diff --git a/AGENTS.md b/AGENTS.md
index f6c7f2f4d..1db68c203 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -9,6 +9,8 @@
 - 2026-03-13: `src-new/astrbot_sdk/api` and several top-level module docstrings overstated v4 compatibility gaps by labeling migrated or compat-backed APIs as "missing". Treat `_legacy_api.py`, `astrbot_sdk.api.*` thin re-exports, and top-level `events.py` / `decorators.py` as a split compatibility surface; do not mechanically recreate the old tree from stale TODO comments.
 - 2026-03-13: Legacy components are expected to share one `LegacyContext` per plugin, matching the old `StarManager` behavior. Creating one compat context per component breaks `_register_component()` / `call_context_function()` cross-component registration chains and diverges from legacy semantics.
 - 2026-03-13: `WorkerSession` cannot assume the caller-provided `repo_root` contains `src-new/astrbot_sdk`. Tests and external bootstraps may pass a temporary repo root while still expecting the in-tree SDK package to launch worker subprocesses via `python -m astrbot_sdk`. Resolve the SDK source directory from the real package location when the supplied root does not contain it.
+- 2026-03-13: `MemoryClient.get()` is part of the supported v4 client surface and must stay in sync with `CapabilityRouter` built-ins. The client method existed while the router forgot to register `memory.get`, which caused a real runtime gap hidden by API shape alone.
+- 2026-03-13: When checking whether a peer has finished remote initialization, avoid `getattr(mock, "remote_peer")` style probes in code that may receive `MagicMock` peers. `MagicMock` fabricates truthy child attributes, so `CapabilityProxy` should read explicit state from `peer.__dict__` or another concrete storage location instead of treating arbitrary attribute access as initialization.
 
 # 开发命令
 
diff --git a/CLAUDE.md b/CLAUDE.md
index f6c7f2f4d..1db68c203 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -9,6 +9,8 @@
 - 2026-03-13: `src-new/astrbot_sdk/api` and several top-level module docstrings overstated v4 compatibility gaps by labeling migrated or compat-backed APIs as "missing". Treat `_legacy_api.py`, `astrbot_sdk.api.*` thin re-exports, and top-level `events.py` / `decorators.py` as a split compatibility surface; do not mechanically recreate the old tree from stale TODO comments.
 - 2026-03-13: Legacy components are expected to share one `LegacyContext` per plugin, matching the old `StarManager` behavior. Creating one compat context per component breaks `_register_component()` / `call_context_function()` cross-component registration chains and diverges from legacy semantics.
 - 2026-03-13: `WorkerSession` cannot assume the caller-provided `repo_root` contains `src-new/astrbot_sdk`. Tests and external bootstraps may pass a temporary repo root while still expecting the in-tree SDK package to launch worker subprocesses via `python -m astrbot_sdk`. Resolve the SDK source directory from the real package location when the supplied root does not contain it.
+- 2026-03-13: `MemoryClient.get()` is part of the supported v4 client surface and must stay in sync with `CapabilityRouter` built-ins. The client method existed while the router forgot to register `memory.get`, which caused a real runtime gap hidden by API shape alone.
+- 2026-03-13: When checking whether a peer has finished remote initialization, avoid `getattr(mock, "remote_peer")` style probes in code that may receive `MagicMock` peers. `MagicMock` fabricates truthy child attributes, so `CapabilityProxy` should read explicit state from `peer.__dict__` or another concrete storage location instead of treating arbitrary attribute access as initialization.
 
 # 开发命令
 
diff --git a/src-new/astrbot_sdk/clients/__init__.py b/src-new/astrbot_sdk/clients/__init__.py
index d7c0861ff..ec1a647b3 100644
--- a/src-new/astrbot_sdk/clients/__init__.py
+++ b/src-new/astrbot_sdk/clients/__init__.py
@@ -1,32 +1,15 @@
-"""客户端模块。
+"""v4 原生能力客户端集合。
 
-提供与 AstrBot 核心通信的客户端接口，通过 RPC 能力代理实现远程调用。
-所有客户端均基于 CapabilityProxy 构建，统一处理方法调用和流式响应。
+这些客户端是 `Context` 的窄接口，分别封装 llm、memory、db、platform
+四类远程 capability。它们只负责能力调用与轻量参数整形，不承载旧版
+`conversation_manager`、`MessageChain` 或 agent loop 语义；这些兼容能力由
+`_legacy_api.py` 与 `api/` compat 子模块处理。
 
