feat: propagate request correlation context

app/adapters/network/http.py

@@ -17,6 +17,8 @@ from requests import Response, Session
 from urllib3.exceptions import InsecureRequestWarning
 from urllib.parse import unquote, quote
 
+from app.runtime.correlation import with_correlation_header
+
 
 urllib3.disable_warnings(InsecureRequestWarning)
 
@@ -418,7 +420,9 @@ class RequestUtils:
             req_method = requests.request
         else:
             req_method = self._session.request
-        kwargs.setdefault("headers", self._headers)
+        kwargs["headers"] = with_correlation_header(
+            kwargs.get("headers", self._headers)
+        )
         kwargs.setdefault("cookies", self._cookies)
         kwargs.setdefault("proxies", self._proxies)
         kwargs.setdefault("timeout", self._timeout)
@@ -1195,7 +1199,9 @@ class AsyncRequestUtils:
         """
         执行实际的异步请求
         """
-        kwargs.setdefault("headers", self._headers)
+        kwargs["headers"] = with_correlation_header(
+            kwargs.get("headers", self._headers)
+        )
         # 共享池下 client 自带默认 timeout，这里用每请求 timeout 覆盖以尊重实例配置
         kwargs.setdefault("timeout", self._timeout)
         # Cookie 在 request() 入口已按 path 处理：
@@ -1329,7 +1335,9 @@ class AsyncRequestUtils:
         :return: 上下文管理器，进入后 yield httpx.Response（出错时 yield None）
         """
         cookies_dict: Optional[dict] = self._cookies if isinstance(self._cookies, dict) else None
-        kwargs.setdefault("headers", self._headers)
+        kwargs["headers"] = with_correlation_header(
+            kwargs.get("headers", self._headers)
+        )
 
         # 与 _make_request 保持一致：复用 keep-alive 时偶遇对端 FIN 的连接，
         # 流式 GET 是幂等的，单次重试即可

app/adapters/web/correlation.py

@@ -0,0 +1,44 @@
+"""HTTP 请求关联 ID 的 ASGI 适配器。"""
+
+from __future__ import annotations
+
+from typing import Any
+
+from app.runtime.correlation import (
+    CORRELATION_ID_HEADER,
+    correlation_scope,
+    normalize_correlation_id,
+)
+
+
+class CorrelationIdMiddleware:
+    """验证入口 ID、绑定请求上下文并把同一 ID 写回响应。"""
+
+    def __init__(self, app: Any) -> None:
+        """保存下游 ASGI 应用。"""
+        self._app = app
+
+    async def __call__(self, scope: dict, receive: Any, send: Any) -> None:
+        """只治理 HTTP scope，并让绑定覆盖完整流式响应生命周期。"""
+        if scope.get("type") != "http":
+            await self._app(scope, receive, send)
+            return
+        raw_headers = dict(scope.get("headers") or [])
+        candidate = raw_headers.get(CORRELATION_ID_HEADER.lower().encode("ascii"))
+        correlation_id = normalize_correlation_id(
+            candidate.decode("ascii", errors="ignore") if candidate else None
+        )
+        scope.setdefault("state", {})["request_id"] = correlation_id
+
+        async def send_with_correlation(message: dict) -> None:
+            """在响应开始帧中覆盖为当前请求的安全关联 ID。"""
+            if message.get("type") == "http.response.start":
+                headers = list(message.get("headers") or [])
+                header_name = CORRELATION_ID_HEADER.lower().encode("ascii")
+                headers = [item for item in headers if item[0].lower() != header_name]
+                headers.append((header_name, correlation_id.encode("ascii")))
+                message["headers"] = headers
+            await send(message)
+
+        with correlation_scope(correlation_id):
+            await self._app(scope, receive, send_with_correlation)

app/factory.py

@@ -8,6 +8,7 @@ from fastapi.responses import JSONResponse
 from starlette.exceptions import HTTPException
 
