diff --git a/run_tests.py b/run_tests.py
index ef914f0cd..3f779af57 100644
--- a/run_tests.py
+++ b/run_tests.py
@@ -9,6 +9,7 @@ Usage:
     python run_tests.py --cov              # Run with coverage
     python run_tests.py -m "not slow"      # Skip slow tests
 """
+
 from __future__ import annotations
 
 import subprocess
@@ -30,11 +31,13 @@ def main() -> int:
     # Handle --cov flag
     if "--cov" in args:
         args.remove("--cov")
-        cmd.extend([
-            "--cov=src-new/astrbot_sdk",
-            "--cov-report=term-missing",
-            "--cov-report=html:.htmlcov",
-        ])
+        cmd.extend(
+            [
+                "--cov=src-new/astrbot_sdk",
+                "--cov-report=term-missing",
+                "--cov-report=html:.htmlcov",
+            ]
+        )
 
     # Default flags if no specific args
     if not args:
diff --git a/src-new/astrbot_sdk/protocol/legacy_adapter.py b/src-new/astrbot_sdk/protocol/legacy_adapter.py
index 7a99cfd36..63edafbb5 100644
--- a/src-new/astrbot_sdk/protocol/legacy_adapter.py
+++ b/src-new/astrbot_sdk/protocol/legacy_adapter.py
@@ -13,7 +13,6 @@ from .messages import (
     InitializeMessage,
     InvokeMessage,
     PeerInfo,
-    ProtocolMessage,
     ResultMessage,
 )
 
diff --git a/src-new/astrbot_sdk/runtime/peer.py b/src-new/astrbot_sdk/runtime/peer.py
index 5fe85357f..d9657f2e4 100644
--- a/src-new/astrbot_sdk/runtime/peer.py
+++ b/src-new/astrbot_sdk/runtime/peer.py
@@ -27,6 +27,13 @@ CancelHandler = Callable[[str], Awaitable[None]]
 
 
 class Peer:
+    """表示协议连接中的一个对等端。
+
+    `Peer` 封装一条双向传输通道上的消息收发、初始化握手、能力调用、
+    流式事件转发与取消处理。这里的 `peer` 指“通信对端/本端”这一网络
+    协议概念，而不是业务上的用户、群聊或会话对象。
+    """
+
     def __init__(
         self,
         *,
@@ -34,6 +41,13 @@ class Peer:
         peer_info: PeerInfo,
         protocol_version: str = "1.0",
     ) -> None:
+        """创建一个协议对等端实例。
+
+        Args:
+            transport: 底层传输实现，负责发送字符串消息并回调入站消息。
+            peer_info: 当前端点对外声明的身份信息。
+            protocol_version: 当前端点支持的协议版本，用于初始化握手校验。
+        """
         self.transport = transport
         self.peer_info = peer_info
         self.protocol_version = protocol_version
@@ -55,19 +69,24 @@ class Peer:
         self._remote_initialized = asyncio.Event()
 
     def set_initialize_handler(self, handler: InitializeHandler) -> None:
+        """注册处理远端 `initialize` 请求的握手处理器。"""
         self._initialize_handler = handler
 
     def set_invoke_handler(self, handler: InvokeHandler) -> None:
+        """注册处理远端 `invoke` 请求的能力调用处理器。"""
         self._invoke_handler = handler
 
     def set_cancel_handler(self, handler: CancelHandler) -> None:
+        """注册处理远端 `cancel` 请求的取消回调。"""
         self._cancel_handler = handler
 
     async def start(self) -> None:
+        """启动传输层并将原始入站消息绑定到当前 `Peer`。"""
         self.transport.set_message_handler(self._handle_raw_message)
         await self.transport.start()
 
     async def stop(self) -> None:
+        """关闭 `Peer` 并清理所有挂起中的请求、流和入站任务。"""
         self._closed = True
         # 终止所有挂起的 RPC，避免调用方永久挂起
         for future in list(self._pending_results.values()):
@@ -88,9 +107,15 @@ class Peer:
         await self.transport.stop()
 
