16 KiB
Agent Run Cancel (Failed Semantics) Implementation Plan
For Claude: REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.
Goal: 为 /api/v1/agent/runs 增加可中断能力,在用户触发 cancel 后真正停止运行中的 agent 流程,并以 RUN_ERROR(code=RUN_CANCELED) 结束,最终将 session 状态落为 failed。
Architecture: 使用“协作取消 + 主任务中断”方案:API 层写入 Redis cancel 信号,runtime 在 worker 进程内并行 watcher 监听信号,命中后先调用 active agent 的 interrupt() 做优雅收尾,再 cancel() 当前 run 主任务做硬兜底。终态统一通过 RUN_ERROR 事件落库,复用现有 FAILED 会话语义,避免数据库枚举迁移。
Tech Stack: FastAPI, TaskIQ, Redis, AgentScope, SQLAlchemy, Flutter, Pytest, Ruff, BasedPyright
Task 1: 先更新协议文档(接口与事件语义)
Files:
- Modify:
docs/protocols/agent/api-endpoints.md - Modify:
docs/protocols/agent/sse-events.md
Step 1: 在 API 文档新增 cancel 端点契约
在 api-endpoints.md 的端点清单添加:
| POST | `/runs/{thread_id}/cancel` | 请求取消指定 run |
并新增章节说明:
- 请求参数:
thread_id+runId(建议 query) - 返回:
202 Accepted+accepted: true - 语义:仅表示“取消请求已接收”,不保证已即时终止
Step 2: 在 SSE 文档补充取消终态语义
在 sse-events.md 的 RUN_ERROR 章节补充:
{
"type": "RUN_ERROR",
"threadId": "...",
"runId": "...",
"message": "run canceled by user",
"code": "RUN_CANCELED"
}
并明确:
RUN_CANCELED是用户主动中断,不是系统异常- 本阶段仍复用 session
failed(向后兼容)
Step 3: 文档自检
检查文档是否同时覆盖:
- HTTP 行为
- SSE 终态事件
- 兼容策略(不引入新 session 状态)
Step 4: 提交文档变更
git add docs/protocols/agent/api-endpoints.md docs/protocols/agent/sse-events.md
git commit -m "docs: define agent run cancel API and RUN_CANCELED error semantics"
Task 2: 打通 API 层到队列层的 cancel 信号写入
Files:
- Modify:
backend/src/v1/agent/schemas.py - Modify:
backend/src/v1/agent/dependencies.py - Modify:
backend/src/v1/agent/service.py - Modify:
backend/src/v1/agent/router.py - Test:
backend/tests/unit/v1/agent/test_service.py - Test:
backend/tests/integration/v1/agent/test_routes.py
Step 1: 增加 cancel 接口响应 schema
在 v1/agent/schemas.py 增加:
class CancelRunResponse(BaseModel):
model_config = ConfigDict(populate_by_name=True, serialize_by_alias=True)
thread_id: str = Field(alias="threadId")
run_id: str = Field(alias="runId")
accepted: bool
Step 2: 扩展队列协议接口
在 QueueClientLike 增加:
async def request_cancel(self, *, thread_id: str, run_id: str, requested_by: str) -> None: ...
Step 3: 在 TaskiqQueueClient 实现 request_cancel
在 v1/agent/dependencies.py 中新增:
- cancel key 规范:
agent:cancel:{thread_id}:{run_id} SET key value EX <ttl>写入取消信号value可写 json 字符串(包含 user_id/timestamp)
Step 4: 在 service 层新增 cancel_run
在 v1/agent/service.py 增加方法:
- 校验 session owner(复用
get_session_owner + ensure_session_owner) - 调用
self._queue.request_cancel(...) - 返回
accepted结果 DTO
Step 5: 在 router 新增 cancel 路由
在 v1/agent/router.py 新增:
@router.post("/runs/{thread_id}/cancel", response_model=CancelRunResponse, status_code=202)
async def cancel_run(...):
...
