 @@ class PromptLayer implements ScopeLayer {
 /** Registry service for the prompt inputs assembled before each model step. */
 export class SystemPrompt extends Service {
  static Config: z<Config> = z.object({
+    includeHarnessIdentity: z.boolean().default(true),
    persona: z.string().default(''),
    // Preserve omission because an explicit empty order lacks the rest marker.
    toolOrder: z.array(z.string()).default(undefined as unknown as string[]),
@@ -260,11 +263,13 @@ export class SystemPrompt extends Service {
    super(ctx, 'systemPrompt')
    this.toolOrder = validateToolOrder(config.toolOrder)
    // Keep harness-owned openers independent of the selected loop plugin.
-    this.section({
-      name: 'harness:identity',
-      order: -100,
-      text: 'You are an AI agent powered by the DeepSeek Harness SDK.',
-    })
+    if (config.includeHarnessIdentity ?? true) {
+      this.section({
+        name: 'harness:identity',
+        order: -100,
+        text: 'You are an AI agent powered by the DeepSeek Harness SDK.',
+      })
+    }
    this.section({
      name: 'deployment:persona',
      order: 0,
--- a/packages/core/system-prompt/tests/system-prompt.spec.ts
+++ b/packages/core/system-prompt/tests/system-prompt.spec.ts
@@ -37,6 +37,18 @@ describe('SystemPrompt', () => {
      expect(renderPrompt(await ctx.systemPrompt.assemble())).toBe(IDENTITY)
    })

+    it('can omit the harness identity for a deployment that owns the complete persona', async () => {
+      const ctx = new Context()
+      await ctx.plugin(SystemPrompt, {
+        includeHarnessIdentity: false,
+        persona: 'You are a helpful software engineer assistant.',
+      })
+
+      const assembly = await ctx.systemPrompt.assemble()
+      expect(assembly.sections.map(section => section.name)).toEqual(['deployment:persona'])
+      expect(renderPrompt(assembly)).toBe('You are a helpful software engineer assistant.')
+    })
+
    it('tolerates a schema-bypassing direct construction (persona omitted)', async () => {
      // ctx.plugin validates + defaults the config first; a direct construction
      // skips the schema, so the ctor's `?? ''` narrowing is what fires.
--- a/packages/core/tools/tests/gen-tool-catalog.spec.ts
+++ b/packages/core/tools/tests/gen-tool-catalog.spec.ts
@@ -23,7 +23,7 @@ describe('gen-tool-catalog collectToolCatalog', () => {
  it('boots every shipped tool package and harvests its model-facing schemas', async () => {
    const catalog = await collectToolCatalog()
    const names = catalog.flatMap(entry => entry.schemas.map(s => s.name)).sort()
-    expect(names).toEqual(['ask_user_question', 'bash', 'cordis_inspect', 'cordis_mount', 'cordis_unmount', 'create_goal', 'edit', 'exit_plan_mode', 'get_goal', 'glob', 'grep', 'lsp', 'ralph', 'read', 'run_code', 'session_event_read', 'session_event_search', 'session_event_trace', 'session_search', 'session_trace', 'skill', 'subagent', 'task_kill', 'task_list', 'task_output', 'terminal_close', 'terminal_list', 'terminal_open', 'terminal_read', 'terminal_send', 'terminal_signal', 'todo_write', 'update_goal', 'web_fetch', 'web_search', 'workflow', 'write'])
+    expect(names).toEqual(['ask_user_question', 'bash', 'bash', 'cordis_inspect', 'cordis_mount', 'cordis_unmount', 'create_goal', 'edit', 'exit_plan_mode', 'get_goal', 'glob', 'grep', 'lsp', 'ralph', 'read', 'run_code', 'session_event_read', 'session_event_search', 'session_event_trace', 'session_search', 'session_trace', 'skill', 'str_replace_editor', 'subagent', 'task_kill', 'task_list', 'task_output', 'terminal_close', 'terminal_list', 'terminal_open', 'terminal_read', 'terminal_send', 'terminal_signal', 'todo_write', 'update_goal', 'web_fetch', 'web_search', 'workflow', 'write'])
    // Every tool carries a JSON-Schema `parameters` object (what the model sees).
    for (const entry of catalog) {
      for (const schema of entry.schemas) {
--- a/packages/examples/agent-spine-demo/README.i18n.yaml
+++ b/packages/examples/agent-spine-demo/README.i18n.yaml
@@ -2,5 +2,5 @@
 # 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 packages/examples/agent-spine-demo/README.md
-README.md: 359e7153be2f480ba3fea4b06782acdc9f89ebb9
-README.zh.md: acd8c06940b03e90e368314cd725846a2b92b656
+README.md: 6bbd99217bcdce0e8a0e8fd22a8d39d0c64224b9
+README.zh.md: 4a7e7a1b7eced9317f94eeddf2442ded9a3e0e13
--- a/packages/examples/agent-spine-demo/README.md
+++ b/packages/examples/agent-spine-demo/README.md
@@ -31,7 +31,7 @@ Read this package for the whole plugin tree and its composition order.
@deepseek-ai/dsh-scope/invariant
@deepseek-ai/dsh-agent-loop/invariant
                                  package-owned relational checks
-@deepseek-ai/dsh-tool-bash        the model-facing bash schema
+@deepseek-ai/dsh-tool-bash        the model-facing bash schema (unless toolBash=false)
@deepseek-ai/dsh-workspace-context  AGENTS.md/CLAUDE.md workspace context loader
@deepseek-ai/dsh-tool-skill       session-prefix skill catalog + model-facing loader schema
@deepseek-ai/dsh-tool-tasks       task_output/task_list/task_kill schemas + completion notices
@@ -55,11 +55,11 @@ This is the [interface/implementation/consumer seam](../../../.agents/notes/impl

 ```ts
 import type { Config } from '@deepseek-ai/dsh-agent-spine-demo'
-// { agents?, maxParallelToolCalls?, persona?, toolOrder?, tools?, dshHome?, sessionTitle?, skills?, workspaceContext, toolBash?, toolTasks?, goals?, invariants? }
+// { agents?, maxParallelToolCalls?, includeHarnessIdentity?, persona?, toolOrder?, tools?, dshHome?, sessionTitle?, skills?, workspaceContext, toolBash?, toolTasks?, goals?, invariants? }
 // workspaceContext requires { maxBytes } or false; the other owner schemas supply defaults.
 ```

-The bundle FORWARDS each field to the child that owns it: `agents` and `maxParallelToolCalls` to `agent-loop` (`agents` defaults to `[]`; the cap defaults there), so each app supplies its own pre-created agents — TUI and headless apps pre-create `main`, while the ACP app creates agents on demand at `session/new`; `persona` and `toolOrder` to `dsh-system-prompt`; `tools` to the tool registry for its presentation mode; `sessionTitle` to the fallback title service; `skills.registry`, `skills.local`, and `skills.tool` to the skill registry, local provider, and model-facing consumer; the required `workspaceContext` choice to `dsh-workspace-context` (`{ maxBytes }` enables loading and `false` disables it); `invariants` to the invariant service; and `toolBash`/`toolTasks` to the two model-facing tool plugins the bundle owns. It always mounts `dsh-llm-retry`, while each leaf adapter owns its nested `retryPolicy`. Omitted `sessionTitle` uses the explicit example policy of 5 words, 40 fallback bytes, and 80 accepted-title bytes. A `goals` object opts into the persisted domain, model tools, and same-session driver while forwarding `goals.domain` and `goals.tool` to their owners; omission or `false` leaves the stack absent so headless callers retain one-turn settlement. Set `skills.enabled: false` to omit both the local provider and model-facing skill tool, and set `toolTasks: false` to retain the task service for foreground producers without exposing `task_output` / `task_list` / `task_kill`. It resolves `dshHome` once through [`@deepseek-ai/dsh-paths`](../../util/paths/README.md) and forwards that absolute value to tool-bash's managed environment and enabled local skill discovery. An absent top-level `dshHome` adopts `skills.local.dshHome`; supplying both with different resolved paths fails loudly. `toolBash.enableRunInBackground` controls only the bash producer; independently loaded producers keep their own config. Workspace instructions register before the skill catalog so their session-prefix message renders first. App packages use `pickSpineConfig()` to copy only these bundle-owned fields.
+The bundle FORWARDS each field to the child that owns it: `agents` and `maxParallelToolCalls` to `agent-loop` (`agents` defaults to `[]`; the cap defaults there), so each app supplies its own pre-created agents — TUI and headless apps pre-create `main`, while the ACP app creates agents on demand at `session/new`; `includeHarnessIdentity`, `persona`, and `toolOrder` to `dsh-system-prompt`; `tools` to the tool registry for its presentation mode; `sessionTitle` to the fallback title service; `skills.registry`, `skills.local`, and `skills.tool` to the skill registry, local provider, and model-facing consumer; the required `workspaceContext` choice to `dsh-workspace-context` (`{ maxBytes }` enables loading and `false` disables it); `invariants` to the invariant service; and `toolBash`/`toolTasks` to the two model-facing tool plugins the bundle owns. It always mounts `dsh-llm-retry`, while each leaf adapter owns its nested `retryPolicy`. Omitted `sessionTitle` uses the explicit example policy of 5 words, 40 fallback bytes, and 80 accepted-title bytes. A `goals` object opts into the persisted domain, model tools, and same-session driver while forwarding `goals.domain` and `goals.tool` to their owners; omission or `false` leaves the stack absent so headless callers retain one-turn settlement. Set `skills.enabled: false` to omit both the local provider and model-facing skill tool, set `toolBash: false` when another plugin owns the `bash` tool name, and set `toolTasks: false` to retain the task service for foreground producers without exposing `task_output` / `task_list` / `task_kill`. It resolves `dshHome` once through [`@deepseek-ai/dsh-paths`](../../util/paths/README.md) and forwards that absolute value to tool-bash's managed environment and enabled local skill discovery. An absent top-level `dshHome` adopts `skills.local.dshHome`; supplying both with different resolved paths fails loudly. `toolBash.enableRunInBackground` controls only the bundled bash producer; independently loaded producers keep their own config. Workspace instructions register before the skill catalog so their session-prefix message renders first. App packages use `pickSpineConfig()` to copy only these bundle-owned fields.

 For example, `{ invariants: { enabled: true, package_allowlist: ['^@deepseek-ai/dsh-'], package_blocklist: ['agent-loop$'] } }` keeps the package-owned companions mounted but suppresses the blocked owner. Blocklist matches override allowlist matches; see [`dsh-invariants`](../../support/invariants/README.md) for regex and lifecycle rules.

@@ -79,5 +79,5 @@ No direct invalidation; the named consumer owns any request-prefix changes.

 ## Known Limitations and Deferred Work

- **Most of the spine set is fixed in code** — `apply()` always mounts the core services and `tool-bash`; config can omit bundled goals, skills, and task-control tools, but swapping the loop or dropping another spine member means composing a different bundle.
+- **Most of the spine set is fixed in code** — `apply()` always mounts the core services; config can omit bundled goals, skills, bash, and task-control tools, but swapping the loop or dropping another spine member means composing a different bundle.
 - **The invariant seam and companions remain fixed members** — `invariants.enabled: false` or package filters suppress checks but do not remove the service or companion registrations; Session's always-on validation and freezing are separate.
--- a/packages/examples/agent-spine-demo/README.zh.md
+++ b/packages/examples/agent-spine-demo/README.zh.md
@@ -31,7 +31,7 @@
@deepseek-ai/dsh-scope/invariant
@deepseek-ai/dsh-agent-loop/invariant
                                  package-owned relational checks
-@deepseek-ai/dsh-tool-bash        the model-facing bash schema
+@deepseek-ai/dsh-tool-bash        the model-facing bash schema (unless toolBash=false)
@deepseek-ai/dsh-workspace-context  AGENTS.md/CLAUDE.md workspace context loader
@deepseek-ai/dsh-tool-skill       session-prefix skill catalog + model-facing loader schema
@deepseek-ai/dsh-tool-tasks       task_output/task_list/task_kill schemas + completion notices
@@ -55,11 +55,11 @@

 ```ts
 import type { Config } from '@deepseek-ai/dsh-agent-spine-demo'
-// { agents?, maxParallelToolCalls?, persona?, toolOrder?, tools?, dshHome?, sessionTitle?, skills?, workspaceContext, toolBash?, toolTasks?, goals?, invariants? }
+// { agents?, maxParallelToolCalls?, includeHarnessIdentity?, persona?, toolOrder?, tools?, dshHome?, sessionTitle?, skills?, workspaceContext, toolBash?, toolTasks?, goals?, invariants? }
 // workspaceContext requires { maxBytes } or false; the other owner schemas supply defaults.
 ```

-组合包将每个字段转发给拥有它的子节点：`agents` 与 `maxParallelToolCalls` 交给 `agent-loop`（`agents` 默认为 `[]`，上限在该处默认），因此每个应用提供自己的预创建 agent；TUI 和无头应用预创建 `main`，ACP 应用则在 `session/new` 按需创建 agent；`persona` 与 `toolOrder` 交给 `dsh-system-prompt`；`tools` 交给工具注册表以配置呈现模式；`sessionTitle` 交给后备标题服务；`skills.registry`、`skills.local` 与 `skills.tool` 分别交给 skill 注册表、本地提供方和面向模型的消费方；必填的 `workspaceContext` 选择交给 `dsh-workspace-context`（`{ maxBytes }` 启用加载，`false` 禁用）；`invariants` 交给不变式服务；`toolBash`/`toolTasks` 交给组合包拥有的两个面向模型工具插件。组合包始终挂载 `dsh-llm-retry`，而每个叶节点适配器拥有自己的嵌套 `retryPolicy`。省略 `sessionTitle` 时采用显式示例策略：5 个词、40 个后备字节、80 个可接受标题字节。`goals` 对象会选用持久化领域、模型工具和同会话 Goal Round 驱动器，并将 `goals.domain` 与 `goals.tool` 转发给各自拥有者；省略或设为 `false` 会让整个栈缺席，使无头调用方继续以单轮次结算。设置 `skills.enabled: false` 会同时省略本地提供方和面向模型的 skill 工具；设置 `toolTasks: false` 会保留供前台生产方使用的任务服务，但不公开 `task_output`/`task_list`/`task_kill`。它对 `dshHome` 只解析一次，解析通过 [`@deepseek-ai/dsh-paths`](../../util/paths/README.md) 完成，并将所得绝对值转发给 tool-bash 的托管环境和已启用的本地 skill 发现。顶层 `dshHome` 缺席时采用 `skills.local.dshHome`；两者同时提供但解析后的路径不同会明确失败。`toolBash.enableRunInBackground` 只控制 bash 生产方；独立加载的生产方保留各自配置。工作区指令先于 skill 目录注册，因此其会话前缀消息先渲染。应用包使用 `pickSpineConfig()`，只复制这些由组合包拥有的字段。
+组合包将每个字段转发给拥有它的子节点：`agents` 与 `maxParallelToolCalls` 交给 `agent-loop`（`agents` 默认为 `[]`，上限在该处默认），因此每个应用提供自己的预创建 agent；TUI 和无头应用预创建 `main`，ACP 应用则在 `session/new` 按需创建 agent；`includeHarnessIdentity`、`persona` 与 `toolOrder` 交给 `dsh-system-prompt`；`tools` 交给工具注册表以配置呈现模式；`sessionTitle` 交给后备标题服务；`skills.registry`、`skills.local` 与 `skills.tool` 分别交给 skill 注册表、本地提供方和面向模型的消费方；必填的 `workspaceContext` 选择交给 `dsh-workspace-context`（`{ maxBytes }` 启用加载，`false` 禁用）；`invariants` 交给不变式服务；`toolBash`/`toolTasks` 交给组合包拥有的两个面向模型工具插件。组合包始终挂载 `dsh-llm-retry`，而每个叶节点适配器拥有自己的嵌套 `retryPolicy`。省略 `sessionTitle` 时采用显式示例策略：5 个词、40 个后备字节、80 个可接受标题字节。`goals` 对象会选用持久化领域、模型工具和同会话 Goal Round 驱动器，并将 `goals.domain` 与 `goals.tool` 转发给各自拥有者；省略或设为 `false` 会让整个栈缺席，使无头调用方继续以单轮次结算。设置 `skills.enabled: false` 会同时省略本地提供方和面向模型的 skill 工具；当另一个插件拥有 `bash` 工具名时设置 `toolBash: false`；设置 `toolTasks: false` 会保留供前台生产方使用的任务服务，但不公开 `task_output`/`task_list`/`task_kill`。它对 `dshHome` 只解析一次，解析通过 [`@deepseek-ai/dsh-paths`](../../util/paths/README.md) 完成，并将所得绝对值转发给 tool-bash 的托管环境和已启用的本地 skill 发现。顶层 `dshHome` 缺席时采用 `skills.local.dshHome`；两者同时提供但解析后的路径不同会明确失败。`toolBash.enableRunInBackground` 只控制内置 bash 生产方；独立加载的生产方保留各自配置。工作区指令先于 skill 目录注册，因此其会话前缀消息先渲染。应用包使用 `pickSpineConfig()`，只复制这些由组合包拥有的字段。

 例如，`{ invariants: { enabled: true, package_allowlist: ['^@deepseek-ai/dsh-'], package_blocklist: ['agent-loop$'] } }` 会让包拥有的配套插件保持挂载，但抑制被阻止的拥有者。Blocklist 匹配优先于 allowlist 匹配；正则表达式与生命周期规则见 [`dsh-invariants`](../../support/invariants/README.md)。