-架构说明：
-    旧版 (src/astrbot_sdk/api/star/context.py):
-        - Context 基类直接提供 llm_generate(), tool_loop_agent(), send_message() 等方法
-        - 使用 MessageChain, ToolSet 等复杂类型
-        - 内置 conversation_manager 会话管理
-
-    新版 (src-new):
-        - Context 组合多个专用客户端 (llm, memory, db, platform)
-        - 每个客户端负责单一领域的功能
-        - 通过 Peer 和 CapabilityProxy 实现远程能力调用
-        - 支持流式响应 (stream_chat)
-
-可用客户端：
-    - LLMClient: 大语言模型调用，支持普通/流式聊天
-    - MemoryClient: 记忆存储，支持搜索、保存、获取、删除
-    - DBClient: 键值数据库，支持 get/set/delete/list
-    - PlatformClient: 平台消息发送，支持文本和图片消息
-
-TODO: (相比旧版缺失的功能):
-    - LLMClient 缺少 tool_loop_agent() Agent 循环能力
-    - LLMClient 缺少 add_llm_tools() 动态工具注册
-    - LLMClient.chat() 缺少 image_urls、tools、contexts 等高级参数支持
-    - Context 缺少 conversation_manager 会话管理器集成
-    - 缺少 MessageChain 消息链构建支持
+当前公开客户端：
+    - LLMClient: 文本/结构化/流式 LLM 调用
+    - MemoryClient: 记忆搜索、保存、读取、删除
+    - DBClient: 键值存储 get/set/delete/list
+    - PlatformClient: 平台消息发送与成员查询
 """
 
 from .db import DBClient
diff --git a/src-new/astrbot_sdk/clients/_proxy.py b/src-new/astrbot_sdk/clients/_proxy.py
index 0d34cfb27..40ca49682 100644
--- a/src-new/astrbot_sdk/clients/_proxy.py
+++ b/src-new/astrbot_sdk/clients/_proxy.py
@@ -29,12 +29,35 @@
 
 from __future__ import annotations
 
-from collections.abc import AsyncIterator
-from typing import Any
+from collections.abc import AsyncIterator, Mapping
+from typing import Any, Protocol
 
 from ..errors import AstrBotError
 
 
+class _CapabilityDescriptorLike(Protocol):
+    supports_stream: bool | None
+
+
+class _CapabilityPeerLike(Protocol):
+    remote_capability_map: Mapping[str, _CapabilityDescriptorLike]
+    remote_peer: Any | None
+
+    async def invoke(
+        self,
+        capability: str,
+        payload: dict[str, Any],
+        *,
+        stream: bool = False,
+    ) -> dict[str, Any]: ...
+
+    async def invoke_stream(
+        self,
+        capability: str,
+        payload: dict[str, Any],
+    ) -> AsyncIterator[Any]: ...
+
+
 class CapabilityProxy:
     """能力代理类，封装 Peer 的能力调用接口。
 
@@ -44,7 +67,7 @@ class CapabilityProxy:
         _peer: 底层 Peer 实例，负责实际的 RPC 通信
     """
 
-    def __init__(self, peer) -> None:
+    def __init__(self, peer: _CapabilityPeerLike) -> None:
         """初始化能力代理。
 
         Args:
@@ -61,7 +84,17 @@ class CapabilityProxy:
         Returns:
             能力描述符，若不存在则返回 None
         """
-        return self._peer.remote_capability_map.get(name)
+        capability_map = getattr(self._peer, "__dict__", {}).get(
+            "remote_capability_map",
+            {},
+        )
+        return capability_map.get(name)
+
+    def _remote_initialized(self) -> bool:
+        peer_state = getattr(self._peer, "__dict__", {})
+        return bool(peer_state.get("remote_peer")) or bool(
+            peer_state.get("remote_capability_map", {})
+        )
 
     def _ensure_available(self, name: str, *, stream: bool) -> None:
         """确保能力可用且支持指定的调用模式。
@@ -75,15 +108,11 @@ class CapabilityProxy:
         """
         descriptor = self._get_descriptor(name)
         if descriptor is None:
-            # 能力不存在，但如果远端尚未初始化则静默返回
-            if self._peer.remote_capability_map:
+            if self._remote_initialized():
                 raise AstrBotError.capability_not_found(name)
             return
         if stream and not descriptor.supports_stream:
             raise AstrBotError.invalid_input(f"{name} 不支持 stream=true")
-        if not stream and descriptor.supports_stream is False:
-            # 仅支持流式的能力也可以用普通调用
-            return
 
     async def call(self, name: str, payload: dict[str, Any]) -> dict[str, Any]:
         """执行普通能力调用（非流式）。
diff --git a/src-new/astrbot_sdk/clients/db.py b/src-new/astrbot_sdk/clients/db.py
index 9d43a288b..6ddf0c1f9 100644
--- a/src-new/astrbot_sdk/clients/db.py
+++ b/src-new/astrbot_sdk/clients/db.py
@@ -73,9 +73,14 @@ class DBClient:
             key: 数据键名
             value: 要存储的字典值
 
