From 05ac66edfab61a9546a838b46273c3987e55620e Mon Sep 17 00:00:00 2001
From: leafyy <wuqizq@outlook.com>
Date: Mon, 7 Sep 2026 11:14:44 +0800
Subject: [PATCH] fix(stage-tamagotchi): show Live2D expressions in settings
 (#2451)

## Summary

- Send a serializable Live2D expression snapshot from the stage renderer
to the separate Settings window.
- Route expression changes back to the renderer that owns the loaded
model, with owner ID checks for stale-window isolation.
- Add browser regressions for the component boundary and the complete
BroadcastChannel round trip.

Fixes #2450

## Verification

- `pnpm typecheck`
- `pnpm lint`
- `../../node_modules/.bin/vitest run --project browser
src/components/scenarios/settings/model-settings/live2d.browser.test.ts`
- `node_modules/.bin/vitest run --config
apps/stage-tamagotchi/vitest.config.ts --project browser
apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime.browser.test.ts`
- `./node_modules/.bin/electron-vite build`
- Vishot Electron capture with the issue Live2D fixture on the merge
base and this branch
- `sem diff upstream/main...HEAD --no-cosmetics -v --file-exts .ts .tsx`

## Visual changes

| Before | After |
|---|---|
|
![](https://github.com/user-attachments/assets/e383ebf3-d60e-4f66-8550-4cab0dc61261)
|
![](https://github.com/user-attachments/assets/b8aee712-c227-44d0-a60c-2dd24cc0b0cd)
|
| Settings / Models / Live2D expressions: empty list | Settings / Models
/ Live2D expressions: model entries are available |
---
 .../model-settings-runtime-owner.ts           |  90 +++++++++
 .../model-settings-runtime-snapshot.ts        |  83 ++++++---
 .../model-settings-runtime.browser.test.ts    | 171 ++++++++++++++++++
 .../src/renderer/pages/index.vue              |  39 ++--
 .../renderer/pages/settings/models/index.vue  |   3 +-
 .../src/shared/model-settings-runtime.ts      |  44 ++++-
 .../src/components/scenes/live2d/Model.vue    |  23 ++-
 .../live2d/expression-controller.test.ts      |  41 +++++
 .../live2d/expression-controller.ts           |  11 +-
 .../src/stores/expression-store.ts            |  81 ++++++++-
 .../model-settings/live2d.browser.test.ts     |  83 +++++++++
 .../settings/model-settings/live2d.vue        |  65 +++----
 .../settings/model-settings/panel.vue         |   3 +
 .../settings/model-settings/runtime.ts        |   5 +
 14 files changed, 628 insertions(+), 114 deletions(-)
 create mode 100644 apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-owner.ts
 create mode 100644 apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime.browser.test.ts
 create mode 100644 packages/stage-ui-live2d/src/composables/live2d/expression-controller.test.ts
 create mode 100644 packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.browser.test.ts

diff --git a/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-owner.ts b/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-owner.ts
new file mode 100644
index 000000000..a9ff76df6
--- /dev/null
+++ b/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-owner.ts
@@ -0,0 +1,90 @@
+import type { Live2DExpressionSettingsCommand } from '@proj-airi/stage-ui-live2d/stores/expression-store'
+import type { ModelSettingsRuntimeSnapshot } from '@proj-airi/stage-ui/components/scenarios/settings/model-settings/runtime'
+import type { MaybeRefOrGetter } from 'vue'
+
+import type { ModelSettingsRuntimeContext } from '../../shared/model-settings-runtime'
+
+import { defineInvokeHandler } from '@moeru/eventa'
+import { onBeforeUnmount, toValue, watch } from 'vue'
+
+import {
+  applyLive2DExpressionSettingsCommand,
+  getModelSettingsRuntimeContext,
+  modelSettingsRuntimeOwnerGone,
+  modelSettingsRuntimeSnapshotChanged,
+  modelSettingsRuntimeSnapshotRequested,
+} from '../../shared/model-settings-runtime'
+
+interface UseModelSettingsRuntimeOwnerOptions {
+  ownerInstanceId: string
+  renderer: MaybeRefOrGetter<ModelSettingsRuntimeSnapshot['renderer'] | undefined>
+  runtimeSnapshot: MaybeRefOrGetter<ModelSettingsRuntimeSnapshot>
+  applyLive2DExpressionCommand: (command: Live2DExpressionSettingsCommand) => void
+  context?: ModelSettingsRuntimeContext
+}
+
+/**
+ * Owns the model-settings channel for the renderer that controls the active model.
+ *
+ * The owner publishes runtime snapshots and accepts commands for its current owner ID.
+ * Commands for stale owners or non-Live2D renderers do not change the expression store.
+ */
+export function useModelSettingsRuntimeOwner(options: UseModelSettingsRuntimeOwnerOptions) {
+  const context = options.context ?? getModelSettingsRuntimeContext()
+
+  function postSnapshot(snapshot: ModelSettingsRuntimeSnapshot) {
+    void context.emit(modelSettingsRuntimeSnapshotChanged, snapshot).catch((error) => {
+      console.warn('[Model Settings Runtime] Failed to publish the runtime snapshot:', error)
+    })
+  }
+
+  watch(() => toValue(options.runtimeSnapshot), (snapshot) => {
+    postSnapshot(snapshot)
+  }, { immediate: true })
+
+  const stopSnapshotRequests = context.on(modelSettingsRuntimeSnapshotRequested, () => {
+    postSnapshot(toValue(options.runtimeSnapshot))
+  })
+  const stopExpressionCommands = defineInvokeHandler(context, applyLive2DExpressionSettingsCommand, (request) => {
+    const currentSnapshot = toValue(options.runtimeSnapshot)
+    if (request.ownerInstanceId !== options.ownerInstanceId) {
+      return {
+        applied: false,
+        snapshot: currentSnapshot,
+        rejectionReason: 'owner-changed',
+      }
+    }
+
+    if (!request.modelId || request.modelId !== currentSnapshot.modelId) {
+      return {
+        applied: false,
+        snapshot: currentSnapshot,
+        rejectionReason: 'model-changed',
+      }
+    }
+
+    if (toValue(options.renderer) !== 'live2d' || currentSnapshot.controlsLocked) {
+      return {
+        applied: false,
+        snapshot: currentSnapshot,
+        rejectionReason: 'runtime-unavailable',
+      }
+    }
+
+    options.applyLive2DExpressionCommand(request.command)
+    return {
+      applied: true,
+      snapshot: toValue(options.runtimeSnapshot),
+    }
+  })
+
+  onBeforeUnmount(() => {
+    stopSnapshotRequests()
+    stopExpressionCommands()
+    void context.emit(modelSettingsRuntimeOwnerGone, {
+      ownerInstanceId: options.ownerInstanceId,
+    }).catch((error) => {
+      console.warn('[Model Settings Runtime] Failed to publish owner shutdown:', error)
+    })
+  })
+}
diff --git a/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-snapshot.ts b/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-snapshot.ts
index ee7e8d615..7c74ce6cb 100644
--- a/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-snapshot.ts
+++ b/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime-snapshot.ts
@@ -1,27 +1,61 @@
+import type { Live2DExpressionSettingsCommand } from '@proj-airi/stage-ui-live2d/stores/expression-store'
 import type {
   ModelSettingsRuntimeSnapshot,
 } from '@proj-airi/stage-ui/components/scenarios/settings/model-settings/runtime'
 
