diff --git a/package.json b/package.json
index 22caa16..e4f68cc 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
     "docs:build": "vitepress build docs",
     "docs:preview": "vitepress preview docs --host 0.0.0.0 --port 4173 --strictPort",
     "test:config": "pnpm run build && node --test dist/config/config.test.js",
-    "test:core": "pnpm run build && node --test dist/cli/args.test.js dist/cli/help.test.js dist/core/services/cli-command-service.test.js dist/core/services/cli-command-deps-runtime-service.test.js dist/core/services/ipc-deps-runtime-service.test.js dist/core/services/anki-jimaku-ipc-deps-runtime-service.test.js dist/core/services/field-grouping-overlay-runtime-service.test.js dist/core/services/numeric-shortcut-session-service.test.js dist/core/services/secondary-subtitle-service.test.js dist/core/services/mpv-render-metrics-service.test.js dist/core/services/mpv-runtime-service.test.js dist/core/services/runtime-options-runtime-service.test.js dist/core/services/overlay-modal-restore-service.test.js dist/core/services/runtime-config-service.test.js dist/core/services/overlay-bridge-runtime-service.test.js dist/core/services/overlay-visibility-facade-service.test.js dist/core/services/overlay-broadcast-runtime-service.test.js dist/core/services/app-ready-runtime-service.test.js dist/core/services/app-shutdown-runtime-service.test.js dist/core/services/mpv-client-deps-runtime-service.test.js dist/core/services/app-lifecycle-deps-runtime-service.test.js dist/core/services/runtime-options-manager-runtime-service.test.js dist/core/services/config-warning-runtime-service.test.js dist/core/services/app-logging-runtime-service.test.js dist/core/services/startup-resource-runtime-service.test.js dist/core/services/config-generation-runtime-service.test.js",
+    "test:core": "pnpm run build && node --test dist/cli/args.test.js dist/cli/help.test.js dist/core/services/cli-command-service.test.js dist/core/services/cli-command-deps-runtime-service.test.js dist/core/services/ipc-deps-runtime-service.test.js dist/core/services/anki-jimaku-ipc-deps-runtime-service.test.js dist/core/services/field-grouping-overlay-runtime-service.test.js dist/core/services/subsync-deps-runtime-service.test.js dist/core/services/numeric-shortcut-session-service.test.js dist/core/services/secondary-subtitle-service.test.js dist/core/services/mpv-render-metrics-service.test.js dist/core/services/mpv-runtime-service.test.js dist/core/services/runtime-options-runtime-service.test.js dist/core/services/overlay-modal-restore-service.test.js dist/core/services/runtime-config-service.test.js dist/core/services/overlay-bridge-runtime-service.test.js dist/core/services/overlay-visibility-facade-service.test.js dist/core/services/overlay-broadcast-runtime-service.test.js dist/core/services/app-ready-runtime-service.test.js dist/core/services/app-shutdown-runtime-service.test.js dist/core/services/mpv-client-deps-runtime-service.test.js dist/core/services/app-lifecycle-deps-runtime-service.test.js dist/core/services/runtime-options-manager-runtime-service.test.js dist/core/services/config-warning-runtime-service.test.js dist/core/services/app-logging-runtime-service.test.js dist/core/services/startup-resource-runtime-service.test.js dist/core/services/config-generation-runtime-service.test.js",
     "test:subtitle": "pnpm run build && node --test dist/subtitle/stages.test.js dist/subtitle/pipeline.test.js",
     "generate:config-example": "pnpm run build && node dist/generate-config-example.js",
     "start": "pnpm run build && electron . --start",
diff --git a/src/core/services/subsync-deps-runtime-service.test.ts b/src/core/services/subsync-deps-runtime-service.test.ts
new file mode 100644
index 0000000..d0c9200
--- /dev/null
+++ b/src/core/services/subsync-deps-runtime-service.test.ts
@@ -0,0 +1,37 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { createSubsyncRuntimeDepsService } from "./subsync-deps-runtime-service";
+
+test("createSubsyncRuntimeDepsService opens manual picker via visible overlay", () => {
+  let inProgress = false;
+  const calls: Array<{ channel: string; payload?: unknown; restore?: string }> = [];
+
+  const deps = createSubsyncRuntimeDepsService({
+    getMpvClient: () => null,
+    getResolvedSubsyncConfig: () => ({
+      defaultMode: "auto",