 from app.api.response import ResponseAPIRoute
+from app.adapters.web.correlation import CorrelationIdMiddleware
 from app.adapters.web.plugin.routes import FastAPIDynamicRouteRegistry
 from app.adapters.web.health import install_health_routes
 from app.application.plugin.routes import configure_plugin_routes
@@ -19,8 +20,9 @@ from app.adapters.web.security.access import (
 from app.application.security.token import create_access_token, decode_access_token
 from app.runtime.extensions.plugin_manager import PluginManager
 from app.runtime.config import settings
+from app.runtime.correlation import get_correlation_id
 from app.runtime.localization import LocaleHelper
-from app.runtime.log import logger
+from app.runtime.log import configure_correlation_id_provider, logger
 from app.schemas.openai import (
     AnthropicErrorDetail,
     AnthropicErrorResponse,
@@ -291,6 +293,7 @@ def create_app() -> FastAPI:
     """
     创建并配置 FastAPI 应用实例。
     """
+    configure_correlation_id_provider(get_correlation_id)
     _app = FastAPI(
         title=settings.PROJECT_NAME,
         version=APP_VERSION,
@@ -317,6 +320,7 @@ def create_app() -> FastAPI:
         allow_methods=["*"],
         allow_headers=["*"],
     )
+    _app.add_middleware(CorrelationIdMiddleware)
 
     @_app.middleware("http")
     async def locale_context_middleware(

app/runtime/correlation.py

@@ -0,0 +1,74 @@
+"""请求与后台工作共用的关联 ID 上下文。"""
+
+from __future__ import annotations
+
+import re
+import uuid
+from contextlib import contextmanager
+from contextvars import ContextVar, Token
+from typing import Any, Callable, Iterator, Mapping
+
+CORRELATION_ID_HEADER = "X-Request-ID"
+MAX_CORRELATION_ID_LENGTH = 64
+_VALID_CORRELATION_ID = re.compile(r"^[A-Za-z0-9][A-Za-z0-9._:-]{0,63}$")
+_CURRENT_CORRELATION_ID: ContextVar[str | None] = ContextVar(
+    "moviepilot_correlation_id",
+    default=None,
+)
+
+
+def normalize_correlation_id(candidate: str | None) -> str:
+    """接受安全的调用方 ID；非法、超长或缺失值均替换为随机 ID。"""
+    if candidate and _VALID_CORRELATION_ID.fullmatch(candidate):
+        return candidate
+    return uuid.uuid4().hex
+
+
+def get_correlation_id(default: str | None = None) -> str | None:
+    """返回当前执行上下文中的关联 ID。"""
+    return _CURRENT_CORRELATION_ID.get() or default
+
+
+def set_correlation_id(correlation_id: str) -> Token[str | None]:
+    """设置当前关联 ID，并返回供调用方精确恢复的 token。"""
+    return _CURRENT_CORRELATION_ID.set(correlation_id)
+
+
+def reset_correlation_id(token: Token[str | None]) -> None:
+    """恢复设置关联 ID 之前的上下文。"""
+    _CURRENT_CORRELATION_ID.reset(token)
+
+
+@contextmanager
+def correlation_scope(correlation_id: str | None) -> Iterator[str | None]:
+    """在当前同步或异步任务作用域内绑定并自动恢复关联 ID。"""
+    if correlation_id is None:
+        yield None
+        return
+    token = set_correlation_id(correlation_id)
+    try:
+        yield correlation_id
+    finally:
+        reset_correlation_id(token)
+
+
+def with_correlation_header(headers: Mapping[str, str] | None) -> dict[str, str]:
+    """复制请求头并在调用方未显式指定时加入当前关联 ID。"""
+    result = dict(headers or {})
+    if any(key.lower() == CORRELATION_ID_HEADER.lower() for key in result):
+        return result
+    correlation_id = get_correlation_id()
+    if correlation_id:
+        result[CORRELATION_ID_HEADER] = correlation_id
+    return result
+
+
+def call_with_correlation(
+    correlation_id: str | None,
+    func: Callable[..., Any],
+    args: tuple[Any, ...],
+    kwargs: dict[str, Any],
+) -> Any:
+    """从可序列化参数恢复关联 ID 后调用函数，供子进程入口使用。"""
+    with correlation_scope(correlation_id):
+        return func(*args, **kwargs)

