diff --git a/apps/web/src/utils/__tests__/document-assets.test.ts b/apps/web/src/utils/__tests__/document-assets.test.ts
index 50f70b703..b5a601044 100644
--- a/apps/web/src/utils/__tests__/document-assets.test.ts
+++ b/apps/web/src/utils/__tests__/document-assets.test.ts
@@ -110,6 +110,24 @@ describe('document asset paths', () => {
     expect(isLocalAssetPath('data:image/png;base64,abc')).toBe(false);
   });
 
+  it('treats same-origin server routes as external (no local-asset wrap)', () => {
+    // Regression: the image-search pipeline returns thumbUrls as
+    // `/api/ai/image-proxy?url=...`. Without this carve-out the
+    // resolver wraps that path through the local-asset bridge and
+    // produces a broken double-wrapped URL like
+    // `/api/local-asset?path=%2Fapi%2Fai%2Fimage-proxy%3Furl%3D...`
+    // which 404s because the local-asset handler can't dispatch on
+    // a route that isn't a real file path. `/api/...` and `/_/...`
+    // are runtime endpoints, not file system assets.
+    expect(isLocalAssetPath('/api/ai/image-proxy?url=https%3A%2F%2Fa.com%2Fb.jpg')).toBe(false);
+    expect(isLocalAssetPath('/api/local-asset?path=foo')).toBe(false);
+    expect(isLocalAssetPath('/_/static/icon.svg')).toBe(false);
+    // Non-API absolute paths are still treated as local file paths
+    // — `/assets/hero.png` could legitimately be a unix-style asset
+    // path embedded in a .pen file.
+    expect(isLocalAssetPath('/assets/hero.png')).toBe(true);
+  });
+
   it('bridges local assets through the app origin when running over http', () => {
     const originalWindow = globalThis.window;
     Object.defineProperty(globalThis, 'window', {
diff --git a/apps/web/src/utils/document-assets.ts b/apps/web/src/utils/document-assets.ts
index 0b1c49bba..39dd61f94 100644
--- a/apps/web/src/utils/document-assets.ts
+++ b/apps/web/src/utils/document-assets.ts
@@ -2,6 +2,15 @@ const EXTERNAL_ASSET_RE = /^(?:data:|https?:|blob:)/i;
 const FILE_URL_RE = /^file:\/\//i;
 const HTTP_PROTOCOL_RE = /^https?:$/i;
 const LOCAL_IMAGE_EXT_RE = /\.(?:png|jpe?g|gif|webp|bmp|svg|avif)$/i;
+// Same-origin server routes the dev server / Nitro serves directly.
+// These are NOT file-system asset paths — they're runtime endpoints
+// (`/api/ai/image-proxy?url=...`, `/api/local-asset?path=...`, etc).
+// Without this carve-out the asset resolver treats them as local
+// file paths and double-wraps them through `/api/local-asset`,
+// producing a broken `/api/local-asset?path=%2Fapi%2Fai%2Fimage-proxy%3F...`
+// URL that only the local-asset handler can dispatch on, which then
+// 404s because `/api/ai/image-proxy?...` isn't a real file path.
+const SAME_ORIGIN_ROUTE_RE = /^\/(?:api|_)\//;
 
 export interface RuntimeAssetSource {
   sourcePath: string | null;
@@ -12,7 +21,10 @@ export interface RuntimeAssetSource {
 
 export function isLocalAssetPath(assetPath: string | null | undefined): boolean {
   if (!assetPath) return false;
-  return !EXTERNAL_ASSET_RE.test(assetPath.trim());
+  const trimmed = assetPath.trim();
+  if (EXTERNAL_ASSET_RE.test(trimmed)) return false;
+  if (SAME_ORIGIN_ROUTE_RE.test(trimmed)) return false;
+  return true;
 }
 
 export function resolveRuntimeAssetSource(