Build and launch your
AI startup
this weekend
RailsFast is the best template to vibe code your app on top of. It's the only SaaS boilerplate designed for AI coding. It gives you a secure and battle-tested full-stack foundation to build any idea on top. And it's built for AI, so you can use Claude Code, Cursor, OpenCode, or Codex to do the heavy lifting for you – fast.
Clone the starter template and get your first $1 in revenue by Monday
Everything included
Avoid the spaghetti mess of vibe coding
You were promised AI would build ideas for you, but all you got was an unholy mess of spaghetti code: things so tangled they're impossible to unravel. Maybe you've tried Lovable, v0, or Bolt, and were excited at first – but ended up suffocated under a pile of errors. Fix one thing, break 10. You reached a point where it was impossible to add new features, and were left with a half-baked project you can’t work on anymore. It’s not your fault, you’re just not putting the AI to work under the best conditions for success.
Dodge the ticking timebomb of AI slop
Fully AI-generated code may get you in trouble. While pressing tab, tab, tab without much thinking you're introducing security holes: unauthenticated services, plaintext credentials, misconfigurations... It's just a matter of time until you're in the headline of the next data breach scandal (remember the Tea app?) You're creating mountains of technical debt that would take a senior engineer months and thousands of dollars to fix. Vibe coding without structure works for quick demos, but fails for real-world software. There's a better way.
Start building from a solid foundation (not thin air)
Save hundreds of hours and celebrate your first paying customer, fast
Let's be honest: all software is 90% the same. We all need to take payments, authenticate users, send emails, handle uploads, do backups... That's exactly what RailsFast handles: the undifferentiated heavy lifting, so you (and your AI) can focus on the 10% that actually matters: getting your first paying customer as fast as humanly possible.
Bypass repetitive work
90% of building a SaaS is setting up stuff over and over again. RailsFast eliminates time drains like manually setting up payments, authentication... which can take hundreds of hours.
Engineered for revenue
RailsFast has been engineered for revenue from the ground up. Every decision has been made with making revenue and running a business as easy and straightforward as possible.
Optimized for SEO & LLMs
Everything in RailsFast has been SEO optimized from the beginning. Get Google to understand and rank your page higher, and OpenAI and LLMs to discover your site easily.
RailsFast is your fastest route to: «I just made my first $200 while I slept last night, holy shit!»*
Everything you need to go from zero to money-making business
RailsFast comes with pretty much everything you'll need to build and run a software business: it's almost a startup-in-a-box. It's a complete full-stack (front-end + back-end), production-ready system – not just a toy or a simple front-end boilerplate.
Users & authentication
Allow your users to register and log in securely. You own and control everything, all data, no need for 3rd party integrations that can be hacked or misconfigured.
- Email/password authentication
- Recover lost password flow
- Email confirmation flow
Payments
Start taking payments and collecting revenue on day one. Full Stripe integration with subscriptions, one-time payments, webhooks, and customer portal.
- Both subscriptions and one-time payments
- Webhook handling
- Customer portal to self-manage subscriptions
Database & migrations
RailsFast comes with PostgreSQL as its database. It's fully configured and ready to go with all migrations out of the box, so you don't have to worry about a thing.
- Postgres is the industry de-facto standard
- Production-ready, ready to power big apps
- Scalable & easy to migrate to managed
Emails
Send transactional emails that look professional and well-branded out of the box. Works for all email clients without having to write any email-specific HTML.
- No more ugly plain text emails
- Comes with signup + payments email flows
- Integrates with SES for cheap emailing
Background jobs & Cron
Schedule and run async tasks at any time. Have a horde of robots working for you in the background, organizing data and performing long-running operations.
- Error handling
- Configurable retries
- Schedule tasks as if they were cron jobs
File uploads
Allow your users to upload images and files to your app, like user avatars, post content, blogpost attachments, etc. Comes with image processing out of the box.