-import type { ModelSettingsRuntimeChannelEvent } from '../../shared/model-settings-runtime'
+import type { ModelSettingsRuntimeContext } from '../../shared/model-settings-runtime'
 
+import { defineInvoke } from '@moeru/eventa'
 import {
   createEmptyModelSettingsRuntimeSnapshot,
 } from '@proj-airi/stage-ui/components/scenarios/settings/model-settings/runtime'
-import { useBroadcastChannel } from '@vueuse/core'
-import { onMounted, onUnmounted, ref, watch } from 'vue'
+import { onMounted, onUnmounted, ref } from 'vue'
 
 import {
-  modelSettingsRuntimeSnapshotChannelName,
+  applyLive2DExpressionSettingsCommand,
+  getModelSettingsRuntimeContext,
+  modelSettingsRuntimeOwnerGone,
+  modelSettingsRuntimeSnapshotChanged,
+  modelSettingsRuntimeSnapshotRequested,
 } from '../../shared/model-settings-runtime'
 
-export function useModelSettingsRuntimeSnapshot() {
+interface UseModelSettingsRuntimeSnapshotOptions {
+  context?: ModelSettingsRuntimeContext
+  /** Maximum wait for the stage owner to respond. @default 1000 */
+  commandTimeoutMs?: number
+}
+
+export function useModelSettingsRuntimeSnapshot(options: UseModelSettingsRuntimeSnapshotOptions = {}) {
   const runtimeSnapshot = ref<ModelSettingsRuntimeSnapshot>(createEmptyModelSettingsRuntimeSnapshot())
-  const { data, post } = useBroadcastChannel<ModelSettingsRuntimeChannelEvent, ModelSettingsRuntimeChannelEvent>({
-    name: modelSettingsRuntimeSnapshotChannelName,
-  })
+  const context = options.context ?? getModelSettingsRuntimeContext()
+  const invokeExpressionCommand = defineInvoke(context, applyLive2DExpressionSettingsCommand)
 
   const requestCurrent = () => {
-    post({ type: 'request-current' })
+    void context.emit(modelSettingsRuntimeSnapshotRequested, undefined)
+  }
+
+  const sendLive2DExpressionCommand = async (command: Live2DExpressionSettingsCommand) => {
+    const snapshot = runtimeSnapshot.value
+    if (!snapshot.ownerInstanceId || !snapshot.modelId || snapshot.renderer !== 'live2d' || snapshot.controlsLocked)
+      return false
+
+    try {
+      const response = await invokeExpressionCommand({
+        ownerInstanceId: snapshot.ownerInstanceId,
+        modelId: snapshot.modelId,
+        command,
+      }, {
+        signal: AbortSignal.timeout(options.commandTimeoutMs ?? 1000),
+      })
+      runtimeSnapshot.value = response.snapshot
+      return response.applied
+    }
+    catch (error) {
+      runtimeSnapshot.value = createEmptyModelSettingsRuntimeSnapshot()
+      requestCurrent()
+      console.warn('[Model Settings Runtime] Failed to apply the Live2D expression command:', error)
+      return false
+    }
   }
 
   const syncFromOwner = () => {
@@ -32,6 +66,17 @@ export function useModelSettingsRuntimeSnapshot() {
       requestCurrent()
   }
 
+  const stopSnapshots = context.on(modelSettingsRuntimeSnapshotChanged, (event) => {
+    if (event.body)
+      runtimeSnapshot.value = event.body
+  })
+  const stopOwnerGone = context.on(modelSettingsRuntimeOwnerGone, (event) => {
+    if (!event.body || runtimeSnapshot.value.ownerInstanceId !== event.body.ownerInstanceId)
+      return
+
+    runtimeSnapshot.value = createEmptyModelSettingsRuntimeSnapshot()
+  })
+
   onMounted(() => {
     requestCurrent()
     window.addEventListener('focus', syncFromOwner)
@@ -41,27 +86,13 @@ export function useModelSettingsRuntimeSnapshot() {
   onUnmounted(() => {
     window.removeEventListener('focus', syncFromOwner)
     document.removeEventListener('visibilitychange', syncFromOwnerWhenVisible)
-  })
-
-  watch(data, (event) => {
-    if (!event)
-      return
-
-    if (event.type === 'snapshot') {
-      runtimeSnapshot.value = event.snapshot
-      return
-    }
-
-    if (event.type === 'owner-gone') {
-      if (runtimeSnapshot.value.ownerInstanceId !== event.ownerInstanceId)
-        return
-
-      runtimeSnapshot.value = createEmptyModelSettingsRuntimeSnapshot()
-    }
+    stopSnapshots()
+    stopOwnerGone()
   })
 
