saas-platform-patterns

Create a SubscriptionService with handler methods for each payment provider webhook event such as created, activated, canceled, and past_due. Each handler updates the Prisma subscription record, provisions or revokes licenses, and emits internal events via EventEmitter2 for side effects like emails.

Generate keys with crypto.randomBytes(32) as hex with a prefix like lic_, store them in a Prisma License model with status and plan fields, and expose a rate-limited POST /licenses/verify endpoint. Cache verification results in memory or Redis with a 5-minute TTL.

Store plans as a static TypeScript config file rather than database records. This keeps pricing changes in version control, avoids schema migrations for plan tweaks, and enables type-safe feature checks at compile time.

Yes, the patterns are provider-agnostic by design. Payment provider SDKs sit behind an abstraction layer, and webhook events are mapped to generic internal handlers, so swapping providers only requires changing the adapter, not business logic.

Track trials with a trial_ prefix on the plan slug and a trialEnd timestamp, then run a scheduled cron task that finds expired trials, marks subscriptions as expired, and provisions a community-tier license. Send reminder emails at 7, 3, and 1 days before expiry.

Frontend feature flags can be modified by users, so they should only control UI visibility. Always verify plan membership server-side using a NestJS guard like PlanGuard with a @RequireFeature decorator before executing protected endpoint logic.