diff --git a/src/features/chat/chat-session-controller.ts b/src/features/chat/chat-session-controller.ts
index 5b709dba..9668170c 100644
--- a/src/features/chat/chat-session-controller.ts
+++ b/src/features/chat/chat-session-controller.ts
@@ -18,6 +18,10 @@ export interface ChatSessionControllerHost {
   forceMessagesToBottom: () => void;
 }
 
+export interface RefreshCapabilityDiagnosticsOptions {
+  cachedSessionMetadata?: boolean;
+}
+
 export class ChatSessionController {
   constructor(private readonly host: ChatSessionControllerHost) {}
 
@@ -33,9 +37,7 @@ export class ChatSessionController {
     const client = this.host.currentClient();
     if (!client) return;
     this.host.state.effectiveConfig = await client.readEffectiveConfig(this.host.vaultPath);
-    await this.refreshModels();
-    await this.refreshSkills();
-    await this.refreshRateLimits();
+    await Promise.all([this.refreshModels(), this.refreshSkills(), this.refreshRateLimits()]);
   }
 
   async startThread(): Promise<Awaited<ReturnType<AppServerClient["startThread"]>> | null> {
@@ -64,8 +66,10 @@ export class ChatSessionController {
     try {
       const response = await client.listModels(false);
       this.host.state.availableModels = response.data;
-    } catch {
+      this.host.state.appServerDiagnostics.probes["model/list"] = capabilityProbeOk("model/list", `${String(response.data.length)} models`);
+    } catch (error) {
       this.host.state.availableModels = [];
+      this.host.state.appServerDiagnostics.probes["model/list"] = capabilityProbeError("model/list", error);
     }
   }
 
@@ -75,8 +79,11 @@ export class ChatSessionController {
     try {
       const response = await client.listSkills(this.host.vaultPath, forceReload);
       this.host.state.availableSkills = response.data.flatMap((entry) => entry.skills).filter((skill) => skill.enabled);
-    } catch {
+      const count = response.data.reduce((total, entry) => total + entry.skills.length, 0);
+      this.host.state.appServerDiagnostics.probes["skills/list"] = capabilityProbeOk("skills/list", `${String(count)} skills`);
+    } catch (error) {
       this.host.state.availableSkills = [];
+      this.host.state.appServerDiagnostics.probes["skills/list"] = capabilityProbeError("skills/list", error);
     }
   }
 
@@ -88,29 +95,45 @@ export class ChatSessionController {
       const rateLimitsByLimitId = response.rateLimitsByLimitId;
       const codexRateLimit = rateLimitsByLimitId && Object.hasOwn(rateLimitsByLimitId, "codex") ? rateLimitsByLimitId["codex"] : undefined;
       this.host.state.rateLimit = codexRateLimit ?? response.rateLimits;
-    } catch {
+      this.host.state.appServerDiagnostics.probes["account/rateLimits/read"] = capabilityProbeOk(
+        "account/rateLimits/read",
+        response.rateLimitsByLimitId ? `${String(Object.keys(response.rateLimitsByLimitId).length)} limits` : "available",
+      );
+    } catch (error) {
       this.host.state.rateLimit = null;
+      this.host.state.appServerDiagnostics.probes["account/rateLimits/read"] = capabilityProbeError("account/rateLimits/read", error);
     }
   }
 
-  async refreshCapabilityDiagnostics(): Promise<void> {
+  async refreshCapabilityDiagnostics(options: RefreshCapabilityDiagnosticsOptions = {}): Promise<void> {
     const client = this.host.currentClient();
     if (!client) return;
 