   return {
     runtimeSnapshot,
     requestCurrent,
+    sendLive2DExpressionCommand,
   }
 }
diff --git a/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime.browser.test.ts b/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime.browser.test.ts
new file mode 100644
index 000000000..dabcd9380
--- /dev/null
+++ b/apps/stage-tamagotchi/src/renderer/composables/model-settings-runtime.browser.test.ts
@@ -0,0 +1,171 @@
+import type { ExpressionEntry, ExpressionGroupDefinition } from '@proj-airi/stage-ui-live2d/stores/expression-store'
+import type { ModelSettingsRuntimeSnapshot } from '@proj-airi/stage-ui/components/scenarios/settings/model-settings/runtime'
+
+import { defineInvoke } from '@moeru/eventa'
+import { createContext as createBroadcastChannelContext } from '@moeru/eventa/adapters/broadcast-channel'
+import { useExpressionStore } from '@proj-airi/stage-ui-live2d/stores/expression-store'
+import { createEmptyModelSettingsRuntimeSnapshot } from '@proj-airi/stage-ui/components/scenarios/settings/model-settings/runtime'
+import { createPinia } from 'pinia'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { cleanup, render } from 'vitest-browser-vue'
+import { computed, defineComponent, shallowRef } from 'vue'
+
+import { applyLive2DExpressionSettingsCommand, modelSettingsRuntimeChannelName } from '../../shared/model-settings-runtime'
+import { useModelSettingsRuntimeOwner } from './model-settings-runtime-owner'
+import { useModelSettingsRuntimeSnapshot } from './model-settings-runtime-snapshot'
+
+const expressionGroups: ExpressionGroupDefinition[] = [{
+  name: 'happy',
+  parameters: [{ parameterId: 'ParamHappy', blend: 'Add', value: 1 }],
+}]
+
+const expressionEntries: ExpressionEntry[] = [{
+  name: 'ParamHappy',
+  parameterId: 'ParamHappy',
+  blend: 'Add',
+  currentValue: 0,
+  defaultValue: 0,
+  modelDefault: 0,
+  targetValue: 1,
+}]
+
+describe('model settings runtime channel', () => {
+  const channelContexts: Array<ReturnType<typeof createBroadcastChannelContext>> = []
+
+  afterEach(() => {
+    cleanup()
+    for (const channelContext of channelContexts)
+      channelContext.dispose()
+    channelContexts.length = 0
+    localStorage.clear()
+  })
+
+  // https://github.com/moeru-ai/airi/issues/2450
+  it('applies an expression command through Eventa and rejects stale runtime identities for Issue #2450', async () => {
+    // ROOT CAUSE:
+    //
+    // The settings window and the stage window have separate Pinia stores.
+    // A component-only test did not cover the channel, owner check, store update, or returned snapshot.
+    //
+    // We fixed this with an Eventa RPC that returns the current owner snapshot.
+    const ownerInstanceId = 'stage-owner'
+    const ownerPinia = createPinia()
+    const settingsPinia = createPinia()
+    const ownerExpressionStore = useExpressionStore(ownerPinia)
+    ownerExpressionStore.registerExpressions('model-a', expressionGroups, expressionEntries)
+
+    const ownerChannelContext = createBroadcastChannelContext(new BroadcastChannel(modelSettingsRuntimeChannelName), { closeOnDispose: true })
+    const settingsChannelContext = createBroadcastChannelContext(new BroadcastChannel(modelSettingsRuntimeChannelName), { closeOnDispose: true })
+    channelContexts.push(ownerChannelContext, settingsChannelContext)
+
+    const renderer = shallowRef<ModelSettingsRuntimeSnapshot['renderer']>('live2d')
+    const ownerSnapshot = computed(() => createEmptyModelSettingsRuntimeSnapshot({
+      ownerInstanceId,
+      modelId: ownerExpressionStore.modelId,
+      renderer: renderer.value,
+      phase: 'mounted',
+      controlsLocked: false,
+      previewAvailable: true,
+      canCapturePreview: false,
+      live2dExpressions: ownerExpressionStore.settingsSnapshot,
+      updatedAt: Date.now(),
+    }))
+
+    let settingsRuntime: ReturnType<typeof useModelSettingsRuntimeSnapshot> | undefined
+    const TestHost = defineComponent({
+      setup() {
+        useModelSettingsRuntimeOwner({
+          ownerInstanceId,
+          renderer: () => renderer.value,
+          runtimeSnapshot: ownerSnapshot,
+          applyLive2DExpressionCommand: command => ownerExpressionStore.applySettingsCommand(command),
+          context: ownerChannelContext.context,
+        })
+        settingsRuntime = useModelSettingsRuntimeSnapshot({
+          context: settingsChannelContext.context,
+        })
+
+        return () => null
+      },
+    })
+
+    await render(TestHost, {
+      global: {
+        plugins: [settingsPinia],
+      },
+    })
+
+    if (!settingsRuntime)
+      throw new Error('The settings runtime did not mount.')
+    const mountedSettingsRuntime = settingsRuntime
+
+    await vi.waitFor(() => expect(mountedSettingsRuntime.runtimeSnapshot.value.live2dExpressions?.groups).toEqual([{
+      name: 'happy',
+      active: false,
+      exposedToLlm: false,
+    }]))
+
+    const invokeExpressionCommand = defineInvoke(settingsChannelContext.context, applyLive2DExpressionSettingsCommand)
+    const staleOwnerResponse = await invokeExpressionCommand({
+      ownerInstanceId: 'stale-owner',
+      modelId: 'model-a',
+      command: { type: 'toggle', name: 'happy' },
+    }, {
+      signal: AbortSignal.timeout(1000),
+    })
+
+    expect(staleOwnerResponse.applied).toBe(false)
+    expect(staleOwnerResponse.rejectionReason).toBe('owner-changed')
+    expect(ownerExpressionStore.settingsSnapshot.groups[0].active).toBe(false)
+
+    const applied = await mountedSettingsRuntime.sendLive2DExpressionCommand({ type: 'toggle', name: 'happy' })
+
+    await vi.waitFor(() => expect(ownerExpressionStore.settingsSnapshot.groups[0].active).toBe(true))
+    await vi.waitFor(() => expect(mountedSettingsRuntime.runtimeSnapshot.value.live2dExpressions?.groups[0].active).toBe(true))
+    expect(applied).toBe(true)
+    expect(useExpressionStore(settingsPinia).expressionGroups.size).toBe(0)
+
+    ownerExpressionStore.registerExpressions('model-b', expressionGroups, expressionEntries)
+    const rejected = await mountedSettingsRuntime.sendLive2DExpressionCommand({ type: 'toggle', name: 'happy' })
+
+    expect(rejected).toBe(false)
+    expect(ownerExpressionStore.settingsSnapshot.groups[0].active).toBe(false)
+    await vi.waitFor(() => expect(mountedSettingsRuntime.runtimeSnapshot.value.modelId).toBe('model-b'))
+  })
+
+  // https://github.com/moeru-ai/airi/issues/2450
+  it('clears a stale snapshot when the stage owner does not answer', async () => {
+    const settingsChannelContext = createBroadcastChannelContext(new BroadcastChannel(modelSettingsRuntimeChannelName), { closeOnDispose: true })
+    channelContexts.push(settingsChannelContext)
+    const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
+
+    let settingsRuntime: ReturnType<typeof useModelSettingsRuntimeSnapshot> | undefined
+    const TestHost = defineComponent({
+      setup() {
+        settingsRuntime = useModelSettingsRuntimeSnapshot({
+          context: settingsChannelContext.context,
+          commandTimeoutMs: 20,
+        })
+        return () => null
+      },
+    })
+
+    await render(TestHost)
+    if (!settingsRuntime)
+      throw new Error('The settings runtime did not mount.')
+
+    settingsRuntime.runtimeSnapshot.value = createEmptyModelSettingsRuntimeSnapshot({
+      ownerInstanceId: 'stale-owner',
+      modelId: 'model-a',
+      renderer: 'live2d',
+      phase: 'mounted',
+      controlsLocked: false,
+    })
+
+    const applied = await settingsRuntime.sendLive2DExpressionCommand({ type: 'toggle', name: 'happy' })
+
+    expect(applied).toBe(false)
+    expect(settingsRuntime.runtimeSnapshot.value.ownerInstanceId).toBe('')
+    expect(warn).toHaveBeenCalledOnce()
+  })
+})
diff --git a/apps/stage-tamagotchi/src/renderer/pages/index.vue b/apps/stage-tamagotchi/src/renderer/pages/index.vue
index 9757bd613..f3c3b1ad1 100644
--- a/apps/stage-tamagotchi/src/renderer/pages/index.vue
+++ b/apps/stage-tamagotchi/src/renderer/pages/index.vue
@@ -2,8 +2,6 @@
 import type { CaptionChannelEvent, HearingInputChannelEvent } from '@proj-airi/stage-shared'
 import type { ModelSettingsRuntimeSnapshot } from '@proj-airi/stage-ui/components/scenarios/settings/model-settings/runtime'
 