- Scale images to different sizes automatically
- Optimize images for webp automatically
- Works with any S3-compatible storage
Where others stop, we double down
Most boilerplate templates stop where the difficult parts begin. We tackle them head-on. That's why RailsFast ships with robust, elegant solutions to common yet complex SaaS problems that you'd need expensive subscriptions or hundreds of hours in engineering to solve.
Pricing plan enforcement
It's one thing to charge money, but it's a completely different thing to define pricing plans and enforce their limits.
- Avoid users going over their plan limits
- Gate access to features based on plan
Usage credits
Most AI apps use some sort of credits system to charge for usage. Fully-featured, robust and production-ready credits system.
- Credits with monthly/weekly/yearly refill
- Allow users to buy power packs at any point
Fake users protection
Blocks disposable emails from signing up to your app, automatically. Prevent unauthentic usage (fake, bot & spam users) in your app.
- Built-in CAPTCHA protection with Turnstile
- Daily update of disposable domain names
Vector database & RAG
RailsFast comes ready to work with pgvector if needed, making your project capable of RAG and AI retrieval.
- Turn your DB into a vector database with RAG capabilities
- No 3rd party databases needed
AI rules & context
Ships with pre-written Cursor rules and rich context that teach agents exactly how your app works, and how to build it right.
- The AI understands your codebase at a glance
- Ready to work with Context7 for extra context
Generative AI & LLMs
RailsFast works out of the box with generative AI services like Replicate or Fal; and LLM APIs like ChatGPT, Claude, etc.
- Build AI-heavy apps easily
- Leverage the most popular AI APIs
Monitoring
Get a status page to check the health of your business at a glance: not only technical systems, but business metrics too.
- Add simple smoke tests to monitor app health
- Ready to use with uptime services
Self-serve API keys
Offer your service as an API easily. Allow users to get a secure API token to interact with your API, and auth them easily.
- Dashboard to manage and self-serve API keys
- Secure token-based API authentication
MRR dashboard
Know instantly key metrics for your SaaS like MRR, ARR, valuation & churn. Keep an eye on the health of your business.
- How much is your business worth?
- See valuation & churn calculations at any point
Caching
Cache entire pages or parts of pages so that your server doesn't read from DB on every request. It just takes one line of code.
- Speed up the load time of any page easily
- Avoid your database being the bottleneck
Pagination
Display large lists of records paginated by default. Comes with pagination UI components & wired for paginated URLs.
- GET params for pagination work out of the box
- Database-performant, ready for production
Rate limiting & scraping protection
Prevent users from making too many requests to your app or API, and protect from DDoS attacks and scraping attempts.
- Add rate limiting to any page or action
- Only one line of code required
Backups
Back up your entire database to the cloud automatically. Daily backups by default, but change easily to hourly, weekly, etc.
- All working out of the box
- Backups live in the cloud for resilience
SEO & Metadata
Rank higher on Google and get discovered by LLMs easier. Everything in RailsFast is optimized for SEO, with the right metadata.
- Easily set OG metadata for FB, X, Discord...
- Set dynamic social images per page
Impersonation
See what your users see. Troubleshoot and debug your app quickly by impersonating your users to get a first-person view.
- Easily log in as any user in your app
- Switch between users easily
Hosting & SSL
Deploy your app easily into any VPS with one single command. All traffic is secured with SSL certificates.
- Free, auto-renewable SSL certificates
- Deploy to your server with one command
Secrets
Other templates handle secrets in insecure ways. All secrets and credentials in RailsFast are encrypted and never commited to git.
- Prevent credential leaks
- No ENV gymnastics needed
Analytics & admin dashboard
Manage users, view analytics, and monitor your business metrics.
- User management
- Analytics dashboard
A library of UI components to build at the speed of light
- Hero
- Navbar
- Pricing cards
- Features
- Bento & grid
- FAQ
- Footer
- Testimonials
- ...and more
RailsFast UI is built with Tailwind CSS, so you can bring your own components or any paid design system like Tailwind Plus
Start seeing your dashboard glowing with your first payments
Get RailsFast now and start building – you could be getting your first sale faster than you can say vibe coding!