     async def wait_closed(self) -> None:
+        """等待底层传输彻底关闭。"""
         await self.transport.wait_closed()
 
     async def wait_until_remote_initialized(self, timeout: float | None = 30.0) -> None:
+        """等待远端完成初始化握手。
+
+        Args:
+            timeout: 等待秒数。传入 `None` 表示无限等待。
+        """
         if timeout is None:
             await self._remote_initialized.wait()
             return
@@ -102,6 +127,15 @@ class Peer:
         *,
         metadata: dict[str, Any] | None = None,
     ) -> InitializeOutput:
+        """向远端发送初始化请求并缓存远端声明的能力信息。
+
+        Args:
+            handlers: 当前端点声明可接收的处理器列表。
+            metadata: 附带给远端的握手元数据。
+
+        Returns:
+            远端返回的初始化结果。
+        """
         self._ensure_usable()
         request_id = self._next_id()
         future: asyncio.Future[ResultMessage] = (
@@ -141,6 +175,14 @@ class Peer:
         stream: bool = False,
         request_id: str | None = None,
     ) -> dict[str, Any]:
+        """发起一次非流式能力调用并等待最终结果。
+
+        Args:
+            capability: 远端能力名。
+            payload: 调用输入。
+            stream: 必须为 `False`；流式场景应改用 `invoke_stream()`。
+            request_id: 可选的请求 ID；未提供时自动生成。
+        """
         self._ensure_usable()
         if stream:
             raise ValueError("stream=True 请使用 invoke_stream()")
@@ -171,6 +213,16 @@ class Peer:
         *,
         request_id: str | None = None,
     ) -> AsyncIterator[EventMessage]:
+        """发起一次流式能力调用并返回事件迭代器。
+
+        调用方会收到 `delta` 事件，`started` 会被内部吞掉，
+        `completed` 用于结束迭代，`failed` 会转换为异常抛出。
+
+        Args:
+            capability: 远端能力名。
+            payload: 调用输入。
+            request_id: 可选的请求 ID；未提供时自动生成。
+        """
         self._ensure_usable()
         request_id = request_id or self._next_id()
         queue: asyncio.Queue[Any] = asyncio.Queue()
@@ -209,17 +261,21 @@ class Peer:
         return iterator()
 
     async def cancel(self, request_id: str, reason: str = "user_cancelled") -> None:
+        """向远端发送取消请求，尝试中止指定 ID 的在途调用。"""
         await self._send(CancelMessage(id=request_id, reason=reason))
 
     def _next_id(self) -> str:
+        """生成当前连接内递增的消息 ID。"""
         self._counter += 1
         return f"msg_{self._counter:04d}"
 
     def _ensure_usable(self) -> None:
+        """确保连接仍处于可用状态，否则立即抛出协议错误。"""
         if self._unusable:
             raise AstrBotError.protocol_error("连接已进入不可用状态")
 
     async def _handle_raw_message(self, payload: str) -> None:
+        """解析原始消息并分发到对应的消息处理分支。"""
         message = parse_message(payload)
         if isinstance(message, ResultMessage):
             await self._handle_result(message)
@@ -245,6 +301,7 @@ class Peer:
             return
 
     async def _handle_initialize(self, message: InitializeMessage) -> None:
+        """处理远端发起的初始化握手并返回握手结果。"""
         self.remote_peer = message.peer
         self.remote_handlers = message.handlers
         self.remote_metadata = message.metadata
@@ -276,6 +333,7 @@ class Peer:
         self._remote_initialized.set()
 
     async def _handle_invoke(self, message: InvokeMessage) -> None:
+        """处理远端发起的能力调用，并按流式或非流式协议返回结果。"""
         active = self._inbound_tasks.get(message.id)
         token = active[1] if active is not None else CancelToken()
         try:
@@ -320,6 +378,7 @@ class Peer:
             )
 
