diff --git a/packages/ptc-runtime/ptc-runtime-node/README.i18n.yaml b/packages/ptc-runtime/ptc-runtime-node/README.i18n.yaml
index 1ecdc1933e..a0ee6f5e6f 100644
--- a/packages/ptc-runtime/ptc-runtime-node/README.i18n.yaml
+++ b/packages/ptc-runtime/ptc-runtime-node/README.i18n.yaml
@@ -30,8 +30,8 @@
   en: 3e7ab293fac35688
   zh: 617ed4930bbef6c7
 /deepseek-ai-dsh-ptc-runtime-node/use-this-package/failures:
-  en: 34a221d0f26b8e47
-  zh: 2fd20ac9c9953c7f
+  en: 66fbe8baf4dc4506
+  zh: b8adee47561365da
 /deepseek-ai-dsh-ptc-runtime-node/understand-the-implementation:
   en: 50e6cd38e298da31
   zh: c8b252b3acf59147
diff --git a/packages/ptc-runtime/ptc-runtime-node/README.md b/packages/ptc-runtime/ptc-runtime-node/README.md
index a7fe249acf..7c032381da 100644
--- a/packages/ptc-runtime/ptc-runtime-node/README.md
+++ b/packages/ptc-runtime/ptc-runtime-node/README.md
@@ -109,6 +109,8 @@ Omitting `timeoutMs` uses the configured elapsed default; numeric requests are v
 
 Program parse errors and thrown exceptions are `exception`; deadline expiry is `timeout`; cancellation is `abort`; unparsable or oversized control traffic and invalid program messages are `protocol`; unavailable confinement is `sandbox-unavailable`; early process exit, lost control transport or failed managed cleanup is `worker-exit`. Control I/O failures retain the transport diagnostic alongside the observed process exit status. The substrate-independent failure name remains `worker-exit` for process providers. Lossy completions are `invalid-output`, and an oversized outer result is `output-limit`, retaining the fitting log prefix. Invalid or unsupported options and calls after disposal reject as caller misuse.
 
+Temporary environments keep a string or `Error` message supplied by the caller; other cancellation reasons, including structured Agent causes, report `execution canceled`. Retained environments report `execution canceled; retained variables were cleared`.
+
 -----
 
 <a id="understand-the-implementation"></a>
diff --git a/packages/ptc-runtime/ptc-runtime-node/README.zh.md b/packages/ptc-runtime/ptc-runtime-node/README.zh.md
index 7a2503ce1f..e20f6f7a7c 100644
--- a/packages/ptc-runtime/ptc-runtime-node/README.zh.md
+++ b/packages/ptc-runtime/ptc-runtime-node/README.zh.md
@@ -109,6 +109,8 @@ PTC 消费方按 [dsh-tool-executor-ptc](../../core/tool-executor-ptc/README.zh.
 
 程序解析错误与抛出异常为 `exception`；截止到期为 `timeout`；取消为 `abort`；无法解析或超量的控制通信以及无效的程序消息为 `protocol`；约束不可用为 `sandbox-unavailable`；进程提前退出、控制通道丢失或受管清理失败为 `worker-exit`。控制通道 I/O 失败时，在观测到的进程退出状态之外保留通道诊断原因。进程提供方保留与执行基底无关的失败名 `worker-exit`。有损完成值为 `invalid-output`，外层结果超限为 `output-limit`，并保留能容纳的日志前缀。无效或不支持的选项，以及资源释放后的调用，以调用方误用拒绝。
 
+临时环境保留调用方提供的字符串或 `Error` 消息；其他取消原因（包括结构化 Agent 原因）显示为 `execution canceled`。保留状态的环境显示为 `execution canceled; retained variables were cleared`。
+
 -----
 