+        Raises:
+            TypeError: 如果 value 不是 dict
+
         示例:
             await ctx.db.set("user_settings", {"theme": "dark", "lang": "zh"})
         """
+        if not isinstance(value, dict):
+            raise TypeError("db.set 的 value 必须是 dict")
         await self._proxy.call("db.set", {"key": key, "value": value})
 
     async def delete(self, key: str) -> None:
@@ -104,4 +109,7 @@ class DBClient:
             # ["user_settings", "user_profile", "user_history"]
         """
         output = await self._proxy.call("db.list", {"prefix": prefix})
-        return [str(item) for item in output.get("keys", [])]
+        keys = output.get("keys")
+        if not isinstance(keys, (list, tuple)):
+            return []
+        return [str(item) for item in keys]
diff --git a/src-new/astrbot_sdk/clients/llm.py b/src-new/astrbot_sdk/clients/llm.py
index 9706b310d..9456d9b35 100644
--- a/src-new/astrbot_sdk/clients/llm.py
+++ b/src-new/astrbot_sdk/clients/llm.py
@@ -1,37 +1,18 @@
 """大语言模型客户端模块。
 
-提供与 LLM 交互的能力，支持普通聊天和流式聊天。
+提供 v4 原生的 LLM 能力调用接口。
 
-与旧版对比：
-    旧版 (src/astrbot_sdk/api/star/context.py):
-        Context.llm_generate(
-            chat_provider_id, prompt, image_urls, tools,
-            system_prompt, contexts, **kwargs
-        )
-        Context.tool_loop_agent(...)  # Agent 循环，自动执行工具调用
-
-    新版:
-        Context.llm.chat(prompt, system, history, model, temperature)
-        Context.llm.chat_raw(prompt, **kwargs)  # 返回完整响应
-        Context.llm.stream_chat(prompt, system, history)  # 流式响应
-
-主要差异：
-    1. 新版移除了 chat_provider_id 参数，由核心自动选择
-    2. 新版简化了参数结构，使用 ChatMessage 模型
-    3. 新版支持流式响应 (stream_chat)
-
-TODO (相比旧版缺失的功能):
-    - 缺少 tool_loop_agent() Agent 循环能力
-    - 缺少 add_llm_tools() 动态工具注册
-    - chat() 缺少 image_urls 多模态图片支持
-    - chat() 缺少 tools 工具集支持
-    - chat() 缺少 contexts 上下文消息列表
-    - 缺少对 OpenAI 兼容的额外参数传递 (**kwargs 支持不完整)
+设计边界：
+    - `chat()` 是便捷文本接口，返回最终文本
+    - `chat_raw()` 返回完整结构化响应
+    - `stream_chat()` 返回文本增量
+    - Agent 循环、动态工具注册等更高层 orchestration 不放在客户端内，
+      由上层运行时或 `_legacy_api.py` 的兼容入口承接
 """
 
 from __future__ import annotations
 
-from collections.abc import AsyncGenerator
+from collections.abc import AsyncGenerator, Mapping, Sequence
 from typing import Any
 
 from pydantic import BaseModel, Field
@@ -60,6 +41,50 @@ class ChatMessage(BaseModel):
     content: str
 
 
+ChatHistoryItem = ChatMessage | Mapping[str, Any]
+
+
+def _serialize_history(
+    history: Sequence[ChatHistoryItem] | None,
+) -> list[dict[str, Any]]:
+    if history is None:
+        return []
+
+    serialized: list[dict[str, Any]] = []
+    for item in history:
+        if isinstance(item, ChatMessage):
+            serialized.append(item.model_dump())
+            continue
+        if isinstance(item, Mapping):
+            serialized.append(dict(item))
+            continue
+        raise TypeError("history 项必须是 ChatMessage 或 mapping")
+    return serialized
+
+
+def _build_chat_payload(
+    prompt: str,
+    *,
+    system: str | None = None,
+    history: Sequence[ChatHistoryItem] | None = None,
+    model: str | None = None,
+    temperature: float | None = None,
+    extra: dict[str, Any] | None = None,
+) -> dict[str, Any]:
+    payload: dict[str, Any] = {"prompt": prompt}
+    if system is not None:
+        payload["system"] = system
+    if history is not None:
+        payload["history"] = _serialize_history(history)
+    if model is not None:
+        payload["model"] = model
+    if temperature is not None:
+        payload["temperature"] = temperature
+    if extra:
+        payload.update(extra)
+    return payload
+
+
 class LLMResponse(BaseModel):
     """LLM 响应模型。
 