app/runtime/event/dispatch.py

@@ -12,6 +12,7 @@ from app.runtime.event.binding import EventBindingResolver
 from app.runtime.event.registry import EventRegistry
 from app.runtime.execution import run_in_threadpool
 from app.runtime.log import logger
+from app.runtime.correlation import correlation_scope
 from app.schemas.types import EventType
 
 
@@ -114,6 +115,7 @@ class EventDispatcher:
                 event_type=event.event_type,
                 event_data=event_data,
                 priority=event.priority,
+                correlation_id=event.correlation_id,
             )
             if inspect.iscoroutinefunction(handler):
                 asyncio.run_coroutine_threadsafe(
@@ -143,16 +145,17 @@ class EventDispatcher:
         if not resolved:
             return
         method, binding, class_name, method_name = resolved
-        try:
-            method(event)
-        except Exception as err:
-            self._error_handler(
-                event=event,
-                module_name=binding.owner_name,
-                class_name=class_name,
-                method_name=method_name,
-                e=err,
-            )
+        with correlation_scope(event.correlation_id):
+            try:
+                method(event)
+            except Exception as err:
+                self._error_handler(
+                    event=event,
+                    module_name=binding.owner_name,
+                    class_name=class_name,
+                    method_name=method_name,
+                    e=err,
+                )
 
     async def invoke_async(self, handler: Callable, event: Any) -> None:
         """解析实例绑定，并按处理器类型选择协程、线程池或同步调用。"""
@@ -160,21 +163,22 @@ class EventDispatcher:
         if not resolved:
             return
         method, binding, class_name, method_name = resolved
-        try:
-            if inspect.iscoroutinefunction(method):
-                await method(event)
-            elif binding.run_sync_in_threadpool or not class_name:
-                await run_in_threadpool(method, event)
-            else:
-                method(event)
-        except Exception as err:
-            self._error_handler(
-                event=event,
-                module_name=binding.owner_name,
-                class_name=class_name,
-                method_name=method_name,
-                e=err,
-            )
+        with correlation_scope(event.correlation_id):
+            try:
+                if inspect.iscoroutinefunction(method):
+                    await method(event)
+                elif binding.run_sync_in_threadpool or not class_name:
+                    await run_in_threadpool(method, event)
+                else:
+                    method(event)
+            except Exception as err:
+                self._error_handler(
+                    event=event,
+                    module_name=binding.owner_name,
+                    class_name=class_name,
+                    method_name=method_name,
+                    e=err,
+                )
 
     @staticmethod
     def should_dispatch_to_target_plugin(

app/runtime/events.py

@@ -21,6 +21,7 @@ from app.runtime.event.dispatch import EventDispatcher
 from app.runtime.event.errors import EventErrorNotifier, EventErrorPolicy
 from app.runtime.event.registry import EventRegistry
 from app.runtime.event.contracts import validate_event_payload
+from app.runtime.correlation import get_correlation_id
 