约束:
runId必填(建议 query)- 非 owner 返回 403
- 参数非法返回 422
Step 6: 写 service 单测(先红)
在 test_service.py 添加:
- owner 可发起 cancel,
queue.request_cancel被调用 - 非 owner cancel 返回 403
Step 7: 运行单测确认失败
Run: uv run pytest backend/tests/unit/v1/agent/test_service.py -k cancel -q
Expected: 至少 1 个测试失败(新逻辑尚未实现)
Step 8: 实现最小代码使测试通过
按 Step 1-5 完成实现,避免额外重构。
Step 9: 运行测试验证通过
Run: uv run pytest backend/tests/unit/v1/agent/test_service.py -k cancel -q
Expected: PASS
Step 10: 增加路由集成测试
在 test_routes.py 增加:
POST /api/v1/agent/runs/{thread_id}/cancel?runId=...返回 202- 响应字段别名正确(
threadId/runId/accepted)
Step 11: 运行路由测试
Run: uv run pytest backend/tests/integration/v1/agent/test_routes.py -k cancel -q
Expected: PASS
Step 12: 提交 API 层变更
git add backend/src/v1/agent/schemas.py backend/src/v1/agent/dependencies.py backend/src/v1/agent/service.py backend/src/v1/agent/router.py backend/tests/unit/v1/agent/test_service.py backend/tests/integration/v1/agent/test_routes.py
git commit -m "feat: add agent run cancel endpoint and Redis cancel signal"
Task 3: runtime runner 植入取消 watcher 与优雅中断
Files:
- Modify:
backend/src/core/agentscope/runtime/runner.py - Test:
backend/tests/unit/core/agentscope/runtime/test_runner.py
Step 1: 在 runner.execute 增加 cancel_checker 参数
更新 execute() 签名:
cancel_checker: Callable[[], Awaitable[bool]] | None = None
并保持默认 None 向后兼容。
Step 2: 增加 active agent 引用与锁
在 AgentScopeRunner.__init__ 增加:
self._active_agent: JsonReActAgent | None = Noneself._active_agent_lock = asyncio.Lock()
Step 3: 在 _run_worker_stage 设置 active agent 生命周期
在 agent.reply_json(...) 前后包裹:
- before: 记录
self._active_agent = agent - finally: 清理引用
Step 4: 新增 _watch_cancel_signal 协程
行为:
- 循环调用
cancel_checker() - 命中后先尝试
await active_agent.interrupt() - 再
run_task.cancel("run canceled by user") - 间隔
await asyncio.sleep(0.2)
Step 5: 在 execute 启停 watcher
run_task = asyncio.current_task()- 如果有
cancel_checker,create_task(_watch_cancel_signal(...)) finally中停止 watcher 并await回收
Step 6: 补 stage 边界取消 gate(关键)
在 router 结束后、worker 开始前检查一次 cancel_checker():
- 为 true 时抛
asyncio.CancelledError
目的:防止“router 已结束但仍进入 worker”。
Step 7: 写 runner 单测(先红)
新增测试用例:
- cancel 信号触发后,
execute抛出CancelledError - worker 未被继续执行(或中途被中断)
Step 8: 运行 runner 测试
Run: uv run pytest backend/tests/unit/core/agentscope/runtime/test_runner.py -k cancel -q
Expected: PASS
Step 9: 提交 runner 变更
git add backend/src/core/agentscope/runtime/runner.py backend/tests/unit/core/agentscope/runtime/test_runner.py
git commit -m "feat: add cooperative cancellation watcher to agentscope runner"
Task 4: orchestrator 与 task worker 处理 CancelledError 终态
Files:
- Modify:
backend/src/core/agentscope/runtime/orchestrator.py - Modify:
backend/src/core/agentscope/runtime/tasks.py - Test:
backend/tests/unit/core/agentscope/runtime/test_orchestrator.py - Test:
backend/tests/unit/core/agentscope/runtime/test_tasks.py
Step 1: orchestrator 单独捕获 CancelledError
在 orchestrator.run() 添加:
except asyncio.CancelledError:
await self._pipeline.emit(... RUN_ERROR code="RUN_CANCELED" ...)