@@ -79,5 +79,5 @@ YAML include 可以去重配置，却无法拥有 bin 或提供前端入口默

 ## 已知限制与暂缓事项

- **大部分主干集合固定在代码中**：`apply()` 始终挂载核心服务与 `tool-bash`；配置可以省略组合包内的目标、skill 与任务控制工具，但要替换循环或删除其他主干成员，就必须组合另一个组合包。
+- **大部分主干集合固定在代码中**：`apply()` 始终挂载核心服务；配置可以省略组合包内的目标、skill、bash 与任务控制工具，但要替换循环或删除其他主干成员，就必须组合另一个组合包。
 - **不变式 seam 与配套插件仍是固定成员**：`invariants.enabled: false` 或包筛选器会抑制检查，但不会移除服务或配套插件注册；Session 始终启用的校验与冻结是另一套机制。
--- a/packages/examples/agent-spine-demo/src/index.ts
+++ b/packages/examples/agent-spine-demo/src/index.ts
@@ -68,9 +68,9 @@ export interface GoalConfig {
 /**
 * Bundle config: each field forwarded verbatim to the child that owns it —
 * `agents` to the agent loop (an app that pre-creates no agents, like the ACP
- * bridge, simply omits it), `persona` and `toolOrder` to the system-prompt
- * plugin (the deployment's persona section and the explicit model-facing tool
- * order), the `tools` object to the tool registry (its presentation `mode`),
+ * bridge, simply omits it), `includeHarnessIdentity`, `persona`, and `toolOrder`
+ * to the system-prompt plugin (the fixed opener, deployment persona, and explicit
+ * model-facing tool order), the `tools` object to the tool registry (its presentation `mode`),
 * `dshHome` to bash environment and local skill discovery, `sessionTitle` to
 * the fallback title service, `skills` to the
 * skill registry/local provider/tool consumer, `workspaceContext` to the
@@ -83,13 +83,16 @@ export interface GoalConfig {
 * workspace context instead requires an explicit byte budget or `false` because
 * it changes model-visible input. Producer opt-in stays producer-local:
 * `toolBash` configures bash only; independently composed producers keep their
- * own config.
+ * own config. Set `toolBash: false` when another plugin owns the model-facing
+ * `bash` name.
 */
 export interface Config {
  /** The agent-loop `agents` list (see dsh-agent-loop's `Config`). */
  agents?: AgentLoopConfig['agents']
  /** Agent-loop concurrency cap; `1` is serial. */
  maxParallelToolCalls?: AgentLoopConfig['maxParallelToolCalls']
+  /** Whether the system prompt includes the fixed Harness identity (default true). */
+  includeHarnessIdentity?: SystemPromptConfig['includeHarnessIdentity']
  /** The deployment persona (see dsh-system-prompt's `Config`). */
  persona?: SystemPromptConfig['persona']
  /** The explicit model-facing tool order (see dsh-system-prompt's `Config`). */
@@ -102,10 +105,14 @@ export interface Config {
  sessionTitle?: SessionTitleConfig
  /** Workspace-context loader controls with an explicit byte budget; set `false` for hermetic prompts. */
  workspaceContext: workspaceContext.Config | false
-  /** Skill registry, local provider, and model-facing consumer config. */
+  /**
+   * Skill registry, local provider, and model-facing consumer config.
+   * Skills use `enabled` because one nested config controls a provider stack;
+   * single model-tool plugins use `Config | false` to disable that one consumer.
+   */
  skills?: SkillConfig
-  /** Model-facing bash tool config, including this producer's background opt-in. */
-  toolBash?: toolBash.Config
+  /** Model-facing bash tool config, or false when another plugin owns `bash`. */
+  toolBash?: toolBash.Config | false
  /** Generic background-task controls; set false to keep the task service without model-facing task tools. */
  toolTasks?: toolTasks.Config | false
  /** Global enablement and package-name filters for invariant companions. */
@@ -127,7 +134,8 @@ export const SessionTitleConfigSchema: z<SessionTitleConfig> = SessionTitleServi
  .default(EXAMPLE_SESSION_TITLE_CONFIG)

 /** The bash-tool config schema exported for app packages that forward `toolBash`. */
-export const ToolBashConfigSchema: z<toolBash.Config> = toolBash.Config
+export const ToolBashConfigSchema: z<toolBash.Config | false> =
+  z.union([z.const(false), toolBash.Config])

 /** The task-control-tool config schema exported for app packages that forward `toolTasks`. */
 export const ToolTasksConfigSchema: z<toolTasks.Config> = toolTasks.Config
@@ -163,6 +171,7 @@ export const Config = z.intersect([
 export function pickSpineConfig(config: Omit<Config, 'agents'>): Omit<Config, 'agents'> {
  return {
    ...config.maxParallelToolCalls !== undefined ? { maxParallelToolCalls: config.maxParallelToolCalls } : {},
+    ...config.includeHarnessIdentity !== undefined ? { includeHarnessIdentity: config.includeHarnessIdentity } : {},
    ...config.persona !== undefined ? { persona: config.persona } : {},
    ...config.toolOrder !== undefined ? { toolOrder: config.toolOrder } : {},
    ...config.tools !== undefined ? { tools: config.tools } : {},
@@ -201,6 +210,7 @@ export function apply(ctx: Context, config: Config): void {
  ctx.plugin(SessionTitleService, config.sessionTitle ?? EXAMPLE_SESSION_TITLE_CONFIG)
  // Owner schemas resolve defaults; forward toolOrder only when explicitly set.
  ctx.plugin(SystemPrompt, {
+    includeHarnessIdentity: config.includeHarnessIdentity ?? true,
    persona: config.persona ?? '',
    ...config.toolOrder !== undefined ? { toolOrder: config.toolOrder } : {},
  })
@@ -223,7 +233,9 @@ export function apply(ctx: Context, config: Config): void {
  ctx.plugin(agentInvariant)
  ctx.plugin(scopeInvariant)
  ctx.plugin(agentLoopInvariant)
-  ctx.plugin(toolBash, Object.assign({}, config.toolBash, { dshHome }))
+  if (config.toolBash !== false) {
+    ctx.plugin(toolBash, Object.assign({}, config.toolBash, { dshHome }))
+  }
  if (config.workspaceContext !== false) {
    ctx.plugin(workspaceContext, config.workspaceContext)
  }
--- a/packages/examples/agent-spine-demo/tests/agent-core.spec.ts
+++ b/packages/examples/agent-spine-demo/tests/agent-core.spec.ts
@@ -4,7 +4,7 @@ import { join } from 'node:path'
 import { tmpdir } from 'node:os'
 import { Context } from 'cordis'
 import Loader from '@cordisjs/plugin-loader'
-import { TOOL_ORDER_REST } from '@deepseek-ai/dsh-system-prompt'
+import { renderPrompt, TOOL_ORDER_REST } from '@deepseek-ai/dsh-system-prompt'
 import * as agentCore from '../src/index.ts'
 import { agentEvents, type Agent } from '@deepseek-ai/dsh-agent'
 import { SessionId } from '@deepseek-ai/dsh-session'
@@ -654,9 +654,27 @@ describe('dsh-agent-spine-demo bundle', () => {
    await ctx.fiber.dispose()
  })

+  it('can omit the bundled bash tool and Harness identity for a compatibility deployment', async () => {
+    const ctx = await mount({
+      includeHarnessIdentity: false,
+      persona: 'You are a helpful software engineer assistant.',
+      workspaceContext: false,
+      skills: { enabled: false },
+      toolBash: false,
+      toolTasks: false,
+    }, true)
+
+    expect(ctx.tools.schemas()).toEqual([])
+    expect(renderPrompt(await ctx.systemPrompt.assemble()))
+      .toBe('You are a helpful software engineer assistant.')
+
+    await ctx.fiber.dispose()
+  })
+
  it('picks shared spine config without leaking front-door fields', () => {
    const appConfig = {
      model: 'front-door-only',
+      includeHarnessIdentity: false,
      persona: 'You are merged.',
      toolOrder: ['zulu'],
      tools: { mode: 'native' as const },
@@ -670,6 +688,7 @@ describe('dsh-agent-spine-demo bundle', () => {
    }

    expect(agentCore.pickSpineConfig(appConfig)).toEqual({
+      includeHarnessIdentity: appConfig.includeHarnessIdentity,
      persona: appConfig.persona,
      toolOrder: appConfig.toolOrder,
      tools: appConfig.tools,
--- a/packages/fs/README.i18n.yaml
+++ b/packages/fs/README.i18n.yaml
@@ -2,5 +2,5 @@
 # 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 packages/fs/README.md
-README.md: 4d954455ea920be4882530bcfe90b48a364c29b5
-README.zh.md: ed154cbbaf7c7f45c42c17799957254fee918153
+README.md: b5e0ac9d1c0c550eb372b8a66fc6358711fddc07
+README.zh.md: ee64a617aa0d9549bcaf00b20821a6d59c6673c8
--- a/packages/fs/README.md
+++ b/packages/fs/README.md
@@ -12,6 +12,7 @@ The filesystem stack: a provider seam (text IO + atomic mutation with an optiona
 | `fs-policy/` | Policy gate plugin: observed-state + read-before-edit + version-guarded write/edit, via the `fs/*` event gate | (no service — `fs/*` listeners) |
 | `tool-fs/` | Model-facing `read`/`write`/`edit` tools AND the executor (reads via `ctx.fs`, owns read windowing, dispatches `fs/*`); preserves filesystem semantics for session-cwd-relative paths and advertises sandbox escalation fields when the mounted `ctx.fs` confines | (registers on `ctx.tools`) |
 | `tool-fs-search/` | Model-facing `glob`/`grep` discovery tools when `rg` is available on the bash executor `PATH`, backed by fixed ripgrep commands through `ctx.bash`, NOT by `ctx.fs` provider methods | (registers on `ctx.tools`) |
+| `tool-str-replace-editor/` | Model-facing `str_replace_editor` with view/create/unique literal replace/line insert operations over `ctx.fs` | (registers on `ctx.tools`) |

 The interface lives at `fs/fs/`. A sandboxed, remote, or project-scoped filesystem backend can replace `fs-local` without touching the seam, the policy gate, or the model-facing tool schemas — `fs-sandbox` is the first such replacement (an in-process path fence over the shared sandbox mode; see [the cross-family fs sandbox Agent Note](../../.agents/notes/implemented/feature/2026-07-14-cross-family-fs-sandbox.md)). The policy (`fs-policy/`) is a plugin that participates only through the `fs/*` event gate, not a service the tool injects — so dropping it gracefully loses the policy and leaves the unconstrained bare provider rather than breaking the tool. A deployment that loads `tool-fs/` is expected to also load it. The mode fence and the read-before-edit gate are orthogonal and compose. Discovery (`tool-fs-search/`) deliberately does NOT extend the provider seam: search is a process-backed `rg` workflow on the bash executor, so filesystem backends stay free of a universal search contract; its tools register only when that executor can find `rg`, and its results are follow-up-readable when the bash workdir and the `read` root are the same workspace (the co-located deployment its README documents).

--- a/packages/fs/README.zh.md
+++ b/packages/fs/README.zh.md
@@ -12,6 +12,7 @@
 | `fs-policy/` | 策略门禁插件：通过 `fs/*` 事件门禁提供已观察状态、编辑前读取和版本防护的写入/编辑 | （无服务，仅有 `fs/*` 监听器） |
 | `tool-fs/` | 面向模型的 `read`/`write`/`edit` 工具以及执行器（通过 `ctx.fs` 读取，拥有读取窗口逻辑，分派 `fs/*`）；为会话 cwd 相对路径保留文件系统语义，并在已挂载的 `ctx.fs` 实施约束时声明沙箱升权字段 | （注册到 `ctx.tools`） |
 | `tool-fs-search/` | 面向模型的 `glob`/`grep` 发现工具；当 `rg` 位于 bash 执行器 `PATH` 上时注册，通过 `ctx.bash` 运行固定 ripgrep 命令，而不是使用 `ctx.fs` 提供方方法 | （注册到 `ctx.tools`） |
+| `tool-str-replace-editor/` | 基于 `ctx.fs` 提供查看／创建／唯一字面量替换／按行插入的模型可见 `str_replace_editor` | （注册到 `ctx.tools`） |

 接口位于 `fs/fs/`。沙箱化、远程或限定项目作用域的文件系统后端可以替换 `fs-local`，而无需更改 seam、策略门禁或面向模型的工具 schema；`fs-sandbox` 是第一个这样的替代实现（基于共享沙箱模式的进程内路径围栏；见[跨能力族 fs 沙箱 Agent Note（agent 决策记录）](../../.agents/notes/implemented/feature/2026-07-14-cross-family-fs-sandbox.md)）。策略（`fs-policy/`）是一个只通过 `fs/*` 事件门禁参与的插件，不是工具注入的服务；因此移除它只会使策略失效，留下不受约束的裸提供方，而不会破坏工具。加载 `tool-fs/` 的部署也应加载该插件。模式围栏与编辑前读取门禁彼此正交，可以组合。发现（`tool-fs-search/`）有意不扩展提供方 seam：搜索是在 bash 执行器上运行 `rg`、基于进程的工作流，因此文件系统后端无需承担通用搜索契约；只有当执行器能找到 `rg` 时，其工具才会注册。如果 bash 工作目录与 `read` 根目录是同一工作区，其结果便可供后续读取，这也是其 README 所述的共置部署。