@@ -100,9 +125,10 @@ class LLMClient:
         prompt: str,
         *,
         system: str | None = None,
-        history: list[ChatMessage] | None = None,
+        history: Sequence[ChatHistoryItem] | None = None,
         model: str | None = None,
         temperature: float | None = None,
+        **kwargs: Any,
     ) -> str:
         """发送聊天请求并返回文本响应。
 
@@ -115,6 +141,7 @@ class LLMClient:
             history: 对话历史，用于保持上下文连续性
             model: 指定使用的模型名称（可选，由核心自动选择）
             temperature: 生成温度，控制随机性（0-1）
+            **kwargs: 额外透传参数，如 `image_urls`、`tools`
 
         Returns:
             LLM 生成的文本内容
@@ -132,13 +159,14 @@ class LLMClient:
         """
         output = await self._proxy.call(
             "llm.chat",
-            {
-                "prompt": prompt,
-                "system": system,
-                "history": [item.model_dump() for item in history or []],
-                "model": model,
-                "temperature": temperature,
-            },
+            _build_chat_payload(
+                prompt,
+                system=system,
+                history=history,
+                model=model,
+                temperature=temperature,
+                extra=kwargs,
+            ),
         )
         return str(output.get("text", ""))
 
@@ -164,12 +192,12 @@ class LLMClient:
             print(f"生成文本: {response.text}")
             print(f"Token 使用: {response.usage}")
         """
+        payload = {"prompt": prompt, **kwargs}
+        if "history" in payload:
+            payload["history"] = _serialize_history(payload["history"])
         output = await self._proxy.call(
             "llm.chat_raw",
-            {
-                "prompt": prompt,
-                **kwargs,
-            },
+            payload,
         )
         return LLMResponse.model_validate(output)
 
@@ -178,7 +206,10 @@ class LLMClient:
         prompt: str,
         *,
         system: str | None = None,
-        history: list[ChatMessage] | None = None,
+        history: Sequence[ChatHistoryItem] | None = None,
+        model: str | None = None,
+        temperature: float | None = None,
+        **kwargs: Any,
     ) -> AsyncGenerator[str, None]:
         """流式聊天，逐块返回响应文本。
 
@@ -188,6 +219,9 @@ class LLMClient:
             prompt: 用户输入的提示文本
             system: 系统提示词
             history: 对话历史
+            model: 指定模型
+            temperature: 采样温度
+            **kwargs: 额外透传参数，如 `image_urls`、`tools`
 
         Yields:
             每个生成的文本块
@@ -198,10 +232,13 @@ class LLMClient:
         """
         async for data in self._proxy.stream(
             "llm.stream_chat",
-            {
-                "prompt": prompt,
-                "system": system,
-                "history": [item.model_dump() for item in history or []],
-            },
+            _build_chat_payload(
+                prompt,
+                system=system,
+                history=history,
+                model=model,
+                temperature=temperature,
+                extra=kwargs,
+            ),
         ):
             yield str(data.get("text", ""))
diff --git a/src-new/astrbot_sdk/clients/memory.py b/src-new/astrbot_sdk/clients/memory.py
index 4dd91cde2..00d9dfcbf 100644
--- a/src-new/astrbot_sdk/clients/memory.py
+++ b/src-new/astrbot_sdk/clients/memory.py
@@ -70,7 +70,10 @@ class MemoryClient:
                 print(item["key"], item["content"])
         """
         output = await self._proxy.call("memory.search", {"query": query})
-        return list(output.get("items", []))
+        items = output.get("items")
+        if not isinstance(items, (list, tuple)):
+            return []
+        return list(items)
 
     async def save(
         self,
diff --git a/src-new/astrbot_sdk/clients/platform.py b/src-new/astrbot_sdk/clients/platform.py
index dbf4470f3..7d1710221 100644
--- a/src-new/astrbot_sdk/clients/platform.py
+++ b/src-new/astrbot_sdk/clients/platform.py
@@ -1,27 +1,11 @@
 """平台客户端模块。
 
