feat(mcp): show MCP loading status before first response

CHANGELOG.md

@@ -11,6 +11,7 @@ Only write entries that are worth mentioning to users.
 
 ## Unreleased
 
+- MCP: Add loading indicators for MCP server connections — Shell displays a "Connecting to MCP servers..." spinner and Web shows a status message while MCP tools are being loaded
 - Web: Fix scrollable file list overflow in the toolbar changes panel
 - Core: Add `compaction_trigger_ratio` config option (default `0.85`) to control when auto-compaction triggers — compaction now fires when context usage reaches the configured ratio or when remaining space falls below `reserved_context_size`, whichever comes first
 - Core: Support custom instructions in `/compact` command (e.g., `/compact keep database discussions`) to guide what the compaction preserves

docs/en/release-notes/changelog.md

@@ -4,6 +4,7 @@ This page documents the changes in each Kimi Code CLI release.
 
 ## Unreleased
 
+- MCP: Add loading indicators for MCP server connections — Shell displays a "Connecting to MCP servers..." spinner and Web shows a status message while MCP tools are being loaded
 - Web: Fix scrollable file list overflow in the toolbar changes panel
 - Core: Add `compaction_trigger_ratio` config option (default `0.85`) to control when auto-compaction triggers — compaction now fires when context usage reaches the configured ratio or when remaining space falls below `reserved_context_size`, whichever comes first
 - Core: Support custom instructions in `/compact` command (e.g., `/compact keep database discussions`) to guide what the compaction preserves

docs/zh/release-notes/changelog.md

@@ -4,6 +4,7 @@
 
 ## 未发布
 
+- MCP：为 MCP 服务器连接添加加载指示器——Shell 在连接 MCP 服务器时显示 "Connecting to MCP servers..." 加载动画，Web 在 MCP 工具加载期间显示状态消息
 - Web：修复工具栏变更面板中文件列表滚动溢出的问题
 - Core：新增 `compaction_trigger_ratio` 配置项（默认 `0.85`），用于控制自动压缩的触发时机——当上下文用量达到配置比例或剩余空间低于 `reserved_context_size` 时触发压缩，以先满足的条件为准
 - Core：`/compact` 命令支持自定义指令（如 `/compact keep database discussions`），可指导压缩时重点保留的内容

src/kimi_cli/acp/session.py

@@ -25,6 +25,8 @@
     CompactionBegin,
     CompactionEnd,
     ContentPart,
+    MCPLoadingBegin,
+    MCPLoadingEnd,
     QuestionRequest,
     StatusUpdate,
     StepBegin,
@@ -158,6 +160,10 @@ async def prompt(self, prompt: list[ACPContentBlock]) -> acp.PromptResponse:
                         pass
                     case CompactionEnd():
                         pass
+                    case MCPLoadingBegin():
+                        pass
+                    case MCPLoadingEnd():
+                        pass
                     case StatusUpdate():
                         pass
                     case ThinkPart(think=think):

src/kimi_cli/soul/kimisoul.py

@@ -48,6 +48,8 @@
     CompactionBegin,
     CompactionEnd,
     ContentPart,
+    MCPLoadingBegin,
+    MCPLoadingEnd,
     StatusUpdate,
     StepBegin,
     StepInterrupted,
@@ -357,7 +359,14 @@ async def _agent_loop(self) -> TurnOutcome:
             self._steer_queue.get_nowait()
 
         if isinstance(self._agent.toolset, KimiToolset):
-            await self._agent.toolset.wait_for_mcp_tools()
+            loading = self._agent.toolset.has_pending_mcp_tools()
+            if loading:
+                wire_send(MCPLoadingBegin())
+            try:
+                await self._agent.toolset.wait_for_mcp_tools()
+            finally:
+                if loading:
+                    wire_send(MCPLoadingEnd())
 
         async def _pipe_approval_to_wire():
             while True:

src/kimi_cli/soul/toolset.py

@@ -338,6 +338,10 @@ async def _connect():
         else:
             await _connect()
 