     async def _handle_cancel(self, message: CancelMessage) -> None:
+        """处理远端取消请求并终止对应的入站任务。"""
         inbound = self._inbound_tasks.get(message.id)
         if inbound is None:
             return
@@ -330,6 +389,7 @@ class Peer:
         task.cancel()
 
     async def _handle_result(self, message: ResultMessage) -> None:
+        """处理非流式结果消息并唤醒等待中的调用方。"""
         future = self._pending_results.pop(message.id, None)
         if future is None:
             queue = self._pending_streams.get(message.id)
@@ -343,6 +403,7 @@ class Peer:
             future.set_result(message)
 
     async def _handle_event(self, message: EventMessage) -> None:
+        """处理流式事件消息并投递到对应请求的事件队列。"""
         queue = self._pending_streams.get(message.id)
         if queue is None:
             future = self._pending_results.get(message.id)
@@ -356,6 +417,7 @@ class Peer:
     async def _send_error_result(
         self, message: InvokeMessage, error: AstrBotError
     ) -> None:
+        """根据调用模式，将错误编码为 `result` 或失败事件发回远端。"""
         if message.stream:
             await self._send(
                 EventMessage(
@@ -376,6 +438,7 @@ class Peer:
     async def _reject_initialize(
         self, message: InitializeMessage, error: AstrBotError
     ) -> None:
+        """拒绝一次初始化握手，并把连接标记为不可继续使用。"""
         await self._send(
             ResultMessage(
                 id=message.id,
@@ -389,8 +452,10 @@ class Peer:
         await self.stop()
 
     async def _send_cancelled_termination(self, message: InvokeMessage) -> None:
+        """把本端取消执行转换为标准化的取消错误响应。"""
         error = AstrBotError.cancelled()
         await self._send_error_result(message, error)
 
     async def _send(self, message) -> None:
+        """序列化协议消息并通过底层传输发送出去。"""
         await self.transport.send(message.model_dump_json(exclude_none=True))
diff --git a/src/astrbot_sdk/tests/test_supervisor.py b/src/astrbot_sdk/tests/test_supervisor.py
index 27eab71ae..379080c2b 100644
--- a/src/astrbot_sdk/tests/test_supervisor.py
+++ b/src/astrbot_sdk/tests/test_supervisor.py
@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import asyncio
 import tempfile
 import unittest
 from pathlib import Path
diff --git a/tests_v4/conftest.py b/tests_v4/conftest.py
index e6f86ecc5..187c878e7 100644
--- a/tests_v4/conftest.py
+++ b/tests_v4/conftest.py
@@ -8,6 +8,7 @@ import pytest
 
 # 将 src-new 加入路径 - 这使得测试可以运行，但不算"已安装"
 import sys
+
 SRC_NEW_PATH = str(Path(__file__).parent.parent / "src-new")
 sys.path.insert(0, SRC_NEW_PATH)
 
@@ -16,6 +17,7 @@ sys.path.insert(0, SRC_NEW_PATH)
 # Async Configuration
 # ============================================================
 
+
 @pytest.fixture(scope="session")
 def event_loop() -> Generator[asyncio.AbstractEventLoop, None, None]:
     """Create an event loop for async tests."""
@@ -29,6 +31,7 @@ def event_loop() -> Generator[asyncio.AbstractEventLoop, None, None]:
 # Transport Fixtures
 # ============================================================
 
+
 class MemoryTransport:
     """In-memory transport for testing peer communication."""
 