--- a/packages/fs/tool-str-replace-editor/README.i18n.yaml
+++ b/packages/fs/tool-str-replace-editor/README.i18n.yaml
@@ -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 packages/fs/tool-str-replace-editor/README.md
+README.md: 97e9e0ab9ade7c7241c1aac3e2489e055d01ff8f
+README.zh.md: 48358eb3c9d81ddad6a83c4ff3ef0cf6542096b1
--- a/packages/fs/tool-str-replace-editor/README.md
+++ b/packages/fs/tool-str-replace-editor/README.md
@@ -0,0 +1,52 @@
+# @deepseek-ai/dsh-tool-str-replace-editor
+
+English | [中文](README.zh.md)
+
+Standalone model-facing `str_replace_editor` over `ctx.fs`. It can be composed with persistent Bash, one-shot Bash, sandboxed Bash, or another terminal surface.
+
+## Config
+
+| Key | Default | Meaning |
+|---|---:|---|
+| `maxOutputChars` | `16000` | Prefix characters retained for file and directory views. |
+| `description` | Editor command guide | Model-facing tool description. |
+
+## Tool
+
+The schema provides `view`, `create`, `str_replace`, and `insert` over absolute paths. File views use one-based line numbers and preserve content tabs, so displayed text remains valid literal replacement input; directory views omit hidden, dependency, and Python-cache entries and descend two levels. Replacement requires one unique literal match and reports errors only in the public `old_str` vocabulary. Insert follows the selected zero-based insertion boundary without adding an implicit trailing newline. Mutations preserve tabs outside the requested edit.
+
+## Model Experience
+
+### Tool schema
+
+#### What the model sees
+
+The generated [`str_replace_editor` schema](../../../docs/tool-catalog.md#deepseek-aidsh-tool-str-replace-editor), including the configured `description`. The plugin contributes no standalone system-prompt section.
+
+#### Token effect
+
+Fixed schema cost while `str_replace_editor` is visible.
+
+#### KV Cache effect
+
+Prefix-stable while the configured description and schema remain unchanged.
+
+### Tool results
+
+#### What the model sees
+
+Views return numbered text or a shallow directory listing. Calls expose file locations, and create/replace calls expose diff cards to presentation surfaces. Mutations return concise confirmations. Long views keep their prefix and append a clipping notice.
+
+#### Token effect
+
+Data-dependent and bounded by `maxOutputChars` plus the fixed clipping notice.
+
+#### KV Cache effect
+
+Append-only tool results follow the reusable request prefix.
+
+## Known Limitations and Deferred Work
+
+- Operations target UTF-8 text; binary files are unsupported.
+- `str_replace` intentionally rejects zero or multiple matches and has no `replace_all` argument.
+- Every mutation goes through `fs/write-intent` or `fs/edit-intent`, resolves the current session sandbox policy, and delegates enforcement to the mounted filesystem and policy plugins.
--- a/packages/fs/tool-str-replace-editor/README.zh.md
+++ b/packages/fs/tool-str-replace-editor/README.zh.md
@@ -0,0 +1,52 @@
+# @deepseek-ai/dsh-tool-str-replace-editor
+
+[English](README.md) | 中文
+
+基于 `ctx.fs` 的独立模型可见 `str_replace_editor`。它可与持久 Bash、一次性 Bash、沙箱 Bash 或其他终端表面组合。
+
+## 配置
+
+| 键 | 默认值 | 含义 |
+|---|---:|---|
+| `maxOutputChars` | `16000` | 文件和目录查看结果保留的前缀字符数。 |
+| `description` | 编辑器命令指南 | 面向模型的工具描述。 |
+
+## 工具
+
+Schema 提供针对绝对路径的 `view`、`create`、`str_replace` 与 `insert`。文件查看使用从一开始的行号，并保留内容中的制表符，因此显示的文本仍可作为有效的字面量替换输入；目录查看忽略隐藏、依赖与 Python 缓存条目并下探两层。替换要求字面量唯一匹配，错误只使用公开的 `old_str` 词汇。插入遵循所选的零基插入边界，不会隐式补尾换行。修改操作会保留请求编辑范围之外的制表符。
+
+## 模型体验
+
+### 工具 schema
+
+#### 模型所见
+
+生成的 [`str_replace_editor` schema](../../../docs/tool-catalog.md#deepseek-aidsh-tool-str-replace-editor)，其中包含配置的 `description`。本插件不贡献独立系统提示词段。
+
+#### Token 影响
+
+`str_replace_editor` 可见时产生固定的 schema 成本。
+
+#### KV Cache 影响
+
+配置的描述与 schema 不变时前缀稳定。
+
+### 工具结果
+
+#### 模型所见
+
+查看操作返回带行号文本或浅层目录列表。调用会向展示层提供文件位置，创建/替换还会提供 diff 卡片。修改操作返回简洁确认。长查看结果保留前缀并追加截断提示。
+
+#### Token 影响
+
+随数据变化，并受 `maxOutputChars` 与固定截断提示约束。
+
+#### KV Cache 影响
+
+工具结果以追加方式位于可复用请求前缀之后。
+
+## 已知限制与延后工作
+
+- 操作面向 UTF-8 文本，不支持二进制文件。
+- `str_replace` 刻意拒绝零匹配或多匹配，且没有 `replace_all` 参数。
+- 每个修改操作都会经过 `fs/write-intent` 或 `fs/edit-intent`，解析当前 session 的沙箱策略，并交由挂载的文件系统与策略插件执行。
--- a/packages/fs/tool-str-replace-editor/package.json
+++ b/packages/fs/tool-str-replace-editor/package.json
@@ -0,0 +1,54 @@
+{
+  "name": "@deepseek-ai/dsh-tool-str-replace-editor",
+  "description": "Model-facing view, create, literal replace, and line insert tool over the Harness filesystem service",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-fs": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "@deepseek-ai/dsh-sandbox": "^0.0.1",
+    "@deepseek-ai/dsh-sandbox-policy": "^0.0.1",
+    "@deepseek-ai/dsh-tools": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "dependencies": {
+    "schemastery": "^3.18.0"
+  },
+  "devDependencies": {
+    "@deepseek-ai/dsh-agent": "workspace:^",
+    "@deepseek-ai/dsh-fs": "workspace:^",
+    "@deepseek-ai/dsh-fs-local": "workspace:^",
+    "@deepseek-ai/dsh-fs-policy": "workspace:^",
+    "@deepseek-ai/dsh-fs-sandbox": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-sandbox": "workspace:^",
+    "@deepseek-ai/dsh-sandbox-policy": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-system-prompt": "workspace:^",
+    "@deepseek-ai/dsh-tools": "workspace:^",
+    "cordis": "^4.0.0-rc.7"
+  }
+}
--- a/packages/fs/tool-str-replace-editor/src/index.ts
+++ b/packages/fs/tool-str-replace-editor/src/index.ts
@@ -0,0 +1,522 @@
+/**
+ * Model-facing `str_replace_editor` over the Harness filesystem seam.
+ * @module @deepseek-ai/dsh-tool-str-replace-editor
+ */
+
+import { isAbsolute } from 'node:path'
+import type { Context } from 'cordis'
+import z from 'schemastery'
+import { FsError } from '@deepseek-ai/dsh-fs'
+import type { FsInfo, FsTarget, FsWriteIntent } from '@deepseek-ai/dsh-fs'
+import { sandboxDenialMarker } from '@deepseek-ai/dsh-sandbox'
+import type { SandboxExecutionPolicy } from '@deepseek-ai/dsh-sandbox'
+import type { SandboxPolicyService } from '@deepseek-ai/dsh-sandbox-policy'
+import { defineTool } from '@deepseek-ai/dsh-tools'
+import type { ToolCallView, ToolRunContext } from '@deepseek-ai/dsh-tools'
+
+const TRUNCATED_MESSAGE = '<response clipped><NOTE>To save on context only part of this file has been shown to you. You should retry this tool after you have searched inside the file with `grep -n` in order to find the line numbers of what you are looking for.</NOTE>'
+
+const DEFAULT_DESCRIPTION = `
+Custom editing tool for viewing, creating and editing files
+* State is persistent across command calls and discussions with the user
+* If \`path\` is a file, \`view\` displays the result of applying \`cat -n\`. If \`path\` is a directory, \`view\` lists non-hidden files and directories up to 2 levels deep
+* The \`create\` command cannot be used if the specified \`path\` already exists as a file
+* If a \`command\` generates a long output, it will be truncated and marked with \`<response clipped>\`
+
+Notes for using the \`str_replace\` command:
+* The \`old_str\` parameter should match EXACTLY one or more consecutive lines from the original file. Be mindful of whitespaces!
+* If the \`old_str\` parameter is not unique in the file, the replacement will not be performed. Make sure to include enough context in \`old_str\` to make it unique
+* The \`new_str\` parameter should contain the edited lines that should replace the \`old_str\`
+`.trim()
+
+function maybeTruncate(content: string, maxOutputChars: number): string {
+  return content.length <= maxOutputChars
+    ? content
+    : content.slice(0, maxOutputChars) + TRUNCATED_MESSAGE
+}
+
+function codepointCompare(left: string, right: string): number {
+  return left < right ? -1 : left > right ? 1 : 0
+}
+
+function matchOffsets(content: string, search: string): number[] {
+  const offsets: number[] = []
+  let offset = 0
+  while (true) {
+    const match = content.indexOf(search, offset)
+    if (match < 0) return offsets
+    offsets.push(match)
+    offset = match + search.length
+  }
+}
+
+function lineNumbersAt(content: string, offsets: readonly number[]): number[] {
+  let line = 1
+  let cursor = 0
+  return offsets.map((offset) => {
+    while (cursor < offset) {
+      if (content[cursor] === '\n') line += 1
+      cursor += 1
+    }
+    return line
+  })
+}
+
+class MutationPolicy {
+  private readonly policy: SandboxPolicyService | undefined
+
+  constructor(ctx: Context) {
+    this.policy = ctx.fs.sandboxMode === undefined ? undefined : ctx.get('sandboxPolicy')
+    if (ctx.fs.sandboxMode !== undefined && this.policy === undefined) {
+      throw new Error('tool-str-replace-editor: the mounted filesystem confines but ctx.sandboxPolicy is missing')
+    }
+  }
+
+  resolve(exec: ToolRunContext): SandboxExecutionPolicy | undefined {
+    return this.policy?.resolve({
+      ...exec.agent === undefined ? {} : { session: exec.agent.session },
+    })
+  }
+
+  mapError(error: unknown, policy: SandboxExecutionPolicy | undefined): unknown {
+    if (!(error instanceof FsError) || error.code !== 'FS_SANDBOX_DENIED') return error
+    const mode = (policy as SandboxExecutionPolicy).mode
+    return new FsError(sandboxDenialMarker(mode), 'FS_SANDBOX_DENIED', { cause: error })
+  }
+}
+
+async function resolveTarget(
+  ctx: Context,
+  path: string,
+  signal: AbortSignal,
+): Promise<FsTarget> {
+  if (path.trim().length === 0) throw new Error('path must be a non-empty string')
+  if (!isAbsolute(path)) {
+    throw new Error(`The path ${path} is not an absolute path, it should start with \`/\`. Maybe you meant /${path}?`)
+  }
+  return ctx.fs.resolve(path, { signal })
+}
+
+async function statExisting(
+  ctx: Context,
+  target: FsTarget,
+  command: 'view' | 'str_replace' | 'insert',
+  exec: ToolRunContext,
+): Promise<FsInfo> {
+  const info = await ctx.fs.stat(target, exec.signal)
+  if (info === undefined) {
+    throw new FsError(
+      `The path ${target.displayPath} does not exist. Please provide a valid path.`,
+      'FS_NOT_FOUND',
+    )
+  }
+  if (info.type === 'directory' && command !== 'view') {
+    throw new FsError(
+      `The path ${target.displayPath} is a directory and only the \`view\` command can be used on directories`,
+      'FS_NOT_REGULAR_FILE',
+    )
+  }
+  return info
+}
+
+function requiredForCommand(
+  value: string | undefined,
+  parameter: string,
+  command: string,
+  allowEmpty = true,
+): string {
+  if (value === undefined) throw new Error(`Parameter \`${parameter}\` is required for command: ${command}`)
+  if (!allowEmpty && value.length === 0) {
+    throw new Error(`Parameter \`${parameter}\` is empty for command: ${command}`)
+  }
+  return value
+}
+
+function formatFileView(
+  path: string,
+  content: string,
+  maxOutputChars: number,
+  viewRange?: number[],
+): string {
+  const allLines = content.split('\n')
+  let lines = allLines
+  let initialLine = 1
+  let finalLine: number | undefined
+  let prompt = `Here's the content of ${path} with line numbers (which has a total of ${allLines.length} lines)`
+  if (viewRange !== undefined) {
+    const [requestedInitialLine, requestedFinalLine] = viewRange
+    if (
+      viewRange.length !== 2
+      || requestedInitialLine === undefined
+      || requestedFinalLine === undefined
+      || !viewRange.every(Number.isInteger)
+    ) {
+      throw new Error('Invalid `view_range`. It should be a list of two integers.')
+    }
+    initialLine = requestedInitialLine
+    finalLine = requestedFinalLine
+    if (initialLine < 1 || initialLine > allLines.length) {
+      throw new Error(
+        `Invalid \`view_range\`: [${viewRange.join(', ')}]. Its first element \`${initialLine}\` should be within the range of lines of the file: [1, ${allLines.length}]`,
+      )
+    }
+    if (finalLine > allLines.length) {
+      throw new Error(
+        `Invalid \`view_range\`: [${viewRange.join(', ')}]. Its second element \`${finalLine}\` should be smaller than the number of lines in the file: \`${allLines.length}\``,
+      )
+    }
+    if (finalLine !== -1 && finalLine < initialLine) {
+      throw new Error(
+        `Invalid \`view_range\`: [${viewRange.join(', ')}]. Its second element \`${finalLine}\` should be larger or equal than its first \`${initialLine}\``,
+      )
+    }
+    lines = finalLine === -1
+      ? allLines.slice(initialLine - 1)
+      : allLines.slice(initialLine - 1, finalLine)
+    prompt += ` with view_range=[${initialLine}, ${finalLine}]`
+  }
+  const numbered = lines
+    .map((line, index) => `${String(initialLine + index).padStart(6, ' ')}  ${line}`)
+    .join('\n')
+  return maybeTruncate(`${prompt}:\n${numbered}\n`, maxOutputChars)
+}
+
+async function listDirectory(
+  ctx: Context,
+  target: FsTarget,
+  maxOutputChars: number,
+  exec: ToolRunContext,
+): Promise<string> {
+  async function visit(dir: FsTarget, depth: number): Promise<string[]> {
+    const entries = await ctx.fs.listDir(dir, exec.signal)
+    const rows: string[] = []
+    for (const entry of entries.filter(candidate =>
+      !candidate.name.startsWith('.')
+      && candidate.name !== 'node_modules'
+      && candidate.name !== '__pycache__')) {
+      const type = entry.type === 'directory' ? 'd' : entry.type === 'file' ? 'f' : '?'
+      rows.push(`${type}\t${entry.target.displayPath}`)
+      if (entry.type === 'directory' && depth < 2) {
+        rows.push(...await visit(entry.target, depth + 1))
+      }
+    }
+    return rows
+  }
+  const rows = [`d\t${target.displayPath}`, ...await visit(target, 1)]
+  rows.sort((left, right) => {
+    const leftPath = left.slice(left.indexOf('\t') + 1)
+    const rightPath = right.slice(right.indexOf('\t') + 1)
+    return codepointCompare(leftPath, rightPath)
+  })
+  const listing = maybeTruncate(rows.join('\n') + '\n', maxOutputChars)
+  return `Here're the files and directories up to 2 levels deep in ${target.displayPath}, excluding hidden items, node_modules, and Python cache directories:\n${listing}\n`
+}
+
+async function viewPath(
+  ctx: Context,
+  path: string,
+  viewRange: number[] | undefined,
+  maxOutputChars: number,
+  exec: ToolRunContext,
+): Promise<string> {
+  const target = await resolveTarget(ctx, path, exec.signal)
+  const info = await statExisting(ctx, target, 'view', exec)
+  if (info.type === 'directory') {
+    if (viewRange !== undefined) {
+      throw new Error('The `view_range` parameter is not allowed when `path` points to a directory.')
+    }
+    return listDirectory(ctx, target, maxOutputChars, exec)
+  }
+  if (info.type !== 'file') {
+    throw new FsError(`cannot view "${target.displayPath}": not a regular file or directory`, 'FS_NOT_REGULAR_FILE')
+  }
+  const content = await ctx.fs.readText(target, exec.signal)
+  ctx.emit('fs/observed', target, info.version, exec)
+  return formatFileView(target.displayPath, content, maxOutputChars, viewRange)
+}
+
+async function createFile(
+  ctx: Context,
+  policy: MutationPolicy,
+  path: string,
+  fileText: string | undefined,
+  exec: ToolRunContext,
+): Promise<string> {
+  const content = requiredForCommand(fileText, 'file_text', 'create')
+  const sandboxPolicy = policy.resolve(exec)
+  const target = await resolveTarget(ctx, path, exec.signal)
+  if (await ctx.fs.stat(target, exec.signal) !== undefined) {
+    throw new Error(`File already exists at: ${target.displayPath}. Cannot overwrite files using command \`create\`.`)
+  }
+  const intent = await ctx.waterfall(
+    'fs/write-intent',
+    target,
+    exec,
+    () => ({ kind: 'createIfAbsent' } as const),
+  )
+  let outcome
+  try {
+    outcome = await ctx.fs.writeText(
+      target,
+      content,
+      intent,
+      exec.signal,
+      sandboxPolicy,
+    )
+  } catch (error: unknown) {
+    throw policy.mapError(error, sandboxPolicy)
+  }
+  ctx.emit('fs/observed', target, outcome.version, exec)
+  return `New file created successfully at: ${target.displayPath}`
+}
+
+async function replaceInFile(
+  ctx: Context,
+  policy: MutationPolicy,
+  path: string,
+  oldStr: string | undefined,
+  newStr: string | undefined,