-import type { ModelSettingsRuntimeChannelEvent } from '../../shared/model-settings-runtime'
-
 import { errorMessageFrom, tryCatch } from '@moeru/std'
 import { electron } from '@proj-airi/electron-eventa'
 import {
@@ -15,6 +13,7 @@ import {
 } from '@proj-airi/electron-vueuse'
 import { createTranscriptBuffer } from '@proj-airi/pipelines-audio'
 import { hearingInputChannelName } from '@proj-airi/stage-shared'
+import { useExpressionStore } from '@proj-airi/stage-ui-live2d/stores/expression-store'
 import { useModelStore, useThreeSceneIsTransparentAtPoint } from '@proj-airi/stage-ui-three'
 import { HoloCoupon } from '@proj-airi/stage-ui/components'
 import {
@@ -40,7 +39,7 @@ import ControlsIsland from '../components/stage-islands/controls-island/index.vu
 import ResourceStatusIsland from '../components/stage-islands/resource-status-island/index.vue'
 
 import { electronOpenOnboarding } from '../../shared/eventa'
-import { modelSettingsRuntimeSnapshotChannelName } from '../../shared/model-settings-runtime'
+import { useModelSettingsRuntimeOwner } from '../composables/model-settings-runtime-owner'
 import { useControlsIslandStore } from '../stores/controls-island'
 import { useStageWindowLifecycleStore } from '../stores/stage-window-lifecycle'
 import { resolveFadeOnHoverInteraction } from '../utils/fade-on-hover'
@@ -100,11 +99,11 @@ const isTransparentByThreeExact = useThreeSceneIsTransparentAtPoint(
 const settingsStore = useSettings()
 const { stageModelRenderer, stageModelSelectedUrl } = storeToRefs(settingsStore)
 const modelStore = useModelStore()
+const expressionStore = useExpressionStore()
 const { sceneMutationLocked, scenePhase } = storeToRefs(modelStore)
 const { stagePaused } = storeToRefs(useStageWindowLifecycleStore())
 const { fadeOnHoverEnabled } = storeToRefs(useControlsIslandStore())
 const modelSettingsRuntimeOwnerInstanceId = `tamagotchi-main-stage:${Math.random().toString(36).slice(2, 10)}`
-const { data: modelSettingsRuntimeChannelEvent, post: postModelSettingsRuntimeChannelEvent } = useBroadcastChannel<ModelSettingsRuntimeChannelEvent, ModelSettingsRuntimeChannelEvent>({ name: modelSettingsRuntimeSnapshotChannelName })
 const shouldUseThreeTransparencyHitTest = computed(() => shouldSampleStageTransparency({
   componentState: componentStateStage.value,
   fadeOnHoverEnabled: fadeOnHoverEnabled.value,
@@ -151,11 +150,13 @@ const modelSettingsRuntimeSnapshot = computed<ModelSettingsRuntimeSnapshot>(() =
 
     return createEmptyModelSettingsRuntimeSnapshot({
       ownerInstanceId: modelSettingsRuntimeOwnerInstanceId,
+      modelId: expressionStore.modelId,
       renderer: 'live2d',
       phase,
       controlsLocked: hasModel ? phase !== 'mounted' : false,
       previewAvailable: hasModel,
       canCapturePreview: false,
+      live2dExpressions: expressionStore.settingsSnapshot,
       updatedAt: Date.now(),
     })
   }
@@ -297,25 +298,13 @@ watch(
   { immediate: true },
 )
 
-// Emit runtime snapshot on change and on request from settings panel
-/**
- * Sends model-settings runtime events without letting closed HMR channels break the stage.
- */
-function postModelSettingsRuntimeEvent(event: ModelSettingsRuntimeChannelEvent) {
-  const { error } = tryCatch(() => postModelSettingsRuntimeChannelEvent(event))
-  if (error)
-    console.warn('[Main Page] Failed to post model settings runtime event:', error)
-}
-
-watch(modelSettingsRuntimeSnapshot, (snapshot) => {
-  postModelSettingsRuntimeEvent({ type: 'snapshot', snapshot })
-}, { immediate: true })
-
-watch(modelSettingsRuntimeChannelEvent, (event) => {
-  if (event?.type !== 'request-current')
-    return
-
-  postModelSettingsRuntimeEvent({ type: 'snapshot', snapshot: modelSettingsRuntimeSnapshot.value })
+useModelSettingsRuntimeOwner({
+  ownerInstanceId: modelSettingsRuntimeOwnerInstanceId,
+  renderer: () => stageModelRenderer.value,
+  runtimeSnapshot: modelSettingsRuntimeSnapshot,
+  applyLive2DExpressionCommand: (command) => {
+    expressionStore.applySettingsCommand(command)
+  },
 })
 
 const settingsAudioDeviceStore = useSettingsAudioDevice()
@@ -756,10 +745,6 @@ onUnmounted(() => {
   }
   hearingInputClearTimers.clear()
   clearHearingInput()
-  postModelSettingsRuntimeEvent({
-    type: 'owner-gone',
-    ownerInstanceId: modelSettingsRuntimeOwnerInstanceId,
-  })
   clearAssistantSpeechResumeTimer()
   void voiceInputInteractionLifecycle.stop().catch(error => reportVoiceInputFailure('stop listening', error))
 })
diff --git a/apps/stage-tamagotchi/src/renderer/pages/settings/models/index.vue b/apps/stage-tamagotchi/src/renderer/pages/settings/models/index.vue
index 9a801458d..96499076a 100644
--- a/apps/stage-tamagotchi/src/renderer/pages/settings/models/index.vue
+++ b/apps/stage-tamagotchi/src/renderer/pages/settings/models/index.vue
@@ -61,7 +61,7 @@ const godotStageStatus = ref<ElectronGodotStageStatus>({
 const switchingGodotStage = ref(false)
 const godotViewError = ref<StageViewErrorPayload>()
 const godotViewSnapshot = ref<StageViewSnapshotPayload | null>(null)
-const { runtimeSnapshot } = useModelSettingsRuntimeSnapshot()
+const { runtimeSnapshot, sendLive2DExpressionCommand } = useModelSettingsRuntimeSnapshot()
 
 let sceneSyncGeneration = 0
 let godotSessionEpoch = 0
@@ -385,6 +385,7 @@ onUnmounted(() => {
           'sm:max-h-[80dvh]',
           'relative',
         ]"
+        @live2d-expression-command="sendLive2DExpressionCommand"
         @patch-godot-view-state="handleGodotViewPatch"
       >
         <template #actions>
diff --git a/apps/stage-tamagotchi/src/shared/model-settings-runtime.ts b/apps/stage-tamagotchi/src/shared/model-settings-runtime.ts
index 1d1209791..e7696fbd0 100644
--- a/apps/stage-tamagotchi/src/shared/model-settings-runtime.ts
+++ b/apps/stage-tamagotchi/src/shared/model-settings-runtime.ts
@@ -1,8 +1,42 @@
+import type { Live2DExpressionSettingsCommand } from '@proj-airi/stage-ui-live2d/stores/expression-store'
 import type { ModelSettingsRuntimeSnapshot } from '@proj-airi/stage-ui/components'
 
-export const modelSettingsRuntimeSnapshotChannelName = 'airi-model-settings-runtime-snapshot'
+import { defineEventa, defineInvokeEventa } from '@moeru/eventa'
+import { createContext as createBroadcastChannelContext } from '@moeru/eventa/adapters/broadcast-channel'
 