-    await Promise.all([
-      this.probeCapability(
-        "model/list",
-        () => client.listModels(false),
-        (response) => `${String(response.data.length)} models`,
-      ),
-      this.probeCapability(
-        "skills/list",
-        () => client.listSkills(this.host.vaultPath),
-        (response) => {
-          const count = response.data.reduce((total, entry) => total + entry.skills.length, 0);
-          return `${String(count)} skills`;
-        },
-      ),
+    const probes: Promise<void>[] = [];
+    if (!options.cachedSessionMetadata) {
+      probes.push(
+        this.probeCapability(
+          "model/list",
+          () => client.listModels(false),
+          (response) => `${String(response.data.length)} models`,
+        ),
+        this.probeCapability(
+          "skills/list",
+          () => client.listSkills(this.host.vaultPath),
+          (response) => {
+            const count = response.data.reduce((total, entry) => total + entry.skills.length, 0);
+            return `${String(count)} skills`;
+          },
+        ),
+        this.probeCapability(
+          "account/rateLimits/read",
+          () => client.readAccountRateLimits(),
+          (response) => (response.rateLimitsByLimitId ? `${String(Object.keys(response.rateLimitsByLimitId).length)} limits` : "available"),
+        ),
+      );
+    }
+
+    probes.push(
       this.probeCapability(
         "hooks/list",
         () => client.listHooks(this.host.vaultPath),
@@ -119,11 +142,6 @@ export class ChatSessionController {
           return `${String(count)} hooks`;
         },
       ),
-      this.probeCapability(
-        "account/rateLimits/read",
-        () => client.readAccountRateLimits(),
-        (response) => (response.rateLimitsByLimitId ? `${String(Object.keys(response.rateLimitsByLimitId).length)} limits` : "available"),
-      ),
       this.probeCapability(
         "mcpServerStatus/list",
         () => client.listMcpServerStatus(),
@@ -152,7 +170,9 @@ export class ChatSessionController {
             .filter(Boolean)
             .join(", ") || "no optional capabilities",
       ),
-    ]);
+    );
+
+    await Promise.all(probes);
   }
 
   recordMcpStartupStatus(name: string, startupStatus: "starting" | "ready" | "failed" | "cancelled", message: string | null): void {
diff --git a/src/features/chat/view.ts b/src/features/chat/view.ts
index f33e7d77..d0e01011 100644
--- a/src/features/chat/view.ts
+++ b/src/features/chat/view.ts
@@ -95,7 +95,11 @@ export class CodexChatView extends ItemView {
   private configSlotEl: HTMLElement | null = null;
   private messagesSlotEl: HTMLElement | null = null;
   private composerSlotEl: HTMLElement | null = null;
+  private scheduledConnectionTimer: number | null = null;
   private scheduledRenderTimer: number | null = null;
+  private scheduledDiagnosticsTimer: number | null = null;
+  private connectingPromise: Promise<void> | null = null;
+  private connectionGeneration = 0;
   private toolbarSignature: string | null = null;
   private forceScrollMessagesToBottomOnNextRender = false;
 
@@ -245,14 +249,18 @@ export class CodexChatView extends ItemView {
       this.closeToolbarPanelOnOutsidePointer(event);
     });
     this.render();
-    await this.ensureConnected();
+    this.scheduleDeferredConnection();
   }
 
   override async onClose(): Promise<void> {
+    this.connectionGeneration += 1;
+    this.connectingPromise = null;
+    this.clearDeferredConnection();
     if (this.scheduledRenderTimer !== null) {
       this.containerEl.win.clearTimeout(this.scheduledRenderTimer);
       this.scheduledRenderTimer = null;
     }
+    this.clearDeferredDiagnostics();
     this.connection.disconnect();
     this.client = null;
   }
@@ -261,29 +269,58 @@ export class CodexChatView extends ItemView {
     this.composerController.setDraft(text, { focus: true, renderIfDetached: true });
   }
 
+  async connect(): Promise<void> {
+    this.clearDeferredConnection();
+    await this.ensureConnected();
+  }
+
   private async ensureConnected(): Promise<void> {
     if (this.connection.isConnected()) {
       this.client = this.connection.currentClient();
       return;
     }
+    if (this.connectingPromise) return this.connectingPromise;
 
+    const generation = this.connectionGeneration;
+    const promise = this.initializeConnection(generation);
+    this.connectingPromise = promise;
+    try {
+      await promise;
+    } finally {
+      if (this.connectingPromise === promise) {
+        this.connectingPromise = null;
+      }
+    }
+  }
+
+  private async initializeConnection(generation: number): Promise<void> {
     this.setStatus("Starting Codex app-server...");
     try {
       this.state.initializeResponse = await this.connection.connect();
+      if (this.isStaleConnectionGeneration(generation)) return;
       this.client = this.connection.currentClient();
       if (!this.client) throw new Error("Codex app-server connection did not initialize.");
       await this.session.refreshSessionMetadata();
-      await this.session.refreshCapabilityDiagnostics();
+      if (this.isStaleConnectionGeneration(generation)) return;
       await this.session.refreshThreadList();
+      if (this.isStaleConnectionGeneration(generation)) return;
+      this.scheduleDeferredDiagnostics();
       this.refreshTabHeader();
       this.setStatus("Connected.");
     } catch (error) {
+      if (this.isStaleConnectionGeneration(generation)) return;
       if (error instanceof StaleConnectionError) return;
       this.setStatus("Connection failed.");
       this.addSystemMessage(error instanceof Error ? error.message : String(error));
       new Notice("Codex app-server connection failed.");
     }
-    this.scheduleRender();
+    if (!this.isStaleConnectionGeneration(generation)) {
+      this.scheduleRender();
+    }
+  }
+
+  private isStaleConnectionGeneration(generation: number): boolean {
+    return generation !== this.connectionGeneration;
   }
 