-提供与聊天平台交互的能力，支持发送消息和获取群组信息。
+提供 v4 原生的平台能力调用。
 
-与旧版对比：
-    旧版 (src/astrbot_sdk/api/star/context.py):
-        Context.send_message(session, message_chain)
-        # 使用 MessageChain 构建复杂消息
-
-    新版:
-        Context.platform.send(session, text)
-        Context.platform.send_image(session, image_url)
-        Context.platform.get_members(session)
-
-主要差异：
-    1. 新版拆分为 send() 和 send_image()，简化使用
-    2. 新版移除 MessageChain，直接使用文本字符串
-    3. 新增 get_members() 获取群成员列表
-
-TODO (相比旧版缺失的功能):
-    - 缺少 MessageChain 复杂消息链支持（多段文本、@提及、表情等）
-    - 缺少发送音频、视频、文件等多媒体消息
-    - 缺少消息撤回、编辑等操作
-    - 缺少获取用户详细信息的方法
+设计边界：
+    - `PlatformClient` 只负责直接的平台 capability
+    - 旧版 `send_message(session, MessageChain)` 兼容由 `_legacy_api.py` 承接
+    - 富消息链构建能力位于 `api.message` compat 子模块，而不是此客户端
 """
 
 from __future__ import annotations
@@ -62,7 +46,7 @@ class PlatformClient:
 
         示例:
             # 发送消息到当前会话
-            await ctx.platform.send(event.session, "收到您的消息！")
+            await ctx.platform.send(event.session_id, "收到您的消息！")
         """
         return await self._proxy.call(
             "platform.send",
@@ -83,7 +67,7 @@ class PlatformClient:
 
         示例:
             await ctx.platform.send_image(
-                event.session,
+                event.session_id,
                 "https://example.com/image.png"
             )
         """
@@ -107,9 +91,12 @@ class PlatformClient:
             - role: 角色 (owner, admin, member)
 
         示例:
-            members = await ctx.platform.get_members(event.session)
+            members = await ctx.platform.get_members(event.session_id)
             for member in members:
                 print(f"{member['nickname']} ({member['user_id']})")
         """
         output = await self._proxy.call("platform.get_members", {"session": session})
-        return list(output.get("members", []))
+        members = output.get("members")
+        if not isinstance(members, (list, tuple)):
+            return []
+        return list(members)
diff --git a/src-new/astrbot_sdk/context.py b/src-new/astrbot_sdk/context.py
index ab749e135..a56fe642e 100644
--- a/src-new/astrbot_sdk/context.py
+++ b/src-new/astrbot_sdk/context.py
@@ -1,4 +1,9 @@
-"""v4 原生运行时上下文。"""
+"""v4 原生运行时上下文。
+
+`Context` 负责组合 v4 原生 capability 客户端。
+旧版 `conversation_manager`、`send_message()` 等兼容入口不在这里实现，
+而由 `_legacy_api.py` 承接。
+"""
 
 from __future__ import annotations
 
@@ -44,6 +49,7 @@ class Context:
         logger: Any | None = None,
     ) -> None:
         proxy = CapabilityProxy(peer)
+        self.peer = peer
         self.llm = LLMClient(proxy)
         self.memory = MemoryClient(proxy)
         self.db = DBClient(proxy)
diff --git a/src-new/astrbot_sdk/runtime/capability_router.py b/src-new/astrbot_sdk/runtime/capability_router.py
index 36bfd59fb..a06adf5be 100644
--- a/src-new/astrbot_sdk/runtime/capability_router.py
+++ b/src-new/astrbot_sdk/runtime/capability_router.py
@@ -15,6 +15,7 @@
     llm.stream_chat: 流式 LLM 聊天
     memory.search: 搜索记忆
     memory.save: 保存记忆
+    memory.get: 读取单条记忆
     memory.delete: 删除记忆
     db.get: 读取 KV 存储
     db.set: 写入 KV 存储
@@ -250,6 +251,11 @@ class CapabilityRouter:
             self.memory_store[key] = value
             return {}
 