+      ffsubsyncPath: "/usr/bin/ffsubsync",
+      alassPath: "/usr/bin/alass",
+      ffmpegPath: "/usr/bin/ffmpeg",
+    }),
+    isSubsyncInProgress: () => inProgress,
+    setSubsyncInProgress: (next) => {
+      inProgress = next;
+    },
+    showMpvOsd: () => {},
+    sendToVisibleOverlay: (channel, payload, options) => {
+      calls.push({ channel, payload, restore: options?.restoreOnModalClose });
+      return true;
+    },
+  });
+
+  deps.setSubsyncInProgress(true);
+  deps.openManualPicker({
+    sourceTracks: [{ id: 1, label: "Japanese Track" }],
+  });
+
+  assert.equal(deps.isSubsyncInProgress(), true);
+  assert.equal(calls.length, 1);
+  assert.equal(calls[0]?.channel, "subsync:open-manual");
+  assert.equal(calls[0]?.restore, "subsync");
+});
diff --git a/src/core/services/subsync-deps-runtime-service.ts b/src/core/services/subsync-deps-runtime-service.ts
new file mode 100644
index 0000000..b9b171e
--- /dev/null
+++ b/src/core/services/subsync-deps-runtime-service.ts
@@ -0,0 +1,44 @@
+import {
+  SubsyncManualPayload,
+} from "../../types";
+import {
+  SubsyncRuntimeDeps,
+} from "./subsync-runtime-service";
+import { SubsyncResolvedConfig } from "../../subsync/utils";
+
+interface MpvClientLike {
+  connected: boolean;
+  currentAudioStreamIndex: number | null;
+  send: (payload: { command: (string | number)[] }) => void;
+  requestProperty: (name: string) => Promise<unknown>;
+}
+
+export interface SubsyncDepsRuntimeOptions {
+  getMpvClient: () => MpvClientLike | null;
+  getResolvedSubsyncConfig: () => SubsyncResolvedConfig;
+  isSubsyncInProgress: () => boolean;
+  setSubsyncInProgress: (inProgress: boolean) => void;
+  showMpvOsd: (text: string) => void;
+  sendToVisibleOverlay: (
+    channel: string,
+    payload?: unknown,
+    options?: { restoreOnModalClose?: "runtime-options" | "subsync" },
+  ) => boolean;
+}
+
+export function createSubsyncRuntimeDepsService(
+  options: SubsyncDepsRuntimeOptions,
+): SubsyncRuntimeDeps {
+  return {
+    getMpvClient: options.getMpvClient,
+    getResolvedSubsyncConfig: options.getResolvedSubsyncConfig,
+    isSubsyncInProgress: options.isSubsyncInProgress,
+    setSubsyncInProgress: options.setSubsyncInProgress,
+    showMpvOsd: options.showMpvOsd,
+    openManualPicker: (payload: SubsyncManualPayload) => {
+      options.sendToVisibleOverlay("subsync:open-manual", payload, {
+        restoreOnModalClose: "subsync",
+      });
+    },
+  };
+}
diff --git a/src/main.ts b/src/main.ts
index e472e3e..4c0fbd9 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -59,7 +59,6 @@ import {
   Keybinding,
   WindowGeometry,
   SecondarySubMode,
-  SubsyncManualPayload,
   SubsyncManualRunRequest,
   SubsyncResult,
   KikuFieldGroupingChoice,
@@ -205,6 +204,7 @@ import { createCliCommandDepsRuntimeService } from "./core/services/cli-command-
 import { createIpcDepsRuntimeService } from "./core/services/ipc-deps-runtime-service";
 import { createAnkiJimakuIpcDepsRuntimeService } from "./core/services/anki-jimaku-ipc-deps-runtime-service";
 import { createFieldGroupingOverlayRuntimeService } from "./core/services/field-grouping-overlay-runtime-service";
+import { createSubsyncRuntimeDepsService } from "./core/services/subsync-deps-runtime-service";
 import { createRuntimeOptionsManagerRuntimeService } from "./core/services/runtime-options-manager-runtime-service";
 import { createAppLoggingRuntimeService } from "./core/services/app-logging-runtime-service";
 import {
@@ -978,7 +978,7 @@ const mineSentenceSession = createNumericShortcutSessionService({
 });
 
 function getSubsyncRuntimeDeps() {
-  return {
+  return createSubsyncRuntimeDepsService({
     getMpvClient: () => mpvClient,
     getResolvedSubsyncConfig: () => getSubsyncConfig(getResolvedConfig().subsync),
     isSubsyncInProgress: () => subsyncInProgress,
@@ -986,12 +986,9 @@ function getSubsyncRuntimeDeps() {
       subsyncInProgress = inProgress;
     },
     showMpvOsd: (text: string) => showMpvOsd(text),
-    openManualPicker: (payload: SubsyncManualPayload) => {
-      sendToVisibleOverlay("subsync:open-manual", payload, {
-        restoreOnModalClose: "subsync",
-      });
-    },
-  };
+    sendToVisibleOverlay: (channel, payload, options) =>
+      sendToVisibleOverlay(channel, payload, options),
+  });
 }
 
 async function triggerSubsyncFromConfig(): Promise<void> {