@@ -74,6 +77,7 @@ def transport_pair() -> tuple[MemoryTransport, MemoryTransport]:
 # Mock/Fake Fixtures
 # ============================================================
 
+
 class FakeEnvManager:
     """Fake environment manager for testing."""
 
diff --git a/tests_v4/test_api_decorators.py b/tests_v4/test_api_decorators.py
index 339b45e39..82fd82740 100644
--- a/tests_v4/test_api_decorators.py
+++ b/tests_v4/test_api_decorators.py
@@ -1,6 +1,7 @@
 """
 Unit tests for API decorators and Star class.
 """
+
 from __future__ import annotations
 
 import pytest
@@ -167,6 +168,7 @@ class TestStarClass:
 
     def test_star_is_new_star_by_default(self):
         """Star subclasses should be recognized as new-style."""
+
         class MyPlugin(Star):
             pass
 
@@ -174,6 +176,7 @@ class TestStarClass:
 
     def test_star_collects_handler_names_from_decorators(self):
         """Star should collect decorated method names in __handlers__."""
+
         class MyPlugin(Star):
             @on_command("hello")
             async def hello(self, event: MessageEvent, ctx: Context):
diff --git a/tests_v4/test_api_event_filter.py b/tests_v4/test_api_event_filter.py
index da38ad266..75fe34187 100644
--- a/tests_v4/test_api_event_filter.py
+++ b/tests_v4/test_api_event_filter.py
@@ -1,9 +1,9 @@
 """
 Tests for api/event/filter.py - Event filter decorators and utilities.
 """
+
 from __future__ import annotations
 
-import pytest
 
 from astrbot_sdk.api.event.filter import ADMIN, command, filter, permission, regex
 from astrbot_sdk.decorators import get_handler_meta
diff --git a/tests_v4/test_api_legacy_context.py b/tests_v4/test_api_legacy_context.py
index f10eda757..99752b50f 100644
--- a/tests_v4/test_api_legacy_context.py
+++ b/tests_v4/test_api_legacy_context.py
@@ -1,9 +1,10 @@
 """
 Tests for _legacy_api.py - Legacy compatibility layer.
 """
+
 from __future__ import annotations
 
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, MagicMock
 
 import pytest
 
diff --git a/tests_v4/test_api_modules.py b/tests_v4/test_api_modules.py
index 2158244f7..27d577513 100644
--- a/tests_v4/test_api_modules.py
+++ b/tests_v4/test_api_modules.py
@@ -1,9 +1,9 @@
 """
 Tests for API module exports and re-exports.
 """
+
 from __future__ import annotations
 
-import pytest
 
 
 class TestApiStarModule:
diff --git a/tests_v4/test_conftest_fixtures.py b/tests_v4/test_conftest_fixtures.py
index 783c24a73..2c00ad51a 100644
--- a/tests_v4/test_conftest_fixtures.py
+++ b/tests_v4/test_conftest_fixtures.py
@@ -3,15 +3,19 @@ Pytest-based tests for transport and peer communication.
 
 These tests demonstrate the pytest fixtures defined in conftest.py.
 """
+
 from __future__ import annotations
 
 import pytest
 
-from astrbot_sdk.context import CancelToken
 from astrbot_sdk.errors import AstrBotError
 from astrbot_sdk.protocol.descriptors import CapabilityDescriptor
-from astrbot_sdk.protocol.messages import EventMessage, InitializeOutput, PeerInfo, ResultMessage
-from astrbot_sdk.runtime.capability_router import CapabilityRouter, StreamExecution
+from astrbot_sdk.protocol.messages import (
+    EventMessage,
+    PeerInfo,
+    ResultMessage,
+)
+from astrbot_sdk.runtime.capability_router import CapabilityRouter
 from astrbot_sdk.runtime.peer import Peer
 