-export type ModelSettingsRuntimeChannelEvent
-  = | { type: 'request-current' }
-    | { type: 'snapshot', snapshot: ModelSettingsRuntimeSnapshot }
-    | { type: 'owner-gone', ownerInstanceId: string }
+export const modelSettingsRuntimeChannelName = 'airi-model-settings-runtime'
+
+/** A settings mutation request for one loaded Live2D model. */
+export interface ApplyLive2DExpressionSettingsCommandRequest {
+  /** Identifies the stage renderer that published the source snapshot. */
+  ownerInstanceId: string
+  /** Identifies the expression store that published the source snapshot. */
+  modelId: string
+  command: Live2DExpressionSettingsCommand
+}
+
+/** The current owner state after it accepts or rejects a settings mutation. */
+export interface ApplyLive2DExpressionSettingsCommandResponse {
+  applied: boolean
+  snapshot: ModelSettingsRuntimeSnapshot
+  rejectionReason?: 'owner-changed' | 'model-changed' | 'runtime-unavailable'
+}
+
+export const modelSettingsRuntimeSnapshotRequested = defineEventa<void>('eventa:model-settings-runtime:snapshot:request')
+export const modelSettingsRuntimeSnapshotChanged = defineEventa<ModelSettingsRuntimeSnapshot>('eventa:model-settings-runtime:snapshot:changed')
+export const modelSettingsRuntimeOwnerGone = defineEventa<{ ownerInstanceId: string }>('eventa:model-settings-runtime:owner:gone')
+export const applyLive2DExpressionSettingsCommand = defineInvokeEventa<
+  ApplyLive2DExpressionSettingsCommandResponse,
+  ApplyLive2DExpressionSettingsCommandRequest
+>('eventa:model-settings-runtime:live2d-expression:apply')
+
+let context: ReturnType<typeof createBroadcastChannelContext>['context'] | undefined
+
+/** The Eventa context that carries model-settings state and commands. */
+export type ModelSettingsRuntimeContext = ReturnType<typeof createBroadcastChannelContext>['context']
+
+/** Returns the Eventa context for model-settings state and commands. */
+export function getModelSettingsRuntimeContext() {
+  context ??= createBroadcastChannelContext(new BroadcastChannel(modelSettingsRuntimeChannelName)).context
+  return context
+}
diff --git a/packages/stage-ui-live2d/src/components/scenes/live2d/Model.vue b/packages/stage-ui-live2d/src/components/scenes/live2d/Model.vue
index ca10c53af..c28909b3f 100644
--- a/packages/stage-ui-live2d/src/components/scenes/live2d/Model.vue
+++ b/packages/stage-ui-live2d/src/components/scenes/live2d/Model.vue
@@ -189,8 +189,10 @@ const live2dShadowEnabled = toRef(() => props.live2dShadowEnabled)
 const internalModelRef = shallowRef<PixiLive2DInternalModel>()
 const expressionController = useExpressionController({
   internalModel: internalModelRef,
-  modelId: props.modelId,
 })
+// This identity belongs to model.value. It changes only when a model load
+// commits, so expression initialization cannot observe a newer prop by mistake.
+let loadedModelId: string | undefined
 // Saved SDK manager references for runtime expression toggle (restore on disable)
 const savedEyeBlink = shallowRef<any>(null)
 const savedExpressionManager = shallowRef<any>(null)
@@ -244,6 +246,7 @@ async function performModelLoad() {
     // Dispose expression controller before destroying the old model
     expressionController.dispose()
     internalModelRef.value = undefined
+    loadedModelId = undefined
 
     try {
       pixiApp.value.stage.removeChild(model.value)
@@ -254,7 +257,11 @@ async function performModelLoad() {
     }
     model.value = undefined
   }
-  if (!modelSrcRef.value) {
+  const pendingModel = {
+    id: props.modelId,
+    src: modelSrcRef.value,
+  }
+  if (!pendingModel.src) {
     console.warn('No Live2D model source provided.')
     modelLoading.value = false
     componentState.value = 'mounted'
@@ -269,7 +276,7 @@ async function performModelLoad() {
     }
 
     const live2DModel = new Live2DModel<PixiLive2DInternalModel>()
-    await Live2DFactory.setupLive2DModel(live2DModel, { url: modelSrcRef.value, id: props.modelId }, { autoInteract: false })
+    await Live2DFactory.setupLive2DModel(live2DModel, { url: pendingModel.src, id: pendingModel.id }, { autoInteract: false })
     availableMotions.value.forEach((motion) => {
       if (motion.motionName in Emotion) {
         motionMap.value[motion.fileName] = motion.motionName
@@ -436,6 +443,7 @@ async function performModelLoad() {
     // toggled off at runtime.
     savedEyeBlink.value = internalModel.eyeBlink
     savedExpressionManager.value = motionManager.expressionManager
+    loadedModelId = pendingModel.id
 
     // --- Expression controller initialisation (conditional)
     if (live2dExpressionEnabled.value) {
@@ -465,7 +473,7 @@ async function performModelLoad() {
   finally {
     modelLoading.value = false
     componentState.value = 'mounted'
-    await initExpressionController(internalModelRef.value).catch((err) => {
+    await initExpressionController(internalModelRef.value, loadedModelId).catch((err) => {
       console.warn('[Model.vue] Expression controller initialization failed:', err)
     })
   }
@@ -478,7 +486,7 @@ async function performModelLoad() {
  * This is intentionally fire-and-forget from loadModel so that a failure in
  * expression loading does not prevent the model itself from rendering.
  */
-async function initExpressionController(internalModel?: PixiLive2DInternalModel) {
+async function initExpressionController(internalModel?: PixiLive2DInternalModel, modelId?: string) {
   // Dispose any previous state (handles model reloads)
   expressionController.dispose()
 
@@ -502,7 +510,7 @@ async function initExpressionController(internalModel?: PixiLive2DInternalModel)
     return response.text()
   }
 
-  await expressionController.initialise(expressionRefs, readExpFile)
+  await expressionController.initialise(modelId, expressionRefs, readExpFile)
 }
 
 async function setMotion(motionName: string, index?: number) {
@@ -738,7 +746,7 @@ watch(live2dExpressionEnabled, (enabled) => {
     }
 
     internalModelRef.value = im
-    initExpressionController(im).catch((err) => {
+    initExpressionController(im, loadedModelId).catch((err) => {
       console.warn('[Model.vue] Expression controller initialisation failed:', err)
     })
   }
@@ -773,6 +781,7 @@ onUnmounted(() => {
   resizeAnimation?.pause()
   disposeShouldUpdateView?.()
   expressionController.dispose()
+  loadedModelId = undefined
 })
 
