Discord Notifications for Stripe Subscriptions

This val processes new subscriptions to komorebi's individual personal use license by sending a notifcation to the community Discord server.

1. Fork this HTTP val
2. Create a new webhook in Stripe
3. Add your val's HTTP endpoint URL into the Stripe webhook
4. Select customer.subscription.updated as the only event to listen to (more on this below)
5. Add your STRIPE_READ_ONLY_API_KEY to your Val Town Env Variables
6. Add your webhook's signing secret as STRIPE_WEBHOOK_SECRET to your Val Town Env Variables
7. Add your Discord webhook URL as STRIPE_DISCORD_WEBHOOK_URL to your Val Town Env Variables

1. Verifies the signature to make sure it's really from Stripe
2. Filters out only newly created subscriptions
3. Sends off the Discord message

Stripe sends webhooks for many different kinds of events. Relevant for us here are:

• customer.subscription.created (what we used to listen for)
• customer.subscription.updated (what we're currently listening for)

The issue with customer.subscription.created is that it triggers too early, before the user's payment actually goes through. This is a problem because in early Nov 2024 we started getting credit card fraudsters testing cards using our service. We started getting lots of notifications for new subscriptions that never actually became active.

Note: if anyone knows good ways to prevent that sort of behavior at the root, please let me know by commenting on this val!

In order to only get notified on a valid subscription, we now subscribe to customer.subscription.updated. This event happens on any subscription change, including renewals and cancellations, so now we have to filter those events to only get new subscriptions, ie where:

Create val
event.data.previous_attributes.status === 'incomplete' && event.data.object.status === 'active'