+        async def memory_get(
+            _request_id: str, payload: dict[str, Any], _token
+        ) -> dict[str, Any]:
+            return {"value": self.memory_store.get(str(payload.get("key", "")))}
+
         async def memory_delete(
             _request_id: str, payload: dict[str, Any], _token
         ) -> dict[str, Any]:
@@ -379,6 +385,15 @@ class CapabilityRouter:
             ),
             call_handler=memory_save,
         )
+        self.register(
+            CapabilityDescriptor(
+                name="memory.get",
+                description="读取单条记忆",
+                input_schema=obj_schema(["key"], key={"type": "string"}),
+                output_schema=obj_schema([], value={"type": "object"}),
+            ),
+            call_handler=memory_get,
+        )
         self.register(
             CapabilityDescriptor(
                 name="memory.delete",
diff --git a/tests_v4/test_capability_proxy.py b/tests_v4/test_capability_proxy.py
index 59627dea6..ba3f22937 100644
--- a/tests_v4/test_capability_proxy.py
+++ b/tests_v4/test_capability_proxy.py
@@ -26,6 +26,7 @@ class MockPeer:
 
     def __init__(self):
         self.remote_capability_map: dict[str, MockCapabilityDescriptor] = {}
+        self.remote_peer = None
         self.invoke = AsyncMock(return_value={"result": "ok"})
         self.invoke_stream = AsyncMock()
 
@@ -104,11 +105,24 @@ class TestCapabilityProxyEnsureAvailable:
         """_ensure_available should pass (return None) when capability map is empty."""
         peer = MagicMock()
         peer.remote_capability_map = {}
+        peer.remote_peer = None
         proxy = CapabilityProxy(peer)
 
         # Should not raise when map is empty
         proxy._ensure_available("any.cap", stream=False)
 
+    def test_ensure_available_raises_when_remote_initialized_without_capability(self):
+        """空 capability 表在远端已初始化后应视为真实缺失。"""
+        peer = MagicMock()
+        peer.remote_capability_map = {}
+        peer.remote_peer = object()
+        proxy = CapabilityProxy(peer)
+
+        with pytest.raises(AstrBotError) as exc_info:
+            proxy._ensure_available("missing.cap", stream=False)
+
+        assert exc_info.value.code == "capability_not_found"
+
     def test_ensure_available_raises_for_stream_not_supported(self):
         """_ensure_available should raise when stream requested but not supported."""
         peer = MagicMock()
diff --git a/tests_v4/test_capability_router.py b/tests_v4/test_capability_router.py
index 1cb5e664c..f50a25b35 100644
--- a/tests_v4/test_capability_router.py
+++ b/tests_v4/test_capability_router.py
@@ -153,6 +153,7 @@ class TestCapabilityRouterInit:
         # Memory capabilities
         assert "memory.search" in capability_names
         assert "memory.save" in capability_names
+        assert "memory.get" in capability_names
         assert "memory.delete" in capability_names
 
         # DB capabilities
@@ -490,8 +491,8 @@ class TestBuiltinMemoryCapabilities:
     """Tests for built-in memory capabilities."""
 
     @pytest.mark.asyncio
-    async def test_memory_save_and_search(self):
-        """memory.save and memory.search should work together."""
+    async def test_memory_save_and_get(self):
+        """memory.save and memory.get should work together."""
         router = CapabilityRouter()
         token = CancelToken()
 
@@ -504,7 +505,31 @@ class TestBuiltinMemoryCapabilities:
             request_id="req-1",
         )
 
-        # Search
+        # Get
+        result = await router.execute(
+            "memory.get",
+            {"key": "test_key"},
+            stream=False,
+            cancel_token=token,
+            request_id="req-2",
+        )
+
+        assert result["value"] == {"data": "test_value"}
+
+    @pytest.mark.asyncio
+    async def test_memory_save_and_search(self):
+        """memory.save and memory.search should work together."""
+        router = CapabilityRouter()
+        token = CancelToken()
+
+        await router.execute(
+            "memory.save",
+            {"key": "test_key", "value": {"data": "test_value"}},
+            stream=False,
+            cancel_token=token,
+            request_id="req-1",
+        )
+
         result = await router.execute(
             "memory.search",
             {"query": "test"},
@@ -516,6 +541,22 @@ class TestBuiltinMemoryCapabilities:
         assert len(result["items"]) == 1
         assert result["items"][0]["key"] == "test_key"
 
+    @pytest.mark.asyncio
+    async def test_memory_get_missing_key(self):
+        """memory.get should return None for missing key."""
+        router = CapabilityRouter()
+        token = CancelToken()
+
+        result = await router.execute(
+            "memory.get",
+            {"key": "missing"},
+            stream=False,
+            cancel_token=token,
+            request_id="req-1",
+        )
+
+        assert result["value"] is None
+
     @pytest.mark.asyncio
     async def test_memory_delete(self):
         """memory.delete should remove saved memory."""
diff --git a/tests_v4/test_context.py b/tests_v4/test_context.py
index 5b6c5f9a1..088485fab 100644
--- a/tests_v4/test_context.py
+++ b/tests_v4/test_context.py
@@ -112,6 +112,18 @@ class TestContext:
 
         assert ctx.plugin_id == "my_plugin"
 
