refactor(agent-mode): remove "Enable Agent Mode" toggle

Agent Mode is always on now (still desktop-only, since it requires
subprocess support). Drop the persisted `agentMode.enabled` flag and
the master toggle from settings, make `isAgentModeEnabled()`
platform-only, and clean up the now-dead toggle-reactive wiring
(ribbon refresh, settings-driven command re-registration).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/agentMode/index.ts

@@ -1,7 +1,7 @@
 import { type App, Platform } from "obsidian";
 import type CopilotPlugin from "@/main";
 import { logError } from "@/logger";
-import { type CopilotSettings, getSettings, useSettingsValue } from "@/settings/model";
+import { getSettings } from "@/settings/model";
 import { backendRegistry, listBackendDescriptors } from "./backends/registry";
 import { AgentChatPersistenceManager } from "./session/AgentChatPersistenceManager";
 import { AgentModelPreloader } from "./session/AgentModelPreloader";
@@ -51,17 +51,16 @@ export { SkillManager, SkillsSettings, useManagedSkills } from "./skills";
 export type { Skill } from "./skills";
 
 /**
- * True when Agent Mode is enabled and the platform supports it. Agent Mode
- * requires subprocess support, so this is always false on mobile regardless
- * of the persisted `enabled` flag (which may have been synced from desktop).
+ * True when the platform supports Agent Mode. Agent Mode is always on, but
+ * requires subprocess support, so this is always false on mobile.
  */
-export function isAgentModeEnabled(settings: CopilotSettings = getSettings()): boolean {
-  return !Platform.isMobile && !!settings.agentMode?.enabled;
+export function isAgentModeEnabled(): boolean {
+  return !Platform.isMobile;
 }
 
-/** React hook variant — re-renders when the setting or platform-derived value changes. */
+/** Hook variant for symmetry with other settings-derived hooks. */
 export function useIsAgentModeEnabled(): boolean {
-  return isAgentModeEnabled(useSettingsValue());
+  return isAgentModeEnabled();
 }
 
 /**
@@ -159,7 +158,7 @@ export function createAgentSessionManager(app: App, plugin: CopilotPlugin): Agen
   }
 
   const settings = getSettings();
-  if (!isAgentModeEnabled(settings)) return manager;
+  if (!isAgentModeEnabled()) return manager;
   // Per-backend preload registration: each backend's status flips
   // independently. The chat UI gates on the active backend's status; the
   // picker reads every backend's status to render per-backend loading rows.

src/commands/index.ts

@@ -25,7 +25,6 @@ import { checkIsPlusUser } from "@/plusUtils";
 import CopilotPlugin from "@/main";
 import { shouldUseMiyo } from "@/miyo/miyoUtils";
 import { getAllQAMarkdownContent } from "@/search/searchUtils";
-import { CopilotSettings } from "@/settings/model";
 import { NoteSelectedTextContext, WebSelectedTextContext } from "@/types/message";
 import { ensureFolderExists, isSourceModeOn } from "@/utils";
 import { Editor, MarkdownView, Notice, TFile } from "obsidian";
@@ -88,11 +87,7 @@ function addCheckCommand(
   });
 }
 
-export function registerCommands(
-  plugin: CopilotPlugin,
-  prev: CopilotSettings | undefined,
-  next: CopilotSettings
-) {
+export function registerCommands(plugin: CopilotPlugin) {
   addEditorCommand(plugin, COMMAND_IDS.COUNT_WORD_AND_TOKENS_SELECTION, async (editor: Editor) => {
     const selectedText = editor.getSelection();
     const wordCount = selectedText.split(" ").length;
@@ -128,9 +123,9 @@ export function registerCommands(
     await plugin.newChat();
   });
 
-  // Re-runs from the settings subscription in main.ts so toggling the
-  // master switch refreshes the command palette.
-  if (isAgentModeEnabled(next)) {
+  // Agent Mode is always on, but requires subprocess support — register the
+  // agent commands on desktop only.
+  if (isAgentModeEnabled()) {
     addCommand(plugin, COMMAND_IDS.OPEN_AGENT_CHAT_WINDOW, () => {
       void plugin.activateAgentView();
     });

src/constants.ts

@@ -1023,7 +1023,6 @@ export const DEFAULT_SETTINGS: CopilotSettings = {
   autoCompactThreshold: 128000,
   convertedDocOutputFolder: DEFAULT_CONVERTED_DOC_OUTPUT_FOLDER,
   agentMode: {
-    enabled: true,
     byok: {},
     mcpServers: [],
     activeBackend: "opencode",

src/main.ts

@@ -91,7 +91,6 @@ import {
   Notice,
   Platform,
   Plugin,
-  setIcon,
   TFile,
   WorkspaceLeaf,
 } from "obsidian";
@@ -183,10 +182,6 @@ export default class CopilotPlugin extends Plugin {
           logError("Failed to persist settings.", error);
           new Notice("Copilot failed to save settings. Check logs and try again.");
         }
-        registerCommands(this, prev, next);
-        if (prev && prev.agentMode?.enabled !== next.agentMode?.enabled) {
-          this.refreshRibbonIcon();
-        }
         // Sign-in / sign-out (isPlusUser flip) or key rotation while signed in.
         if (
           prev?.isPlusUser !== next.isPlusUser ||
@@ -289,7 +284,7 @@ export default class CopilotPlugin extends Plugin {
       () => (this.canUseAgentView() ? this.activateAgentView() : this.activateView())
     );
 