+  exec: ToolRunContext,
+): Promise<string> {
+  const sandboxPolicy = policy.resolve(exec)
+  const target = await resolveTarget(ctx, path, exec.signal)
+  const intent = await ctx.waterfall('fs/edit-intent', target, exec, () => undefined)
+  const oldValue = requiredForCommand(oldStr, 'old_str', 'str_replace', false)
+  const newValue = newStr ?? ''
+  const info = await statExisting(ctx, target, 'str_replace', exec)
+  if (info.type !== 'file') {
+    throw new FsError(`cannot edit "${target.displayPath}": not a regular file`, 'FS_NOT_REGULAR_FILE')
+  }
+  const before = await ctx.fs.readText(target, exec.signal)
+  const offsets = matchOffsets(before, oldValue)
+  const offset = offsets[0]
+  if (offset === undefined) {
+    throw new FsError(
+      `No replacement was performed, old_str \`${oldValue}\` did not appear verbatim in ${target.displayPath}.`,
+      'FS_EDIT_NOT_FOUND',
+    )
+  }
+  if (offsets.length > 1) {
+    const lines = lineNumbersAt(before, offsets)
+    throw new FsError(
+      `No replacement was performed. Multiple occurrences of old_str \`${oldValue}\` in lines [${lines.join(', ')}]. Please ensure it is unique`,
+      'FS_AMBIGUOUS_EDIT',
+    )
+  }
+  let outcome
+  try {
+    outcome = await ctx.fs.writeText(
+      target,
+      before.slice(0, offset) + newValue + before.slice(offset + oldValue.length),
+      intent === undefined
+        ? { kind: 'replaceIfVersion', version: info.version }
+        : { kind: 'replaceIfVersion', version: intent.version },
+      exec.signal,
+      sandboxPolicy,
+    )
+  } catch (error: unknown) {
+    throw policy.mapError(error, sandboxPolicy)
+  }
+  ctx.emit('fs/observed', target, outcome.version, exec)
+  return `The file ${target.displayPath} has been edited successfully.`
+}
+
+async function insertInFile(
+  ctx: Context,
+  policy: MutationPolicy,
+  path: string,
+  insertLine: number | undefined,
+  newStr: string | undefined,
+  exec: ToolRunContext,
+): Promise<string> {
+  if (insertLine === undefined) throw new Error('Parameter `insert_line` is required for command: insert')
+  const value = requiredForCommand(newStr, 'new_str', 'insert')
+  const sandboxPolicy = policy.resolve(exec)
+  const target = await resolveTarget(ctx, path, exec.signal)
+  const intent = await ctx.waterfall('fs/edit-intent', target, exec, () => undefined)
+  const info = await statExisting(ctx, target, 'insert', exec)
+  if (info.type !== 'file') {
+    throw new FsError(`cannot insert into "${target.displayPath}": not a regular file`, 'FS_NOT_REGULAR_FILE')
+  }
+  const before = await ctx.fs.readText(target, exec.signal)
+  const lines = before.split('\n')
+  if (!Number.isInteger(insertLine) || insertLine < 0 || insertLine > lines.length) {
+    throw new Error(
+      `Invalid \`insert_line\` parameter: ${insertLine}. It should be within the range of lines of the file: [0, ${lines.length}]`,
+    )
+  }
+  const after = [
+    ...lines.slice(0, insertLine),
+    ...value.split('\n'),
+    ...lines.slice(insertLine),
+  ].join('\n')
+  const expected: FsWriteIntent = intent === undefined
+    ? { kind: 'replaceIfVersion', version: info.version }
+    : { kind: 'replaceIfVersion', version: intent.version }
+  let outcome
+  try {
+    outcome = await ctx.fs.writeText(target, after, expected, exec.signal, sandboxPolicy)
+  } catch (error: unknown) {
+    throw policy.mapError(error, sandboxPolicy)
+  }
+  ctx.emit('fs/observed', target, outcome.version, exec)
+  return `The file ${target.displayPath} has been edited successfully.`
+}
+
+interface ResolvedConfig {
+  maxOutputChars: number
+  description: string
+}
+
+function presentEditorCall(args: {
+  command: 'view' | 'create' | 'str_replace' | 'insert'
+  path: string
+  file_text?: string
+  insert_line?: number
+  new_str?: string
+  old_str?: string
+}): ToolCallView {
+  switch (args.command) {
+    case 'view':
+      return {
+        card: 'generic',
+        title: `view ${args.path}`,
+        kind: 'read',
+        locations: [{ path: args.path }],
+      }
+    case 'create':
+      return {
+        card: 'diff',
+        title: `create ${args.path}`,
+        diffs: [{ path: args.path, oldText: null, newText: args.file_text ?? '' }],
+        locations: [{ path: args.path }],
+      }
+    case 'str_replace':
+      return {
+        card: 'diff',
+        title: `str_replace ${args.path}`,
+        diffs: [{
+          path: args.path,
+          oldText: args.old_str ?? null,
+          newText: args.new_str ?? '',
+        }],
+        locations: [{ path: args.path }],
+      }
+    case 'insert':
+      return {
+        card: 'generic',
+        title: `insert ${args.path}`,
+        kind: 'edit',
+        locations: [{
+          path: args.path,
+          ...args.insert_line === undefined ? {} : { line: Math.max(1, args.insert_line + 1) },
+        }],
+      }
+  }
+}
+
+/** Register the model-facing `str_replace_editor` tool. */
+function registerStrReplaceEditor(ctx: Context, config: ResolvedConfig): void {
+  const policy = new MutationPolicy(ctx)
+  ctx.tools.register(defineTool({
+    name: 'str_replace_editor',
+    description: config.description,
+    parameters: {
+      command: {
+        type: 'string',
+        required: true,
+        enum: ['view', 'create', 'str_replace', 'insert'],
+        description: 'The commands to run. Allowed options are: `view`, `create`, `str_replace`, `insert`.',
+      },
+      path: {
+        type: 'string',
+        required: true,
+        description: 'Absolute path to file or directory, e.g. `/repo/file.py` or `/repo`.',
+      },
+      file_text: {
+        type: 'string',
+        description: 'Required parameter of `create` command, with the content of the file to be created.',
+      },
+      insert_line: {
+        type: 'integer',
+        description: 'Required parameter of `insert` command. The `new_str` will be inserted AFTER the line `insert_line` of `path`.',
+      },
+      new_str: {
+        type: 'string',
+        description: 'Optional parameter of `str_replace` command containing the new string (if not given, no string will be added). Required parameter of `insert` command containing the string to insert.',
+      },
+      old_str: {
+        type: 'string',
+        description: 'Required parameter of `str_replace` command containing the string in `path` to replace.',
+      },
+      view_range: {
+        type: 'array',
+        items: { type: 'integer' },
+        description: 'Optional parameter of `view` command when `path` points to a file. If none is given, the full file is shown. If provided, the file will be shown in the indicated line number range, e.g. [11, 12] will show lines 11 and 12. Indexing at 1 to start. Setting `[start_line, -1]` shows all lines from `start_line` to the end of the file.',
+      },
+    },
+    output: {
+      schema: { type: 'string' },
+      render: (_args, value) => [{ type: 'text', text: value }],
+    },
+    async execute(args, exec) {
+      switch (args.command) {
+        case 'view':
+          return viewPath(ctx, args.path, args.view_range, config.maxOutputChars, exec)
+        case 'create':
+          return createFile(ctx, policy, args.path, args.file_text, exec)
+        case 'str_replace':
+          return replaceInFile(
+            ctx,
+            policy,
+            args.path,
+            args.old_str,
+            args.new_str,
+            exec,
+          )
+        case 'insert':
+          return insertInFile(
+            ctx,
+            policy,
+            args.path,
+            args.insert_line,
+            args.new_str,
+            exec,
+          )
+      }
+    },
+    presentCall: presentEditorCall,
+  }))
+}
+
+export const name = 'tool-str-replace-editor'
+export const inject = ['tools', 'fs']
+
+/** Configuration for the string-replacement editor tool. */
+export interface Config {
+  /** Maximum returned view characters before clipping (default 16000). */
+  maxOutputChars?: number
+  /** Model-facing tool description. */
+  description?: string
+}
+
+/** Runtime configuration schema for the string-replacement editor tool. */
+export const Config: z<Config> = z.object({
+  maxOutputChars: z.number().default(16_000),
+  description: z.string().default(DEFAULT_DESCRIPTION),
+})
+
+/** Register one `str_replace_editor` tool over `ctx.fs`. */
+export function apply(ctx: Context, config: Config): void {
+  const resolved: ResolvedConfig = {
+    maxOutputChars: config.maxOutputChars ?? 16_000,
+    description: config.description ?? DEFAULT_DESCRIPTION,
+  }
+  if (!Number.isSafeInteger(resolved.maxOutputChars) || resolved.maxOutputChars <= 0) {
+    throw new Error('tool-str-replace-editor: maxOutputChars must be a positive safe integer')
+  }
+  if (resolved.description.trim().length === 0) {
+    throw new Error('tool-str-replace-editor: description must be non-empty')
+  }
+  registerStrReplaceEditor(ctx, resolved)
+}
--- a/packages/fs/tool-str-replace-editor/src/invariant.ts
+++ b/packages/fs/tool-str-replace-editor/src/invariant.ts
@@ -0,0 +1,30 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-tool-str-replace-editor`.
+ * @module @deepseek-ai/dsh-tool-str-replace-editor/invariant
+ */
+
+/* jscpd:ignore-start */
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-tool-str-replace-editor'
+
+/** Cordis companion plugin name. */
+export const name = 'tool-str-replace-editor-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/**
+ * No runtime invariant: the tool adapter owns no independent durable state;
+ * filesystem mutation relations stay with the provider and policy plugins.
+ */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */
--- a/packages/fs/tool-str-replace-editor/tests/tools.spec.ts
+++ b/packages/fs/tool-str-replace-editor/tests/tools.spec.ts
@@ -0,0 +1,547 @@
+import { mkdtemp, mkdir, readFile, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import { FsVersion } from '@deepseek-ai/dsh-fs'
+import { CallId } from '@deepseek-ai/dsh-llm'
+import { Session, SessionId } from '@deepseek-ai/dsh-session'
+import AgentRegistry from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import LocalFileSystem from '@deepseek-ai/dsh-fs-local'
+import * as FsPolicy from '@deepseek-ai/dsh-fs-policy'
+import SandboxedFileSystem from '@deepseek-ai/dsh-fs-sandbox'
+import SandboxPolicy from '@deepseek-ai/dsh-sandbox-policy'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import ToolRegistry from '@deepseek-ai/dsh-tools'
+import * as ToolStrReplaceEditor from '@deepseek-ai/dsh-tool-str-replace-editor'
+
+const contexts: Context[] = []
+const roots: string[] = []
+let callNumber = 0
+
+afterEach(async () => {
+  for (const ctx of contexts.splice(0)) await ctx.fiber.dispose()
+  for (const root of roots.splice(0)) await rm(root, { recursive: true, force: true })
+})
+
+function agent(ctx: Context, cwd: string): Agent {
+  const id = SessionId(`str-replace-editor-owner-${callNumber}`)
+  const scope = ctx.plugin(() => {})
+  const value: Agent = {
+    id,
+    options: {},
+    session: new Session(id, [], { version: 0, id, createdAt: 0, cwd }),
+    status: 'idle',
+    acceptsNextStep: false,
+    ctx: scope.ctx,
+    followup: () => {},
+    steer: () => {},
+    inject: () => {},
+    send: () => {},
+    updateInbox: () => 'not-found',
+    cancel() {},
+    whenIdle: () => Promise.resolve(),
+  }
+  ctx.agents.register(value)
+  return value
+}
+
+function text(result: { content: { type: string; text?: string }[] }): string {
+  return result.content.filter(block => block.type === 'text').map(block => block.text).join('')
+}
+
+function call(ctx: Context, owner: Agent | undefined, args: unknown) {
+  return ctx.tools.execute({
+    signal: new AbortController().signal,
+    callId: CallId(`str-replace-editor-${++callNumber}`),
+    name: 'str_replace_editor',
+    arguments: args,
+    ...owner === undefined ? {} : { agent: owner },
+  })
+}
+
+async function setup(
+  config: ToolStrReplaceEditor.Config = {},
+  options: { fsPolicy?: boolean; sandboxMode?: 'read-only' | 'workspace-write' | 'danger-full-access' } = {},
+) {
+  const root = await mkdtemp(join(tmpdir(), 'dsh-tool-str-replace-editor-'))
+  roots.push(root)
+  const ctx = new Context()
+  contexts.push(ctx)
+  await ctx.plugin(SystemPrompt)
+  await ctx.plugin(ToolRegistry)
+  await ctx.plugin(AgentRegistry)
+  if (options.sandboxMode === undefined) {
+    await ctx.plugin(LocalFileSystem, { cwd: root })
+  } else {
+    await ctx.plugin(SandboxPolicy, { mode: options.sandboxMode, workspaceRoot: root })
+    await ctx.plugin(SandboxedFileSystem, { cwd: root })
+  }
+  if (options.fsPolicy === true) await ctx.plugin(FsPolicy)
+  const fiber = await ctx.plugin(ToolStrReplaceEditor, config)
+  return { ctx, root, fiber, owner: agent(ctx, root) }
+}
+
+describe('tool-str-replace-editor', () => {
+  it('registers the standalone schema and configurable description', async () => {
+    const { ctx, fiber } = await setup({ description: 'custom editor description' })
+    const schema = ctx.tools.schemas()[0]
+    expect(ctx.tools.schemas().map(item => item.name)).toEqual(['str_replace_editor'])
+    expect(schema?.description).toBe('custom editor description')
+    const properties = (schema?.parameters as {
+      properties: Record<string, { type?: string; items?: { type?: string } }>
+    }).properties
+    expect(properties).not.toHaveProperty('replace_all')
+    expect(properties.insert_line?.type).toBe('integer')
+    expect(properties.view_range?.items?.type).toBe('integer')
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'view',
+      path: '/workspace/a.txt',
+    })).toMatchObject({
+      card: 'generic',
+      kind: 'read',
+      locations: [{ path: '/workspace/a.txt' }],
+    })
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'create',
+      path: '/workspace/a.txt',
+      file_text: 'hello',
+    })).toMatchObject({
+      card: 'diff',
+      diffs: [{ path: '/workspace/a.txt', oldText: null, newText: 'hello' }],
+    })
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'str_replace',
+      path: '/workspace/a.txt',
+      old_str: 'old',
+      new_str: 'new',
+    })).toMatchObject({
+      card: 'diff',
+      diffs: [{ path: '/workspace/a.txt', oldText: 'old', newText: 'new' }],
+    })
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'insert',
+      path: '/workspace/a.txt',
+      insert_line: 0,
+      new_str: 'x',
+    })).toMatchObject({
+      card: 'generic',
+      kind: 'edit',
+      locations: [{ path: '/workspace/a.txt', line: 1 }],
+    })
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'create',
+      path: '/workspace/empty.txt',
+    })).toMatchObject({
+      diffs: [{ path: '/workspace/empty.txt', oldText: null, newText: '' }],
+    })
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'str_replace',
+      path: '/workspace/a.txt',
+    })).toMatchObject({
+      diffs: [{ path: '/workspace/a.txt', oldText: null, newText: '' }],
+    })
+    expect(ctx.tools.get('str_replace_editor')?.presentCall?.({
+      command: 'insert',
+      path: '/workspace/a.txt',
+    })).toMatchObject({
+      locations: [{ path: '/workspace/a.txt' }],
+    })
+
+    await fiber.dispose()
+    expect(ctx.tools.schemas()).toEqual([])
+    expect(ctx.tools.get('str_replace_editor')).toBeUndefined()
+  })
+
+  it('creates, views, replaces, and inserts with the canonical model-facing output', async () => {
+    const { ctx, root, owner } = await setup()
+    const sample = join(root, 'sample.txt')
+    expect(text(await call(ctx, owner, {
+      command: 'create',
+      path: sample,
+      file_text: 'one\ntwo\nthree\n',
+    }))).toBe(`New file created successfully at: ${sample}`)
+
+    expect(text(await call(ctx, owner, {
+      command: 'view',
+      path: sample,
+      view_range: [2, -1],
+    }))).toBe([
+      `Here's the content of ${sample} with line numbers (which has a total of 4 lines) with view_range=[2, -1]:`,
+      '     2  two',
+      '     3  three',
+      '     4  ',
+      '',
+    ].join('\n'))
+
+    expect(text(await call(ctx, owner, {
