diff --git a/apps/memos-local-plugin/adapters/deepseek-harness/index.ts b/apps/memos-local-plugin/adapters/deepseek-harness/index.ts
index 53ab3eec4..5c839f104 100644
--- a/apps/memos-local-plugin/adapters/deepseek-harness/index.ts
+++ b/apps/memos-local-plugin/adapters/deepseek-harness/index.ts
@@ -132,14 +132,15 @@ export function deepSeekHarnessAutoRecoveryEnabled(config: ResolvedConfig): bool
     config.algorithm.lightweightMemory.enabled;
 }
 
-/** Locate the prebuilt Viewer assets in source and packed-package layouts. */
-export function resolveDeepSeekHarnessViewerStaticRoot(): string {
-  const adapterDir = dirname(fileURLToPath(import.meta.url));
-  const candidates = [
-    resolve(adapterDir, "..", "..", "..", "viewer", "dist"),
-    resolve(adapterDir, "..", "..", "viewer", "dist"),
-  ];
-  return candidates.find((candidate) => existsSync(candidate)) ?? candidates[0]!;
+/** Locate Viewer assets without depending on whether they are built yet. */
+export function resolveDeepSeekHarnessViewerStaticRoot(
+  adapterDir: string = dirname(fileURLToPath(import.meta.url)),
+): string {
+  const runtimeRoot = resolve(adapterDir, "..", "..");
+  const pluginRoot = existsSync(resolve(runtimeRoot, "package.json"))
+    ? runtimeRoot
+    : dirname(runtimeRoot);
+  return resolve(pluginRoot, "viewer", "dist");
 }
 
 /** Keep the unauthenticated first-run Viewer strictly on local interfaces. */
diff --git a/apps/memos-local-plugin/tests/unit/adapters/deepseek-harness-viewer.test.ts b/apps/memos-local-plugin/tests/unit/adapters/deepseek-harness-viewer.test.ts
index 5b90c7f83..3b5e9ed98 100644
--- a/apps/memos-local-plugin/tests/unit/adapters/deepseek-harness-viewer.test.ts
+++ b/apps/memos-local-plugin/tests/unit/adapters/deepseek-harness-viewer.test.ts
@@ -1,3 +1,5 @@
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
 import { resolve } from "node:path";
 
 import { afterEach, describe, expect, it, vi } from "vitest";
@@ -233,6 +235,36 @@ describe("DeepSeek Harness Viewer lifecycle", () => {
     expect(runtime.isDeepSeekHarnessViewerLoopbackHost("192.168.1.20")).toBe(false);
   });
 
+  it("resolves Viewer assets deterministically in source and packed layouts", async () => {
+    const runtime = await loadAdapter();
+    const fixtureRoot = mkdtempSync(resolve(tmpdir(), "memos-dsh-viewer-layout-"));
+    // A package root may itself be named `dist`; package.json is the stable
+    // layout marker. Deliberately leave viewer/dist unbuilt, as in clean CI.
+    const packageRoot = resolve(fixtureRoot, "dist");
+    mkdirSync(resolve(packageRoot, "adapters/deepseek-harness"), {
+      recursive: true,
+    });
+    mkdirSync(resolve(packageRoot, "dist/adapters/deepseek-harness"), {
+      recursive: true,
+    });
+    writeFileSync(resolve(packageRoot, "package.json"), "{}\n", "utf8");
+
+    try {
+      expect(
+        runtime.resolveDeepSeekHarnessViewerStaticRoot(
+          resolve(packageRoot, "adapters/deepseek-harness"),
+        ),
+      ).toBe(resolve(packageRoot, "viewer/dist"));
+      expect(
+        runtime.resolveDeepSeekHarnessViewerStaticRoot(
+          resolve(packageRoot, "dist/adapters/deepseek-harness"),
+        ),
+      ).toBe(resolve(packageRoot, "viewer/dist"));
+    } finally {
+      rmSync(fixtureRoot, { recursive: true, force: true });
+    }
+  });
+
   it("starts the bundled Viewer on the DSH-owned loopback endpoint", async () => {
     const lifecycle: string[] = [];
     const runtime = await loadAdapter({ lifecycle });