diff --git a/DEMO.md b/DEMO.md
new file mode 100644
index 0000000..4de07e0
--- /dev/null
+++ b/DEMO.md
@@ -0,0 +1,36 @@
+Prompt 1:
+
+You're testing a web app by hand, using your browser tool. Don't write any code.
+
+App: https://deploy-preview-10--endform-playwright-tutorial.netlify.app
+
+1. Go to `/sign-up` and create an account with a made-up email like `demo-<random>@example.com` and the password `testpassword123`.
+2. On the Team Settings page (`/dashboard`), invite a teammate using another made-up email, with the Member role, and wait for "Invitation sent successfully".
+3. Open the Activity page from the sidebar.
+4. Check that the newest (top) entry says "You invited a team member".
+
+Report PASS or FAIL. Describe exactly what you saw at each step, including the full list of entries on the Activity page.
+
+Prompt 2:
+
+In this repo (branch `demo/invite-activity-after-response`), write a new Playwright test at `tests/team-invite-activity.live.spec.ts`. Explore the app first, using existing tests and functionality through an endform live test.
+
+- Start a session inside an existing test that already has a logged-in new user: `tests/duplicate-invite.spec.ts` or similar using endform live test.
+- Step through the scenario one action at a time. To expore and figure out which playwright code makes sense for the test.
+  - invite a teammate from the Team Settings page (`/dashboard`);
+  - wait for "Invitation sent successfully";
+  - open the Activity page from the sidebar;
+  - check that the newest entry is "You invited a team member".
+- Once every step has worked live, stop the session and create a nice new playwright test for this flow.
+- Follow the suite's conventions: the `testWithNewUser` fixture from `tests/test-with-new-user.ts`, `test.step` blocks, role-based locators, and a unique invite email per run.
+- Finish by running it once with `npx endform test team-invite-activity.live`.
+
+Next commands:
+
+p playwright test team-invite-activity --debug --no-deps
+
+p endform test team-invite-activity --repeat-each=100 --no-deps
+
+Then ask:
+
+look at `team-invite-activity` playwright/endform runs from the last hour. What's the pass rate, and what's the most common failure? Is it a bug in the app or noise in the test?
diff --git a/app/(login)/actions.ts b/app/(login)/actions.ts
index f22b1cf..41f9906 100644
--- a/app/(login)/actions.ts
+++ b/app/(login)/actions.ts
@@ -3,6 +3,7 @@
 import { and, eq } from "drizzle-orm";
 import { cookies } from "next/headers";
 import { redirect } from "next/navigation";
+import { after } from "next/server";
 import { z } from "zod";
 import { logActivity } from "@/lib/auth/activity";
 import { signup } from "@/lib/auth/login";
@@ -22,6 +23,7 @@ import {
 	type User,
 	users,
 } from "@/lib/db/schema";
+import { sendInvitationEmail } from "@/lib/email";
 import { isFaultActive } from "@/lib/faults";
 
 const signInSchema = z.object({
@@ -365,14 +367,13 @@ export const inviteTeamMember = validatedActionWithUser(
 			})
 			.returning();
 
-		await logActivity(
-			userWithTeam.teamId,
-			user.id,
-			ActivityType.INVITE_TEAM_MEMBER,
-		);
-
-		// TODO: Send invitation email and include ?inviteId={id} to sign-up URL
-		// await sendInvitationEmail(email, userWithTeam.team.name, role)
+		// Email the invitee and log the invite once the response has been sent,
+		// so inviting feels instant.
+		const teamId = userWithTeam.teamId;
+		after(async () => {
+			await sendInvitationEmail(email, role);
+			await logActivity(teamId, user.id, ActivityType.INVITE_TEAM_MEMBER);
+		});
 
 		return { success: "Invitation sent successfully", id: invitation[0].id };
 	},
diff --git a/endform.config.ts b/endform.config.ts
new file mode 100644
index 0000000..d087c33
--- /dev/null
+++ b/endform.config.ts
@@ -0,0 +1,5 @@
+import { defineEndformConfig } from "endform";
+
+export default defineEndformConfig({
+	organizationId: "68prmZ74",
+});
diff --git a/lib/email.ts b/lib/email.ts
new file mode 100644
index 0000000..fc7dc8a
--- /dev/null
+++ b/lib/email.ts
@@ -0,0 +1,14 @@
+import "server-only";
+
+// Stand-in for a transactional email provider. Most sends are quick but, like
+// most third-party APIs, it has a slow tail.
+export async function sendInvitationEmail(email: string, role: string) {
+	const latencyMs =
+		Math.random() < 0.15
+			? 6000 + Math.random() * 3000
+			: 50 + Math.random() * 100;
+	await new Promise((resolve) => setTimeout(resolve, latencyMs));
+	console.log(
+		`[email] sent ${role} invitation to ${email} in ${Math.round(latencyMs)}ms`,
+	);
+}
diff --git a/playwright.config.ts b/playwright.config.ts
index 4b54bbc..5b1f26f 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -10,7 +10,8 @@ import type { PlaywrightOpentelemetryUseOptions } from "playwright-opentelemetry
 // dotenv.config({ path: path.resolve(__dirname, '.env') });
 
 export const baseURL =
-	process.env.BASE_URL || "https://endform-playwright-tutorial.vercel.app";
+	process.env.BASE_URL ||
+	"https://deploy-preview-10--endform-playwright-tutorial.netlify.app";
 
 const playwrightOtelEnabled = Boolean(
 	process.env.PLAYWRIGHT_TRACE_API_ENDPOINT ||
@@ -47,7 +48,9 @@ export default defineConfig<PlaywrightOpentelemetryUseOptions>({
 		// baseURL: "http://localhost:3000",
 
 		/* Collect trace when retrying the failed test. See https://playwright.dev/docs/trace-viewer */
-		trace: playwrightOtelEnabled ? "on" : "retain-on-failure",
+		// trace: playwrightOtelEnabled ? "on" : "retain-on-failure",
+		trace: "on",
+		// trace: "retain-on-failure",
 		playwrightOpentelemetry: playwrightOtelEnabled
 			? {
 					trace: "on",