Add billing / payments

Wire Stripe to Convex using @convex-dev/stripe: a checkout action, an httpAction webhook registered by the component (signature-verified automatically), subscription state stored in the component's tables, and server-side gating via a query.

Steps

1. Install the component: npm install @convex-dev/stripe.
2. Create convex/convex.config.ts:

``ts import { defineApp } from 'convex/server'; import stripe from '@convex-dev/stripe/convex.config.js'; const app = defineApp(); app.use(stripe); export default app; ``

1. Store Stripe keys in Convex env (use the env micro power): STRIPESECRETKEY (sktest… / sklive…) and STRIPEWEBHOOKSECRET (whsec_…).
2. Create convex/http.ts to register the webhook route (the component handles signature verification automatically):

``ts import { httpRouter } from 'convex/server'; import { components } from './_generated/api'; import { registerRoutes } from '@convex-dev/stripe'; const http = httpRouter(); registerRoutes(http, components.stripe, { webhookPath: '/stripe/webhook' }); export default http; ``

1. Create convex/billing.ts with a checkout action and a subscription-gate query:

``ts import { action, query } from './generated/server'; import { components } from './generated/api'; import { StripeSubscriptions } from '@convex-dev/stripe'; import { v } from 'convex/values'; const stripeClient = new StripeSubscriptions(components.stripe, {}); export const createSubscriptionCheckout = action({ args: { priceId: v.string() }, returns: v.object({ sessionId: v.string(), url: v.union(v.string(), v.null()) }), handler: async (ctx, args) => { const identity = await ctx.auth.getUserIdentity(); if (!identity) throw new Error('Not authenticated'); const customer = await stripeClient.getOrCreateCustomer(ctx, { userId: identity.subject, email: identity.email, name: identity.name }); return await stripeClient.createCheckoutSession(ctx, { priceId: args.priceId, customerId: customer.customerId, mode: 'subscription', successUrl: ${process.env.SITEURL ?? 'http://localhost:3000'}/?success=true, cancelUrl: ${process.env.SITEURL ?? 'http://localhost:3000'}/?canceled=true, subscriptionMetadata: { userId: identity.subject } }); }, }); export const isSubscribed = query({ args: {}, returns: v.boolean(), handler: async (ctx) => { const identity = await ctx.auth.getUserIdentity(); if (!identity) return false; const subscriptions = await ctx.runQuery(components.stripe.public.listSubscriptionsByUserId, { userId: identity.subject }); return subscriptions.some((sub) => sub.status === 'active' || sub.status === 'trialing'); }, }); ``

1. Run npx convex dev --once — it will install the component and push the functions. Verify output shows ✔ Installed component stripe.
2. In Stripe Dashboard → Webhooks: add endpoint https://<deployment>.convex.site/stripe/webhook, subscribe to checkout.session.completed, customer.subscription., invoice., paymentintent.*. Copy the signing secret as STRIPEWEBHOOK_SECRET.

Rules

• Use @convex-dev/stripe (npm: @convex-dev/stripe@^0.1.4) — it handles webhook signature verification internally via registerRoutes; do NOT write a manual constructEvent webhook.
• Stripe keys live in Convex env (use the env micro power): STRIPESECRETKEY and STRIPEWEBHOOKSECRET.
• Gate on server-stored subscription state via isSubscribed query (reads component tables), not client claims.
• convex/convex.config.ts must import from '@convex-dev/stripe/convex.config.js' (not .ts) — the .js extension is required by the Convex bundler.