diff --git a/tests/e2e/helpers/api.ts b/tests/e2e/helpers/api.ts
index a00cb88..ca0f998 100644
--- a/tests/e2e/helpers/api.ts
+++ b/tests/e2e/helpers/api.ts
@@ -43,6 +43,8 @@ export interface RadioConfig {
   cr: number;
 }
 
+export type RadioAdvertMode = 'flood' | 'zero_hop';
+
 export function getRadioConfig(): Promise<RadioConfig> {
   return fetchJson('/radio/config');
 }
@@ -58,6 +60,13 @@ export function rebootRadio(): Promise<{ status: string; message: string }> {
   return fetchJson('/radio/reboot', { method: 'POST' });
 }
 
+export function sendAdvertisement(mode: RadioAdvertMode = 'flood'): Promise<{ status: string }> {
+  return fetchJson('/radio/advertise', {
+    method: 'POST',
+    body: JSON.stringify({ mode }),
+  });
+}
+
 // --- Channels ---
 
 export interface Channel {
@@ -128,6 +137,22 @@ export function deleteContact(publicKey: string): Promise<{ status: string }> {
   return fetchJson(`/contacts/${publicKey}`, { method: 'DELETE' });
 }
 
+export async function getContactByKey(publicKey: string): Promise<Contact | undefined> {
+  const normalized = publicKey.toLowerCase();
+  const contacts = await getContacts(500, 0);
+  return contacts.find((contact) => contact.public_key.toLowerCase() === normalized);
+}
+
+export function setContactRoutingOverride(
+  publicKey: string,
+  route: string
+): Promise<{ status: string; public_key: string }> {
+  return fetchJson(`/contacts/${publicKey}/routing-override`, {
+    method: 'POST',
+    body: JSON.stringify({ route }),
+  });
+}
+
 // --- Messages ---
 