+    def test_context_keeps_peer_reference(self, transport_pair):
+        """Context should retain the underlying peer for advanced diagnostics."""
+        left, _ = transport_pair
+
+        peer = Peer(
+            transport=left,
+            peer_info=PeerInfo(name="test", role="plugin", version="v4"),
+        )
+        ctx = Context(peer=peer, plugin_id="my_plugin")
+
+        assert ctx.peer is peer
+
     def test_context_has_logger(self, transport_pair):
         """Context should have a logger bound with plugin_id."""
         left, _ = transport_pair
diff --git a/tests_v4/test_db_client.py b/tests_v4/test_db_client.py
index 86a230ecd..33403ec18 100644
--- a/tests_v4/test_db_client.py
+++ b/tests_v4/test_db_client.py
@@ -125,6 +125,15 @@ class TestDBClientSet:
             {"key": "nested", "value": {"level1": {"level2": {"level3": "deep"}}}},
         )
 
+    @pytest.mark.asyncio
+    async def test_set_raises_type_error_for_non_dict_value(self):
+        """set() should reject non-dict values before calling proxy."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        client = DBClient(proxy)
+
+        with pytest.raises(TypeError, match="db.set 的 value 必须是 dict"):
+            await client.set("bad", "not a dict")
+
 
 class TestDBClientDelete:
     """Tests for DBClient.delete() method."""
@@ -201,6 +210,17 @@ class TestDBClientList:
 
         assert result == ["123", "456"]
 
+    @pytest.mark.asyncio
+    async def test_list_returns_empty_list_for_malformed_keys(self):
+        """list() should ignore malformed non-list key payloads."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"keys": "not-a-list"})
+
+        client = DBClient(proxy)
+        result = await client.list()
+
+        assert result == []
+
     @pytest.mark.asyncio
     async def test_list_with_none_prefix(self):
         """list() should handle None prefix."""
diff --git a/tests_v4/test_llm_client.py b/tests_v4/test_llm_client.py
index 4fd02a20d..6d6669089 100644
--- a/tests_v4/test_llm_client.py
+++ b/tests_v4/test_llm_client.py
@@ -123,6 +123,25 @@ class TestLLMClientChat:
         assert len(call_args["history"]) == 2
         assert call_args["history"][0] == {"role": "user", "content": "Hello"}
 
+    @pytest.mark.asyncio
+    async def test_chat_accepts_dict_history_and_extra_kwargs(self):
+        """chat() should normalize dict history items and pass through extras."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"text": "OK"})
+
+        client = LLMClient(proxy)
+        await client.chat(
+            "How are you?",
+            history=[{"role": "user", "content": "Hello"}],
+            image_urls=["https://example.com/a.png"],
+            tools=[{"name": "search"}],
+        )
+
+        call_args = proxy.call.call_args[0][1]
+        assert call_args["history"] == [{"role": "user", "content": "Hello"}]
+        assert call_args["image_urls"] == ["https://example.com/a.png"]
+        assert call_args["tools"] == [{"name": "search"}]
+
     @pytest.mark.asyncio
     async def test_chat_with_model_and_temperature(self):
         """chat() should pass model and temperature."""
@@ -184,6 +203,21 @@ class TestLLMClientChatRaw:
         assert call_args["custom_param"] == "value"
         assert call_args["another"] == 123
 
+    @pytest.mark.asyncio
+    async def test_chat_raw_normalizes_history_items(self):
+        """chat_raw() should serialize ChatMessage history items before proxy call."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"text": "OK"})
+
+        client = LLMClient(proxy)
+        await client.chat_raw(
+            "Test",
+            history=[ChatMessage(role="user", content="Hello")],
+        )
+
+        call_args = proxy.call.call_args[0][1]
+        assert call_args["history"] == [{"role": "user", "content": "Hello"}]
+
 
 class TestLLMClientStreamChat:
     """Tests for LLMClient.stream_chat() method."""
@@ -232,6 +266,33 @@ class TestLLMClientStreamChat:
         assert captured_payload["system"] == "Be nice"
         assert len(captured_payload["history"]) == 1
 
