v1.1 — KeelStack Engine is live

v1.0 was a production-ready Node.js + TypeScript backend starter. v1.1 is something more specific: a failure safety engine.

The problem with most backend templates isn't the happy path — it's what breaks silently in production. Duplicate Stripe charges when users double-click. Webhook race conditions on Stripe retries. Background jobs that vanish on worker crash with no log. AI loops burning your monthly API budget because one user has no limit.

v1.1 adds direct fixes for all four:

— Idempotency middleware on all payment routes

— Webhook deduplication guard (survives Stripe retries)

— Retry-safe job runner with exponential backoff and dead-letter logging

— Per-user LLM token budgets with cost attribution

597 tests passing. 93.13% statement coverage enforced by CI threshold — not claimed, enforced. 37 end-to-end flows. 0 known vulnerabilities.

Also ships with 15 Cursor/Claude prompts pre-loaded with layer rules and protected file paths — so AI writes architecture-compliant code without breaking existing integrations.

One-time payment, $29 for early builders. Source code you own and deploy.

Looking for developers who want to audit it ruthlessly — free access in exchange for honest feedback. DM me or email founder@keelstack.me.