 <a id="understand-the-implementation"></a>
diff --git a/packages/ptc-runtime/ptc-runtime-node/src/worker.ts b/packages/ptc-runtime/ptc-runtime-node/src/worker.ts
index ff5307c320..20814d19d2 100644
--- a/packages/ptc-runtime/ptc-runtime-node/src/worker.ts
+++ b/packages/ptc-runtime/ptc-runtime-node/src/worker.ts
@@ -107,7 +107,9 @@ export class ProgramWorker {
   }
 
   private abortMessage(signal: AbortSignal | undefined): string {
-    return this.retainsState ? 'execution canceled; retained variables were cleared' : messageOf(signal?.reason)
+    if (this.retainsState) return 'execution canceled; retained variables were cleared'
+    const reason: unknown = signal?.reason
+    return typeof reason === 'string' || reason instanceof Error ? messageOf(reason) : 'execution canceled'
   }
 
   private async evaluate(spec: PtcRunSpec, bindings: Map<string, PtcBindingNamespace>): Promise<PtcRunResult> {
diff --git a/packages/ptc-runtime/ptc-runtime-node/tests/host-failures.spec.ts b/packages/ptc-runtime/ptc-runtime-node/tests/host-failures.spec.ts
index 5a5aad761e..da669c3a45 100644
--- a/packages/ptc-runtime/ptc-runtime-node/tests/host-failures.spec.ts
+++ b/packages/ptc-runtime/ptc-runtime-node/tests/host-failures.spec.ts
@@ -129,6 +129,21 @@ describe('Node runtime host failures', () => {
     expect(h.resolveExecutable).not.toHaveBeenCalled()
   })
 
+  it.each<[unknown, string]>([
+    [{ kind: 'user' }, 'execution canceled'],
+    [{ kind: 'parent' }, 'execution canceled'],
+    [{ kind: 'hook', reason: 'policy stopped the turn' }, 'execution canceled'],
+    [{ kind: 'disposed' }, 'execution canceled'],
+    [null, 'execution canceled'],
+    [new Error('stop requested'), 'stop requested'],
+    ['stop requested', 'stop requested'],
+  ])('renders pre-start cancellation %j as %s', async (reason, message) => {
+    const h = await setup()
+    const result = await h.start({ ...request, signal: AbortSignal.abort(reason) }, NO_INITIAL_FRAME)
+    expect(result.error).toEqual({ kind: 'abort', message })
+    expect(h.resolveExecutable).not.toHaveBeenCalled()
+  })
+
   it('keeps a null-deadline run active past the numeric ceiling until cancellation', async () => {
     const h = await setup({ timeoutMs: 20, maxTimeoutMs: 40 })
     const booted = Promise.withResolvers<undefined>()
diff --git a/packages/ptc-runtime/ptc-runtime-node/tests/runtime.spec.ts b/packages/ptc-runtime/ptc-runtime-node/tests/runtime.spec.ts
index 03688e1ae4..ec7bae7fe4 100644
--- a/packages/ptc-runtime/ptc-runtime-node/tests/runtime.spec.ts
+++ b/packages/ptc-runtime/ptc-runtime-node/tests/runtime.spec.ts
@@ -186,9 +186,14 @@ describe('Node program process', () => {
     const entered = Promise.withResolvers<undefined>()
     const controller = new AbortController()
     const active = run({ ...timing, program: 'void tools.enter({}); for (;;) {}', signal: controller.signal, bindings: bindings({ enter: async () => { entered.resolve(undefined); return null } }) })
-    await entered.promise
-    controller.abort('stop')
-    expect((await active).error).toEqual({ kind: 'abort', message: 'stop' })
+    try {
+      await entered.promise
+      controller.abort({ kind: 'user' })
+      expect((await active).error).toEqual({ kind: 'abort', message: 'execution canceled' })
+    } finally {
+      controller.abort('test cleanup')
+      await active
+    }
   })
 
