Release v0.1.28: Stripe Checkout for Credit Top-Ups

February 15, 2026

What changed

• Stripe Checkout integration — The billing.topUp mutation now creates a Stripe Checkout Session and redirects users to Stripe's hosted payment page, replacing the previous system that added credits without payment verification.
• Webhook-based fulfillment — New /api/webhooks/stripe endpoint verifies Stripe signatures and atomically adds credits only after confirmed payment.
• Audit logging — Both checkout initiation and completed payments are recorded in the audit log with Stripe session IDs, amounts, and balance snapshots.
• Graceful degradation — New Stripe client singleton returns null when STRIPE_SECRET_KEY is not set, so the app still boots in development without Stripe configured.
• Tests — Unit tests cover the Stripe client module and webhook handler (signature verification, metadata validation, credit addition, audit logging).

Why it matters

Credits are now backed by real payments. The previous virtual credit system allowed unlimited credits without any payment — this release closes that security gap.

Technical notes

• New dependency: stripe@^17.0.0
• Two new required env vars: STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET
• Credit updates use sql expressions for atomic increments (no race conditions)
• Currency is GBP (£)