Invites & Viral Loops

// pages/invite.tsx
import { useEffect } from "react";

const appId = process.env.NEXT_PUBLIC_APP_ID;

export default function InvitePage({ code }: { code: string }) {
	useEffect(() => {
		// Redirect to mini app
		window.location.href = `https://world.org/mini-app?app_id=${appId}&path=${encodeURIComponent(`/invite?code=${code}`)}`
	}, [code])

	return <div>Redirecting to mini app...</div>
}

function generateInviteLink(userId: string): string {
  const baseUrl = "https://world.org/mini-app";
  const appId = "your_app_id";
  const path = encodeURIComponent(`/invite?code=${userId}`);

  return `${baseUrl}?app_id=${appId}&path=${path}`;
}

import { MiniKit } from "@worldcoin/minikit-js";

async function shareInvite() {
  const inviteLink = generateInviteLink(currentUser.id);

  try {
    await MiniKit.share({
      title: "Join me on [Your App Name]!",
      text: `I'm using this amazing mini app. Join me and we both get rewards! 🎁`,
      url: inviteLink,
    });

    // Track the share event
    trackEvent("invite_link_created", {
      user_id: currentUser.id,
      share_method: "native",
    });
  } catch (error) {
    console.error("Share failed:", error);
  }
}

// On app initialization
function handleReferral() {
  const urlParams = new URLSearchParams(window.location.search);
  const refCode = urlParams.get("code");

  if (refCode && !currentUser.referredBy) {
    // Credit the referrer
    fetch("/api/process-referral", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        newUserId: currentUser.id,
        referrerCode: refCode,
      }),
    });
  }
}

// api/process-referral.ts
export async function processReferral(data: {
  newUserId: string;
  referrerCode: string;
}) {
  // Require a stored World ID nullifier for newUserId, set when they verified
  // with IDKit — not a Wallet Auth session, which only proves wallet control.
  if (!(await hasVerifiedWorldId(data.newUserId))) {
    return { success: false, reason: "unverified_user" };
  }

  const referrer = await getUserByCode(data.referrerCode);
  if (!referrer) {
    return { success: false, reason: "invalid_referrer" };
  }

  if (referrer.id === data.newUserId) {
    return { success: false, reason: "self_referral" };
  }

  // Atomically claim the referral (e.g. INSERT ... ON CONFLICT DO NOTHING on
  // a unique referred_user_id column), then read back the stored referrer. If
  // two requests race, only one INSERT succeeds.
  const claimedBy = await claimReferral(data.newUserId, referrer.id);
  if (claimedBy !== referrer.id) {
    return { success: false, reason: "already_referred" };
  }

  // Credit both users. Each credit has its own idempotency key (unique in your
  // credits table; treat a duplicate as success), so retrying processReferral
  // after a partial failure writes only the missing credit.
  await Promise.all([
    creditUser(referrer.id, {
      type: "referral_bonus",
      amount: 100,
      reason: "Friend joined via your invite",
      idempotencyKey: `referral:${data.newUserId}:referrer`,
    }),
    creditUser(data.newUserId, {
      type: "signup_bonus",
      amount: 50,
      reason: "Welcome bonus for joining via invite",
      idempotencyKey: `referral:${data.newUserId}:referee`,
    }),
  ]);

  return { success: true };
}

https://play.google.com/store/apps/details?id=com.worldcoin&referrer=app_id%3D{app_id}%26path%3D{path}

// Essential tracking events
const events = {
  invite_link_created: { user_id, share_method },
  invite_link_clicked: { ref_code, source },
  signup_source_invite: { ref_code, new_user_id },
  referral_reward_granted: { referrer_id, new_user_id, reward_amount },
};