+      command: 'str_replace',
+      path: sample,
+      old_str: 'two',
+      new_str: 'TWO',
+    }))).toBe(`The file ${sample} has been edited successfully.`)
+    expect(text(await call(ctx, owner, {
+      command: 'str_replace',
+      path: sample,
+      old_str: 'TWO',
+    }))).toBe(`The file ${sample} has been edited successfully.`)
+    expect(text(await call(ctx, owner, {
+      command: 'insert',
+      path: sample,
+      insert_line: 1,
+      new_str: 'between',
+    }))).toBe(`The file ${sample} has been edited successfully.`)
+    expect(await readFile(sample, 'utf8')).toBe('one\nbetween\n\nthree\n')
+  })
+
+  it('writes replacement text literally', async () => {
+    const { ctx, root, owner } = await setup()
+    const sample = join(root, 'literal.txt')
+    const replacement = "$&|$`|$'|$$"
+    await writeFile(sample, 'before OLD after')
+
+    expect((await call(ctx, owner, {
+      command: 'str_replace',
+      path: sample,
+      old_str: 'OLD',
+      new_str: replacement,
+    })).isError).toBe(false)
+    expect(await readFile(sample, 'utf8')).toBe(`before ${replacement} after`)
+  })
+
+  it('lists visible entries to depth two and clips at the configured view limit', async () => {
+    const { ctx, root, owner } = await setup({ maxOutputChars: 10_000 })
+    await mkdir(join(root, 'dir', 'nested', 'third'), { recursive: true })
+    await mkdir(join(root, 'dir', 'node_modules', 'pkg'), { recursive: true })
+    await mkdir(join(root, 'dir', 'node_modules_old'), { recursive: true })
+    await mkdir(join(root, 'dir', '__pycache__'), { recursive: true })
+    await mkdir(join(root, 'dir', '__pycache__backup'), { recursive: true })
+    await writeFile(join(root, 'dir', 'visible.txt'), 'ok')
+    await writeFile(join(root, 'dir', '.hidden'), 'hidden')
+    await writeFile(join(root, 'dir', 'nested', 'child.txt'), 'child')
+    await writeFile(join(root, 'dir', 'nested', 'third', 'too-deep.txt'), 'deep')
+    await writeFile(join(root, 'dir', 'node_modules', 'pkg', 'index.js'), 'hidden dependency')
+    await writeFile(join(root, 'dir', 'node_modules_old', 'kept.js'), 'visible source')
+    await writeFile(join(root, 'dir', '__pycache__', 'module.pyc'), 'cache')
+    await writeFile(join(root, 'dir', '__pycache__backup', 'kept.py'), 'visible source')
+    const listDir = ctx.fs.listDir.bind(ctx.fs)
+    const otherTarget = await ctx.fs.resolve(join(root, 'dir', 'other'))
+    ctx.fs.listDir = async (target, signal) => {
+      const entries = await listDir(target, signal)
+      return target.displayPath === join(root, 'dir')
+        ? [
+          { name: 'same-target', type: 'other', target: otherTarget },
+          { name: 'other', type: 'other', target: otherTarget },
+          ...entries.toReversed(),
+        ]
+        : entries
+    }
+
+    const listing = text(await call(ctx, owner, { command: 'view', path: join(root, 'dir') }))
+    expect(listing).not.toContain('.hidden')
+    expect(listing).not.toContain('too-deep.txt')
+    expect(listing).not.toContain('index.js')
+    expect(listing).not.toContain('module.pyc')
+    expect(listing).toContain('node_modules_old/kept.js')
+    expect(listing).toContain('__pycache__backup/kept.py')
+
+    const clipped = await setup({ maxOutputChars: 10 })
+    await writeFile(join(clipped.root, 'large.txt'), 'x'.repeat(100))
+    expect(text(await call(clipped.ctx, clipped.owner, {
+      command: 'view',
+      path: join(clipped.root, 'large.txt'),
+    })))
+      .toContain('<response clipped>')
+  })
+
+  it('matches canonical empty-line, range, and end-insert behavior', async () => {
+    const { ctx, root, owner } = await setup()
+    const empty = join(root, 'empty.txt')
+    const newline = join(root, 'newline.txt')
+    const plain = join(root, 'plain.txt')
+    await writeFile(empty, '')
+    await writeFile(newline, '\n')
+    await writeFile(plain, 'one\ntwo')
+
+    expect(text(await call(ctx, owner, { command: 'view', path: empty })))
+      .toContain('(which has a total of 1 lines):\n     1  \n')
+    expect(text(await call(ctx, owner, { command: 'view', path: newline })))
+      .toContain('(which has a total of 2 lines):\n     1  \n     2  \n')
+    expect(text(await call(ctx, owner, {
+      command: 'view',
+      path: plain,
+      view_range: [1, 2],
+    }))).toContain('     2  two')
+    expect(text(await call(ctx, undefined, {
+      command: 'view',
+      path: plain,
+    }))).toContain('     1  one')
+    expect((await call(ctx, undefined, {
+      command: 'create',
+      path: join(root, 'ownerless.txt'),
+      file_text: 'ownerless',
+    })).isError).toBe(false)
+
+    await call(ctx, owner, {
+      command: 'insert',
+      path: plain,
+      insert_line: 2,
+      new_str: 'three',
+    })
+    expect(await readFile(plain, 'utf8')).toBe('one\ntwo\nthree')
+
+    await writeFile(newline, 'one\n')
+    await call(ctx, owner, {
+      command: 'insert',
+      path: newline,
+      insert_line: 2,
+      new_str: 'three',
+    })
+    expect(await readFile(newline, 'utf8')).toBe('one\n\nthree')
+  })
+
+  it('uses old_str-only replacement failures and rejects relative paths', async () => {
+    const { ctx, root, owner } = await setup()
+    const ambiguous = join(root, 'ambiguous.txt')
+    await writeFile(ambiguous, 'same\nother\nsame')
+
+    const missing = await call(ctx, owner, {
+      command: 'str_replace',
+      path: ambiguous,
+      old_str: 'absent',
+      new_str: 'x',
+    })
+    expect(missing.isError).toBe(true)
+    expect(text(missing)).toContain(`old_str \`absent\` did not appear verbatim in ${ambiguous}`)
+    expect(text(missing)).not.toContain('old_string')
+
+    const repeated = await call(ctx, owner, {
+      command: 'str_replace',
+      path: ambiguous,
+      old_str: 'same',
+      new_str: 'x',
+    })
+    expect(repeated.isError).toBe(true)
+    expect(text(repeated)).toContain('Multiple occurrences of old_str `same` in lines [1, 3]')
+    expect(text(repeated)).not.toContain('replace_all')
+
+    await writeFile(ambiguous, 'alpha\nbeta\nmiddle\nalpha\nbeta')
+    const repeatedMultiline = await call(ctx, owner, {
+      command: 'str_replace',
+      path: ambiguous,
+      old_str: 'alpha\nbeta',
+      new_str: 'x',
+    })
+    expect(text(repeatedMultiline))
+      .toContain('Multiple occurrences of old_str `alpha\nbeta` in lines [1, 4]')
+
+    const mixedEol = join(root, 'mixed-eol.txt')
+    await writeFile(mixedEol, 'alpha\r\nbeta\nmiddle\nalpha\nbeta')
+    expect((await call(ctx, owner, {
+      command: 'str_replace',
+      path: mixedEol,
+      old_str: 'alpha\r\nbeta',
+      new_str: 'replaced',
+    })).isError).toBe(false)
+    expect(await readFile(mixedEol, 'utf8')).toBe('replaced\nmiddle\nalpha\nbeta')
+
+    const relative = await call(ctx, owner, { command: 'view', path: 'ambiguous.txt' })
+    expect(relative.isError).toBe(true)
+    expect(text(relative)).toContain('is not an absolute path')
+    expect(await readFile(ambiguous, 'utf8')).toBe('alpha\nbeta\nmiddle\nalpha\nbeta')
+  })
+
+  it('reports invalid commands or arguments without mutating files', async () => {
+    const { ctx, root, owner } = await setup()
+    const ambiguous = join(root, 'ambiguous.txt')
+    const empty = join(root, 'empty.txt')
+    const trailingNewline = join(root, 'trailing-newline.txt')
+    const threeLines = join(root, 'three-lines.txt')
+    const directory = join(root, 'directory')
+    await writeFile(ambiguous, 'same same')
+    await writeFile(empty, '')
+    await writeFile(trailingNewline, 'one\n')
+    await writeFile(threeLines, 'one\ntwo\nthree')
+    await mkdir(directory)
+
+    const cases = [
+      { command: 'view', path: '' },
+      { command: 'view', path: join(root, 'missing.txt') },
+      { command: 'view', path: ambiguous, view_range: [1] },
+      { command: 'view', path: ambiguous, view_range: [0, 1] },
+      { command: 'view', path: ambiguous, view_range: [1.5, 2] },
+      { command: 'view', path: threeLines, view_range: [1, 99] },
+      { command: 'view', path: threeLines, view_range: [2, 1] },
+      { command: 'view', path: directory, view_range: [1, 1] },
+      { command: 'create', path: join(root, 'new.txt') },
+      { command: 'create', path: ambiguous, file_text: 'overwrite' },
+      { command: 'str_replace', path: ambiguous, new_str: 'x' },
+      { command: 'str_replace', path: ambiguous, old_str: '', new_str: 'x' },
+      { command: 'insert', path: ambiguous, new_str: 'x' },
+      { command: 'insert', path: ambiguous, insert_line: -1, new_str: 'x' },
+      { command: 'insert', path: ambiguous, insert_line: 1.5, new_str: 'x' },
+      { command: 'insert', path: ambiguous, insert_line: 99, new_str: 'x' },
+      { command: 'insert', path: empty, insert_line: 2, new_str: 'x' },
+      { command: 'insert', path: directory, insert_line: 0, new_str: 'x' },
+    ]
+    for (const args of cases) {
+      expect((await call(ctx, owner, args)).isError).toBe(true)
+    }
+    expect(await readFile(ambiguous, 'utf8')).toBe('same same')
+
+    ctx.fs.stat = async () => ({ version: FsVersion('special'), type: 'other' })
+    const special = await call(ctx, owner, { command: 'view', path: join(root, 'special') })
+    expect(special.isError).toBe(true)
+    expect(special.error).toMatchObject({ info: { code: 'FS_NOT_REGULAR_FILE' } })
+    expect((await call(ctx, owner, {
+      command: 'str_replace',
+      path: join(root, 'special'),
+      old_str: 'x',
+      new_str: 'y',
+    })).error).toMatchObject({ info: { code: 'FS_NOT_REGULAR_FILE' } })
+    expect((await call(ctx, owner, {
+      command: 'insert',
+      path: join(root, 'special'),
+      insert_line: 0,
+      new_str: 'x',
+    })).error).toMatchObject({ info: { code: 'FS_NOT_REGULAR_FILE' } })
+  })
+
+  it('delegates read-before-edit decisions to fs-policy', async () => {
+    const { ctx, root, owner } = await setup({}, { fsPolicy: true })
+    const existing = join(root, 'existing.txt')
+    const created = join(root, 'created.txt')
+    await writeFile(existing, 'before')
+
+    const blindEdit = await call(ctx, owner, {
+      command: 'str_replace',
+      path: existing,
+      old_str: 'before',
+      new_str: 'after',
+    })
+    expect(blindEdit.error).toMatchObject({ info: { code: 'FS_NOT_OBSERVED' } })
+    expect(await readFile(existing, 'utf8')).toBe('before')
+
+    await call(ctx, owner, { command: 'view', path: existing })
+    expect((await call(ctx, owner, {
+      command: 'str_replace',
+      path: existing,
+      old_str: 'before',
+      new_str: 'after',
+    })).isError).toBe(false)
+    expect(await readFile(existing, 'utf8')).toBe('after')
+
+    expect((await call(ctx, owner, {
+      command: 'insert',
+      path: existing,
+      insert_line: 1,
+      new_str: 'tail',
+    })).isError).toBe(false)
+    expect(await readFile(existing, 'utf8')).toBe('after\ntail')
+
+    expect((await call(ctx, owner, {
+      command: 'create',
+      path: created,
+      file_text: 'new',
+    })).isError).toBe(false)
+    expect(await readFile(created, 'utf8')).toBe('new')
+  })
+
+  it('passes the session sandbox policy to every mutation', async () => {
+    const { ctx, root, owner } = await setup({}, { sandboxMode: 'read-only' })
+    const path = join(root, 'blocked.txt')
+    const result = await call(ctx, owner, {
+      command: 'create',
+      path,
+      file_text: 'blocked',
+    })
+    expect(result.error).toMatchObject({ info: { code: 'FS_SANDBOX_DENIED' } })
+    expect(text(result)).toContain('[sandbox: file access denied under read-only mode]')
+
+    const ownerless = await call(ctx, undefined, {
+      command: 'create',
+      path: join(root, 'ownerless-blocked.txt'),
+      file_text: 'blocked',
+    })
+    expect(ownerless.error).toMatchObject({ info: { code: 'FS_SANDBOX_DENIED' } })
+  })
+
+  it('preserves tabs outside the edited region', async () => {
+    const { ctx, root, owner } = await setup()
+    const path = join(root, 'Makefile')
+    await writeFile(path, 'target:\n\told\nremove\n')
+    expect(text(await call(ctx, owner, { command: 'view', path })))
+      .toContain('     2  \told')
+    await call(ctx, owner, {
+      command: 'str_replace',
+      path,
+      old_str: '\told',
+      new_str: '\tnew',
+    })
+    await call(ctx, owner, {
+      command: 'str_replace',
+      path,
+      old_str: 'remove\n',
+    })
+    await call(ctx, owner, {
+      command: 'insert',
+      path,
+      insert_line: 1,
+      new_str: '\tkept',
+    })
+    expect(await readFile(path, 'utf8')).toBe('target:\n\tkept\n\tnew\n')
+  })
+
+  it('reports missing sandbox-policy composition during plugin startup', async () => {
+    const root = await mkdtemp(join(tmpdir(), 'dsh-tool-str-replace-editor-missing-policy-'))
+    roots.push(root)
+    const ctx = new Context()
+    contexts.push(ctx)
+    await ctx.plugin(SystemPrompt)
+    await ctx.plugin(ToolRegistry)
+    await ctx.plugin(AgentRegistry)
+    await ctx.plugin(LocalFileSystem, { cwd: root })
+    Object.defineProperty(ctx.fs, 'sandboxMode', { value: 'read-only' })
+
+    await expect(ctx.plugin(ToolStrReplaceEditor))
+      .rejects.toThrow('the mounted filesystem confines but ctx.sandboxPolicy is missing')
+  })
+
+  it('maps unexpected backend write failures for replace and insert', async () => {
+    const { ctx, root, owner } = await setup()
+    const path = join(root, 'backend-error.txt')
+    await writeFile(path, 'old\n')
+    const failWrite = async (): Promise<never> => {
+      throw new Error('backend write failed')
+    }
+    ctx.fs.writeText = failWrite
+
+    const replace = await call(ctx, owner, {
+      command: 'str_replace',
+      path,
+      old_str: 'old',
+      new_str: 'new',
+    })
+    expect(replace.isError).toBe(true)
+    expect(text(replace)).toContain('backend write failed')
+
+    const insert = await call(ctx, owner, {
+      command: 'insert',
+      path,
+      insert_line: 1,
+      new_str: 'new',
+    })
+    expect(insert.isError).toBe(true)
+    expect(text(insert)).toContain('backend write failed')
+  })
+
+  it('rejects invalid plugin config', () => {
+    expect(() => {
+      ToolStrReplaceEditor.apply(new Context(), { maxOutputChars: 0 })
+    }).toThrow('maxOutputChars must be a positive safe integer')
+    expect(() => {
+      ToolStrReplaceEditor.apply(new Context(), { description: ' ' })
+    }).toThrow('description must be non-empty')
+  })
+})
--- a/packages/fs/tool-str-replace-editor/tsconfig.json
+++ b/packages/fs/tool-str-replace-editor/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": ["src"],
+  "references": [
+    { "path": "../../../vendor/cordis" },
+    { "path": "../../core/tools" },
+    { "path": "../fs" },
+    { "path": "../../sandbox/sandbox" },
+    { "path": "../../sandbox/sandbox-policy" },
+    { "path": "../../support/invariants" }
+  ]
+}
--- a/packages/pty/README.i18n.yaml
+++ b/packages/pty/README.i18n.yaml
@@ -2,5 +2,5 @@
 # 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 packages/pty/README.md
-README.md: a9121455519a5f83a63a005cb857fec0f0e06b92
-README.zh.md: 4e36ef934d31861d72748b9b9585695f86749171
+README.md: e54dcf64db083665f37b7dc19a7a92e21494442b
+README.zh.md: 0bb7e565a5799002ffb8b74dce12e129a7b2665e
--- a/packages/pty/README.md
+++ b/packages/pty/README.md
@@ -9,5 +9,6 @@ English | [中文](README.zh.md)
 | [`pty`](pty/README.md) (`@deepseek-ai/dsh-pty`) | Backend registry, branded ids, exact-Agent ownership, session operations, and awaited cleanup | `ctx.pty` |
 | `pty-local` (`@deepseek-ai/dsh-pty-local`) | Local `node-pty` backend, readiness detection, bounded terminal state, sandboxing, and process-session supervision | registers on `ctx.pty` |
 | `tool-pty` (`@deepseek-ai/dsh-tool-pty`) | Six model-facing tools and generic task integration for background sends | registers on `ctx.tools` |
+| `tool-bash-persistent` (`@deepseek-ai/dsh-tool-bash-persistent`) | One model-facing `bash` backed by an owner-scoped reusable PTY shell | consumes `ctx.pty`, registers on `ctx.tools` |