 export interface MessagePath {
diff --git a/tests/e2e/specs/dev-flightless-direct-route.spec.ts b/tests/e2e/specs/dev-flightless-direct-route.spec.ts
new file mode 100644
index 0000000..fd48b5a
--- /dev/null
+++ b/tests/e2e/specs/dev-flightless-direct-route.spec.ts
@@ -0,0 +1,135 @@
+import { test, expect } from '@playwright/test';
+import {
+  createContact,
+  deleteContact,
+  getContactByKey,
+  getMessages,
+  setContactRoutingOverride,
+} from '../helpers/api';
+
+const DEV_ONLY_ENV = 'MESHCORE_ENABLE_DEV_FLIGHTLESS_ROUTE_E2E';
+const FLIGHTLESS_NAME = 'FlightlessDt🥝';
+const FLIGHTLESS_PUBLIC_KEY =
+  'ae92577bae6c269a1da3c87b5333e1bdb007e372b66e94204b9f92a6b52a62b1';
+const DEVELOPER_ONLY_NOTICE =
+  `Developer-only hardware test. This scenario assumes ${FLIGHTLESS_NAME} ` +
+  `(${FLIGHTLESS_PUBLIC_KEY.slice(0, 12)}...) is a nearby reachable node for the author's test radio. ` +
+  `Set ${DEV_ONLY_ENV}=1 to run it intentionally.`;
+
+function escapeRegex(value: string): string {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+test.describe('Developer-only direct-route learning for FlightlessDt🥝', () => {
+  test('zero-hop adverts then DM ACK learns a direct route', { tag: '@developer-only' }, async ({
+    page,
+  }, testInfo) => {
+    testInfo.annotations.push({ type: 'notice', description: DEVELOPER_ONLY_NOTICE });
+    if (process.env[DEV_ONLY_ENV] !== '1') {
+      test.skip(true, DEVELOPER_ONLY_NOTICE);
+    }
+
+    test.setTimeout(180_000);
+    console.warn(`[developer-only e2e] ${DEVELOPER_ONLY_NOTICE}`);
+
+    try {
+      await deleteContact(FLIGHTLESS_PUBLIC_KEY);
+    } catch {
+      // Best-effort reset; the contact may not exist yet in the temp E2E DB.
+    }
+
+    await createContact(FLIGHTLESS_PUBLIC_KEY, FLIGHTLESS_NAME);
+    await setContactRoutingOverride(FLIGHTLESS_PUBLIC_KEY, '');
+
+    await expect
+      .poll(
+        async () => {
+          const contact = await getContactByKey(FLIGHTLESS_PUBLIC_KEY);
+          return contact?.direct_path_len ?? null;
+        },
+        {
+          timeout: 10_000,
+          message: 'Waiting for recreated FlightlessDt contact to start in flood mode',
+        }
+      )
+      .toBe(-1);
+
+    await page.goto('/#settings/radio');
+    await expect(page.getByRole('status', { name: 'Radio OK' })).toBeVisible();
+
+    const zeroHopButton = page.getByRole('button', { name: 'Send Zero-Hop Advertisement' });
+    await expect(zeroHopButton).toBeVisible();
+
+    await zeroHopButton.click();
+    await expect(page.getByText('Zero-hop advertisement sent')).toBeVisible({ timeout: 15_000 });
+
+    await page.waitForTimeout(5_000);
+
+    await zeroHopButton.click();
+    await expect(page.getByText('Zero-hop advertisement sent')).toBeVisible({ timeout: 15_000 });
+
+    await page.getByRole('button', { name: /Back to Chat/i }).click();
+    await expect(page.getByRole('button', { name: /Back to Chat/i })).toBeHidden({
+      timeout: 15_000,
+    });
+
+    const searchInput = page.getByLabel('Search conversations');
+    await searchInput.fill(FLIGHTLESS_PUBLIC_KEY.slice(0, 12));
+    await expect(page.getByText(FLIGHTLESS_NAME, { exact: true })).toBeVisible({
+      timeout: 15_000,
+    });
+    await page.getByText(FLIGHTLESS_NAME, { exact: true }).click();
+    await expect
+      .poll(() => page.url(), {
+        timeout: 15_000,
+        message: 'Waiting for FlightlessDt conversation route to load',
+      })
+      .toContain(`#contact/${encodeURIComponent(FLIGHTLESS_PUBLIC_KEY)}`);
+    await expect(
+      page.getByPlaceholder(new RegExp(`message\\s+${escapeRegex(FLIGHTLESS_NAME)}`, 'i'))
+    ).toBeVisible({ timeout: 15_000 });
+
+    const text = `dev-flightless-direct-${Date.now()}`;
+    const input = page.getByPlaceholder(/message/i);
+    await input.fill(text);
+    await page.getByRole('button', { name: 'Send', exact: true }).click();
+    await expect(page.getByText(text)).toBeVisible({ timeout: 15_000 });
+
+    await expect
+      .poll(
+        async () => {
+          const messages = await getMessages({
+            type: 'PRIV',
+            conversation_key: FLIGHTLESS_PUBLIC_KEY,
+            limit: 25,
+          });
+          const match = messages.find((message) => message.outgoing && message.text === text);
+          return match?.acked ?? 0;
+        },
+        {
+          timeout: 90_000,
+          message: 'Waiting for FlightlessDt DM ACK',
+        }
+      )
+      .toBeGreaterThan(0);
+
+    await expect
+      .poll(
+        async () => {
+          const contact = await getContactByKey(FLIGHTLESS_PUBLIC_KEY);
+          return contact?.direct_path_len ?? null;
+        },
+        {
+          timeout: 90_000,
+          message: 'Waiting for FlightlessDt route to update from flood to direct',
+        }
+      )
+      .toBe(0);
+
+    const learnedContact = await getContactByKey(FLIGHTLESS_PUBLIC_KEY);
+    expect(learnedContact?.direct_path ?? '').toBe('');
+
+    await page.locator('[title="View contact info"]').click();
+    await expect(page.getByLabel('Contact Info')).toBeVisible({ timeout: 15_000 });
+  });
+});