+    @pytest.mark.asyncio
+    async def test_stream_chat_passes_extra_kwargs(self):
+        """stream_chat() should pass through advanced kwargs."""
+        proxy = MagicMock(spec=CapabilityProxy)
+
+        captured_payload = None
+
+        async def mock_stream(name, payload):
+            nonlocal captured_payload
+            captured_payload = payload
+            yield {"text": "Done"}
+
+        proxy.stream = mock_stream
+
+        client = LLMClient(proxy)
+        chunks = []
+        async for chunk in client.stream_chat(
+            "Test",
+            image_urls=["https://example.com/a.png"],
+            tools=[{"name": "search"}],
+        ):
+            chunks.append(chunk)
+
+        assert chunks == ["Done"]
+        assert captured_payload["image_urls"] == ["https://example.com/a.png"]
+        assert captured_payload["tools"] == [{"name": "search"}]
+
     @pytest.mark.asyncio
     async def test_stream_chat_yields_empty_string_for_missing_text(self):
         """stream_chat() should yield empty string if text is missing."""
diff --git a/tests_v4/test_memory_client.py b/tests_v4/test_memory_client.py
index 2a1b40052..d5d6f4a6b 100644
--- a/tests_v4/test_memory_client.py
+++ b/tests_v4/test_memory_client.py
@@ -71,6 +71,17 @@ class TestMemoryClientSearch:
         proxy.call.assert_called_once_with("memory.search", {"query": ""})
         assert result == []
 
+    @pytest.mark.asyncio
+    async def test_search_returns_empty_list_for_malformed_items(self):
+        """search() should ignore malformed non-list item payloads."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"items": "bad"})
+
+        client = MemoryClient(proxy)
+        result = await client.search("test")
+
+        assert result == []
+
 
 class TestMemoryClientSave:
     """Tests for MemoryClient.save() method."""
@@ -160,6 +171,44 @@ class TestMemoryClientSave:
             await client.save("key", [1, 2, 3])
 
 
+class TestMemoryClientGet:
+    """Tests for MemoryClient.get() method."""
+
+    @pytest.mark.asyncio
+    async def test_get_returns_dict_value(self):
+        """get() should return dict value from proxy response."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"value": {"theme": "dark"}})
+
+        client = MemoryClient(proxy)
+        result = await client.get("user_pref")
+
+        proxy.call.assert_called_once_with("memory.get", {"key": "user_pref"})
+        assert result == {"theme": "dark"}
+
+    @pytest.mark.asyncio
+    async def test_get_returns_none_for_missing_value(self):
+        """get() should return None when memory is absent."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"value": None})
+
+        client = MemoryClient(proxy)
+        result = await client.get("missing")
+
+        assert result is None
+
+    @pytest.mark.asyncio
+    async def test_get_returns_none_for_non_dict_value(self):
+        """get() should ignore malformed non-dict payloads."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"value": "bad"})
+
+        client = MemoryClient(proxy)
+        result = await client.get("bad")
+
+        assert result is None
+
+
 class TestMemoryClientDelete:
     """Tests for MemoryClient.delete() method."""
 
diff --git a/tests_v4/test_platform_client.py b/tests_v4/test_platform_client.py
index eeb679898..b072fc17c 100644
--- a/tests_v4/test_platform_client.py
+++ b/tests_v4/test_platform_client.py
@@ -47,7 +47,7 @@ class TestPlatformClientSend:
         proxy.call = AsyncMock(return_value={})
 
         client = PlatformClient(proxy)
-        result = await client.send("session-1", "")
+        await client.send("session-1", "")
 
         call_args = proxy.call.call_args[0][1]
         assert call_args["text"] == ""
@@ -145,6 +145,17 @@ class TestPlatformClientGetMembers:
 
         assert result == []
 
+    @pytest.mark.asyncio
+    async def test_get_members_returns_empty_list_for_malformed_payload(self):
+        """get_members() should ignore malformed non-list payloads."""
+        proxy = AsyncMock(spec=CapabilityProxy)
+        proxy.call = AsyncMock(return_value={"members": "bad"})
+
+        client = PlatformClient(proxy)
+        result = await client.get_members("group-1")
+
+        assert result == []
+
     @pytest.mark.asyncio
     async def test_get_members_with_private_session(self):
         """get_members() should work with private session."""
@@ -152,7 +163,7 @@ class TestPlatformClientGetMembers:
         proxy.call = AsyncMock(return_value={"members": [{"id": "single_user"}]})
 
         client = PlatformClient(proxy)
-        result = await client.get_members("private-123")
+        await client.get_members("private-123")
 
         call_args = proxy.call.call_args[0][1]
         assert call_args["session"] == "private-123"