 The design and deferred boundaries live in the [persistent PTY Agent Note](../../.agents/notes/implemented/feature/2026-07-16-persistent-pty-sessions.md).
--- a/packages/pty/README.zh.md
+++ b/packages/pty/README.zh.md
@@ -9,5 +9,6 @@
 | [`pty`](pty/README.md)（`@deepseek-ai/dsh-pty`） | 后端注册表、品牌化 id、精确到 agent（智能体）的所有权、会话操作与等待清理完成的机制 | `ctx.pty` |
 | `pty-local`（`@deepseek-ai/dsh-pty-local`） | 本地 `node-pty` 后端、就绪检测、有界终端状态、沙箱与进程会话监管 | 注册到 `ctx.pty` |
 | `tool-pty`（`@deepseek-ai/dsh-tool-pty`） | 6 个面向模型的工具，以及用于后台发送的通用任务集成 | 注册到 `ctx.tools` |
+| `tool-bash-persistent`（`@deepseek-ai/dsh-tool-bash-persistent`） | 一个由所有者隔离可复用 PTY shell 支撑的模型可见 `bash` | 消费 `ctx.pty`，注册到 `ctx.tools` |

 设计与暂缓边界记录在[持久 PTY Agent Note（agent 决策记录）](../../.agents/notes/implemented/feature/2026-07-16-persistent-pty-sessions.md) 中。
--- a/packages/pty/tool-bash-persistent/README.i18n.yaml
+++ b/packages/pty/tool-bash-persistent/README.i18n.yaml
@@ -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 packages/pty/tool-bash-persistent/README.md
+README.md: cfb3acf41803f5b06ecb3f56ee8ffc29ce9147b1
+README.zh.md: a525485933344a8f9bc218456c099efdef572902
--- a/packages/pty/tool-bash-persistent/README.md
+++ b/packages/pty/tool-bash-persistent/README.md
@@ -0,0 +1,50 @@
+# @deepseek-ai/dsh-tool-bash-persistent
+
+English | [中文](README.zh.md)
+
+Model-facing `bash(command)` backed by one owner-scoped `ctx.pty` shell. The package owns the tool contract and shell reuse; deployments select the PTY backend and sandbox policy.
+
+## Config
+
+| Key | Default | Meaning |
+|---|---:|---|
+| `backendType` | `shell` | Registered PTY backend used for each Agent shell. |
+| `timeoutMs` | `300000` | Wall-clock limit for one command; timeout closes the shell. |
+| `maxOutputChars` | `16000` | Maximum retained command-output characters; fixed diagnostics are added afterward. |
+| `description` | Persistent-shell description | Model-facing environment contract. |
+
+## Model Experience
+
+### Tool schema
+
+#### What the model sees
+
+The generated [`bash` schema](../../../docs/tool-catalog.md#deepseek-aidsh-tool-bash-persistent), including the configured `description`. The plugin contributes no standalone system-prompt section; the deployment owns persona and environment guidance.
+
+#### Token effect
+
+Fixed schema cost while `bash` is visible.
+
+#### KV Cache effect
+
+Prefix-stable while the configured description and schema remain unchanged.
+
+### Tool results
+
+#### What the model sees
+
+Commands share one shell per Agent, so cwd, exported variables, activated environments, functions, and background jobs persist across calls. Results exclude private completion markers and the shell prompt. A nonzero wrapped command appends `[exit code: N]`; a shell that exits before reporting that status instead appends `[shell exited: code N]`, `[shell killed by signal: SIG]`, or `[shell exited]` when the backend supplies neither, then resets and tells the model that the next call starts fresh. Long output keeps the earliest retained prefix plus a clipping notice. If the PTY has already dropped that prefix, the result says so explicitly instead of presenting a tail as complete output. Timeout returns bounded partial output, closes the uncertain shell, and reports the reset.
+
+#### Token effect
+
+Data-dependent. `maxOutputChars` bounds retained command output; fixed clipping, lost-prefix, status, timeout, and reset diagnostics can extend the result.
+
+#### KV Cache effect
+
+Append-only tool results follow the reusable request prefix.
+
+## Known Limitations and Deferred Work
+
+- The tool requires an owning Agent and a real PTY backend.
+- Explicit `exit` and timeout discard shell state. Cancellation also resets and discards the result, even when a complete status marker is already observable; the next call starts a fresh shell.
+- Environment facts such as network access and package mirrors belong in the configured `description`, not this package's default.
--- a/packages/pty/tool-bash-persistent/README.zh.md
+++ b/packages/pty/tool-bash-persistent/README.zh.md
@@ -0,0 +1,50 @@
+# @deepseek-ai/dsh-tool-bash-persistent
+
+[English](README.md) | 中文
+
+模型可见的 `bash(command)`，底层复用一个按所有者隔离的 `ctx.pty` shell。该包拥有工具契约和 shell 复用；PTY 后端与沙箱策略由部署选择。
+
+## 配置
+
+| 键 | 默认值 | 含义 |
+|---|---:|---|
+| `backendType` | `shell` | 每个 Agent shell 使用的已注册 PTY 后端。 |
+| `timeoutMs` | `300000` | 单条命令的墙钟时间上限；超时会关闭 shell。 |
+| `maxOutputChars` | `16000` | 命令输出最多保留的字符数；固定诊断会在此后追加。 |
+| `description` | 持久 shell 描述 | 面向模型的环境契约。 |
+
+## 模型体验
+
+### 工具 schema
+
+#### 模型所见
+
+生成的 [`bash` schema](../../../docs/tool-catalog.md#deepseek-aidsh-tool-bash-persistent)，其中包含配置的 `description`。本插件不贡献独立系统提示词段；persona 与环境指导由部署负责。
+
+#### Token 影响
+
+`bash` 可见时产生固定的 schema 成本。
+
+#### KV Cache 影响
+
+配置的描述与 schema 不变时前缀稳定。
+
+### 工具结果
+
+#### 模型所见
+
+每个 Agent 的命令共享一个 shell，因此 cwd、导出的环境变量、已激活环境、函数和后台任务会跨调用保留。结果不包含私有完成标记和 shell 提示符。经封装的命令以非零状态结束时，结果会追加 `[exit code: N]`；若 shell 在报告该状态前退出，则改为追加 `[shell exited: code N]`、`[shell killed by signal: SIG]`，或在后端既未提供退出码也未提供信号时追加 `[shell exited]`；随后重置 shell，并告知模型下次调用从新 shell 开始。长输出保留仍可读取的最早前缀并追加截断提示；若 PTY 已丢弃真正的开头，结果会明确说明，而不是把尾部伪装成完整输出。超时返回有界的部分输出、关闭状态不确定的 shell，并报告该重置。
+
+#### Token 影响
+
+随数据变化。`maxOutputChars` 限制保留的命令输出；固定的截断、前缀丢失、状态、超时与重置诊断可能使结果更长。
+
+#### KV Cache 影响
+
+工具结果以追加方式位于可复用请求前缀之后。
+
+## 已知限制与延后工作
+
+- 工具需要拥有它的 Agent 和真实 PTY 后端。
+- 显式 `exit` 与超时会丢弃 shell 状态。取消同样会重置 shell 并丢弃结果，即使已经能观察到完整状态标记也是如此；下次调用创建新 shell。
+- 网络访问、软件包镜像等环境事实应写入配置的 `description`，而非包默认描述。
--- a/packages/pty/tool-bash-persistent/package.json
+++ b/packages/pty/tool-bash-persistent/package.json
@@ -0,0 +1,55 @@
+{
+  "name": "@deepseek-ai/dsh-tool-bash-persistent",
+  "description": "Model-facing owner-scoped persistent Bash tool backed by the Harness PTY service",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-agent": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "@deepseek-ai/dsh-pty": "^0.0.1",
+    "@deepseek-ai/dsh-timeout": "^0.0.1",
+    "@deepseek-ai/dsh-tools": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "dependencies": {
+    "schemastery": "^3.18.0"
+  },
+  "devDependencies": {
+    "@cordisjs/plugin-include": "workspace:^",
+    "@cordisjs/plugin-loader": "workspace:^",
+    "@deepseek-ai/dsh-agent": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-pty": "workspace:^",
+    "@deepseek-ai/dsh-pty-local": "workspace:^",
+    "@deepseek-ai/dsh-sandbox": "workspace:^",
+    "@deepseek-ai/dsh-sandbox-policy": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-system-prompt": "workspace:^",
+    "@deepseek-ai/dsh-timeout": "workspace:^",
+    "@deepseek-ai/dsh-tools": "workspace:^",
+    "cordis": "^4.0.0-rc.7"
+  }
+}
--- a/packages/pty/tool-bash-persistent/src/index.ts
+++ b/packages/pty/tool-bash-persistent/src/index.ts
@@ -0,0 +1,445 @@
+/**
+ * Model-facing persistent `bash` tool over the owner-scoped PTY seam.
+ * @module @deepseek-ai/dsh-tool-bash-persistent
+ */
+
+import { randomUUID } from 'node:crypto'
+import type { Context } from 'cordis'
+import z from 'schemastery'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import type { PtyReadResult, PtySendResult, PtySessionId } from '@deepseek-ai/dsh-pty'
+import { deadline, timeoutOf } from '@deepseek-ai/dsh-timeout'
+import { defineTool } from '@deepseek-ai/dsh-tools'
+
+// TODO: Replace the file-search advice; arbitrary command output need not come from a searchable file.
+const TRUNCATED_MESSAGE = '<response clipped><NOTE>To save on context only part of this file has been shown to you. You should retry this tool after you have searched inside the file with `grep -n` in order to find the line numbers of what you are looking for.</NOTE>'
+const LOST_PREFIX_MESSAGE = '<response clipped><NOTE>The beginning of this command output was dropped by the terminal scrollback limit. The following text is the earliest retained output.</NOTE>\n'
+const SHELL_RESET_MESSAGE = 'The persistent bash shell was reset; the next bash call starts from the workspace with a fresh current directory and environment.'
+const SHELL_PROMPT = '__DSH_PERSISTENT_BASH_PROMPT__ '
+const TIMEOUT_CODE = 'PERSISTENT_BASH_TIMEOUT'
+// One page is enough to find a just-emitted completion marker; the full
+// scrollback is assembled only when a command settles or needs partial output.
+const SCROLLBACK_PAGE_LINES = 1_000
+const POLL_INTERVAL_MS = 25
+
+const DEFAULT_DESCRIPTION = 'Run commands in a persistent bash shell. State, including the current directory and exported environment variables, persists across calls for this agent.'
+
+interface ResolvedConfig {
+  backendType: string
+  timeoutMs: number
+  maxOutputChars: number
+  description: string
+}
+
+interface CommandMarkers {
+  start: string
+  end: string
+}
+
+interface RetainedOutput {
+  text: string
+  truncated: boolean
+}
+
+interface CapturedOutput {
+  text: string
+  incomplete: boolean
+  exitCode?: number
+}
+
+interface PersistentShells {
+  get(owner: Agent, signal: AbortSignal): Promise<PtySessionId>
+  reset(owner: Agent, reason: string): Promise<void>
+}
+
+function maybeTruncate(content: string, maxOutputChars: number, incomplete = false): string {
+  if (content.length <= maxOutputChars && !incomplete) return content
+  return content.length <= maxOutputChars
+    ? content + TRUNCATED_MESSAGE
+    : content.slice(0, maxOutputChars) + TRUNCATED_MESSAGE
+}
+
+function markers(): CommandMarkers {
+  const nonce = randomUUID()
+  return {
+    start: `__DSH_PERSISTENT_BASH_START_${nonce}__`,
+    end: `__DSH_PERSISTENT_BASH_END_${nonce}:`,
+  }
+}
+
+function quoteForBash(value: string): string {
+  return `$'${value
+    .replaceAll('\\', '\\\\')
+    .replaceAll("'", "\\'")
+    .replaceAll('\r', '\\r')
+    .replaceAll('\n', '\\n')}'`
+}
+
+function wrapCommand(command: string, marker: CommandMarkers): string {
+  // Keep the wrapper on one physical line. An interactive bash prints PS2 for
+  // embedded newlines before executing the buffer, which would leak terminal
+  // prompts and marker source text into the model-facing result.
+  return `printf '%s\\n' ${quoteForBash(marker.start)}; eval -- ${quoteForBash(command)}; __dsh_persistent_bash_status=$?; printf '%s%s\\n' ${quoteForBash(marker.end)} "$__dsh_persistent_bash_status"`
+}
+
+function stripPrompt(text: string): string {
+  let result = text.replace(/\r?\n$/, '')
+  while (result.endsWith(SHELL_PROMPT)) {
+    result = result.slice(0, -SHELL_PROMPT.length)
+  }
+  return result.endsWith('\n') ? result.slice(0, -1) : result
+}
+
+function commandOutput(
+  snapshot: RetainedOutput,
+  marker: CommandMarkers,
+): CapturedOutput | undefined {
+  const text = snapshot.text
+  const end = text.lastIndexOf(marker.end)
+  const status = /^(\d+)\r?\n/.exec(text.slice(end + marker.end.length))?.[1]
+  if (status === undefined) return undefined
+  const startMarker = text.lastIndexOf(marker.start, end)
+  const start = startMarker < 0 ? 0 : startMarker + marker.start.length
+  return {
+    text: stripPrompt(text.slice(start, end).replace(/^\r?\n/, '')),
+    incomplete: startMarker < 0,
+    exitCode: Number(status),
+  }
+}
+
+function promptCompleted(result: PtySendResult): boolean {
+  return result.viewport.endsWith(SHELL_PROMPT)
+    || result.viewport.endsWith(`${SHELL_PROMPT}\r\n`)
+    || result.viewport.endsWith(`${SHELL_PROMPT}\n`)
+}
+
+function partialOutput(
+  snapshot: RetainedOutput,
+  marker: CommandMarkers,
+  fallback: string,
+  fallbackTruncated = false,
+): CapturedOutput {
+  const startMarker = snapshot.text.lastIndexOf(marker.start)
+  if (startMarker >= 0) {
+    return {
+      text: stripPrompt(snapshot.text.slice(startMarker + marker.start.length).replace(/^\r?\n/, '')),
+      incomplete: false,
+    }
+  }
+  const fallbackStart = fallback.lastIndexOf(marker.start)
+  const afterStart = fallbackStart < 0
+    ? fallback
+    : fallback.slice(fallbackStart + marker.start.length).replace(/^\r?\n/, '')
+  const fallbackEnd = afterStart.lastIndexOf(marker.end)
+  const beforeEnd = fallbackEnd < 0 ? afterStart : afterStart.slice(0, fallbackEnd)
+  return {
+    text: stripPrompt(beforeEnd.replaceAll(SHELL_PROMPT, '')),
+    incomplete: fallbackTruncated || fallbackStart < 0,
+  }
+}
+
+async function pause(): Promise<void> {
+  await new Promise(resolve => setTimeout(resolve, POLL_INTERVAL_MS))
+}
+
+function nextScrollbackOffset(page: PtyReadResult, offset: number): number | undefined {
+  if (page.text.length === 0 || page.lineEnd <= offset) return undefined
+  return page.lineEnd
+}
+
+function retainedScrollback(
+  ctx: Context,
+  owner: Agent,
+  id: PtySessionId,
+  latest = ctx.pty.read(owner, id, { offset: 0, count: SCROLLBACK_PAGE_LINES }),
+): RetainedOutput {
+  const pages: string[] = latest.text.length === 0 ? [] : [latest.text]
+  let offset = latest.lineEnd
+  let truncated = latest.truncated
+  while (true) {
+    if (offset >= latest.totalLines) break
+    const page = ctx.pty.read(owner, id, { offset, count: SCROLLBACK_PAGE_LINES })
+    truncated ||= page.truncated
+    if (page.text.length > 0) pages.unshift(page.text)
+    const next = nextScrollbackOffset(page, offset)
+    if (next === undefined || next >= page.totalLines) break
+    offset = next
+  }
+  return { text: pages.join('\n'), truncated }
+}
+
+function renderCaptured(output: CapturedOutput, maxOutputChars: number): string {
+  const rendered = maybeTruncate(output.text, maxOutputChars, output.incomplete)
+  const withPrefix = output.incomplete && output.text.length > 0
+    ? LOST_PREFIX_MESSAGE + rendered
+    : rendered
+  const marker = output.exitCode !== undefined && output.exitCode !== 0
+    ? `[exit code: ${output.exitCode}]`
+    : undefined
+  return appendStatusMarker(withPrefix, marker)
+}
+
+function appendStatusMarker(content: string, marker: string | undefined): string {
+  if (marker === undefined) return content
+  return content.length === 0 ? marker : `${content}\n${marker}`
+}
+
+function renderShellExitStatus(
+  content: string,
+  exitCode: number | null,
+  signal: NodeJS.Signals | null,
+): string {
+  const marker = signal !== null
+    ? `[shell killed by signal: ${signal}]`
+    : exitCode !== null
+      ? `[shell exited: code ${exitCode}]`
+      : '[shell exited]'
+  return appendStatusMarker(content, marker)
+}
+
+function persistentShells(ctx: Context, config: ResolvedConfig): PersistentShells {
+  const pending = new WeakMap<Agent, Promise<PtySessionId>>()
+  const live = new Map<Agent, PtySessionId>()
+  const creating = new Set<Promise<PtySessionId>>()
+  const ownerCleanupInstalled = new WeakSet<Agent>()
+  const lifecycle = new AbortController()
+
+  const close = async (owner: Agent, id: PtySessionId, reason: string): Promise<void> => {
+    if (!ctx.pty.list(owner).some(snapshot => snapshot.sessionId === id)) return
+    await ctx.pty.kill(owner, id, reason)
+  }
+
+  ctx.effect(() => async () => {
+    lifecycle.abort(new Error('tool-bash-persistent disposed during shell creation'))
+    await Promise.allSettled([...creating])
+    const closing = [...live].map(async ([owner, id]) => { await close(owner, id, 'tool-bash-persistent disposed') })
+    await Promise.all(closing)
+    live.clear()
+  }, 'tool-bash-persistent shell cleanup')
+
+  const reset = async (owner: Agent, reason: string): Promise<void> => {
+    pending.delete(owner)
+    const id = live.get(owner)
+    live.delete(owner)
+    if (id !== undefined) await close(owner, id, reason)
+  }
+
+  const get = (owner: Agent, signal: AbortSignal): Promise<PtySessionId> => {
+    const existing = pending.get(owner)
+    if (existing !== undefined) return existing
+    const combinedSignal = AbortSignal.any([signal, lifecycle.signal])
+    const creation = (async () => {
+      try {
+        const cwd = owner.session.header.cwd
+        const spawned = await ctx.pty.spawn(owner, {
+          type: config.backendType,
+          ...cwd === undefined ? {} : { cwd },
+        }, combinedSignal)
+        live.set(owner, spawned.sessionId)
+        if (!ownerCleanupInstalled.has(owner)) {
+          ownerCleanupInstalled.add(owner)
+          owner.ctx.effect(() => () => {
+            pending.delete(owner)
+            live.delete(owner)
+          }, 'tool-bash-persistent owner cache cleanup')
+        }
+        const setup = ctx.pty.startSend(owner, spawned.sessionId, {
+          text: `stty -echo; PS1=${quoteForBash(SHELL_PROMPT)}`,
+          submit: true,
+          signal: combinedSignal,
+        })
+        const result = await setup.done
+        if (result.sessionStatus.kind === 'exited' || result.waitReason === 'timeout') {
+          throw new Error('persistent bash shell did not accept initialization')
+        }
+        return spawned.sessionId
+      } catch (error: unknown) {
+        await reset(owner, 'persistent bash initialization failed')
+        throw error
+      }
+    })()
+    const tracked = creation.finally(() => {
+      creating.delete(tracked)
+    })
+    creating.add(tracked)
+    pending.set(owner, tracked)
+    return tracked
+  }
+
+  return { get, reset }
+}
+
+async function executeCommand(
+  ctx: Context,
+  shells: PersistentShells,
+  owner: Agent,
+  command: string,
+  config: ResolvedConfig,
+  upstream: AbortSignal,
+): Promise<string> {
+  using commandDeadline = deadline(upstream, config.timeoutMs, TIMEOUT_CODE)
+  const id = await shells.get(owner, commandDeadline.signal)
+  const marker = markers()
+  const wrapped = wrapCommand(command, marker)