   async startNewThread(): Promise<void> {
@@ -321,10 +358,11 @@ export class CodexChatView extends ItemView {
   }
 
   private async refreshDiagnostics(): Promise<void> {
-    const alreadyConnected = this.connection.isConnected();
+    this.clearDeferredDiagnostics();
     await this.ensureConnected();
     if (!this.client) return;
-    if (alreadyConnected) await this.session.refreshCapabilityDiagnostics();
+    this.clearDeferredDiagnostics();
+    await this.session.refreshCapabilityDiagnostics();
     this.render();
   }
 
@@ -916,6 +954,10 @@ export class CodexChatView extends ItemView {
   private async reconnectFromToolbar(): Promise<void> {
     const threadId = this.state.activeThreadId;
     this.state.openDetails.delete("status-panel");
+    this.connectionGeneration += 1;
+    this.connectingPromise = null;
+    this.clearDeferredConnection();
+    this.clearDeferredDiagnostics();
     this.connection.reconnect();
     this.client = null;
     this.state.busy = false;
@@ -1013,6 +1055,40 @@ export class CodexChatView extends ItemView {
     }, 50);
   }
 
+  private scheduleDeferredConnection(): void {
+    if (this.scheduledConnectionTimer !== null || this.connection.isConnected()) return;
+    this.scheduledConnectionTimer = this.containerEl.win.setTimeout(() => {
+      this.scheduledConnectionTimer = null;
+      void this.ensureConnected();
+    }, 1_500);
+  }
+
+  private clearDeferredConnection(): void {
+    if (this.scheduledConnectionTimer === null) return;
+    this.containerEl.win.clearTimeout(this.scheduledConnectionTimer);
+    this.scheduledConnectionTimer = null;
+  }
+
+  private scheduleDeferredDiagnostics(): void {
+    if (this.scheduledDiagnosticsTimer !== null) return;
+    this.scheduledDiagnosticsTimer = this.containerEl.win.setTimeout(() => {
+      this.scheduledDiagnosticsTimer = null;
+      void this.refreshDeferredDiagnostics();
+    }, 1_000);
+  }
+
+  private clearDeferredDiagnostics(): void {
+    if (this.scheduledDiagnosticsTimer === null) return;
+    this.containerEl.win.clearTimeout(this.scheduledDiagnosticsTimer);
+    this.scheduledDiagnosticsTimer = null;
+  }
+
+  private async refreshDeferredDiagnostics(): Promise<void> {
+    if (!this.connection.isConnected()) return;
+    await this.session.refreshCapabilityDiagnostics({ cachedSessionMetadata: true });
+    this.render();
+  }
+
   private renderShell(root: HTMLElement): void {
     root.empty();
     root.addClass("codex-panel");
diff --git a/src/main.ts b/src/main.ts
index 3b59f346..58a2b616 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -54,7 +54,9 @@ export default class CodexPanelPlugin extends Plugin {
       active: true,
       reveal: true,
     });
-    return leaf.view as CodexChatView;
+    const view = leaf.view as CodexChatView;
+    await view.connect();
+    return view;
   }
 
   async activateNewView(): Promise<CodexChatView> {
@@ -63,7 +65,9 @@ export default class CodexPanelPlugin extends Plugin {
 
     await leaf.setViewState({ type: VIEW_TYPE_CODEX_PANEL, active: true });
     await this.app.workspace.revealLeaf(leaf);
-    return leaf.view as CodexChatView;
+    const view = leaf.view as CodexChatView;
+    await view.connect();
+    return view;
   }
 
