diff --git a/.changeset/calm-bridges-build.md b/.changeset/calm-bridges-build.md
new file mode 100644
index 000000000000..a24f99771a6e
--- /dev/null
+++ b/.changeset/calm-bridges-build.md
@@ -0,0 +1,5 @@
+---
+'@ai-sdk/harness-claude-code': patch
+---
+
+fix(harness-claude-code): avoid invalid bridge asset paths in bundled applications
diff --git a/packages/harness-claude-code/src/claude-code-bootstrap.test.ts b/packages/harness-claude-code/src/claude-code-bootstrap.test.ts
new file mode 100644
index 000000000000..777953ee572c
--- /dev/null
+++ b/packages/harness-claude-code/src/claude-code-bootstrap.test.ts
@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest';
+import { resolveBridgeAssetUrl } from './claude-code-bootstrap';
+
+describe('resolveBridgeAssetUrl', () => {
+  it('resolves bridge assets beside source and bundled modules', () => {
+    const sourceModuleUrl = new URL(
+      './claude-code-bootstrap.ts',
+      import.meta.url,
+    );
+    const bundledModuleUrl = new URL('../dist/index.js', import.meta.url);
+
+    expect(
+      resolveBridgeAssetUrl({
+        name: 'package.json',
+        moduleUrl: sourceModuleUrl,
+      }),
+    ).toEqual(new URL('./bridge/package.json', import.meta.url));
+    expect(
+      resolveBridgeAssetUrl({
+        name: 'package.json',
+        moduleUrl: bundledModuleUrl,
+      }),
+    ).toEqual(new URL('../dist/bridge/package.json', import.meta.url));
+  });
+});
diff --git a/packages/harness-claude-code/src/claude-code-bootstrap.ts b/packages/harness-claude-code/src/claude-code-bootstrap.ts
index 7a45beb9f301..452dc5bf53a6 100644
--- a/packages/harness-claude-code/src/claude-code-bootstrap.ts
+++ b/packages/harness-claude-code/src/claude-code-bootstrap.ts
@@ -51,19 +51,23 @@ export async function getClaudeCodeBootstrap(): Promise<HarnessV1Bootstrap> {
 }
 
 async function readBridgeAsset(name: string): Promise<string> {
-  const candidates = [
-    new URL(`./bridge/${name}`, import.meta.url),
-    new URL(`../bridge/${name}`, import.meta.url),
-  ];
-  let lastErr: unknown;
-  for (const url of candidates) {
-    try {
-      return await readFile(fileURLToPath(url), 'utf8');
-    } catch (err) {
-      const code = (err as NodeJS.ErrnoException).code;
-      if (code !== 'ENOENT') throw err;
-      lastErr = err;
-    }
-  }
-  throw lastErr ?? new Error(`bridge asset not found: ${name}`);
+  return readFile(
+    fileURLToPath(
+      resolveBridgeAssetUrl({
+        name,
+        moduleUrl: import.meta.url,
+      }),
+    ),
+    'utf8',
+  );
+}
+
+export function resolveBridgeAssetUrl({
+  name,
+  moduleUrl,
+}: {
+  name: string;
+  moduleUrl: string | URL;
+}): URL {
+  return new URL(`./bridge/${name}`, moduleUrl);
 }