 
@@ -98,7 +102,6 @@ class TestProtocolErrors:
 
     async def test_stream_true_receiving_result_is_error(self, transport_pair):
         """stream=true receiving result should raise protocol error."""
-        import asyncio
 
         left, right = transport_pair
 
@@ -113,7 +116,9 @@ class TestProtocolErrors:
         stream = await plugin.invoke_stream(
             "llm.stream_chat", {"prompt": "bad"}, request_id="stream-1"
         )
-        await left.send(ResultMessage(id="stream-1", success=True, output={}).model_dump_json())
+        await left.send(
+            ResultMessage(id="stream-1", success=True, output={}).model_dump_json()
+        )
 
         with pytest.raises(AstrBotError) as exc_info:
             async for _ in stream:
@@ -134,9 +139,7 @@ class TestCapabilityRouter:
         invalid_names = ["llm", "llm.chat.extra", "LLM.chat", "llm.Chat"]
         for name in invalid_names:
             with pytest.raises(ValueError) as exc_info:
-                router.register(
-                    CapabilityDescriptor(name=name, description="invalid")
-                )
+                router.register(CapabilityDescriptor(name=name, description="invalid"))
             assert name in str(exc_info.value)
 
     def test_reserved_namespaces_rejected_for_exposed(self):
@@ -146,9 +149,7 @@ class TestCapabilityRouter:
         reserved_names = ["handler.demo", "system.health", "internal.trace"]
         for name in reserved_names:
             with pytest.raises(ValueError) as exc_info:
-                router.register(
-                    CapabilityDescriptor(name=name, description="reserved")
-                )
+                router.register(CapabilityDescriptor(name=name, description="reserved"))
             assert name in str(exc_info.value)
 
     def test_reserved_namespaces_allowed_for_hidden(self):
diff --git a/tests_v4/test_context.py b/tests_v4/test_context.py
index 6ebabd4a3..5b6c5f9a1 100644
--- a/tests_v4/test_context.py
+++ b/tests_v4/test_context.py
@@ -1,6 +1,7 @@
 """
 Unit tests for Context module.
 """
+
 from __future__ import annotations
 
 import asyncio
diff --git a/tests_v4/test_decorators.py b/tests_v4/test_decorators.py
index cceff5691..2edf7382d 100644
--- a/tests_v4/test_decorators.py
+++ b/tests_v4/test_decorators.py
@@ -1,9 +1,9 @@
 """
 Tests for decorators.py - Handler decorator infrastructure.
 """
+
 from __future__ import annotations
 
-import pytest
 
 from astrbot_sdk.decorators import (
     HANDLER_META_ATTR,
@@ -57,6 +57,7 @@ class TestGetHandlerMeta:
 
     def test_returns_none_for_undecorated_function(self):
         """get_handler_meta should return None for undecorated functions."""
+
         async def plain_function():
             pass
 
@@ -212,6 +213,7 @@ class TestOnEventDecorator:
         event_types = ["message_received", "user_joined", "custom_event"]
 
         for event_type in event_types:
+
             @on_event(event_type)
             async def handler():
                 pass
diff --git a/tests_v4/test_entrypoints.py b/tests_v4/test_entrypoints.py
index da0e7fd66..76d529f81 100644
--- a/tests_v4/test_entrypoints.py
+++ b/tests_v4/test_entrypoints.py
@@ -28,7 +28,7 @@ def _is_astrbot_sdk_installed_in_site_packages() -> bool:
 @pytest.mark.integration
 @pytest.mark.skipif(
     not _is_astrbot_sdk_installed_in_site_packages(),
-    reason="astrbot_sdk not installed in site-packages (run: pip install -e .)"
+    reason="astrbot_sdk not installed in site-packages (run: pip install -e .)",
 )
 class EntryPointTest(unittest.TestCase):
     def test_import_package(self) -> None:
diff --git a/tests_v4/test_events.py b/tests_v4/test_events.py
index eb1f874f6..6872cc7f7 100644
--- a/tests_v4/test_events.py
+++ b/tests_v4/test_events.py
@@ -1,9 +1,9 @@
 """
 Unit tests for Events module.
 """
+
 from __future__ import annotations
 
-import asyncio
 
 import pytest