+  let first = true
+  let fallback = ''
+  let fallbackTruncated = false
+
+  while (true) {
+    let operation
+    let result
+    try {
+      operation = ctx.pty.startSend(owner, id, {
+        text: first ? wrapped : '',
+        submit: first,
+        signal: commandDeadline.signal,
+      })
+      first = false
+      result = await operation.done
+    } catch (error: unknown) {
+      await shells.reset(owner, 'persistent bash send failed')
+      throw error
+    }
+    const incremental = operation.readOutput()
+    fallback = incremental.delta.length > 0 ? fallback + incremental.delta : result.viewport
+    fallbackTruncated ||= incremental.truncated || result.truncated
+    const latest = ctx.pty.read(owner, id, { offset: 0, count: SCROLLBACK_PAGE_LINES })
+    const timedOut = timeoutOf(commandDeadline.signal, TIMEOUT_CODE)
+    if (timedOut !== undefined) {
+      const snapshot = retainedScrollback(ctx, owner, id, latest)
+      const partial = renderCaptured(
+        partialOutput(snapshot, marker, fallback, fallbackTruncated),
+        config.maxOutputChars,
+      )
+      await shells.reset(owner, 'persistent bash command timed out')
+      return [
+        // TODO: Report a timeout only; this signal does not establish an OOM.
+        `Your command timed out after ${Math.round(timedOut.timeoutMs / 1000)} seconds or experienced an OOM error. Below is partial output:`,
+        partial,
+        SHELL_RESET_MESSAGE,
+      ].join('\n')
+    }
+    if (commandDeadline.signal.aborted) {
+      await shells.reset(owner, 'persistent bash command aborted')
+      commandDeadline.signal.throwIfAborted()
+    }
+    if (latest.text.includes(marker.end)) {
+      const complete = commandOutput(retainedScrollback(ctx, owner, id, latest), marker)
+      if (complete !== undefined) return renderCaptured(complete, config.maxOutputChars)
+    }
+    if (result.sessionStatus.kind === 'exited') {
+      const snapshot = retainedScrollback(ctx, owner, id, latest)
+      await shells.reset(owner, 'persistent bash shell exited')
+      return [
+        renderShellExitStatus(
+          renderCaptured(partialOutput(snapshot, marker, fallback, fallbackTruncated), config.maxOutputChars),
+          result.sessionStatus.exitCode,
+          result.sessionStatus.signal,
+        ),
+        SHELL_RESET_MESSAGE,
+      ].filter(part => part.length > 0).join('\n')
+    }
+    if (promptCompleted(result)) {
+      const snapshot = retainedScrollback(ctx, owner, id, latest)
+      return renderCaptured(
+        partialOutput(snapshot, marker, fallback, fallbackTruncated),
+        config.maxOutputChars,
+      )
+    }
+    await pause()
+  }
+}
+
+/**
+ * Register the model-facing persistent `bash` tool.
+ * @param ctx - plugin context carrying tools and the owner-scoped PTY service.
+ * @param config - selected PTY backend and command deadline.
+ */
+function registerPersistentBash(ctx: Context, config: ResolvedConfig): void {
+  const shells = persistentShells(ctx, config)
+  const queues = new WeakMap<Agent, Promise<void>>()
+
+  const serialized = async <T>(owner: Agent, operation: () => Promise<T>): Promise<T> => {
+    const prior = queues.get(owner) ?? Promise.resolve()
+    const run = prior.then(operation, operation)
+    const tail = run.then(() => undefined, () => undefined)
+    queues.set(owner, tail)
+    try {
+      return await run
+    } finally {
+      if (queues.get(owner) === tail) queues.delete(owner)
+    }
+  }
+
+  ctx.tools.register(defineTool({
+    name: 'bash',
+    description: config.description,
+    parameters: {
+      command: {
+        type: 'string',
+        required: true,
+        description: 'The bash command to run. Relative path is preferred in the command.',
+      },
+    },
+    output: {
+      schema: { type: 'string' },
+      render: (_args, value) => [{ type: 'text', text: value }],
+    },
+    async execute(args, exec) {
+      if (args.command.trim().length === 0) throw new Error('command must be a non-empty string')
+      const owner = exec.agent
+      if (owner === undefined) throw new Error('bash requires an owning agent session')
+      return serialized(owner, async () => {
+        exec.signal.throwIfAborted()
+        return executeCommand(ctx, shells, owner, args.command, config, exec.signal)
+      })
+    },
+    presentCall: args => ({ card: 'terminal', title: args.command }),
+  }))
+}
+
+export const name = 'tool-bash-persistent'
+export const inject = ['tools', 'pty']
+
+/** Configuration for the persistent Bash tool. */
+export interface Config {
+  /** PTY backend used for each owner-isolated persistent shell (default `shell`). */
+  backendType?: string
+  /** Wall-clock limit for one command (default 300000). */
+  timeoutMs?: number
+  /** Maximum returned command-output characters before clipping (default 16000). */
+  maxOutputChars?: number
+  /** Model-facing tool description; deployments may describe their environment. */
+  description?: string
+}
+
+/** Runtime configuration schema for the persistent Bash tool. */
+export const Config: z<Config> = z.object({
+  backendType: z.string().default('shell'),
+  timeoutMs: z.number().default(300_000),
+  maxOutputChars: z.number().default(16_000),
+  description: z.string().default(DEFAULT_DESCRIPTION),
+})
+
+/** Register one owner-scoped persistent `bash` tool. */
+export function apply(ctx: Context, config: Config): void {
+  const resolved: ResolvedConfig = {
+    backendType: config.backendType ?? 'shell',
+    timeoutMs: config.timeoutMs ?? 300_000,
+    maxOutputChars: config.maxOutputChars ?? 16_000,
+    description: config.description ?? DEFAULT_DESCRIPTION,
+  }
+  if (resolved.backendType.trim().length === 0) {
+    throw new Error('tool-bash-persistent: backendType must be non-empty')
+  }
+  if (!Number.isSafeInteger(resolved.timeoutMs) || resolved.timeoutMs <= 0) {
+    throw new Error('tool-bash-persistent: timeoutMs must be a positive safe integer')
+  }
+  if (!Number.isSafeInteger(resolved.maxOutputChars) || resolved.maxOutputChars <= 0) {
+    throw new Error('tool-bash-persistent: maxOutputChars must be a positive safe integer')
+  }
+  if (resolved.description.trim().length === 0) {
+    throw new Error('tool-bash-persistent: description must be non-empty')
+  }
+  registerPersistentBash(ctx, resolved)
+}
--- a/packages/pty/tool-bash-persistent/src/invariant.ts
+++ b/packages/pty/tool-bash-persistent/src/invariant.ts
@@ -0,0 +1,31 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-tool-bash-persistent`.
+ * @module @deepseek-ai/dsh-tool-bash-persistent/invariant
+ */
+
+/* jscpd:ignore-start */
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-tool-bash-persistent'
+
+/** Cordis companion plugin name. */
+export const name = 'tool-bash-persistent-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/**
+ * No runtime invariant: the adapter's private owner-to-shell cache has no
+ * observable event or data relation. Lifecycle tests prove its cleanup without
+ * adding a public surface solely for an invariant.
+ */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */
--- a/packages/pty/tool-bash-persistent/tests/loader-composition.spec.ts
+++ b/packages/pty/tool-bash-persistent/tests/loader-composition.spec.ts
@@ -0,0 +1,157 @@
+import { mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { pathToFileURL } from 'node:url'
+import { afterEach, describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import Loader from '@cordisjs/plugin-loader'
+import Include from '@cordisjs/plugin-include'
+import { CallId } from '@deepseek-ai/dsh-llm'
+import { Session, SessionId } from '@deepseek-ai/dsh-session'
+import AgentRegistry from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import PtyService from '@deepseek-ai/dsh-pty'
+import * as PtyLocal from '@deepseek-ai/dsh-pty-local'
+import SandboxProvider from '@deepseek-ai/dsh-sandbox'
+import type { ConfinedArgv, SandboxPolicy } from '@deepseek-ai/dsh-sandbox'
+import SandboxPolicyService from '@deepseek-ai/dsh-sandbox-policy'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import ToolRegistry from '@deepseek-ai/dsh-tools'
+import * as ToolBashPersistent from '@deepseek-ai/dsh-tool-bash-persistent'
+
+let root: string | undefined
+let context: Context | undefined
+
+afterEach(async () => {
+  await context?.fiber.dispose()
+  context = undefined
+  if (root !== undefined) await rm(root, { recursive: true, force: true })
+  root = undefined
+})
+
+class PassthroughSandbox extends SandboxProvider {
+  confine(argv: readonly string[], _policy: SandboxPolicy): ConfinedArgv {
+    return { argv: [...argv], enforcement: 'full', denialSignatures: [], runnerFailureSignatures: [] }
+  }
+}
+
+function agent(ctx: Context, cwd: string): Agent {
+  const id = SessionId('persistent-bash-loader-agent')
+  const scope = ctx.plugin(() => {})
+  const value: Agent = {
+    id,
+    options: {},
+    session: new Session(id, [], { version: 0, id, createdAt: 0, cwd }),
+    status: 'idle',
+    acceptsNextStep: false,
+    ctx: scope.ctx,
+    followup: () => {},
+    steer: () => {},
+    inject: () => {},
+    send: () => {},
+    updateInbox: () => 'not-found',
+    cancel() {},
+    whenIdle: () => Promise.resolve(),
+  }
+  ctx.agents.register(value)
+  return value
+}
+
+function text(result: { content: { type: string; text?: string }[] }): string {
+  return result.content.filter(block => block.type === 'text').map(block => block.text).join('')
+}
+
+const suite = process.platform === 'linux' || process.platform === 'darwin' ? describe : describe.skip
+
+suite('persistent Bash through a real cordis.yml Loader composition', () => {
+  it('preserves cwd and environment across calls', async () => {
+    root = await mkdtemp(join(tmpdir(), 'dsh-persistent-bash-loader-'))
+    const configPath = join(root, 'cordis.yml')
+    await writeFile(configPath, [
+      "- name: '@deepseek-ai/dsh-agent'",
+      "- name: '@deepseek-ai/dsh-system-prompt'",
+      "- name: '@deepseek-ai/dsh-tools'",
+      "- name: '@deepseek-ai/dsh-pty'",
+      "- name: '@deepseek-ai/dsh-test-sandbox'",
+      "- name: '@deepseek-ai/dsh-sandbox-policy'",
+      '  config:',
+      '    mode: danger-full-access',
+      `    workspaceRoot: ${JSON.stringify(root)}`,
+      "- name: '@deepseek-ai/dsh-pty-local'",
+      '  config:',
+      '    pollIntervalMs: 10',
+      '    exactProbeAfterMs: 20',
+      '    idleSilenceMs: 100',
+      '    handoffGraceMs: 100',
+      '    scrollbackLines: 20000',
+      '    timeoutMs: 2000',
+      '    disposeGraceMs: 500',
+      "- name: '@deepseek-ai/dsh-tool-bash-persistent'",
+      '  config:',
+      '    timeoutMs: 5000',
+      '',
+    ].join('\n'))
+
+    context = new Context()
+    context.baseUrl = pathToFileURL(root).href + '/'
+    await context.plugin(Loader)
+    context.loader.builtins.include = Include
+    const modules = new Map<string, unknown>([
+      ['@deepseek-ai/dsh-agent', AgentRegistry],
+      ['@deepseek-ai/dsh-system-prompt', SystemPrompt],
+      ['@deepseek-ai/dsh-tools', ToolRegistry],
+      ['@deepseek-ai/dsh-pty', PtyService],
+      ['@deepseek-ai/dsh-test-sandbox', PassthroughSandbox],
+      ['@deepseek-ai/dsh-sandbox-policy', SandboxPolicyService],
+      ['@deepseek-ai/dsh-pty-local', PtyLocal],
+      ['@deepseek-ai/dsh-tool-bash-persistent', ToolBashPersistent],
+    ])
+    context.loader.internal = {
+      version: 'v2',
+      async import(specifier: string) {
+        if (!modules.has(specifier)) throw new Error(`unexpected Loader import: ${specifier}`)
+        return modules.get(specifier)
+      },
+    } as unknown as NonNullable<typeof context.loader.internal>
+    await context.loader.create({ name: 'cordis:include', config: { path: pathToFileURL(configPath).href } })
+    await context.loader.await()
+
+    const owner = agent(context, root)
+    const signal = new AbortController().signal
+    const execute = (id: string, command: string) => context!.tools.execute({
+      signal,
+      callId: CallId(id),
+      name: 'bash',
+      arguments: { command },
+      agent: owner,
+    })
+
+    expect(context.tools.schemas().map(schema => schema.name)).toEqual(['bash'])
+    await execute('state', 'export KEEP=loader; mkdir -p nested; cd nested')
+    const observed = text(await execute('observe', 'printf "cwd=%s keep=%s\\n" "$PWD" "$KEEP"'))
+    expect(observed).toContain(`cwd=${join(root, 'nested')} keep=loader`)
+    expect(observed).not.toContain('DSH_PERSISTENT_BASH')
+
+    const multiline = text(await execute(
+      'multiline',
+      'value="line one"\nprintf "%s:%s\\n" "$value" "it\'s fine"',
+    ))
+    expect(multiline).toBe("line one:it's fine")
+    expect(multiline).not.toContain('DSH_PERSISTENT_BASH')
+
+    const heredoc = text(await execute(
+      'heredoc',
+      "cat <<'EOF'\nalpha\nbeta\nEOF",
+    ))
+    expect(heredoc).toBe('alpha\nbeta')
+
+    const large = text(await execute('large-output', 'seq 1 12050'))
+    expect(large.startsWith('1\n2\n3\n')).toBe(true)
+    expect(large).toContain('<response clipped>')
+    expect(large).not.toContain('beginning of this command output was dropped')
+
+    const exited = text(await execute('exit', 'exit'))
+    expect(exited).toContain('next bash call starts from the workspace')
+    expect(text(await execute('after-exit', 'printf "%s\\n" "$PWD"'))).toBe(root)
+  }, 20_000)
+})
--- a/packages/pty/tool-bash-persistent/tests/tools.spec.ts
+++ b/packages/pty/tool-bash-persistent/tests/tools.spec.ts
@@ -0,0 +1,538 @@
+import { afterEach, describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import { CallId } from '@deepseek-ai/dsh-llm'
+import { Session, SessionId } from '@deepseek-ai/dsh-session'
+import AgentRegistry from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import PtyService from '@deepseek-ai/dsh-pty'
+import type {
+  PtyBackend,
+  PtyBackendSession,
+  PtyReadRequest,
+  PtySendOperation,
+  PtySendRequest,
+  PtySessionStatus,
+  PtySignal,
+  PtyWaitReason,
+} from '@deepseek-ai/dsh-pty'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import ToolRegistry from '@deepseek-ai/dsh-tools'
+import * as ToolBashPersistent from '@deepseek-ai/dsh-tool-bash-persistent'
+
+const contexts: Context[] = []
+let callNumber = 0
+
+afterEach(async () => {
+  for (const ctx of contexts.splice(0)) await ctx.fiber.dispose()
+})
+
+function agent(ctx: Context, cwd: string | undefined): Agent {
+  const id = SessionId(`persistent-bash-owner-${callNumber}`)
+  const scope = ctx.plugin(() => {})
+  const value: Agent = {
+    id,
+    options: {},
+    session: new Session(id, [], {
+      version: 0,
+      id,
+      createdAt: 0,
+      ...cwd === undefined ? {} : { cwd },
+    }),
+    status: 'idle',
+    acceptsNextStep: false,
+    ctx: scope.ctx,
+    followup: () => {},
+    steer: () => {},
+    inject: () => {},
+    send: () => {},
+    updateInbox: () => 'not-found',
+    cancel() {},
+    whenIdle: () => Promise.resolve(),
+  }
+  ctx.agents.register(value)
+  return value
+}
+
+function text(result: { content: { type: string; text?: string }[] }): string {
+  return result.content.filter(block => block.type === 'text').map(block => block.text).join('')
+}
+
+function call(
+  ctx: Context,
+  owner: Agent | undefined,
+  command: string,
+  signal = new AbortController().signal,
+) {
+  return ctx.tools.execute({
+    signal,
+    callId: CallId(`persistent-bash-${++callNumber}`),
+    name: 'bash',
+    arguments: { command },
+    ...owner === undefined ? {} : { agent: owner },
+  })
+}
+
+type StubMode =
+  | 'normal'
+  | 'prompt-only'
+  | 'prompt-crlf'
+  | 'empty-read'
+  | 'stalled-read'
+  | 'exit'
+  | 'signal-exit'
+  | 'unknown-exit'
+  | 'wait-for-abort'
+  | 'end-on-abort'
+  | 'idle-then-normal'
+  | 'large'
+  | 'nonzero'
+  | 'torn-status'
+  | 'finish-torn-status'
+  | 'end-only'
+  | 'init-exit'
+  | 'init-timeout'
+  | 'spawn-error'
+  | 'send-error'
+  | 'prompt-after-idle'
+  | 'empty-page-after-latest'
+
+class StubPtySession implements PtyBackendSession {
+  readonly motd = '__DSH_PERSISTENT_BASH_PROMPT__ '
+  readonly pid = 123
+  statusValue: PtySessionStatus = { kind: 'running' }
+  scrollback = this.motd
+  closed: string[] = []
+  mode: StubMode
+  sends = 0
+  pendingText = ''
+  historyTruncated = false
+
+  constructor(mode: StubMode) {
+    this.mode = mode
+  }
+
+  startSend(request: PtySendRequest): PtySendOperation {
+    this.sends += 1
+    if (request.text.startsWith('stty -echo')) {
+      if (this.mode === 'init-exit') {
+        this.statusValue = { kind: 'exited', exitCode: 1, signal: null }
+        return this.operation(Promise.resolve(this.result('', 'session_exit')))
+      }
+      if (this.mode === 'init-timeout') {
+        return this.operation(Promise.resolve(this.result('', 'timeout')))
+      }
+      return this.operation(Promise.resolve(this.result(this.motd, 'stdin_read')))
+    }
+    if (this.mode === 'send-error') throw new Error('stub send failed')
+    if (this.mode === 'wait-for-abort' || this.mode === 'end-on-abort') {
+      const done = new Promise<ReturnType<StubPtySession['result']>>((resolve) => {
+        request.signal?.addEventListener('abort', () => {
+          const start = /__DSH_PERSISTENT_BASH_START_[^_]+(?:-[^_]+)*__/.exec(request.text)?.[0]
+          const end = /__DSH_PERSISTENT_BASH_END_[^:]+:/.exec(request.text)?.[0]
+          const output = this.mode === 'end-on-abort'