   it('closes a still-running descendant before returning the program result', async () => {
diff --git a/snapshots/sdk/ptc-cancel/cancel.mjs b/snapshots/sdk/ptc-cancel/cancel.mjs
new file mode 100644
index 0000000000..0f7e8ebb9d
--- /dev/null
+++ b/snapshots/sdk/ptc-cancel/cancel.mjs
@@ -0,0 +1,10 @@
+/** Cancel only after a real PTC process has dispatched its readiness tool. */
+export const name = 'ptc-cancel-fixture'
+export const inject = ['tools']
+export function apply(ctx) {
+  ctx.on('tools/result', (exec) => {
+    if (exec.name === 'working_directory' && exec.parent !== undefined) {
+      exec.agent.cancel({ kind: 'user' })
+    }
+  })
+}
diff --git a/snapshots/sdk/ptc-cancel/runtime.cordis.yml b/snapshots/sdk/ptc-cancel/runtime.cordis.yml
new file mode 100644
index 0000000000..4b3df2b8c7
--- /dev/null
+++ b/snapshots/sdk/ptc-cancel/runtime.cordis.yml
@@ -0,0 +1,5 @@
+- insert:
+    - id: ptc-runtime
+      name: '@deepseek-ai/dsh-ptc-runtime-node'
+    - id: ptc-cancel-fixture
+      name: './cancel.mjs'
diff --git a/snapshots/sdk/ptc-cancel/session.v4.jsonl b/snapshots/sdk/ptc-cancel/session.v4.jsonl
new file mode 100644
index 0000000000..cf5deccb0a
--- /dev/null
+++ b/snapshots/sdk/ptc-cancel/session.v4.jsonl
@@ -0,0 +1,21 @@
+{"type":"session","version":4,"id":"{{session:1}}","createdAt":1785014439563,"cwd":"{{cwd}}","isSeeded":false,"delegationDepth":0}
+{"type":"permission/preset","data":{"preset":"danger-full-access"}}
+{"type":"sandbox/mode","data":{"mode":"danger-full-access"}}
+{"type":"approval/policy","data":{"policy":"never"}}
+{"type":"agent/inbox/spliced","data":{"target":"next-turn","start":0,"inserted":[{"content":[{"type":"text","text":"Start a run_code program, call working_directory, then keep running until I stop it."}],"source":{"kind":"user"},"role":"user","id":"{{message:1}}"}]}}
+{"type":"turn/start","data":{"turn":1}}
+{"type":"agent/inbox/spliced","data":{"target":"next-turn","start":0,"removedCount":1,"inserted":[]}}
+{"type":"step/start","data":{"turn":1,"step":1}}
+{"type":"system/message","data":{"turn":1,"step":1,"message":{"role":"system","content":[{"type":"text","text":"{{system}}"}],"source":{"kind":"system-prompt"},"id":"{{message:2}}"}},"surfaceOp":"append"}
+{"type":"user/message","data":{"content":[{"type":"text","text":"Start a run_code program, call working_directory, then keep running until I stop it."}],"source":{"kind":"user"},"role":"user","id":"{{message:1}}"},"surfaceOp":"append"}
+{"type":"user/message","data":{"content":[{"type":"text","text":"Current runtime context. This snapshot supersedes earlier runtime-context snapshots.\n\nCurrent working directory: \"{{cwd}}\".\n\nCurrent DSH file policy: danger-full-access. The DSH file sandbox does not restrict file modifications by available operations.\n\nApproval prompts are disabled in this session: actions that require approval are rejected automatically — do not request sandbox escalation (do not set `sandbox_permissions`)."}],"source":{"kind":"runtime-context","form":"snapshot","sections":[{"name":"working-directory:current","text":"Current working directory: \"{{cwd}}\"."},{"name":"sandbox:policy","text":"Current DSH file policy: danger-full-access. The DSH file sandbox does not restrict file modifications by available operations."},{"name":"approval:policy","text":"Approval prompts are disabled in this session: actions that require approval are rejected automatically — do not request sandbox escalation (do not set `sandbox_permissions`)."}]},"role":"user","id":"{{message:3}}"},"surfaceOp":"append"}
+{"type":"request/header","data":{"header":{"config":{"provider":"deepseek-official","model":"deepseek-v4-flash"},"tools":"{{tools}}"},"reason":"initial"}}
+{"type":"request/context","data":{"provider":"deepseek-official","model":"deepseek-v4-flash"}}
+{"type":"session/title","data":{"title":"Start a run_code program, call","messageSeqs":[8],"source":{"kind":"fallback"}}}