raise
保留现有 except Exception 处理系统错误。
Step 2: task 层构造 cancel_checker 并注入 runtime.run
在 tasks.py:
- 构造 key:
agent:cancel:{thread_id}:{run_id} - 定义
async def cancel_checker() -> bool: return bool(await redis.exists(key)) - 调用
runtime.run(..., cancel_checker=cancel_checker)
Step 3: task 层补资源清理
在 run_agentscope_task 的 finally:
- 删除 cancel key 或缩短 TTL
- 记录日志(仅必要字段)
Step 4: 写 orchestrator 单测(先红)
验证:
- 收到
CancelledError时发RUN_ERROR且code == "RUN_CANCELED"
Step 5: 写 tasks 单测(先红)
验证:
- runtime 收到的
cancel_checker可用 - key 命中时上抛
CancelledError路径成立
Step 6: 运行测试
Run: uv run pytest backend/tests/unit/core/agentscope/runtime/test_orchestrator.py backend/tests/unit/core/agentscope/runtime/test_tasks.py -k cancel -q
Expected: PASS
Step 7: 提交 runtime 编排层变更
git add backend/src/core/agentscope/runtime/orchestrator.py backend/src/core/agentscope/runtime/tasks.py backend/tests/unit/core/agentscope/runtime/test_orchestrator.py backend/tests/unit/core/agentscope/runtime/test_tasks.py
git commit -m "fix: emit RUN_CANCELED error when run task is interrupted"
Task 5: 事件流与持久化一致性回归
Files:
- Modify:
backend/tests/unit/core/agentscope/events/test_store.py - Modify:
backend/tests/unit/core/agentscope/events/test_agui_codec.py - Modify:
backend/tests/integration/v1/agent/test_sse_flow_live.py
Step 1: 补 event store 行为测试
新增断言:
- 当
RUN_ERROR且code=RUN_CANCELED时,session 状态依然为FAILED
Step 2: 补 codec 测试
新增断言:
RUN_ERROR的code字段能正确透传到 wire event
Step 3: 补 SSE 集成测试
场景:
- 触发
/runs - 触发
/runs/{thread_id}/cancel - SSE 最终出现
RUN_ERROR(code=RUN_CANCELED)
Step 4: 运行事件相关测试
Run: uv run pytest backend/tests/unit/core/agentscope/events/test_store.py backend/tests/unit/core/agentscope/events/test_agui_codec.py backend/tests/integration/v1/agent/test_sse_flow_live.py -k "cancel or run_error" -q
Expected: PASS
Step 5: 提交事件层变更
git add backend/tests/unit/core/agentscope/events/test_store.py backend/tests/unit/core/agentscope/events/test_agui_codec.py backend/tests/integration/v1/agent/test_sse_flow_live.py
git commit -m "test: cover RUN_CANCELED propagation across store codec and SSE"
Task 6: 全量验证与发布前检查
Files:
- Modify:
docs/protocols/agent/api-endpoints.md(如需补充最终字段) - Modify:
docs/protocols/agent/sse-events.md(如需补充最终字段)
Step 1: 运行受影响单元测试集合
Run:
uv run pytest backend/tests/unit/v1/agent/test_service.py backend/tests/unit/core/agentscope/runtime/test_runner.py backend/tests/unit/core/agentscope/runtime/test_orchestrator.py backend/tests/unit/core/agentscope/runtime/test_tasks.py backend/tests/unit/core/agentscope/events/test_store.py backend/tests/unit/core/agentscope/events/test_agui_codec.py -q
Expected: PASS
Step 2: 运行受影响集成测试集合
Run:
uv run pytest backend/tests/integration/v1/agent/test_routes.py backend/tests/integration/v1/agent/test_sse_flow_live.py -q
Expected: PASS
Step 3: 运行静态检查
Run:
uv run ruff check backend/src backend/tests
uv run basedpyright
Expected: PASS(无新增 lint/type 错误)
Step 4: 手工验证路径
手工流程:
- 发起
/runs - 立刻调用
/runs/{thread_id}/cancel?runId=... - 观察 SSE:应以
RUN_ERROR(code=RUN_CANCELED)结束 - 检查 session:
status=failed
Step 5: 最终提交