 DEFAULT_EVENT_PRIORITY = 10  # 事件的默认优先级
 MIN_EVENT_CONSUMER_THREADS = 1  # 最小事件消费者线程数
@@ -35,11 +36,13 @@ class Event:
 
     def __init__(self, event_type: Union[EventType, ChainEventType],
                  event_data: Optional[Union[Dict, ChainEventData]] = None,
-                 priority: Optional[int] = DEFAULT_EVENT_PRIORITY):
+                 priority: Optional[int] = DEFAULT_EVENT_PRIORITY,
+                 correlation_id: Optional[str] = None):
         """
         :param event_type: 事件的类型，支持 EventType 或 ChainEventType
         :param event_data: 可选，事件携带的数据，默认为空字典
         :param priority: 可选，事件的优先级，默认为 10
+        :param correlation_id: 生产事件时固化的请求关联 ID
         """
         payload_problems = validate_event_payload(event_type, event_data)
         if payload_problems:
@@ -52,6 +55,7 @@ class Event:
         self.event_type = event_type  # 事件类型
         self.event_data = event_data or {}  # 事件数据
         self.priority = priority  # 事件优先级
+        self.correlation_id = correlation_id or get_correlation_id()
 
     def __repr__(self) -> str:
         """

app/runtime/execution.py

@@ -1,6 +1,7 @@
 import asyncio
 import inspect
 import time
+from contextvars import copy_context
 from functools import partial, wraps
 from typing import Any, Callable
 
@@ -16,7 +17,8 @@ async def run_in_threadpool(
     """在线程中执行同步函数，保持 FastAPI 旧帮助函数的参数语义。"""
     if kwargs:
         func = partial(func, **kwargs)
-    return await run_sync(func, *args)
+    context = copy_context()
+    return await run_sync(context.run, func, *args)
 
 
 def retry(ExceptionToCheck: Any,

app/runtime/log.py

@@ -12,12 +12,11 @@ from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime
 from logging.handlers import RotatingFileHandler
 from pathlib import Path
-from typing import Any, Dict, Optional, Protocol
+from typing import Any, Callable, Dict, Optional, Protocol
 
 import click
 from pydantic import BaseModel, ConfigDict
 
-
 class LogConfigModel(BaseModel):
     """描述日志级别、格式和文件写入策略。"""
 
@@ -28,8 +27,12 @@ class LogConfigModel(BaseModel):
     LOG_LEVEL: str = "INFO"
     LOG_MAX_FILE_SIZE: int = 5
     LOG_BACKUP_COUNT: int = 10
-    LOG_CONSOLE_FORMAT: str = "%(leveltext)s[%(name)s] %(asctime)s %(message)s"
-    LOG_FILE_FORMAT: str = "【%(levelname)s】%(asctime)s - %(message)s"
+    LOG_CONSOLE_FORMAT: str = (
+        "%(leveltext)s[%(name)s] %(asctime)s [%(correlation_id)s] %(message)s"
+    )
+    LOG_FILE_FORMAT: str = (
+        "【%(levelname)s】%(asctime)s [%(correlation_id)s] - %(message)s"
+    )
     ASYNC_FILE_QUEUE_SIZE: int = 1000
     ASYNC_FILE_WORKERS: int = 2
     BATCH_WRITE_SIZE: int = 50
@@ -60,6 +63,7 @@ class LogEntry:
         self.message = message
         self.file_path = file_path
         self.timestamp = timestamp or datetime.now()
+        self.correlation_id = _get_log_correlation_id()
 
 
 class LogWriter(Protocol):
@@ -73,6 +77,18 @@ class LogWriter(Protocol):
 
 
 log_settings = LogSettings()
+_correlation_id_provider: Callable[[], str | None] = lambda: None
+
+
+def configure_correlation_id_provider(provider: Callable[[], str | None]) -> None:
+    """由组合根注入日志关联 ID 读取端口，保持日志模块为依赖叶节点。"""
+    global _correlation_id_provider
+    _correlation_id_provider = provider
+
+
+def _get_log_correlation_id() -> str:
+    """读取当前关联 ID；未装配或无请求上下文时返回稳定占位符。"""
+    return _correlation_id_provider() or "-"
 