   async openThreadInNewView(threadId: string): Promise<CodexChatView> {
diff --git a/tests/features/chat/chat-session-controller.test.ts b/tests/features/chat/chat-session-controller.test.ts
new file mode 100644
index 00000000..77e671f1
--- /dev/null
+++ b/tests/features/chat/chat-session-controller.test.ts
@@ -0,0 +1,61 @@
+import { describe, expect, it, vi } from "vitest";
+
+import type { AppServerClient } from "../../../src/app-server/client";
+import { ChatSessionController } from "../../../src/features/chat/chat-session-controller";
+import { createChatState } from "../../../src/features/chat/chat-state";
+import type { Model } from "../../../src/generated/app-server/v2/Model";
+import type { RateLimitSnapshot } from "../../../src/generated/app-server/v2/RateLimitSnapshot";
+import type { SkillMetadata } from "../../../src/generated/app-server/v2/SkillMetadata";
+
+describe("ChatSessionController", () => {
+  it("reuses cached session metadata for deferred diagnostics", async () => {
+    const state = createChatState();
+
+    const listModels = vi.fn().mockResolvedValue({ data: [{ model: "gpt-5.1" } as Model] });
+    const listSkills = vi.fn().mockResolvedValue({ data: [{ skills: [{ name: "writer", enabled: true } as SkillMetadata] }] });
+    const readAccountRateLimits = vi.fn().mockResolvedValue({ rateLimits: {} as RateLimitSnapshot });
+    const listHooks = vi.fn().mockResolvedValue({ data: [{ cwd: "/vault", hooks: [] }] });
+    const client = {
+      readEffectiveConfig: vi.fn().mockResolvedValue({}),
+      listModels,
+      listSkills,
+      readAccountRateLimits,
+      listHooks,
+      listMcpServerStatus: vi.fn().mockResolvedValue({ data: [] }),
+      listCollaborationModes: vi.fn().mockResolvedValue({ data: [] }),
+      readModelProviderCapabilities: vi.fn().mockResolvedValue({}),
+    } as unknown as AppServerClient;
+
+    const controller = new ChatSessionController({
+      state,
+      vaultPath: "/vault",
+      currentClient: () => client,
+      runtimeSnapshot: () => ({}) as never,
+      forceMessagesToBottom: () => undefined,
+    });
+
+    await controller.refreshSessionMetadata();
+    listModels.mockClear();
+    listSkills.mockClear();
+    readAccountRateLimits.mockClear();
+
+    await controller.refreshCapabilityDiagnostics({ cachedSessionMetadata: true });
+
+    expect(listModels).not.toHaveBeenCalled();
+    expect(listSkills).not.toHaveBeenCalled();
+    expect(readAccountRateLimits).not.toHaveBeenCalled();
+    expect(listHooks).toHaveBeenCalledWith("/vault");
+    expect(state.appServerDiagnostics.probes["model/list"]).toMatchObject({
+      status: "ok",
+      summary: "1 models",
+    });
+    expect(state.appServerDiagnostics.probes["skills/list"]).toMatchObject({
+      status: "ok",
+      summary: "1 skills",
+    });
+    expect(state.appServerDiagnostics.probes["account/rateLimits/read"]).toMatchObject({
+      status: "ok",
+      summary: "available",
+    });
+  });
+});
diff --git a/tests/features/chat/view-connection.test.ts b/tests/features/chat/view-connection.test.ts
new file mode 100644
index 00000000..2328cbc8
--- /dev/null
+++ b/tests/features/chat/view-connection.test.ts
@@ -0,0 +1,152 @@
+// @vitest-environment jsdom
+
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+import { DEFAULT_SETTINGS } from "../../../src/settings/model";
+import { notices } from "../../mocks/obsidian";
+import { installObsidianDomShims } from "./ui/dom-test-helpers";
+
+const connectionMock = vi.hoisted(() => {
+  const state = {
+    client: null as Record<string, unknown> | null,
+    connectCalls: 0,
+    connected: false,
+  };
+
+  return {
+    state,
+    reset(): void {
+      state.client = null;
+      state.connectCalls = 0;
+      state.connected = false;
+    },
+  };
+});
+
+vi.mock("../../../src/app-server/connection-manager", () => {
+  class StaleConnectionError extends Error {}
+
+  class ConnectionManager {
+    connect(): Promise<unknown> {
+      connectionMock.state.connectCalls += 1;
+      connectionMock.state.connected = true;
+      return Promise.resolve({
+        userAgent: "codex-test",
