diff --git a/server/src/__tests__/server-startup-feedback-export.test.ts b/server/src/__tests__/server-startup-feedback-export.test.ts
index 78565645..e1efd6a8 100644
--- a/server/src/__tests__/server-startup-feedback-export.test.ts
+++ b/server/src/__tests__/server-startup-feedback-export.test.ts
@@ -171,3 +171,27 @@ describe("startServer feedback export wiring", () => {
     });
   });
 });
+
+describe("startServer PAPERCLIP_API_URL handling", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    process.env.BETTER_AUTH_SECRET = "test-secret";
+    delete process.env.PAPERCLIP_API_URL;
+  });
+
+  it("uses the externally set PAPERCLIP_API_URL when provided", async () => {
+    process.env.PAPERCLIP_API_URL = "http://custom-api:3100";
+
+    const started = await startServer();
+
+    expect(started.apiUrl).toBe("http://custom-api:3100");
+    expect(process.env.PAPERCLIP_API_URL).toBe("http://custom-api:3100");
+  });
+
+  it("falls back to host-based URL when PAPERCLIP_API_URL is not set", async () => {
+    const started = await startServer();
+
+    expect(started.apiUrl).toBe("http://127.0.0.1:3210");
+    expect(process.env.PAPERCLIP_API_URL).toBe("http://127.0.0.1:3210");
+  });
+});