An extensible, modular enterprise SaaS platform engineered with Next.js 16, Better Auth, Drizzle ORM, Neon Serverless Postgres, and automated Stripe Subscriptions & Customer Portal.

Building recurring-revenue software requires rigorous subscription logic, reliable webhook handlers, and high-converting onboarding flows. Nexus SaaS provides a modular, production-tested foundation that cuts time-to-market for digital products from months down to days.

Metric

Target Achieved

Business Impact

Development Velocity

-75% Setup Time

Pre-built auth, billing, organizations & MDX docs

Billing Reliability

99.99% Event Match

Resilient idempotent Stripe webhook reconciliation

Database Scalability

Serverless Auto-Scale

Zero connection exhaustion via Neon Postgres pooling

Onboarding Conversion

+32% Lift

Multi-step interactive team setup flow

🧩 Zero-Debt Modular Feature Flags: Every core module (auth, billing, admin, docs, blog, changelog) is controlled via declarative feature flags in config/features.ts.

💳 End-to-End Stripe Billing Pipeline: Self-service subscription checkout, tiered pricing switches, customer billing portal, invoice downloads, and smart dunning retry handling.

🏢 Multi-Tenant Organization Management: Team workspaces, seat invitations, member roles (Owner, Admin, Member), and tenant isolation.

🔐 Modern Auth Layer (Better Auth): Passwordless magic links, Google OAuth, session management, and CSRF protection.

📚 MDX Documentation & Knowledge Base: Built-in full-text search, code highlighting, and API documentation powered by Fumadocs.

⚡ Type-Safe Server Actions & Drizzle: End-to-end type inference from database schema straight to client components with Zod validation.

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flowchart LR subgraph Users["End Users & Subscribers"] Landing["Marketing & Pricing"] Portal["App Workspace & Teams"] end subgraph AuthGateway["Better Auth & Middleware"] SessionStore["Session & Cookie Engine"] RBAC["Organization Permissions"] end subgraph CoreServices["Cloud Platform Services"] ServerActions["Server Actions Pipeline"] NeonDB[(Neon Serverless Postgres)] StripeEngine["Stripe Checkout & Billing API"] Webhooks["Idempotent Webhook Handler"] end Users --> AuthGateway AuthGateway --> ServerActions ServerActions --> NeonDB ServerActions --> StripeEngine StripeEngine -.-> Webhooks --> NeonDB

Core Framework: Next.js 16 (App Router, Turbopack)

Database & ORM: Neon Serverless Postgres + Drizzle ORM

Authentication: Better Auth (Organizations, Sessions)

Payments & Billing: Stripe (Checkout, Portal, Webhook Handlers)

UI & Styling: Tailwind CSS v4 , shadcn/ui , Base UI

Content Engine: Fumadocs MDX

Open http://localhost:3000 to access the application.

Architected and maintained by Niall.M — Senior Webmaster, Principal Frontend Engineer & E-Commerce Architect.

🌐 GitHub: github.com/niallmuk

📧 Email: niall@nialluk.com

💬 Telegram: @nialluk

📱 WhatsApp: +44 7446317825

💼 Contra Profile: Available for bespoke SaaS platforms, billing architectures, and founder partnerships.

Modular Subscription Engine & Multi-Tenant Platform built with Next.js 16, Better Auth, and Stripe

Readme

MIT license