diff --git a/.changeset/desktop-dock-tile.md b/.changeset/desktop-dock-tile.md
new file mode 100644
index 00000000..9f1977aa
--- /dev/null
+++ b/.changeset/desktop-dock-tile.md
@@ -0,0 +1,5 @@
+---
+"@pymodel/pythinker-desktop": patch
+---
+
+Stop a second, unnamed Pythinker icon appearing in the macOS Dock while the app runs.
diff --git a/.changeset/remove-managed-kimi-endpoints.md b/.changeset/remove-managed-kimi-endpoints.md
index ccda57f9..232e5b63 100644
--- a/.changeset/remove-managed-kimi-endpoints.md
+++ b/.changeset/remove-managed-kimi-endpoints.md
@@ -1,5 +1,5 @@
 ---
-"@pymodel/pythinker-code": minor
+"@pymodel/pythinker-code": major
 ---
 
 Remove the hosted self-update checks, default plugin marketplace catalog, official plugin badges, tips banner, and sign-up links; Kimi now serves only as a model provider through OAuth or an API key. Set PYTHINKER_CODE_PLUGIN_MARKETPLACE_URL to keep using a plugin catalog.
diff --git a/.changeset/subagent-execution-inspector.md b/.changeset/subagent-execution-inspector.md
index 6aef96eb..a25fcd78 100644
--- a/.changeset/subagent-execution-inspector.md
+++ b/.changeset/subagent-execution-inspector.md
@@ -2,4 +2,4 @@
 "@pymodel/pythinker-code": patch
 ---
 
-Allow sub agent activity cards to open their live execution transcript.
+Allow subagent activity cards to open their live execution transcript.
diff --git a/apps/desktop/src/host-supervisor.ts b/apps/desktop/src/host-supervisor.ts
index 66e3aa4a..58d1f9cf 100644
--- a/apps/desktop/src/host-supervisor.ts
+++ b/apps/desktop/src/host-supervisor.ts
@@ -1,6 +1,7 @@
 /** Supervise the loopback Web Host used by the first desktop application. */
 
 import { spawn, spawnSync, type ChildProcessByStdio } from 'node:child_process'
+import { basename, join } from 'node:path'
 import type { Readable } from 'node:stream'
 
 const READINESS_PREFIX = 'Pythinker server: '
@@ -312,6 +313,31 @@ export function createHostSupervisor(options: HostSupervisorOptions): HostSuperv
   return { start, shutdown }
 }
 
+/**
+ * Resolve the executable that runs the Host on a packaged macOS app.
+ *
+ * The app must not re-exec its own main binary. LaunchServices registers that
+ * child as a second `Foreground` application under the same bundle id, so it
+ * takes a Dock tile of its own — drawn with the generic Unix-executable icon,
+ * since a bare executable has no icon to show. `ELECTRON_RUN_AS_NODE` stops the
+ * child from becoming a browser process but does not stop that registration.
+ * The bundled Electron helper declares `LSUIElement`, so it runs the very same
+ * Node runtime with no Dock tile and no second app.
+ * @param options - Platform, the app's own executable, its `Frameworks` directory, and an existence probe.
+ * @returns The helper executable when the bundle ships one, otherwise `execPath` unchanged.
+ */
+export function resolveHostExecutable(options: {
+  readonly platform: string
+  readonly execPath: string
+  readonly frameworksPath: string
+  readonly exists: (path: string) => boolean
+}): string {
+  if (options.platform !== 'darwin') return options.execPath
+  const name = basename(options.execPath)
+  const helper = join(options.frameworksPath, `${name} Helper.app`, 'Contents', 'MacOS', `${name} Helper`)
+  return options.exists(helper) ? helper : options.execPath
+}
+
 /** Options for the real Pythinker server child. */
 export interface SpawnPythinkerServerOptions {
   /** Node-compatible executable selected by the desktop app. */
diff --git a/apps/desktop/src/main.ts b/apps/desktop/src/main.ts
index 581f4ed1..8c5bb96a 100644
--- a/apps/desktop/src/main.ts
+++ b/apps/desktop/src/main.ts
@@ -30,6 +30,7 @@ import {
   isPortInUseError,
   parseRunningServerConflict,
   resolveDesktopPort,
+  resolveHostExecutable,
   spawnPythinkerServer,
   type HostSupervisor,
 } from './host-supervisor'
@@ -112,7 +113,12 @@ function hostPaths(): { nodeExecutable: string; cliEntry: string; cwd: string; e
     }
   }
   return {
-    nodeExecutable: process.execPath,
+    nodeExecutable: resolveHostExecutable({
+      platform: process.platform,
+      execPath: process.execPath,
+      frameworksPath: join(process.resourcesPath, '..', 'Frameworks'),
+      exists: existsSync,
+    }),
     cliEntry: join(process.resourcesPath, 'host/node_modules/@pymodel/pythinker-code/dist/main.mjs'),
     cwd: app.getPath('home'),
     electronRunAsNode: true,
diff --git a/apps/desktop/tests/host-supervisor.spec.ts b/apps/desktop/tests/host-supervisor.spec.ts
index 96f26f32..0729b936 100644
--- a/apps/desktop/tests/host-supervisor.spec.ts
+++ b/apps/desktop/tests/host-supervisor.spec.ts
@@ -3,6 +3,7 @@ import { afterEach, describe, expect, it, vi } from 'vitest'
 import {
   createHostSupervisor,
   createReadinessParser,
+  resolveHostExecutable,
   type HostChild,
 } from '../src/host-supervisor'
 import * as hostSupervisor from '../src/host-supervisor'
@@ -509,3 +510,51 @@ describe('desktop Host process', () => {
     expect(spawnSync).not.toHaveBeenCalled()
   })
 })
+
+describe('resolveHostExecutable', () => {
+  const APP = '/Applications/Pythinker.app/Contents/MacOS/Pythinker'
+  const FRAMEWORKS = '/Applications/Pythinker.app/Contents/Frameworks'
+  const HELPER = `${FRAMEWORKS}/Pythinker Helper.app/Contents/MacOS/Pythinker Helper`
+
+  it('runs the Host from the LSUIElement helper so it takes no Dock tile of its own', () => {
+    // Re-execing the app's own binary registers a second Foreground app under
+    // the same bundle id, which shows up as a stray generic-executable icon in
+    // the Dock next to the real app.
+    const seen: string[] = []
+    const resolved = resolveHostExecutable({
+      platform: 'darwin',
+      execPath: APP,
+      frameworksPath: FRAMEWORKS,
+      exists: path => {
+        seen.push(path)
+        return path === HELPER
+      },
+    })
+    expect(resolved).toBe(HELPER)
+    expect(seen).toEqual([HELPER])
+  })
+
+  it('keeps the app executable when the bundle ships no matching helper', () => {
+    expect(
+      resolveHostExecutable({
+        platform: 'darwin',
+        execPath: APP,
+        frameworksPath: FRAMEWORKS,
+        exists: () => false,
+      }),
+    ).toBe(APP)
+  })
+
+  it('leaves non-macOS platforms alone', () => {
+    for (const platform of ['win32', 'linux']) {
+      expect(
+        resolveHostExecutable({
+          platform,
+          execPath: 'C:\\Program Files\\Pythinker\\Pythinker.exe',
+          frameworksPath: 'C:\\Program Files\\Pythinker\\Frameworks',
+          exists: () => true,
+        }),
+      ).toBe('C:\\Program Files\\Pythinker\\Pythinker.exe')
+    }
+  })
+})