 function listMotionGroups() {
diff --git a/packages/stage-ui-live2d/src/composables/live2d/expression-controller.test.ts b/packages/stage-ui-live2d/src/composables/live2d/expression-controller.test.ts
new file mode 100644
index 000000000..4ec632226
--- /dev/null
+++ b/packages/stage-ui-live2d/src/composables/live2d/expression-controller.test.ts
@@ -0,0 +1,41 @@
+import type { PixiLive2DInternalModel } from './motion-manager'
+
+import { createPinia, setActivePinia } from 'pinia'
+import { describe, expect, it } from 'vitest'
+import { shallowRef } from 'vue'
+
+import { useExpressionStore } from '../../stores/expression-store'
+import { useExpressionController } from './expression-controller'
+
+describe('useExpressionController', () => {
+  it('registers expressions with the identity of each loaded model', async () => {
+    // ROOT CAUSE:
+    //
+    // Model.vue creates one expression controller, then reuses it when the
+    // component loads another model. The controller captured the first model
+    // ID at setup time, so model B expressions were registered as model A.
+    //
+    // We fixed this by passing the identity of each completed model load into
+    // the matching expression initialization.
+    setActivePinia(createPinia())
+
+    const internalModel = shallowRef({
+      coreModel: {
+        getParameterDefaultValueById: () => 0,
+      },
+    } as unknown as PixiLive2DInternalModel)
+    const controller = useExpressionController({ internalModel })
+    const expressionStore = useExpressionStore()
+    const expressionRefs = [{ Name: 'Happy', File: 'happy.exp3.json' }]
+    const readExpFile = async () => JSON.stringify({
+      Type: 'Live2D Expression',
+      Parameters: [{ Id: 'ParamMouthForm', Value: 1, Blend: 'Add' }],
+    })
+
+    await controller.initialise('model-a', expressionRefs, readExpFile)
+    expect(expressionStore.modelId).toBe('model-a')
+
+    await controller.initialise('model-b', expressionRefs, readExpFile)
+    expect(expressionStore.modelId).toBe('model-b')
+  })
+})
diff --git a/packages/stage-ui-live2d/src/composables/live2d/expression-controller.ts b/packages/stage-ui-live2d/src/composables/live2d/expression-controller.ts
index 3c9ed7339..8da7268be 100644
--- a/packages/stage-ui-live2d/src/composables/live2d/expression-controller.ts
+++ b/packages/stage-ui-live2d/src/composables/live2d/expression-controller.ts
@@ -39,12 +39,6 @@ export interface ExpressionControllerOptions {
    * while a model is being swapped).
    */
   internalModel: Ref<PixiLive2DInternalModel | undefined>
-
-  /**
-   * An optional model identifier used for persistence scoping.
-   * Falls back to `'unknown'` if not provided.
-   */
-  modelId?: string
 }
 
 /**
@@ -66,12 +60,15 @@ export function useExpressionController(options: ExpressionControllerOptions) {
    * Parse model3.json expression references and the corresponding exp3 data,
    * then register everything in the store.
    *
+   * @param modelId        - The identifier captured for this model load. It
+   *                         scopes expression persistence to the loaded model.
    * @param expressionRefs - `FileReferences.Expressions` from model3.json
    * @param readExpFile    - An async function that reads the content of an
    *                         exp3.json file given its path (relative to the
    *                         model root inside the ZIP / OPFS).
    */
   async function initialise(
+    modelId: string | undefined,
     expressionRefs: Model3ExpressionRef[],
     readExpFile: (path: string) => Promise<string>,
   ) {
@@ -126,7 +123,7 @@ export function useExpressionController(options: ExpressionControllerOptions) {
     }
 
     store.registerExpressions(
-      options.modelId ?? 'unknown',
+      modelId ?? 'unknown',
       groups,
       Array.from(entryMap.values()),
     )
diff --git a/packages/stage-ui-live2d/src/stores/expression-store.ts b/packages/stage-ui-live2d/src/stores/expression-store.ts
index e50f38747..573627995 100644
--- a/packages/stage-ui-live2d/src/stores/expression-store.ts
+++ b/packages/stage-ui-live2d/src/stores/expression-store.ts
@@ -1,5 +1,5 @@
 import { defineStore } from 'pinia'
-import { ref } from 'vue'
+import { computed, ref } from 'vue'
 
 // ---------------------------------------------------------------------------
 // Types
@@ -71,6 +71,35 @@ export interface ExpressionToolResult {
   available?: string[]
 }
 
+/** Controls which Live2D expressions the model exposes to LLM tools. */
+export type Live2DExpressionLlmMode = 'all' | 'none' | 'custom'
+
+/** A serializable expression group used by model settings in another renderer. */
+export interface Live2DExpressionSettingsGroupSnapshot {
+  /** Expression name declared by the loaded model. */
+  name: string
+  /** Whether the owning renderer currently applies this expression. */
+  active: boolean
+  /** Whether custom LLM exposure includes this expression. */
+  exposedToLlm: boolean
+}
+
+/** The serializable settings state owned by the renderer that loaded the Live2D model. */
+export interface Live2DExpressionSettingsSnapshot {
+  /** Expression groups discovered by the owning renderer. */
+  groups: Live2DExpressionSettingsGroupSnapshot[]
+  /** Current LLM exposure policy. */
+  llmMode: Live2DExpressionLlmMode
+}
+
+/** A settings operation sent to the renderer that owns the Live2D model. */
+export type Live2DExpressionSettingsCommand
+  = | { type: 'toggle', name: string }
+    | { type: 'set-llm-mode', mode: Live2DExpressionLlmMode }
+    | { type: 'set-llm-exposed', name: string, exposed: boolean }
+    | { type: 'save-defaults' }
+    | { type: 'reset-all' }
+
 // ---------------------------------------------------------------------------
 // Persistence helpers  (localStorage – no extra dependency needed)
 // ---------------------------------------------------------------------------
@@ -120,7 +149,7 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
   const expressionGroups = ref<Map<string, ExpressionGroupDefinition>>(new Map())
 
   /** LLM exposure mode: 'all' exposes everything, 'none' exposes nothing, 'custom' uses per-group map. */
-  const llmMode = ref<'all' | 'none' | 'custom'>('none')
+  const llmMode = ref<Live2DExpressionLlmMode>('none')
 
   /** Per-group LLM exposure flags (only used when llmMode === 'custom'). */
   const llmExposed = ref<Map<string, boolean>>(new Map())
@@ -150,6 +179,25 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
     return Array.from(expressions.value.keys())
   }
 
+  function isGroupActive(group: ExpressionGroupDefinition): boolean {
+    return group.parameters.some((parameter) => {
+      if (parameter.value === 0)
+        return false
+
+      const entry = expressions.value.get(parameter.parameterId)
+      return entry != null && entry.currentValue === parameter.value
+    })
+  }
+
+  const settingsSnapshot = computed<Live2DExpressionSettingsSnapshot>(() => ({
+    groups: Array.from(expressionGroups.value.values(), group => ({
+      name: group.name,
+      active: isGroupActive(group),
+      exposedToLlm: llmExposed.value.get(group.name) ?? false,
+    })),
+    llmMode: llmMode.value,
+  }))
+
   // ---- public API ----------------------------------------------------------
 
   /**
@@ -290,12 +338,7 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
       // A group is "active" when at least one of its non-zero (activation)
       // params is currently set to the exp3 value.  Zero-valued params are
       // "reset" instructions and are excluded from the active check.
-      const isActive = resolved.group.parameters.some((p) => {
-        if (p.value === 0)
-          return false
-        const entry = expressions.value.get(p.parameterId)
-        return entry && entry.currentValue === p.value
-      })
+      const isActive = isGroupActive(resolved.group)
       const states: ExpressionState[] = []
       for (const param of resolved.group.parameters) {
         const entry = expressions.value.get(param.parameterId)
@@ -360,7 +403,7 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
 
   // ---- LLM exposure --------------------------------------------------------
 
-  function setLlmMode(mode: 'all' | 'none' | 'custom') {
+  function setLlmMode(mode: Live2DExpressionLlmMode) {
     llmMode.value = mode
   }
 