+    def has_pending_mcp_tools(self) -> bool:
+        """Return True if the background MCP tool-loading task is still running."""
+        return self._mcp_loading_task is not None and not self._mcp_loading_task.done()
+
     async def wait_for_mcp_tools(self) -> None:
         """Wait for background MCP tool loading to finish."""
         task = self._mcp_loading_task

src/kimi_cli/ui/shell/visualize.py

@@ -36,6 +36,8 @@
     CompactionEnd,
     ContentPart,
     DiffDisplayBlock,
+    MCPLoadingBegin,
+    MCPLoadingEnd,
     QuestionRequest,
     ShellDisplayBlock,
     StatusUpdate,
@@ -748,6 +750,7 @@ def __init__(self, initial_status: StatusUpdate, cancel_event: asyncio.Event | N
 
         self._mooning_spinner: Spinner | None = None
         self._compacting_spinner: Spinner | None = None
+        self._mcp_loading_spinner: Spinner | None = None
 
         self._current_content_block: _ContentBlock | None = None
         self._tool_call_blocks: dict[str, _ToolCallBlock] = {}
@@ -852,7 +855,9 @@ def refresh_soon(self) -> None:
     def compose(self) -> RenderableType:
         """Compose the live view display content."""
         blocks: list[RenderableType] = []
-        if self._mooning_spinner is not None:
+        if self._mcp_loading_spinner is not None:
+            blocks.append(self._mcp_loading_spinner)
+        elif self._mooning_spinner is not None:
             blocks.append(self._mooning_spinner)
         elif self._compacting_spinner is not None:
             blocks.append(self._compacting_spinner)
@@ -875,6 +880,7 @@ def dispatch_wire_message(self, msg: WireMessage) -> None:
 
         if isinstance(msg, StepBegin):
             self.cleanup(is_interrupt=False)
+            self._mcp_loading_spinner = None
             self._mooning_spinner = Spinner("moon", "")
             self.refresh_soon()
             return
@@ -895,6 +901,12 @@ def dispatch_wire_message(self, msg: WireMessage) -> None:
             case CompactionEnd():
                 self._compacting_spinner = None
                 self.refresh_soon()
+            case MCPLoadingBegin():
+                self._mcp_loading_spinner = Spinner("dots", "Connecting to MCP servers...")
+                self.refresh_soon()
+            case MCPLoadingEnd():
+                self._mcp_loading_spinner = None
+                self.refresh_soon()
             case StatusUpdate():
                 self._status_block.update(msg)
             case ContentPart():

src/kimi_cli/wire/types.py

@@ -88,6 +88,18 @@ class CompactionEnd(BaseModel):
     pass
 
 
+class MCPLoadingBegin(BaseModel):
+    """Indicates that MCP tool loading is in progress."""
+
+    pass
+
+
+class MCPLoadingEnd(BaseModel):
+    """Indicates that MCP tool loading has finished."""
+
+    pass
+
+
 class StatusUpdate(BaseModel):
     """
     An update on the current status of the soul.
@@ -349,6 +361,8 @@ def resolved(self) -> bool:
     | StepInterrupted
     | CompactionBegin
     | CompactionEnd
+    | MCPLoadingBegin
+    | MCPLoadingEnd
     | StatusUpdate
     | ContentPart
     | ToolCall
@@ -431,6 +445,8 @@ def to_wire_message(self) -> WireMessage:
     "StepInterrupted",
     "CompactionBegin",
     "CompactionEnd",
+    "MCPLoadingBegin",
+    "MCPLoadingEnd",
     "StatusUpdate",
     "ContentPart",
     "ToolCall",

tests/core/test_wire_message.py

@@ -14,6 +14,8 @@
     CompactionBegin,
     CompactionEnd,
     ImageURLPart,
+    MCPLoadingBegin,
+    MCPLoadingEnd,
     QuestionItem,
     QuestionOption,
     QuestionRequest,
@@ -87,6 +89,14 @@ async def test_wire_message_serde():
     assert serialize_wire_message(msg) == snapshot({"type": "CompactionEnd", "payload": {}})
     _test_serde(msg)
 