git add docs/protocols/agent/api-endpoints.md docs/protocols/agent/sse-events.md backend/src/v1/agent/*.py backend/src/core/agentscope/runtime/*.py backend/tests/unit/core/agentscope/runtime/*.py backend/tests/unit/core/agentscope/events/*.py backend/tests/unit/v1/agent/test_service.py backend/tests/integration/v1/agent/test_routes.py backend/tests/integration/v1/agent/test_sse_flow_live.py
git commit -m "feat: support run cancellation with RUN_CANCELED failed semantics"
风险与回滚
- 风险 1:cancel key 误命中导致误中断
- 缓解:key 粒度使用
thread_id + run_id,并设置 TTL
- 缓解:key 粒度使用
- 风险 2:中断时出现重复终态事件
- 缓解:在 orchestrator 保证 CancelledError 只走
RUN_ERROR分支,避免继续发RUN_FINISHED
- 缓解:在 orchestrator 保证 CancelledError 只走
- 风险 3:高并发下 Redis 轮询压力上升
- 缓解:轮询间隔 200ms,后续按并发量评估改为 pub/sub
回滚策略:
- 回滚
router/service/dependenciescancel 新接口 - 回滚
runner/orchestrator/taskscancel 注入逻辑 - 保持原
POST /runs与 SSE 流程不变
Task 7: 前端接入 cancel API(发送后“停止生成”按钮走后端真实取消)
Files:
- Modify:
apps/lib/features/chat/data/services/ag_ui_service.dart - Modify:
apps/lib/features/chat/presentation/bloc/chat_bloc.dart - Modify:
apps/lib/features/chat/data/models/ag_ui_event.dart - Modify:
apps/lib/features/home/ui/screens/home_screen_interactions.dart - Test:
apps/test/features/chat/data/services/ag_ui_service_test.dart - Test:
apps/test/features/chat/presentation/chat_bloc_attachment_sync_test.dart
Step 1: 在 AgUiService 维护当前运行态标识
在 AgUiService 增加字段:
_activeThreadIdForRun: String?_activeRunId: String?
并在 sendMessage 成功拿到 /runs 响应后设置这两个字段;在收到目标 run 的终态事件(RUN_FINISHED / RUN_ERROR)后清理。
Step 2: 将 cancelCurrentRun 从“仅断 SSE”升级为“先调用后端 cancel,再本地收流”
AgUiService.cancelCurrentRun() 改为:
- 若
_activeThreadIdForRun或_activeRunId为空:退化为当前行为(仅关闭 SSE) - 否则先调用:
POST /api/v1/agent/runs/{threadId}/cancel?runId={runId}
- 请求成功后再执行
_cancelActiveSseSubscription()(避免继续占用本地连接) - 不论后端是否即时生效,都清理本地 active run 字段,防止重复 cancel
说明:这一步就是把“发送消息后的停止按钮”真正连到后端取消能力。
Step 3: 错误语义细化(前端展示友好)
在 chat_bloc.dart 处理 RunErrorEvent 时:
- 如果
errorEvent.code == 'RUN_CANCELED',错误文案不按失败提示展示(可置空或显示“已停止生成”) - 仍执行
_resetRunState与 tool 卡片收尾,保持 UI 一致性
Step 4: 保持现有按钮入口,不改交互入口路径
home_screen_interactions.dart 里的 _onStopGenerating -> _chatBloc.cancelCurrentRun() 已经是正确入口,继续复用。
仅调整 Toast 文案策略:
- 请求已发出:
已请求停止 - 收到
RUN_ERROR(code=RUN_CANCELED):最终态已停止生成
Step 5: 写 AgUiService 测试(先红)
在 ag_ui_service_test.dart 增加:
cancelCurrentRun会调用新端点/api/v1/agent/runs/{threadId}/cancel- query 参数包含
runId - 调用后会关闭当前 SSE subscription
Step 6: 写 ChatBloc 测试(先红)
在 chat_bloc_attachment_sync_test.dart 增加:
- 收到
RunErrorEvent(message: 'run canceled by user', code: 'RUN_CANCELED')后:isWaitingFirstToken/isStreaming/isCancelling全部归零- 不显示普通失败文案(或显示取消态文案,按你们最终文案策略断言)
Step 7: 运行 Flutter 测试
Run:
flutter test apps/test/features/chat/data/services/ag_ui_service_test.dart apps/test/features/chat/presentation/chat_bloc_attachment_sync_test.dart
Expected: PASS
Step 8: 前端接入提交
git add apps/lib/features/chat/data/services/ag_ui_service.dart apps/lib/features/chat/presentation/bloc/chat_bloc.dart apps/lib/features/chat/data/models/ag_ui_event.dart apps/lib/features/home/ui/screens/home_screen_interactions.dart apps/test/features/chat/data/services/ag_ui_service_test.dart apps/test/features/chat/presentation/chat_bloc_attachment_sync_test.dart
git commit -m "feat: wire stop-generating button to backend run cancel API"