SaaS Builder skill walkthrough: auth, billing, dashboard in one prompt
The SaaS Builder skill is our most popular file by a wide margin. It's the one behind adworthy.ai, admix.software, and a growing list of live products. But I keep getting questions about what it actually does under the hood.
So this is the full walkthrough. What the skill contains, how it guides your AI agent, and what you get when you say "build me a SaaS for X."
What's in the skill file
The SaaS Builder skill is a structured instruction file—about 3,000 words of concentrated architecture knowledge. It's not code. It's not a template. It's a set of patterns, conventions, and decisions that tell your AI agent how to build a production-grade SaaS product.
Here's what it covers:
Project structure. How to organize your Next.js app. Where components go. Where API routes live. How to separate server and client code. This sounds basic, but bad project structure is the number one reason AI-generated code turns into a mess after the first few features.
Authentication patterns. Email/password, OAuth (Google, GitHub), magic links, and email verification. The skill specifies which Supabase auth methods to use, how to handle sessions, where to store user metadata, and how to build protected routes that redirect unauthenticated users.
Database schema design. How to model users, subscriptions, and your core business data. The skill includes patterns for row-level security in Supabase, which means your data access rules are enforced at the database level instead of scattered across API routes.
Stripe billing. This is the section most founders care about. Checkout session creation, webhook handling with proper verification, subscription lifecycle management (created, updated, cancelled, past due), and the customer billing portal. The patterns handle the edge cases that trip people up: duplicate webhooks, failed payments, plan changes mid-cycle.
Dashboard layout. Sidebar navigation, responsive design, data tables, stat cards, and the overall layout structure. The skill uses shadcn/ui components, which means the output looks professional without any design work from you.
API route patterns. How to structure your server-side logic, handle errors consistently, validate input, and return proper responses. The skill enforces patterns that scale—your first API route and your fiftieth follow the same conventions.
Deployment configuration. Environment variables, Vercel settings, and the config needed to go from local development to live production in one push.
The workflow: from prompt to product
Let me walk through exactly what happens when you use this skill. I'll use a real example: building a SaaS that lets restaurant owners manage reservations.
Step 1: Drop the skill file
You download the SaaS Builder skill and place it in your project directory. Most agents pick up files in the root directory or a .claude folder automatically. With Claude Code, you can also reference it directly.
Step 2: Describe what you want
You open Claude Code and type something like:
"Build a SaaS for restaurant owners to manage table reservations. Users sign up, add their restaurant, create a seating layout, and manage incoming reservations. Include a dashboard with today's reservations, a calendar view, and Stripe billing with a free tier (up to 50 reservations/month) and a pro tier ($29/month, unlimited)."
That's the prompt. One paragraph. The skill file provides the architectural context that turns this paragraph into a real product.
Step 3: The agent scaffolds
The agent reads the skill file and your description. It generates the project structure, installs dependencies, sets up the Supabase schema (users table, restaurants table, reservations table, subscriptions table), and creates the basic route structure.
Within 10-15 minutes, you have a Next.js project with the right file organization, database tables created, and a running dev server showing a login page.
Step 4: Auth comes to life
The agent builds the full auth flow based on the skill's patterns. Sign up page with email and password. Login page. Email verification flow. Password reset. Session management using Supabase's auth helpers.
The skill tells the agent to create a middleware that checks auth on protected routes and redirects to login if the session is expired. It also specifies how to store the user's restaurant association in the profiles table so the dashboard knows which restaurant's data to show.
This is where you'd normally spend a day or two if you were building from scratch. With the skill, the agent handles it in one pass. You test the flow—sign up, verify email, log in—and it works.
Step 5: The dashboard takes shape
Based on the skill's dashboard patterns, the agent builds a sidebar layout with navigation links: Dashboard, Reservations, Calendar, Settings, Billing. The main content area shows today's reservations in a table, a few stat cards (total reservations today, upcoming this week, capacity), and quick actions.
The skill specifies shadcn/ui components for everything, so the UI is consistent and looks professional. Data tables with sorting and filtering. Cards with proper spacing. A responsive layout that works on mobile.
Step 6: Stripe billing wires up
You tell the agent to add billing. The skill's Stripe patterns kick in. The agent creates a pricing page with your two tiers. Sets up Stripe checkout sessions. Builds webhook handlers for checkout.session.completed, customer.subscription.updated, and customer.subscription.deleted.
It creates a subscriptions table that tracks the current plan for each restaurant. API routes check the subscription status before allowing actions that exceed the free tier limit. The customer portal link lets users manage their own billing.
The webhook handler includes idempotency checks so duplicate Stripe events don't cause double actions. The skill specifies this because it's a bug that bites almost every first-time Stripe integration, and most tutorials don't mention it.
Step 7: Polish and ship
The remaining work is your specific business logic—the reservation management features unique to your product. But the foundation is solid. Auth works. Billing works. The dashboard is laid out and functional. You're building on a real architecture instead of stitching together tutorial code.
Why patterns matter more than templates
A template gives you a starting point that you modify. The problem: every modification risks breaking something because you don't understand the template author's decisions.
A skill gives your AI agent an understanding of how the pieces fit together. The agent generates code tailored to your specific product, following patterns that have been validated in production. If you need something the skill doesn't explicitly cover, the agent can still build it because it understands the architecture well enough to extend it consistently.
That's why two people using the same SaaS Builder skill end up with different codebases that both follow good patterns. The skill adapts to what you're building instead of forcing you into a rigid structure.
What the skill doesn't do
I want to be straight about this. The SaaS Builder skill handles the architecture and common SaaS patterns. It doesn't handle your unique business logic.
For the restaurant reservation example: the skill won't generate the calendar view logic specific to table management. It won't know your restaurant's specific seating layout format. Those features are your product's differentiator, and you'll need to describe them to the agent and iterate.
What the skill does is ensure that when you build those custom features, they sit on top of a solid foundation. The auth works. The billing works. The database is properly structured. The API patterns are consistent. So you spend your time on the hard, interesting problems instead of re-inventing the wheel on auth and billing for the thousandth time.
Try it yourself
The SaaS Builder skill costs $29. You buy it once and use it on every SaaS project you build. It works with Claude Code, Cursor, Windsurf, and any AI coding agent that accepts instruction files.
If you've been wanting to build a SaaS product and the technical setup has been the blocker, this skill removes that blocker. Open Claude Code, describe what you want, and let the skill handle the architecture.
Frequently Asked Questions
What does the SaaS Builder skill include?
Production-tested patterns for authentication (email, OAuth, magic links), Stripe billing (checkout, webhooks, subscription management), dashboard layouts with shadcn/ui, API route design, database schema patterns with row-level security, and Vercel deployment configuration.
Can I customize what the SaaS Builder skill generates?
Absolutely. The skill provides patterns, not rigid templates. You describe your specific product and the AI agent applies the patterns to your use case. Two different SaaS products built with the same skill will have different codebases that both follow good architecture.
Does the SaaS Builder skill work with any AI coding agent?
Yes. It works with Claude Code, Cursor, Windsurf, and any agent that reads instruction files. The skill file is structured text, not an SDK or API integration. Any agent can parse and follow it.
How long does it take to build a SaaS with this skill?
Most founders have a working SaaS with auth, billing, and a dashboard in 1-3 days. The exact timeline depends on the complexity of your custom features. adworthy.ai shipped in 3 days with paying customers on day 4.