+    msg = MCPLoadingBegin()
+    assert serialize_wire_message(msg) == snapshot({"type": "MCPLoadingBegin", "payload": {}})
+    _test_serde(msg)
+
+    msg = MCPLoadingEnd()
+    assert serialize_wire_message(msg) == snapshot({"type": "MCPLoadingEnd", "payload": {}})
+    _test_serde(msg)
+
     msg = StatusUpdate(context_usage=0.5)
     assert serialize_wire_message(msg) == snapshot(
         {

tests_e2e/test_wire_skills_mcp.py

@@ -287,6 +287,8 @@ def ping(text: str) -> str:
                     "type": "TurnBegin",
                     "payload": {"user_input": "call mcp"},
                 },
+                {"method": "event", "type": "MCPLoadingBegin", "payload": {}},
+                {"method": "event", "type": "MCPLoadingEnd", "payload": {}},
                 {"method": "event", "type": "StepBegin", "payload": {"n": 1}},
                 {
                     "method": "event",

web/src/hooks/useSessionStream.ts

@@ -348,6 +348,9 @@ export function useSessionStream(
   // Track compaction indicator message so we can remove it on CompactionEnd
   const compactionMessageIdRef = useRef<string | null>(null);
 
+  // Track MCP loading indicator message so we can remove it on MCPLoadingEnd
+  const mcpLoadingMessageIdRef = useRef<string | null>(null);
+
   // Wrapped setMessages
   const setMessages: typeof setMessagesInternal = useCallback((action) => {
     setMessagesInternal(action);
@@ -1759,6 +1762,31 @@ export function useSessionStream(
           break;
         }
 
+        case "MCPLoadingBegin": {
+          const mcpMsgId = getNextMessageId("assistant");
+          mcpLoadingMessageIdRef.current = mcpMsgId;
+          setMessages((prev) => [
+            ...prev,
+            {
+              id: mcpMsgId,
+              role: "assistant",
+              variant: "status",
+              content: "Connecting to MCP servers…",
+              isStreaming: true,
+            },
+          ]);
+          break;
+        }
+
+        case "MCPLoadingEnd": {
+          const mcpMsgId = mcpLoadingMessageIdRef.current;
+          mcpLoadingMessageIdRef.current = null;
+          if (mcpMsgId) {
+            setMessages((prev) => prev.filter((m) => m.id !== mcpMsgId));
+          }
+          break;
+        }
+
         default:
           break;
       }
@@ -2347,9 +2375,16 @@ export function useSessionStream(
     pendingApprovalRequestsRef.current.clear();
     pendingQuestionRequestsRef.current.clear();
 
+    // Remove lingering MCP loading indicator (e.g. MCPLoadingEnd was never received)
+    const mcpMsgId = mcpLoadingMessageIdRef.current;
+    if (mcpMsgId) {
+      mcpLoadingMessageIdRef.current = null;
+      setMessages((prev) => prev.filter((m) => m.id !== mcpMsgId));
+    }
+
     // Mark all streaming/subagent messages as complete
     completeStreamingMessages();
-  }, [completeStreamingMessages, setAwaitingFirstResponse]);
+  }, [completeStreamingMessages, setAwaitingFirstResponse, setMessages]);
 
   // Send cancel request or disconnect if stream not ready
   const cancel = useCallback(() => {

web/src/hooks/wireTypes.ts

@@ -153,6 +153,16 @@ export type CompactionEndEvent = {
   payload?: Record<string, never>;
 };
 
+export type MCPLoadingBeginEvent = {
+  type: "MCPLoadingBegin";
+  payload?: Record<string, never>;
+};
+
+export type MCPLoadingEndEvent = {
+  type: "MCPLoadingEnd";
+  payload?: Record<string, never>;
+};
+
 export type ApprovalRequestEvent = {
   type: "ApprovalRequest";
   payload: {
@@ -224,6 +234,8 @@ export type WireEvent =
   | SessionNoticeEvent
   | CompactionBeginEvent
   | CompactionEndEvent
+  | MCPLoadingBeginEvent
+  | MCPLoadingEndEvent
   | ApprovalRequestEvent
   | ApprovalRequestResolvedEvent
   | QuestionRequestEvent