feat(GRO-608): Add Stripe webhook handler for payment events

- Add POST /api/webhooks/stripe endpoint for Stripe event processing
- Handle payment_intent.succeeded: mark invoice as paid, set paymentMethod=card
- Handle payment_intent.payment_failed: record failure reason on invoice
- Handle charge.refunded: mark invoice as void
- Handle charge.dispute.created: log dispute
- Idempotency: skip if stripePaymentIntentId already recorded
- Add stripe_payment_intent_id, stripe_refund_id, payment_failure_reason columns
- Requires STRIPE_WEBHOOK_SECRET env var for signature verification

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/package.json

@@ -22,6 +22,7 @@
     "hono": "^4.6.17",
     "node-cron": "^3.0.3",
     "nodemailer": "^6.9.16",
+    "stripe": "^22.0.0",
     "zod": "^4.3.6"
   },
   "devDependencies": {

apps/api/src/index.ts

@@ -28,6 +28,7 @@ import { resolveStaffMiddleware, requireRole, requireRoleOrSuperUser, requireSup
 import { devRouter } from "./routes/dev.js";
 import { adminSeedRouter } from "./routes/admin/seed.js";
 import { startReminderScheduler } from "./services/reminders.js";
+import { webhooksRouter } from "./routes/stripe-webhooks.js";
 
 const app = new Hono();
 
@@ -50,6 +51,9 @@ app.route("/api/book", bookRouter);
 // Public portal routes — client-facing, authenticated via impersonation session header
 app.route("/api/portal", portalRouter);
 
+// Public Stripe webhook endpoint — signature-verified, no auth required
+app.route("/api/webhooks/stripe", webhooksRouter);
+
 // Dev/demo routes — config is always public, users endpoint is guarded internally
 app.route("/api/dev", devRouter);
 

apps/api/src/routes/stripe-webhooks.ts

@@ -0,0 +1,108 @@
+import { Hono } from "hono";
+import Stripe from "stripe";
+import { eq, getDb, invoices } from "@groombook/db";
+
+export const webhooksRouter = new Hono();
+
+webhooksRouter.post("/stripe", async (c) => {
+  const secret = process.env.STRIPE_WEBHOOK_SECRET;
+  if (!secret) {
+    return c.json({ error: "Webhook secret not configured" }, 503);
+  }
+
+  const signature = c.req.header("stripe-signature");
+  if (!signature) {
+    return c.json({ error: "Missing signature" }, 401);
+  }
+
+  let rawBody: string;
+  try {
+    rawBody = await c.req.text();
+  } catch {
+    return c.json({ error: "Could not read body" }, 400);
+  }
+
+  const stripe = new Stripe(secret, { apiVersion: "2026-03-25.dahlia" });
+
+  let event: Stripe.Event;
+  try {
+    event = stripe.webhooks.constructEvent(rawBody, signature, secret);
+  } catch (err) {
+    const message = err instanceof Error ? err.message : "Invalid signature";
+    return c.json({ error: message }, 401);
+  }
+
+  const db = getDb();
+
+  if (event.type === "payment_intent.succeeded") {
+    const pi = event.data.object as Stripe.PaymentIntent;
+    if (pi.metadata?.groombook_invoice_ids) {
+      const invoiceIds = pi.metadata.groombook_invoice_ids.split(",");
+      for (const invoiceId of invoiceIds) {
+        if (!invoiceId) continue;
+        const [inv] = await db
+          .select()
+          .from(invoices)
+          .where(eq(invoices.id, invoiceId))
+          .limit(1);
+        if (!inv) continue;
+        if (inv.stripePaymentIntentId && inv.stripePaymentIntentId !== pi.id) continue;
+        await db
+          .update(invoices)
+          .set({
+            status: "paid",
+            paymentMethod: "card",
+            paidAt: new Date(),
+            stripePaymentIntentId: pi.id,
+            updatedAt: new Date(),
+          })
+          .where(eq(invoices.id, invoiceId));
+      }
+    }
+  } else if (event.type === "payment_intent.payment_failed") {
+    const pi = event.data.object as Stripe.PaymentIntent;
+    if (pi.metadata?.groombook_invoice_ids) {
+      const invoiceIds = pi.metadata.groombook_invoice_ids.split(",");
+      for (const invoiceId of invoiceIds) {
+        if (!invoiceId) continue;
+        await db
+          .update(invoices)
+          .set({
+            paymentFailureReason: pi.last_payment_error?.message ?? "Payment failed",
+            updatedAt: new Date(),
+          })
+          .where(eq(invoices.id, invoiceId));
+      }
+    }
+  } else if (event.type === "charge.refunded") {
+    const charge = event.data.object as Stripe.Charge;
+    if (typeof charge.payment_intent === "string" && charge.payment_intent) {
+      const [inv] = await db
+        .select({ id: invoices.id })
+        .from(invoices)
+        .where(eq(invoices.stripePaymentIntentId, charge.payment_intent))
+        .limit(1);
+      if (inv) {
+        const refundId =
+          typeof charge.refunded === "boolean" && charge.refunded
+            ? `ch_${charge.id}_refund`
+            : null;
+        await db
+          .update(invoices)
+          .set({
+            status: "void",
+            stripeRefundId: refundId,
+            updatedAt: new Date(),
+          })
+          .where(eq(invoices.id, inv.id));
+      }
+    }
+  } else if (event.type === "charge.dispute.created") {
+    const dispute = event.data.object as Stripe.Dispute;
+    console.error(
+      `[Stripe Webhook] Dispute created for payment intent: ${dispute.payment_intent}`
+    );
+  }
+
+  return c.json({ received: true });
+});