 
 class NonBlockingFileHandler:
@@ -169,7 +185,7 @@ class NonBlockingFileHandler:
     @staticmethod
     def _to_record(entry: LogEntry) -> logging.LogRecord:
         """把日志条目转换为标准库日志记录。"""
-        return logging.LogRecord(
+        record = logging.LogRecord(
             name="",
             level=getattr(logging, entry.level.upper(), logging.INFO),
             pathname="",
@@ -179,6 +195,8 @@ class NonBlockingFileHandler:
             exc_info=None,
             created=entry.timestamp.timestamp(),
         )
+        record.correlation_id = entry.correlation_id
+        return record
 
     def _batch_writer(self) -> None:
         """持续收集队列日志，并在停止哨兵后排空已有批次。"""
@@ -258,6 +276,7 @@ class CustomFormatter(logging.Formatter):
         separator = " " * max(8 - len(record.levelname), 0)
         colorizer = _LEVEL_NAME_COLORS.get(record.levelno, str)
         record.leveltext = colorizer(record.levelname + ":") + separator
+        record.correlation_id = _get_log_correlation_id()
         return super().format(record)
 
 

app/runtime/thread.py

@@ -1,4 +1,5 @@
 from concurrent.futures import ThreadPoolExecutor
+from contextvars import copy_context
 
 from app.runtime.config import settings
 from app.foundation.singleton import Singleton
@@ -20,7 +21,8 @@ class ThreadHelper(metaclass=Singleton):
         :param kwargs: 参数
         :return: future
         """
-        return self.pool.submit(func, *args, **kwargs)
+        context = copy_context()
+        return self.pool.submit(context.run, func, *args, **kwargs)
 
     def shutdown(self):
         """

app/scheduler.py

@@ -45,6 +45,7 @@ from app.runtime.gc import get_memory_usage
 from app.runtime.reload import ConfigReloadMixin
 from app.foundation.singleton import SingletonClass
 from app.runtime.scheduling import TimerUtils
+from app.runtime.correlation import call_with_correlation, get_correlation_id
 
 lock = threading.Lock()
 SCHEDULER_PROGRESS_PREFIX = "scheduler"
@@ -856,7 +857,10 @@ class Scheduler(ConfigReloadMixin, metaclass=SingletonClass):
                 deferred_finish = __start_coro(func(*args, **kwargs))
             elif run_in_process:
                 # 多进程运行
-                p = multiprocessing.Process(target=func, args=args, kwargs=kwargs)
+                p = multiprocessing.Process(
+                    target=call_with_correlation,
+                    args=(get_correlation_id(), func, args, kwargs),
+                )
                 p.start()
                 p.join()
             else:

docs/refactor/backend-architecture-next-stage.md

@@ -731,6 +731,17 @@ app/scheduler.py # APScheduler 兼容 Facade
 4. 日志 formatter 增加结构字段，不在消息字符串中到处手拼。
 5. 外部请求可传标准 trace headers 或项目 correlation header，但不得泄露用户 token。
 
+**实施记录（2026-08-21）**：
+
+- 新增受 64 字符安全字符集约束的 `moviepilot_correlation_id` ContextVar 和纯 ASGI middleware；合法
+  `X-Request-ID` 原样使用，非法值重新生成，`request.state`、普通响应和 SSE 握手响应回写同一个 ID。
+- 平台日志 formatter 以独立 `correlation_id` 字段输出；`app.runtime.execution`、共享 `ThreadHelper`、
+  Event 生产/消费均显式复制或恢复上下文。Event 在生产时固化 ID，广播线程不能用自己的空上下文覆盖它。
+- Scheduler 多进程入口把关联 ID 作为显式可序列化参数传入，不依赖 fork 继承；`RequestUtils` 和
+  `AsyncRequestUtils` 在调用方未指定时传播 `X-Request-ID`，不读取或复制任何鉴权 token。
+- 并发请求、非法头、线程池、事件处理、SSE、同步/异步外呼和显式外呼头覆盖均有专项测试；原 API
+  响应、健康探针、日志和搜索流式测试保持通过。
+
 #### ARCH-261：指标与可选 OpenTelemetry Adapter
 