-    registerCommands(this, undefined, getSettings());
+    registerCommands(this);
 
     // Tool initialization is now handled automatically in CopilotPlusChainRunner and AutonomousAgentChainRunner
 
@@ -781,10 +776,6 @@ export default class CopilotPlugin extends Plugin {
       new Notice("Agent Chat is not available on mobile.");
       return null;
     }
-    if (!isAgentModeEnabled()) {
-      new Notice("Enable Agent Mode in Copilot settings first.");
-      return null;
-    }
     if (!this.agentSessionManager) {
       new Notice("Agent Chat is not initialized.");
       return null;
@@ -796,16 +787,6 @@ export default class CopilotPlugin extends Plugin {
     return !!this.agentSessionManager && isAgentModeEnabled();
   }
 
-  private refreshRibbonIcon() {
-    if (!this.ribbonIconEl) return;
-    const agentReady = this.canUseAgentView();
-    const icon = agentReady ? "bot" : "message-square";
-    const tooltip = agentReady ? "Open Copilot Agent Chat" : "Open Copilot Chat";
-    setIcon(this.ribbonIconEl, icon);
-    this.ribbonIconEl.setAttribute("aria-label", tooltip);
-    this.ribbonIconEl.setAttribute("title", tooltip);
-  }
-
   async loadSettings() {
     const rawData = (await this.loadData()) as unknown;
     const settings = await loadSettingsWithKeychain(rawData, (d) => this.saveData(d));

src/settings/model.test.ts

@@ -187,7 +187,6 @@ describe("sanitizeSettings - agentMode shape migration", () => {
       agentMode: undefined as unknown as never,
     });
     expect(sanitized.agentMode).toEqual({
-      enabled: true,
       byok: {},
       mcpServers: [],
       activeBackend: "opencode",

src/settings/model.ts

@@ -230,7 +230,6 @@ export interface CopilotSettings {
   settingsVersion?: number;
   /** Agent Mode (ACP-backed BYOK agent harness). Desktop only. */
   agentMode: {
-    enabled: boolean;
     byok: { anthropic?: string; openai?: string; google?: string };
     /**
      * User-configured MCP servers passed to the agent on session start.
@@ -844,7 +843,6 @@ function sanitizeAgentMode(raw: unknown): CopilotSettings["agentMode"] {
     return { ...DEFAULT_SETTINGS.agentMode };
   }
   const r = raw as Record<string, unknown>;
-  const enabled = typeof r.enabled === "boolean" ? r.enabled : DEFAULT_SETTINGS.agentMode.enabled;
   const byok =
     r.byok && typeof r.byok === "object"
       ? (r.byok as { anthropic?: string; openai?: string; google?: string })
@@ -904,7 +902,6 @@ function sanitizeAgentMode(raw: unknown): CopilotSettings["agentMode"] {
   };
 
   return {
-    enabled,
     byok,
     mcpServers,
     activeBackend,

src/settings/v2/components/AgentSettings.tsx

@@ -50,34 +50,21 @@ export const AgentSettings: React.FC = () => {
       <div className="tw-mb-3 tw-text-xl tw-font-bold">Agents (alpha)</div>
       <div className="tw-space-y-4">
         <SettingItem
-          type="switch"
-          title="Enable Agent Mode"
-          description="BYOK agent harness backed by a local ACP subprocess. Desktop only."
-          checked={settings.agentMode.enabled}
-          onCheckedChange={(checked) =>
-            setSettings((cur) => ({ agentMode: { ...cur.agentMode, enabled: checked } }))
+          type="select"
+          title="Default backend"
+          description="Used when you click + to start a new session and for auto-spawn on mount. Selecting a model from the model picker also updates this."
+          value={settings.agentMode.activeBackend}
+          onChange={(value) =>
+            setSettings((cur) => ({ agentMode: { ...cur.agentMode, activeBackend: value } }))
           }
+          options={orderedDescriptors.map((d) => ({ label: d.displayName, value: d.id }))}
         />
 
-        {settings.agentMode.enabled && (
-          <SettingItem
-            type="select"
-            title="Default backend"
-            description="Used when you click + to start a new session and for auto-spawn on mount. Selecting a model from the model picker also updates this."
-            value={settings.agentMode.activeBackend}
-            onChange={(value) =>
-              setSettings((cur) => ({ agentMode: { ...cur.agentMode, activeBackend: value } }))
-            }
-            options={orderedDescriptors.map((d) => ({ label: d.displayName, value: d.id }))}
-          />
-        )}
+        <McpServersPanel />
 
-        {settings.agentMode.enabled && <McpServersPanel />}
-
-        {settings.agentMode.enabled &&
-          orderedDescriptors.map((descriptor) => (
-            <BackendSection key={descriptor.id} descriptor={descriptor} plugin={plugin} />
-          ))}
+        {orderedDescriptors.map((descriptor) => (
+          <BackendSection key={descriptor.id} descriptor={descriptor} plugin={plugin} />
+        ))}
       </div>
     </section>
   );