+{"type":"assistant/message","data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"ptc-cancel","name":"run_code","arguments":"{\"code\":\"await tools.working_directory({}); for (;;) {}\",\"description\":\"Run until stopped\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"{{message:4}}"},"stream":[{"type":"chunk","time":1792996619936,"chunk":{"type":"block-start","index":0,"blockType":"tool-call"}},{"type":"tool-call-chunks","time0":1792996619936,"index":0,"dt":[],"id":"ptc-cancel","name":"run_code","args":["{\"code\":\"await tools.working_directory({}); for (;;) {}\",\"description\":\"Run until stopped\"}"]},{"type":"chunk","time":1792996619936,"chunk":{"type":"block-end","index":0,"block":{"type":"tool-call","id":"ptc-cancel","name":"run_code","arguments":"{\"code\":\"await tools.working_directory({}); for (;;) {}\",\"description\":\"Run until stopped\"}"}}},{"type":"chunk","time":1792996619936,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}]},"surfaceOp":"append"}
+{"type":"tool/call","data":{"turn":1,"step":1,"callId":"ptc-cancel","name":"run_code","arguments":"{\"code\":\"await tools.working_directory({}); for (;;) {}\",\"description\":\"Run until stopped\"}"}}
+{"type":"tool/ptc-dispatch-start","data":{"rootCallId":"ptc-cancel","parentCallId":"ptc-cancel","subCallId":"ptc-cancel:ptc:1","name":"working_directory","arguments":{}}}
+{"type":"tool/ptc-dispatch","data":{"rootCallId":"ptc-cancel","parentCallId":"ptc-cancel","subCallId":"ptc-cancel:ptc:1","name":"working_directory","arguments":{},"isError":false,"content":[{"type":"text","text":"{{cwd}}"}]}}
+{"type":"tool/result","data":{"turn":1,"step":1,"message":{"role":"tool","source":{"kind":"tool","callId":"ptc-cancel"},"toolCallId":"ptc-cancel","content":[{"type":"text","text":"Error: code run failed (abort): execution canceled\nFile sandbox: danger-full-access."}],"isError":true,"id":"{{message:5}}"},"error":{"name":"CodeRunFailedError","code":"CODE_RUN_FAILED"}},"sourceEventSeqs":[14],"surfaceOp":"append"}
+{"type":"step/end","data":{"turn":1,"step":1}}
+{"type":"turn/end","data":{"turn":1,"reason":{"kind":"aborted","reason":{"kind":"user"}}}}
diff --git a/snapshots/sdk/ptc-cancel/snapshot.yml b/snapshots/sdk/ptc-cancel/snapshot.yml
new file mode 100644
index 0000000000..50f022e261
--- /dev/null
+++ b/snapshots/sdk/ptc-cancel/snapshot.yml
@@ -0,0 +1,7 @@
+version: 1
+scenario: ptc-cancel
+profile: sdk
+composition: ptc
+recording: authored
+header:
+  class: ptc
diff --git a/snapshots/sdk/sdk.snapshot.ts b/snapshots/sdk/sdk.snapshot.ts
index 2f5bbb00b5..587996d653 100644
--- a/snapshots/sdk/sdk.snapshot.ts
+++ b/snapshots/sdk/sdk.snapshot.ts
@@ -159,6 +159,9 @@ const SDK_ASSERTIONS: Readonly<Record<string, SdkAssertions>> = {
     patches: [fileURLToPath(new URL('./tool-error-details/runtime.cordis.yml', import.meta.url))],
     expectedFinalResponse: 'ERROR_DETAILS_OK',
   },
+  'ptc-cancel': {
+    patches: [fileURLToPath(new URL('./ptc-cancel/runtime.cordis.yml', import.meta.url))],
+  },
   'ptc-turn': {
     patches: [fileURLToPath(new URL('./ptc-turn/runtime.cordis.yml', import.meta.url))],
     expectedFinalResponse: 'CODE_ONE+CODE_TWO',
@@ -1010,6 +1013,17 @@ describe('TypeScript SDK snapshots over the jsonrpc runtime', () => {
       )
       reconcileCatalogCreationTimes(ordered.map(log => log.content), 'validate')
       const actualContext = contextOf(ordered, cwd)
+      if (scenario.name === 'ptc-cancel') {
+        const events = results.flatMap(result => result.events)
+        expect(events.find(event => event.type === 'tool/result')).toMatchObject({ data: { message: {
+          toolCallId: 'ptc-cancel',
+          isError: true,
+          content: [{ type: 'text', text: 'Error: code run failed (abort): execution canceled\nFile sandbox: danger-full-access.' }],
+        } } })
+        expect(events.find(event => event.type === 'turn/end')).toMatchObject({
+          data: { reason: { kind: 'aborted', reason: { kind: 'user' } } },
+        })
+      }
       if (scenario.name === 'minimal-image-compaction') {
         const events = results.flatMap(result => result.events)
         const failures = events.filter(event => event.type === 'turn/end' && event.data.reason.kind === 'error')