 先定义内部观测端口和低基数指标：

tests/fixtures/architecture/dependency-baseline.json

@@ -13,8 +13,8 @@
     "runtime_to_db": [],
     "workflow_to_db": []
   },
-  "edge_count": 6223,
-  "edge_sha256": "f64e5083ab697022127780800617474d12f10b05a6fea26787e751a3f8a00421",
+  "edge_count": 6232,
+  "edge_sha256": "2139dcdcfc12b4f29c732471744d09b0990c51867d4ad227026b00fa947c90d8",
   "edges": [
     "app -> app.runtime",
     "app -> app.runtime.compat",
@@ -104,6 +104,8 @@
     "app.adapters.network.doh -> app.runtime.config",
     "app.adapters.network.doh -> app.runtime.log",
     "app.adapters.network.doh -> app.runtime.reload",
+    "app.adapters.network.http -> app.runtime",
+    "app.adapters.network.http -> app.runtime.correlation",
     "app.adapters.system.display -> app.foundation",
     "app.adapters.system.display -> app.foundation.singleton",
     "app.adapters.system.display -> app.runtime",
@@ -151,6 +153,8 @@
     "app.adapters.system.rust -> app.runtime",
     "app.adapters.system.rust -> app.runtime.config",
     "app.adapters.system.rust -> app.runtime.log",
+    "app.adapters.web.correlation -> app.runtime",
+    "app.adapters.web.correlation -> app.runtime.correlation",
     "app.adapters.web.health -> app.runtime",
     "app.adapters.web.health -> app.runtime.health",
     "app.adapters.web.security.access -> app.runtime",
@@ -3719,6 +3723,7 @@
     "app.domain.title -> app.schemas.types",
     "app.factory -> app.adapters",
     "app.factory -> app.adapters.web",
+    "app.factory -> app.adapters.web.correlation",
     "app.factory -> app.adapters.web.health",
     "app.factory -> app.adapters.web.plugin",
     "app.factory -> app.adapters.web.plugin.routes",
@@ -3733,6 +3738,7 @@
     "app.factory -> app.application.security.token",
     "app.factory -> app.runtime",
     "app.factory -> app.runtime.config",
+    "app.factory -> app.runtime.correlation",
     "app.factory -> app.runtime.extensions",
     "app.factory -> app.runtime.extensions.plugin_manager",
     "app.factory -> app.runtime.localization",
@@ -5353,6 +5359,7 @@
     "app.runtime.event.contracts -> app.schemas.event",
     "app.runtime.event.contracts -> app.schemas.types",
     "app.runtime.event.dispatch -> app.runtime",
+    "app.runtime.event.dispatch -> app.runtime.correlation",
     "app.runtime.event.dispatch -> app.runtime.event",
     "app.runtime.event.dispatch -> app.runtime.event.binding",
     "app.runtime.event.dispatch -> app.runtime.event.registry",
@@ -5372,6 +5379,7 @@
     "app.runtime.events -> app.foundation.singleton",
     "app.runtime.events -> app.runtime",
     "app.runtime.events -> app.runtime.config",
+    "app.runtime.events -> app.runtime.correlation",
     "app.runtime.events -> app.runtime.event",
     "app.runtime.events -> app.runtime.event.binding",
     "app.runtime.events -> app.runtime.event.contracts",
@@ -5558,6 +5566,7 @@
     "app.scheduler -> app.foundation.singleton",
     "app.scheduler -> app.runtime",
     "app.scheduler -> app.runtime.config",
+    "app.scheduler -> app.runtime.correlation",
     "app.scheduler -> app.runtime.events",
     "app.scheduler -> app.runtime.extensions",
     "app.scheduler -> app.runtime.extensions.plugin_manager",
@@ -6240,7 +6249,7 @@
     "app.workflow.actions.transfer_file -> app.workflow",
     "app.workflow.actions.transfer_file -> app.workflow.actions"
   ],
-  "module_count": 776,
+  "module_count": 778,
   "modules": [
     "app",
     "app.adapters",
@@ -6280,6 +6289,7 @@
     "app.adapters.system.rust",
     "app.adapters.system.stdio",
     "app.adapters.web",
+    "app.adapters.web.correlation",
     "app.adapters.web.health",
     "app.adapters.web.plugin",
     "app.adapters.web.plugin.routes",
@@ -6870,6 +6880,7 @@
     "app.runtime.compat.manifest",
     "app.runtime.compat.resource_imports",
     "app.runtime.config",
+    "app.runtime.correlation",
     "app.runtime.debounce",
     "app.runtime.event",
     "app.runtime.event.binding",