@@ -377,6 +420,24 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
     return llmExposed.value.get(name) ?? false
   }
 
+  /** Applies a settings command in the renderer that owns the Live2D runtime. */
+  function applySettingsCommand(command: Live2DExpressionSettingsCommand): ExpressionToolResult | void {
+    switch (command.type) {
+      case 'toggle':
+        return toggle(command.name)
+      case 'set-llm-mode':
+        setLlmMode(command.mode)
+        return
+      case 'set-llm-exposed':
+        setLlmExposed(command.name, command.exposed)
+        return
+      case 'save-defaults':
+        return saveDefaults()
+      case 'reset-all':
+        return resetAll()
+    }
+  }
+
   // ---- private -------------------------------------------------------------
 
   function applyValue(entry: ExpressionEntry, value: number, duration?: number) {
@@ -405,6 +466,7 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
     expressionGroups,
     llmMode,
     llmExposed,
+    settingsSnapshot,
 
     // Actions
     registerExpressions,
@@ -418,5 +480,6 @@ export const useExpressionStore = defineStore('live2d-expressions', () => {
     setLlmMode,
     setLlmExposed,
     isExposedToLlm,
+    applySettingsCommand,
   }
 })
diff --git a/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.browser.test.ts b/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.browser.test.ts
new file mode 100644
index 000000000..16189d926
--- /dev/null
+++ b/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.browser.test.ts
@@ -0,0 +1,83 @@
+import type { ModelSettingsRuntimeSnapshot } from './runtime'
+
+import { createPinia } from 'pinia'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { cleanup, render } from 'vitest-browser-vue'
+import { createI18n } from 'vue-i18n'
+
+function createTestI18n() {
+  return createI18n({
+    legacy: false,
+    locale: 'en',
+    missingWarn: false,
+    fallbackWarn: false,
+    messages: { en: {} },
+  })
+}
+
+describe('live2D model settings', () => {
+  afterEach(() => {
+    cleanup()
+    localStorage.clear()
+  })
+
+  // https://github.com/moeru-ai/airi/issues/2450
+  it('renders a remote expression snapshot and emits a command without changing the local store', async () => {
+    // ROOT CAUSE:
+    //
+    // The Electron stage renderer loaded the model and registered its expressions.
+    // The separate settings renderer read a different Pinia store, so the list stayed empty.
+    //
+    // We fixed this by sending a serializable expression snapshot from the stage owner.
+    Object.assign(window, { Live2DCubismCore: {} })
+    const [{ useExpressionStore, useSettingsLive2d }, { default: Live2DSettings }] = await Promise.all([
+      import('@proj-airi/stage-ui-live2d'),
+      import('./live2d.vue'),
+    ])
+
+    const pinia = createPinia()
+    const live2dSettings = useSettingsLive2d(pinia)
+    live2dSettings.live2dExpressionEnabled = true
+
+    const runtimeSnapshot = {
+      ownerInstanceId: 'stage-owner',
+      modelId: 'test-model',
+      renderer: 'live2d',
+      phase: 'mounted',
+      controlsLocked: false,
+      previewAvailable: true,
+      canCapturePreview: false,
+      updatedAt: 1,
+      live2dExpressions: {
+        groups: [
+          { name: 'happy', active: false, exposedToLlm: false },
+          { name: 'surprised', active: true, exposedToLlm: false },
+        ],
+        llmMode: 'none',
+      },
+    } satisfies ModelSettingsRuntimeSnapshot
+
+    const onLive2dExpressionCommand = vi.fn()
+
+    const screen = await render(Live2DSettings, {
+      props: {
+        palette: [],
+        runtimeSnapshot,
+        onLive2dExpressionCommand,
+      },
+      global: {
+        plugins: [pinia, createTestI18n()],
+      },
+    })
+
+    await screen.getByText('settings.live2d.expressions.title', { exact: true }).click()
+    await expect.element(screen.getByText('happy', { exact: true })).toBeVisible()
+    await expect.element(screen.getByText('surprised', { exact: true })).toBeVisible()
+
+    const expressionSwitches = screen.getByRole('switch').all()
+    await expressionSwitches[1].click()
+
+    expect(onLive2dExpressionCommand).toHaveBeenCalledWith({ type: 'toggle', name: 'happy' })
+    expect(useExpressionStore(pinia).expressionGroups.size).toBe(0)
+  })
+})
diff --git a/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.vue b/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.vue
index 0011119d3..ccd6b57fb 100644
--- a/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.vue
+++ b/packages/stage-ui/src/components/scenarios/settings/model-settings/live2d.vue
@@ -1,5 +1,9 @@
 <script setup lang="ts">
-import type { Live2DMotionDriver } from '@proj-airi/stage-ui-live2d'
+import type {
+  Live2DExpressionLlmMode,
+  Live2DExpressionSettingsCommand,
+  Live2DMotionDriver,
+} from '@proj-airi/stage-ui-live2d'
 import type { SelectTabOption } from '@proj-airi/ui'
 
 import type { ModelSettingsRuntimeSnapshot } from './runtime'
@@ -24,8 +28,9 @@ const props = withDefaults(defineProps<{
 }>(), {
   allowExtractColors: true,
 })
-defineEmits<{
+const emit = defineEmits<{
   (e: 'extractColorsFromModel'): void
+  (e: 'live2dExpressionCommand', command: Live2DExpressionSettingsCommand): void
 }>()
 
 const { t } = useI18n()
@@ -67,20 +72,16 @@ const {
 } = storeToRefs(live2d)
 
 const expressionStore = useExpressionStore()
-const { expressions, expressionGroups } = storeToRefs(expressionStore)
+const expressionSettingsSnapshot = computed(() => props.runtimeSnapshot.live2dExpressions ?? expressionStore.settingsSnapshot)
+const usesRemoteExpressionRuntime = computed(() => props.runtimeSnapshot.live2dExpressions != null)
 
-/**
- * Check if an expression group is currently active.
- * Only considers non-zero exp3 params (zero-valued params are "reset" instructions).
- * A group is active when at least one of its activation params matches the exp3 value.
- */
-function isGroupActive(group: { parameters: { parameterId: string, value: number }[] }): boolean {
-  return group.parameters.some((p) => {
-    if (p.value === 0)
-      return false // Skip reset params
-    const entry = expressions.value.get(p.parameterId)
-    return entry != null && entry.currentValue === p.value
-  })
+function applyExpressionSettingsCommand(command: Live2DExpressionSettingsCommand) {
+  if (usesRemoteExpressionRuntime.value) {
+    emit('live2dExpressionCommand', command)
+    return
+  }
+
+  expressionStore.applySettingsCommand(command)
 }
 
