From 8ede30ca8746fe45a450608f916df6dd1f256bbf Mon Sep 17 00:00:00 2001
From: Thibault Le Ouay Ducasse <thibaultleouay@gmail.com>
Date: Wed, 9 Sep 2026 09:19:20 +0200
Subject: [PATCH] stripe: fix bug

---
 packages/api/src/router/stripe/index.ts   | 13 ++++++++++++-
 packages/api/src/router/stripe/webhook.ts | 11 ++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/packages/api/src/router/stripe/index.ts b/packages/api/src/router/stripe/index.ts
index cf92edc8..3e09f742 100644
--- a/packages/api/src/router/stripe/index.ts
+++ b/packages/api/src/router/stripe/index.ts
@@ -210,11 +210,22 @@ export const stripeRouter = createTRPCRouter({
           });
         }
 
+        // Classify before mutating Stripe. An item on a price neither table
+        // knows throws, and throwing *after* the update would leave the
+        // customer re-priced and billed while the workspace kept the old plan
+        // — a split the webhook cannot repair either, since it throws on the
+        // same item.
+        buildFromSubscriptionOrThrow(current);
+
         // Only the plan item is listed, so Stripe leaves every other item
-        // untouched and the addons survive the plan change.
+        // untouched and the addons survive the plan change. Clearing
+        // `cancel_at_period_end` resumes a subscription the customer had
+        // scheduled to cancel — choosing a paid plan says they mean to keep
+        // paying.
         const updated = await stripe.subscriptions.update(current.id, {
           items: [{ id: planItem.id, price: priceId }],
           proration_behavior: "create_prorations",
+          cancel_at_period_end: false,
         });
 
         const built = buildFromSubscriptionOrThrow(updated);
diff --git a/packages/api/src/router/stripe/webhook.ts b/packages/api/src/router/stripe/webhook.ts
index 7f8d2142..958411bf 100644
--- a/packages/api/src/router/stripe/webhook.ts
+++ b/packages/api/src/router/stripe/webhook.ts
@@ -170,6 +170,16 @@ export const webhookRouter = createTRPCRouter({
       });
     }
 
+    // A replayed or late `checkout.session.completed` can name a subscription
+    // that a newer one has already superseded. Writing it would move the
+    // workspace back to the older plan while the newer subscription keeps
+    // billing, so leave the workspace to that subscription's own events.
+    const { active, current } = await getCurrentSubscription(customerId);
+
+    if (current && current.created > subscription.created) {
+      return;
+    }
+
     const built = buildFromSubscriptionOrThrow(subscription);
     if (!built) {
       console.error("Invalid plan");
@@ -182,7 +192,6 @@ export const webhookRouter = createTRPCRouter({
     // Checkout always opens a new subscription, so anything else still active
     // predates it and would keep billing. Retire it here instead of waiting
     // for an unrelated `customer.subscription.updated` to come along.
-    const { active } = await getCurrentSubscription(customerId);
     await cancelSupersededSubscriptions(active, subscription);
 
     await updateWorkspacePlan({
-- 
2.51.2