tests/test_correlation.py

@@ -0,0 +1,180 @@
+"""请求关联 ID 在 HTTP、线程、事件和外部请求边界的传播测试。"""
+
+import asyncio
+import logging
+from types import SimpleNamespace
+from unittest.mock import MagicMock
+
+import httpx
+import pytest
+from starlette.applications import Starlette
+from starlette.responses import JSONResponse, StreamingResponse
+from starlette.routing import Route
+
+from app.adapters.network.http import AsyncRequestUtils, RequestUtils
+from app.adapters.web.correlation import CorrelationIdMiddleware
+from app.runtime.correlation import (
+    CORRELATION_ID_HEADER,
+    call_with_correlation,
+    correlation_scope,
+    get_correlation_id,
+    normalize_correlation_id,
+)
+from app.runtime.event.dispatch import EventDispatcher
+from app.runtime.events import Event
+from app.runtime.execution import run_in_threadpool
+from app.runtime.log import CustomFormatter, configure_correlation_id_provider
+from app.schemas.types import EventType
+
+
+def _correlation_app() -> Starlette:
+    """构造同时包含普通响应和 SSE 风格流式响应的最小应用。"""
+
+    async def current_id(_request):
+        """返回当前协程看到的关联 ID。"""
+        await asyncio.sleep(0)
+        return JSONResponse({"request_id": get_correlation_id()})
+
+    async def stream_id(_request):
+        """在响应开始后读取关联 ID，验证上下文覆盖完整流生命周期。"""
+        async def content():
+            """生成一条 SSE 数据。"""
+            await asyncio.sleep(0)
+            yield f"data: {get_correlation_id()}\n\n"
+
+        return StreamingResponse(content(), media_type="text/event-stream")
+
+    app = Starlette(
+        routes=[
+            Route("/id", current_id),
+            Route("/stream", stream_id),
+        ]
+    )
+    app.add_middleware(CorrelationIdMiddleware)
+    return app
+
+
+@pytest.mark.asyncio
+async def test_concurrent_requests_keep_isolated_ids_and_stream_context() -> None:
+    """并发请求及流式响应必须各自保留入口 ID。"""
+    transport = httpx.ASGITransport(app=_correlation_app())
+    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
+        first, second = await asyncio.gather(
+            client.get("/id", headers={CORRELATION_ID_HEADER: "request-one"}),
+            client.get("/id", headers={CORRELATION_ID_HEADER: "request-two"}),
+        )
+        stream = await client.get(
+            "/stream", headers={CORRELATION_ID_HEADER: "stream-request"}
+        )
+
+    assert first.json()["request_id"] == first.headers[CORRELATION_ID_HEADER]
+    assert second.json()["request_id"] == second.headers[CORRELATION_ID_HEADER]
+    assert first.headers[CORRELATION_ID_HEADER] != second.headers[CORRELATION_ID_HEADER]
+    assert stream.headers[CORRELATION_ID_HEADER] == "stream-request"
+    assert stream.text == "data: stream-request\n\n"
+    assert get_correlation_id() is None
+
+
+@pytest.mark.asyncio
+async def test_invalid_request_id_is_replaced_and_threadpool_copies_context() -> None:
+    """日志注入型入口值被替换，线程池仍读取替换后的安全 ID。"""
+    transport = httpx.ASGITransport(app=_correlation_app())
+    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
+        response = await client.get(
+            "/id", headers={CORRELATION_ID_HEADER: "bad id!"}
+        )
+
+    generated = response.headers[CORRELATION_ID_HEADER]
+    assert generated != "bad id!"
+    assert normalize_correlation_id(generated) == generated