 const selectedRuntimeMotion = ref<string>('')
@@ -762,7 +763,7 @@ function handleMotionSelect(selectedMotionPath: string | number | undefined) {
     <div v-if="!live2dExpressionEnabled" py-2 text-xs text-neutral-500 dark:text-neutral-400>
       {{ t('settings.live2d.expressions.sdk-preset-preserved-notice') }}
     </div>
-    <template v-else-if="expressionGroups.size === 0">
+    <template v-else-if="expressionSettingsSnapshot.groups.length === 0">
       <div py-2 text-sm text-neutral-500 dark:text-neutral-400>
         {{ t('settings.live2d.expressions.no-expression') }}
       </div>
@@ -771,14 +772,14 @@ function handleMotionSelect(selectedMotionPath: string | number | undefined) {
       <!-- Expression preview toggles -->
       <div flex flex-col gap-2>
         <div
-          v-for="[groupName, group] in expressionGroups"
-          :key="groupName"
+          v-for="group in expressionSettingsSnapshot.groups"
+          :key="group.name"
           flex items-center justify-between
         >
-          <span text-sm text-neutral-700 dark:text-neutral-300>{{ groupName }}</span>
+          <span text-sm text-neutral-700 dark:text-neutral-300>{{ group.name }}</span>
           <Checkbox
-            :model-value="isGroupActive(group)"
-            @update:model-value="expressionStore.toggle(groupName)"
+            :model-value="group.active"
+            @update:model-value="applyExpressionSettingsCommand({ type: 'toggle', name: group.name })"
           />
         </div>
       </div>
@@ -786,37 +787,37 @@ function handleMotionSelect(selectedMotionPath: string | number | undefined) {
       <div mt-4 flex flex-wrap items-center gap-3>
         <span whitespace-nowrap text-sm text-neutral-600 dark:text-neutral-400>{{ t('settings.live2d.expressions.expose-to-llm-toggle') }}</span>
         <SelectTab
-          :model-value="expressionStore.llmMode"
+          :model-value="expressionSettingsSnapshot.llmMode"
           :options="llmModeOptions"
           size="sm"
-          @update:model-value="(v: string) => expressionStore.setLlmMode(v as 'all' | 'none' | 'custom')"
+          @update:model-value="(mode: string) => applyExpressionSettingsCommand({ type: 'set-llm-mode', mode: mode as Live2DExpressionLlmMode })"
         />
       </div>
-      <span v-if="expressionStore.llmMode !== 'none'" text-xs text-neutral-500 dark:text-neutral-400>
+      <span v-if="expressionSettingsSnapshot.llmMode !== 'none'" text-xs text-neutral-500 dark:text-neutral-400>
         {{ t('settings.live2d.expressions.llm-integration-wip') }}
       </span>
 
       <!-- Custom per-expression LLM toggles (only when mode = 'custom') -->
-      <div v-if="expressionStore.llmMode === 'custom'" mt-2 flex flex-col gap-2 border-l-2 border-neutral-200 pl-3 dark:border-neutral-700>
+      <div v-if="expressionSettingsSnapshot.llmMode === 'custom'" mt-2 flex flex-col gap-2 border-l-2 border-neutral-200 pl-3 dark:border-neutral-700>
         <div
-          v-for="[groupName] in expressionGroups"
-          :key="`llm-${groupName}`"
+          v-for="group in expressionSettingsSnapshot.groups"
+          :key="`llm-${group.name}`"
           flex items-center justify-between
         >
-          <span text-xs text-neutral-600 dark:text-neutral-400>{{ groupName }}</span>
+          <span text-xs text-neutral-600 dark:text-neutral-400>{{ group.name }}</span>
           <Checkbox
-            :model-value="expressionStore.llmExposed.get(groupName) ?? false"
-            @update:model-value="(v: boolean) => expressionStore.setLlmExposed(groupName, v)"
+            :model-value="group.exposedToLlm"
+            @update:model-value="(exposed: boolean) => applyExpressionSettingsCommand({ type: 'set-llm-exposed', name: group.name, exposed })"
           />
         </div>
       </div>
 
       <!-- Action buttons -->
       <div mt-4 flex gap-2>
-        <Button @click="expressionStore.saveDefaults()">
+        <Button @click="applyExpressionSettingsCommand({ type: 'save-defaults' })">
           {{ t('settings.live2d.expressions.save-default') }}
         </Button>
-        <Button @click="expressionStore.resetAll()">
+        <Button @click="applyExpressionSettingsCommand({ type: 'reset-all' })">
           {{ t('settings.live2d.expressions.reset') }}
         </Button>
       </div>
diff --git a/packages/stage-ui/src/components/scenarios/settings/model-settings/panel.vue b/packages/stage-ui/src/components/scenarios/settings/model-settings/panel.vue
index 6d88c2593..ad32af9a6 100644
--- a/packages/stage-ui/src/components/scenarios/settings/model-settings/panel.vue
+++ b/packages/stage-ui/src/components/scenarios/settings/model-settings/panel.vue
@@ -4,6 +4,7 @@ import type {
   StageViewPatch,
   StageViewSnapshotPayload,
 } from '@proj-airi/stage-shared/godot-stage'
+import type { Live2DExpressionSettingsCommand } from '@proj-airi/stage-ui-live2d/stores/expression-store'
 
 import type { DisplayModel } from '../../../../stores/display-models'
 import type { ModelSettingsRuntimeSnapshot } from './runtime'
@@ -37,6 +38,7 @@ interface ModelSettingsPanelProps {
 
 interface ModelSettingsPanelEmits {
   extractColorsFromModel: []
+  live2dExpressionCommand: [command: Live2DExpressionSettingsCommand]
   patchGodotViewState: [patch: StageViewPatch]
 }
 
@@ -110,6 +112,7 @@ async function handleModelPick(selectedModel: DisplayModel | undefined) {
         :palette="palette"
         :runtime-snapshot="runtimeSnapshot"
         @extract-colors-from-model="emit('extractColorsFromModel')"
+        @live2d-expression-command="emit('live2dExpressionCommand', $event)"
       />
       <VRM
         v-if="effectiveRenderer === 'vrm'"
diff --git a/packages/stage-ui/src/components/scenarios/settings/model-settings/runtime.ts b/packages/stage-ui/src/components/scenarios/settings/model-settings/runtime.ts
index 8347ede03..f192e9cb4 100644
--- a/packages/stage-ui/src/components/scenarios/settings/model-settings/runtime.ts
+++ b/packages/stage-ui/src/components/scenarios/settings/model-settings/runtime.ts
@@ -1,4 +1,5 @@
 import type { StageAvatarBoundsPayload, StageViewState } from '@proj-airi/stage-shared/godot-stage'
+import type { Live2DExpressionSettingsSnapshot } from '@proj-airi/stage-ui-live2d/stores/expression-store'
 
 import type { StageModelRenderer } from '../../../../stores/settings/stage-model'
 
@@ -7,11 +8,14 @@ export type ModelSettingsRuntimePhase = 'pending' | 'loading' | 'binding' | 'mou
 
 export interface ModelSettingsRuntimeSnapshot {
   ownerInstanceId: string
+  /** Identifies the loaded model state that produced the runtime controls. */
+  modelId: string
   renderer: ModelSettingsRuntimeRenderer
   phase: ModelSettingsRuntimePhase
   controlsLocked: boolean
   previewAvailable: boolean
   canCapturePreview: boolean
+  live2dExpressions?: Live2DExpressionSettingsSnapshot
   lastError?: string
   updatedAt: number
 }
@@ -21,6 +25,7 @@ export function createEmptyModelSettingsRuntimeSnapshot(
 ): ModelSettingsRuntimeSnapshot {
   return {
     ownerInstanceId: '',
+    modelId: '',
     renderer: 'disabled',
     phase: 'pending',
     controlsLocked: false,