Stripe · Twilio · SendGrid

What it is

Stripe for billing and subscriptions; Twilio for SMS, WhatsApp and voice; SendGrid for transactional + marketing email. The trio that powers commerce in every modern AI product.

How Vaaani uses it

• Subscription billing with metered AI usage (per-token, per-call)
• WhatsApp AI agents with media + button responses
• OTP / 2FA via SMS
• Drip email sequences triggered by AI-detected events

Why it makes the cut

Reinventing payments or telephony is a months-long mistake. These three give you 90% of every AI-product's commercial layer in days.

Sample code

const stripe = require("stripe")(process.env.STRIPE_SECRET);

const sub = await stripe.subscriptions.create({
  customer: customerId,
  items: [{ price: "price_ai_pro" }],
  metadata: { workspace: "acme" },
});