+        codexHome: "/tmp/codex",
+        platformFamily: "unix",
+        platformOs: "macos",
+      });
+    }
+
+    currentClient(): unknown {
+      return connectionMock.state.connected ? connectionMock.state.client : null;
+    }
+
+    isConnected(): boolean {
+      return connectionMock.state.connected;
+    }
+
+    reconnect(): void {
+      this.disconnect();
+    }
+
+    disconnect(): void {
+      connectionMock.state.connected = false;
+    }
+  }
+
+  return { ConnectionManager, StaleConnectionError };
+});
+
+installObsidianDomShims();
+
+describe("CodexChatView connection lifecycle", () => {
+  beforeEach(() => {
+    vi.useRealTimers();
+    notices.length = 0;
+    connectionMock.reset();
+  });
+
+  it("shares post-initialize metadata loading across concurrent connect calls", async () => {
+    const client = connectedClient();
+    connectionMock.state.client = client;
+    const view = await chatView();
+
+    await Promise.all([view.connect(), view.connect()]);
+
+    expect(connectionMock.state.connectCalls).toBe(1);
+    expect(client.readEffectiveConfig).toHaveBeenCalledTimes(1);
+    expect(client.listModels).toHaveBeenCalledTimes(1);
+    expect(client.listSkills).toHaveBeenCalledTimes(1);
+    expect(client.readAccountRateLimits).toHaveBeenCalledTimes(1);
+    expect(client.listThreads).toHaveBeenCalledTimes(1);
+  });
+
+  it("ignores stale connection work after the view closes", async () => {
+    let resolveConfig!: (value: unknown) => void;
+    const client = connectedClient({
+      readEffectiveConfig: vi.fn(
+        () =>
+          new Promise((resolve) => {
+            resolveConfig = resolve;
+          }),
+      ),
+    });
+    connectionMock.state.client = client;
+    const view = await chatView();
+
+    const connecting = view.connect();
+    await Promise.resolve();
+    await view.onClose();
+    resolveConfig({});
+    await connecting;
+
+    expect(notices).toEqual([]);
+    expect(client.listThreads).not.toHaveBeenCalled();
+  });
+});
+
+function connectedClient(overrides: Partial<ReturnType<typeof baseClient>> = {}): ReturnType<typeof baseClient> {
+  return {
+    ...baseClient(),
+    ...overrides,
+  };
+}
+
+function baseClient() {
+  return {
+    readEffectiveConfig: vi.fn().mockResolvedValue({}),
+    listModels: vi.fn().mockResolvedValue({ data: [] }),
+    listSkills: vi.fn().mockResolvedValue({ data: [] }),
+    readAccountRateLimits: vi.fn().mockResolvedValue({ rateLimits: null }),
+    listThreads: vi.fn().mockResolvedValue({ data: [] }),
+  };
+}
+
+async function chatView() {
+  const { CodexChatView } = await import("../../../src/features/chat/view");
+  const containerEl = document.createElement("div");
+  containerEl.createDiv();
+  containerEl.createDiv();
+  return new CodexChatView(
+    {
+      app: {
+        vault: {
+          on: vi.fn(() => ({})),
+        },
+      },
+      containerEl,
+    } as never,
+    {
+      settings: {
+        ...DEFAULT_SETTINGS,
+        codexPath: "codex",
+        sendShortcut: "enter",
+      },
+      vaultPath: "/vault",
+      openThreadInNewView: vi.fn(),
+      openTurnDiff: vi.fn(),
+      refreshOpenThreadLists: vi.fn(),
+    },
+  );
+}
diff --git a/tests/mocks/obsidian.ts b/tests/mocks/obsidian.ts
index 1d15b495..4a56f127 100644
--- a/tests/mocks/obsidian.ts
+++ b/tests/mocks/obsidian.ts
@@ -44,6 +44,29 @@ export class Notice {
   }
 }
 
+export class ItemView {
+  readonly app: App;
+  readonly containerEl: HTMLElement;
+
+  constructor(readonly leaf: { app?: App; containerEl?: HTMLElement }) {
+    ensureElementHelpers();
+    this.app = leaf.app ?? {};
+    this.containerEl = leaf.containerEl ?? document.createElement("div");
+  }
+
+  registerDomEvent<K extends keyof DocumentEventMap>(element: Document, type: K, callback: (event: DocumentEventMap[K]) => void): void {
+    element.addEventListener(type, callback);
+  }
+
+  registerEvent(_eventRef: unknown): void {
+    // Test mock placeholder.
+  }
+}
+
+export class MarkdownView {
+  file: TFile | null = null;
+}
+
 export class PluginSettingTab {
   containerEl: HTMLElement;