Suprascribe

Recurring charges hide in email. Suprascribe reads a connected mailbox, pulls out the receipts and renewal notices, and turns them into a subscription dashboard, so the trial you forgot and the annual plan renewing next week sit in the same list with their real cost.

It is a Next.js 15 application in TypeScript, with Supabase Postgres and row-level security keeping user data separate, Supabase Auth covering Google, Microsoft and Apple sign-in, and the Vercel AI SDK abstracting more than ten model providers. One service fetches mail through the Gmail API, Microsoft Graph or IMAP, and another asks a model to extract subscription details from the message text.

The tiers split along what discovery costs to run.

• Free features: the dashboard, unlimited manual entries, multi-currency support and bring your own key discovery.
• Paid features: automatic discovery from Gmail, Outlook, iCloud or any IMAP account, full history, search, grouping, quick unsubscribe, a calendar view and renewal reminders.
• Key storage: model keys you supply are encrypted at rest with AES-256-GCM and decrypted only while a request runs.
• Mail safety: outbound requests to mail servers refuse private and loopback ranges along with cloud metadata endpoints.
• Payment safety: Stripe webhooks are checked against their signature, and an idempotency guard stops a duplicate tier upgrade.

Running your own copy needs Node.js 20, Yarn v4 and a Supabase project, with Stripe, Resend and Brandfetch optional. The AGPL-3.0 license means a modified copy offered as a network service has to publish its source to the people using it.