+            ? `${start ?? ''}\ninterrupted\n${end ?? ''}130\n${this.motd}`
+            : 'partial output'
+          this.scrollback += output
+          resolve(this.result(output, 'stdin_read'))
+        }, { once: true })
+      })
+      return this.operation(done)
+    }
+    if (this.mode === 'idle-then-normal') {
+      this.mode = 'normal'
+      this.pendingText = request.text
+      return this.operation(Promise.resolve(this.result('', 'inferred_idle')))
+    }
+    if (this.mode === 'prompt-after-idle') {
+      if (request.text.length > 0) {
+        const start = /__DSH_PERSISTENT_BASH_START_[^_]+(?:-[^_]+)*__/.exec(request.text)?.[0]
+        const output = `${start ?? ''}\npartial syntax output\n`
+        this.scrollback += output
+        return this.operation(Promise.resolve(this.result(output, 'inferred_idle')))
+      }
+      const output = `bash: syntax error\n${this.motd}`
+      this.scrollback += output
+      return this.operation(Promise.resolve(this.result(output, 'stdin_read')))
+    }
+    if (this.mode === 'prompt-only' || this.mode === 'prompt-crlf') {
+      const newline = this.mode === 'prompt-crlf' ? '\r\n' : '\n'
+      const output = `bash: syntax error${newline}${this.motd}${newline}`
+      this.scrollback += output
+      return this.operation(Promise.resolve(this.result(output, 'stdin_read')))
+    }
+    const sent = request.text.length > 0 ? request.text : this.pendingText
+    this.pendingText = ''
+    const start = /__DSH_PERSISTENT_BASH_START_[^_]+(?:-[^_]+)*__/.exec(sent)?.[0]
+    const end = /__DSH_PERSISTENT_BASH_END_[^:]+:/.exec(sent)?.[0]
+    if (this.mode === 'torn-status') {
+      const output = `${start ?? ''}\nhello from stub\n${end ?? ''}`
+      this.scrollback += output
+      this.mode = 'finish-torn-status'
+      return this.operation(Promise.resolve(this.result(output, 'inferred_idle')))
+    }
+    if (this.mode === 'finish-torn-status') {
+      const output = `7\n${this.motd}`
+      this.scrollback += output
+      return this.operation(Promise.resolve(this.result(output, 'stdin_read')))
+    }
+    if (this.mode === 'end-only') {
+      const output = `recovered output\n${end ?? ''}0\n${this.motd}`
+      this.scrollback += output
+      return this.operation(Promise.resolve(this.result(output, 'stdin_read')))
+    }
+    const commandOutput = this.mode === 'large'
+      ? 'x'.repeat(100)
+      : this.mode === 'nonzero' ? '' : 'hello from stub'
+    const exitCode = this.mode === 'nonzero' ? 7 : 0
+    const output = `${start ?? ''}\n${commandOutput}\n${end ?? ''}${exitCode}\n${this.motd}`
+    this.scrollback += output
+    if (this.mode === 'exit' || this.mode === 'signal-exit' || this.mode === 'unknown-exit') {
+      const exitedOutput = `${start ?? ''}\nhello from stub\n`
+      this.scrollback = this.scrollback.slice(0, -output.length) + exitedOutput
+      this.statusValue = this.mode === 'signal-exit'
+        ? { kind: 'exited', exitCode: null, signal: 'SIGTERM' }
+        : this.mode === 'exit'
+          ? { kind: 'exited', exitCode: 9, signal: null }
+          : { kind: 'exited', exitCode: null, signal: null }
+      return this.operation(Promise.resolve(this.result(exitedOutput, 'session_exit')))
+    }
+    return this.operation(Promise.resolve(this.result(output, 'stdin_read')))
+  }
+
+  read(request: PtyReadRequest) {
+    if (this.mode === 'empty-read') {
+      return { text: '', totalLines: 0, lineBegin: 0, lineEnd: 0, truncated: false }
+    }
+    if (this.mode === 'stalled-read') {
+      return { text: 'stalled', totalLines: 1, lineBegin: 0, lineEnd: 0, truncated: false }
+    }
+    if (this.mode === 'empty-page-after-latest' && (request.offset ?? 0) > 0) {
+      return { text: '', totalLines: 2, lineBegin: 1, lineEnd: 1, truncated: false }
+    }
+    const lines = this.scrollback.split('\n')
+    return {
+      text: this.scrollback,
+      totalLines: this.mode === 'empty-page-after-latest' ? lines.length + 1 : lines.length,
+      lineBegin: 0,
+      lineEnd: this.mode === 'empty-page-after-latest' ? 1 : lines.length,
+      truncated: this.historyTruncated,
+    }
+  }
+
+  signal(_signal: PtySignal) {
+    return Promise.resolve({ delivered: true as const, targetPgid: 123 })
+  }
+
+  status() {
+    return this.statusValue
+  }
+
+  async close(reason: string) {
+    this.closed.push(reason)
+    this.statusValue = { kind: 'exited', exitCode: 0, signal: null }
+  }
+
+  private result(viewport: string, waitReason: PtyWaitReason) {
+    return { viewport, waitReason, sessionStatus: this.statusValue, truncated: false }
+  }
+
+  private operation(done: Promise<ReturnType<StubPtySession['result']>>): PtySendOperation {
+    return {
+      done,
+      readOutput: () => ({ delta: '', truncated: false }),
+      cancel: () => false,
+    }
+  }
+}
+
+function stubBackend(initialMode: StubMode = 'normal') {
+  const sessions: StubPtySession[] = []
+  const backend: PtyBackend = {
+    type: 'stub',
+    async spawn() {
+      if (initialMode === 'spawn-error') throw new Error('stub spawn failed')
+      const session = new StubPtySession(initialMode)
+      sessions.push(session)
+      return session
+    },
+  }
+  return { backend, sessions }
+}
+
+async function setup(
+  config: ToolBashPersistent.Config = { backendType: 'stub' },
+  initialMode: StubMode = 'normal',
+) {
+  const ctx = new Context()
+  contexts.push(ctx)
+  await ctx.plugin(SystemPrompt)
+  await ctx.plugin(ToolRegistry)
+  await ctx.plugin(AgentRegistry)
+  await ctx.plugin(PtyService)
+  const stub = stubBackend(initialMode)
+  ctx.pty.registerBackend(stub.backend)
+  const fiber = await ctx.plugin(ToolBashPersistent, config)
+  return { ctx, stub, fiber, owner: agent(ctx, '/workspace') }
+}
+
+describe('tool-bash-persistent', () => {
+  it('registers a configurable schema and reuses one owner shell', async () => {
+    const { ctx, owner, stub, fiber } = await setup({
+      backendType: 'stub',
+      description: 'deployment-specific persistent shell',
+    })
+    const schema = ctx.tools.schemas()[0]
+    expect(ctx.tools.schemas().map(item => item.name)).toEqual(['bash'])
+    expect(schema?.description).toBe('deployment-specific persistent shell')
+    expect(schema?.parameters).toMatchObject({
+      required: ['command'],
+      properties: { command: { type: 'string' } },
+    })
+    expect(ctx.tools.get('bash')?.presentCall?.({ command: 'pwd' }))
+      .toEqual({ card: 'terminal', title: 'pwd' })
+
+    expect(text(await call(ctx, owner, 'echo one'))).toBe('hello from stub')
+    expect(text(await call(ctx, owner, 'echo two'))).toBe('hello from stub')
+    expect(stub.sessions).toHaveLength(1)
+    expect(stub.sessions[0]?.sends).toBe(3)
+
+    const ownerWithoutCwd = agent(ctx, undefined)
+    expect(text(await call(ctx, ownerWithoutCwd, 'pwd'))).toBe('hello from stub')
+    expect(stub.sessions).toHaveLength(2)
+
+    await fiber.dispose()
+    expect(ctx.tools.schemas()).toEqual([])
+    expect(ctx.tools.get('bash')).toBeUndefined()
+  })
+
+  it('handles inferred idle, prompt fallback, shell exit, clipping, and cleanup', async () => {
+    const { ctx, owner, stub, fiber } = await setup({
+      backendType: 'stub',
+      maxOutputChars: 10,
+    })
+    await call(ctx, owner, 'warm up')
+    const session = stub.sessions[0]!
+
+    session.mode = 'idle-then-normal'
+    expect(text(await call(ctx, owner, 'silent then complete'))).toContain('hello from')
+
+    session.mode = 'prompt-only'
+    const promptFallback = text(await call(ctx, owner, 'bad {'))
+    expect(promptFallback).toContain('bash: synt')
+    expect(promptFallback).not.toContain('DSH_PERSISTENT_BASH_PROMPT')
+
+    session.mode = 'prompt-crlf'
+    session.scrollback = ''
+    const crlfPromptFallback = text(await call(ctx, owner, 'bad {'))
+    expect(crlfPromptFallback).toContain('bash: synt')
+    expect(crlfPromptFallback).not.toContain('DSH_PERSISTENT_BASH_PROMPT')
+
+    session.mode = 'end-only'
+    session.scrollback = ''
+    const missingStart = text(await call(ctx, owner, 'recover marker'))
+    expect(missingStart).toContain('recovered')
+    expect(missingStart).toContain('beginning of this command output was dropped')
+    expect(missingStart).toContain('<response clipped>')
+
+    session.mode = 'large'
+    expect(text(await call(ctx, owner, 'large'))).toContain('<response clipped>')
+
+    session.mode = 'nonzero'
+    expect(text(await call(ctx, owner, 'false'))).toBe('[exit code: 7]')
+
+    session.mode = 'exit'
+    const exited = text(await call(ctx, owner, 'exit'))
+    expect(exited).toContain('hello from')
+    expect(exited).toContain('[shell exited: code 9]')
+    expect(exited).not.toContain('[exit code: 9]')
+    expect(exited).toContain('next bash call starts from the workspace')
+    expect(session.closed).toContain('persistent bash shell exited')
+
+    await call(ctx, owner, 'new shell')
+    expect(stub.sessions).toHaveLength(2)
+    const replacement = stub.sessions[1]!
+    replacement.mode = 'signal-exit'
+    expect(text(await call(ctx, owner, 'kill shell')))
+      .toContain('[shell killed by signal: SIGTERM]')
+
+    await call(ctx, owner, 'another shell')
+    expect(stub.sessions).toHaveLength(3)
+    const externallyClosed = ctx.pty.list(owner)[0]?.sessionId
+    expect(externallyClosed).toBeDefined()
+    await ctx.pty.kill(owner, externallyClosed!, 'external cleanup')
+    await fiber.dispose()
+    expect(stub.sessions[2]?.closed).toEqual(['external cleanup'])
+  })
+
+  it('waits for status digits after a torn completion marker', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub', maxOutputChars: 1_000 })
+    await call(ctx, owner, 'warm up')
+    stub.sessions[0]!.mode = 'torn-status'
+    stub.sessions[0]!.scrollback = ''
+
+    expect(text(await call(ctx, owner, 'torn status'))).toBe('hello from stub\n[exit code: 7]')
+  })
+
+  it('reports a shell exit when the backend has no code or signal', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub' })
+    await call(ctx, owner, 'warm up')
+    stub.sessions[0]!.mode = 'unknown-exit'
+
+    expect(text(await call(ctx, owner, 'exit without status'))).toContain('[shell exited]')
+  })
+
+  it('marks a short missing-prefix result and tolerates exhausted scrollback pages', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub', maxOutputChars: 1_000 })
+    await call(ctx, owner, 'warm up')
+    const session = stub.sessions[0]!
+
+    session.mode = 'end-only'
+    session.scrollback = ''
+    expect(text(await call(ctx, owner, 'missing start')))
+      .toContain('beginning of this command output was dropped')
+
+    session.mode = 'empty-read'
+    expect(text(await call(ctx, owner, 'empty page'))).toContain('hello from stub')
+
+    session.mode = 'stalled-read'
+    expect(text(await call(ctx, owner, 'stalled page'))).toContain('hello from stub')
+
+    session.mode = 'empty-page-after-latest'
+    expect(text(await call(ctx, owner, 'empty continuation page'))).toContain('hello from stub')
+  })
+
+  it('sanitizes a prompt fallback reached after multiple polling rounds', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub', maxOutputChars: 1_000 })
+    await call(ctx, owner, 'warm up')
+    const session = stub.sessions[0]!
+    session.mode = 'prompt-after-idle'
+    session.scrollback = ''
+    const result = text(await call(ctx, owner, 'bad {'))
+    expect(result).toContain('partial syntax output')
+    expect(result).toContain('bash: syntax error')
+    expect(result).not.toContain('DSH_PERSISTENT_BASH_PROMPT')
+    expect(result).not.toContain('DSH_PERSISTENT_BASH_START')
+  })
+
+  it('does not attribute old scrollback truncation to a complete current command', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub', maxOutputChars: 1_000 })
+    await call(ctx, owner, 'warm up')
+    stub.sessions[0]!.historyTruncated = true
+    const result = text(await call(ctx, owner, 'short command'))
+    expect(result).toBe('hello from stub')
+    expect(result).not.toContain('<response clipped>')
+    expect(result).not.toContain('beginning of this command output was dropped')
+  })
+
+  it('closes a timed-out shell and reports bounded partial output', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub', timeoutMs: 10 })
+    await call(ctx, owner, 'warm up')
+    stub.sessions[0]!.mode = 'wait-for-abort'
+    const result = await call(ctx, owner, 'hang')
+    expect(text(result)).toContain('timed out after 0 seconds or experienced an OOM error')
+    expect(text(result)).toContain('partial output')
+    expect(text(result)).toContain('next bash call starts from the workspace')
+    expect(stub.sessions[0]?.closed).toContain('persistent bash command timed out')
+  })
+
+  it.each(['wait-for-abort', 'end-on-abort'] as const)(
+    'cancels %s work, resets the shell, and releases a queued call',
+    async (mode) => {
+      const { ctx, owner, stub } = await setup({ backendType: 'stub', timeoutMs: 5_000 })
+      await call(ctx, owner, 'warm up')
+      stub.sessions[0]!.mode = mode
+      const controller = new AbortController()
+      const cancelled = call(ctx, owner, 'hang', controller.signal)
+      const queued = call(ctx, owner, 'after cancellation')
+      setTimeout(() => {
+        controller.abort(new Error('caller stopped'))
+      }, 5)
+
+      expect((await cancelled).isError).toBe(true)
+      expect(text(await queued)).toBe('hello from stub')
+      expect(stub.sessions[0]?.closed).toContain('persistent bash command aborted')
+      expect(stub.sessions).toHaveLength(2)
+    },
+  )
+
+  it.each(['init-exit', 'init-timeout'] as const)(
+    'fails initialization and closes the unusable shell for %s',
+    async (mode) => {
+      const { ctx, owner, stub } = await setup({ backendType: 'stub' }, mode)
+      expect((await call(ctx, owner, 'pwd')).isError).toBe(true)
+      expect(stub.sessions[0]?.closed).toContain('persistent bash initialization failed')
+    },
+  )
+
+  it('clears a failed spawn without trying to close an unpublished shell', async () => {
+    const { ctx, owner, stub } = await setup({ backendType: 'stub' }, 'spawn-error')
+    expect((await call(ctx, owner, 'pwd')).isError).toBe(true)
+    expect(stub.sessions).toHaveLength(0)
+  })
+
+  it('resets a cached shell after startSend fails', async () => {
+    const { ctx, owner, stub } = await setup()
+    await call(ctx, owner, 'warm up')
+    stub.sessions[0]!.mode = 'send-error'
+    expect((await call(ctx, owner, 'fails')).isError).toBe(true)
+    expect(stub.sessions[0]?.closed).toContain('persistent bash send failed')
+    expect(text(await call(ctx, owner, 'recovers'))).toBe('hello from stub')
+    expect(stub.sessions).toHaveLength(2)
+  })
+
+  it('cancels and awaits a pending shell spawn when the plugin is disposed', async () => {
+    const ctx = new Context()
+    contexts.push(ctx)
+    await ctx.plugin(SystemPrompt)
+    await ctx.plugin(ToolRegistry)
+    await ctx.plugin(AgentRegistry)
+    await ctx.plugin(PtyService)
+    const spawnStarted = Promise.withResolvers<undefined>()
+    const spawnAborted = Promise.withResolvers<undefined>()
+    ctx.pty.registerBackend({
+      type: 'slow',
+      spawn: spec => new Promise((_resolve, reject) => {
+        spawnStarted.resolve(undefined)
+        spec.signal?.addEventListener('abort', () => {
+          spawnAborted.resolve(undefined)
+          const reason: unknown = spec.signal?.reason
+          reject(reason instanceof Error
+            ? reason
+            : new Error('slow PTY spawn aborted', { cause: reason }))
+        }, { once: true })
+      }),
+    })
+    const fiber = await ctx.plugin(ToolBashPersistent, { backendType: 'slow' })
+    const owner = agent(ctx, '/workspace')
+    const running = call(ctx, owner, 'pwd')
+    await spawnStarted.promise
+    await fiber.dispose()
+    await spawnAborted.promise
+    expect((await running).isError).toBe(true)
+    expect(ctx.pty.list(owner)).toEqual([])
+  })
+
+  it('rejects invalid config and invalid calls', async () => {
+    const { ctx, owner, stub } = await setup()
+    expect((await call(ctx, undefined, 'pwd')).isError).toBe(true)
+    expect(text(await call(ctx, owner, ' '))).toContain('command must be a non-empty string')
+
+    const controller = new AbortController()
+    controller.abort(new Error('caller stopped'))
+    expect((await call(ctx, owner, 'pwd', controller.signal)).isError).toBe(true)
+    expect(stub.sessions).toHaveLength(0)
+
+    expect(() => {
+      ToolBashPersistent.apply(new Context(), { backendType: '' })
+    }).toThrow('backendType must be non-empty')
+    expect(() => {
+      ToolBashPersistent.apply(new Context(), { timeoutMs: 0 })
+    }).toThrow('timeoutMs must be a positive safe integer')
+    expect(() => {
+      ToolBashPersistent.apply(new Context(), { maxOutputChars: 0 })
+    }).toThrow('maxOutputChars must be a positive safe integer')
+    expect(() => {
+      ToolBashPersistent.apply(new Context(), { description: ' ' })
+    }).toThrow('description must be non-empty')
+  })
+})
--- a/packages/pty/tool-bash-persistent/tsconfig.json
+++ b/packages/pty/tool-bash-persistent/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": ["src"],
+  "references": [
+    { "path": "../../../vendor/cordis" },
+    { "path": "../../core/agent" },
+    { "path": "../../core/tools" },
+    { "path": "../pty" },
+    { "path": "../../support/invariants" },
+    { "path": "../../util/timeout" }
+  ]
+}