+    with correlation_scope("thread-request"):
+        observed = await run_in_threadpool(get_correlation_id)
+    assert observed == "thread-request"
+
+
+def test_event_dispatch_restores_producer_correlation_id() -> None:
+    """后台事件处理器使用事件生产时固化的 ID，而非消费者线程上下文。"""
+    observed = []
+
+    def handler(_event):
+        """记录处理器实际看到的关联 ID。"""
+        observed.append(get_correlation_id())
+
+    resolver = MagicMock()
+    resolver.resolve.return_value = (
+        handler,
+        SimpleNamespace(owner_name="test", run_sync_in_threadpool=False),
+        "Handler",
+        "handle",
+    )
+    registry = MagicMock()
+    dispatcher = EventDispatcher(
+        registry=registry,
+        binding_resolver=resolver,
+        executor=MagicMock(),
+        event_loop=MagicMock(),
+        event_factory=Event,
+        error_handler=MagicMock(),
+    )
+    with correlation_scope("producer-request"):
+        event = Event(EventType.SystemError, {})
+    with correlation_scope("consumer-request"):
+        dispatcher.invoke_sync(handler, event)
+
+    assert event.correlation_id == "producer-request"
+    assert observed == ["producer-request"]
+    assert get_correlation_id() is None
+
+
+def test_sync_external_request_and_formatter_receive_correlation_id() -> None:
+    """同步外呼头和结构化日志字段使用同一个当前 ID。"""
+    configure_correlation_id_provider(get_correlation_id)
+    response = httpx.Response(200)
+    session = MagicMock()
+    session.request.return_value = response
+    formatter = CustomFormatter("%(correlation_id)s %(message)s")
+    record = logging.LogRecord("test", logging.INFO, "", 0, "message", (), None)
+
+    with correlation_scope("outgoing-request"):
+        RequestUtils(session=session).request("GET", "https://example.com")
+        rendered = formatter.format(record)
+
+    headers = session.request.call_args.kwargs["headers"]
+    assert headers[CORRELATION_ID_HEADER] == "outgoing-request"
+    assert rendered == "outgoing-request message"
+
+
+def test_process_entry_restores_serialized_correlation_id() -> None:
+    """多进程入口使用显式 payload 恢复 ID，不依赖 fork 偶然继承上下文。"""
+    with correlation_scope("parent-request"):
+        observed = call_with_correlation(
+            "serialized-request",
+            get_correlation_id,
+            (),
+            {},
+        )
+
+    assert observed == "serialized-request"
+
+
+@pytest.mark.asyncio
+async def test_async_external_request_preserves_explicit_header() -> None:
+    """异步外呼默认传播当前 ID，但不得覆盖调用方显式 trace 边界。"""
+    observed = []
+
+    async def respond(request: httpx.Request) -> httpx.Response:
+        """记录 MockTransport 收到的请求头。"""
+        observed.append(request.headers[CORRELATION_ID_HEADER])
+        return httpx.Response(200)
+
+    async with httpx.AsyncClient(transport=httpx.MockTransport(respond)) as client:
+        utils = AsyncRequestUtils(client=client)
+        with correlation_scope("context-request"):
+            await utils.request("GET", "https://example.com/default")
+            await utils.request(
+                "GET",
+                "https://example.com/explicit",
+                headers={CORRELATION_ID_HEADER: "explicit-request"},
+            )
+
+    assert observed == ["context-request", "explicit-request"]