Start building now
Rails: your secret weapon for the age of AI
RailsFast is based on Ruby on Rails (not on Next / React / JS), and that's not by chance: Rails is the best framework for vibe coding. Ruby on Rails will be your unfair advantage in the age of AI-assisted coding, and here's why:
AI knows Rails better
Rails launched in the early 00s, so there are 20+ years worth of Rails code and content online that LLMs have been thoroughly trained on. No JS framework has been around for as long as Rails has.
Rails code is stable over time
Rails codebases look pretty much the same today as 20 years ago. This is not only good for us humans, but especially for AI: Rails training data is very stable, so AIs learned Rails better than other frameworks.
Rails conventions help AI thrive
Rails (unlike JS frameworks) has very strong conventions on how things are done. AI gets Rails very intuitively, because everything is mostly always the same across all projects, whereas JS projects are all different.
Rails is 10x less verbose
Rails code is 10x less verbose than JS code. This means if you're vibe coding your app, you'll use 10x less tokens to generate the same result, and context windows will take 10x longer to get filled. You'll move 10x faster, pay 10x less in API credits, and the AI is less likely to hallucinate because it can see the whole project at once, rather than getting its context cut off early.
Rails is the one-man framework
Rails was designed so an entire codebase could fit in one single engineer's head. This is still true, and what's even better: in the age of AI, this means LLMs have it much easier with Rails to understand an entire project at a glance. This allows a single founder to build unicorn-scale software with just AI, without hiring a team.
Rails is better for SEO
No matter what they say, JavaScript sites don't rank as well. I've tested it, and it's been an uphill battle with Google every single time. Search engines impose crawling budgets for JS websites, which is not the case for frameworks that serve plain, easily parseable, ready-to-consume HTML, like Rails. As a result, Rails makes your site more easily discoverable by Google and AI.
YC uses and recommends Rails*
Y Combinator (the famous startup accelerator that launched companies like Twitch, Reddit, or Dropbox) recently posted their «Vibe Coding Playbook», where they mention Ruby on Rails as their current top choice for tech stack. They write their own internal apps in Rails, too.
You can still use JS within Rails!
Rails apps are just web apps, so you can use all the JavaScript you want within them! Rails ships with Turbo and Stimulus, two tools that minimize the amount of custom JS you'll have to write, but you're fully free to bring in React, Vue, Svelte, or any JS framework!
iOS + Android, same codebase
If mobile (iOS + Android) apps are down the roadmap for you, Rails also comes with Hotwire Native, a technology that allows you to ship hybrid mobile apps very easily, sharing most of the code with the base web app, and allowing you to add fully native screens if needed!
Stop getting surprise Vercel bills. RailsFast runs on $5 servers.
| Vercel and similar |
The RailsFast Way
Your own VPS server
|
|
|---|---|---|
| Monthly price |
😳 $1,000+ Surprise bills
|
FLAT Predictable, fixed price
|
| Viral traffic | ❌ Unpredictably high bills when your site goes viral or traffic spikes | ✅ Plenty of TBs of traffic are usually included with most VPSs, and overage is cheap |
| What's it good for | ❌ Quick & dirty prototyping, toy projects | ✅ Self-hosting is the gold standard in the industry: mature, robust applications end up migrating away from PaaS like Vercel at some point |
| How it feels | ❌ High anxiety, fear of opening the dashboard and seeing surprise bills, need to constantly keep an eye on usage, punishment for growing fast | ✅ Control, predictability, and relief |
Battle-tested with millions of real users
- I've been building, shipping, and scaling Rails apps for the last 10+ years
- I built and sold PromptHero, one of the biggest AI image communities on the internet, scaling it to 4 million monthly users on the exact stack you're getting with RailsFast
- I've made 15+ open source gems for Ruby on Rails, with over 120,000+ downloads
- This exact stack generated me millions of free SEO clicks over the years*
RailsFast scores 10/10 email deliverability on mail-tester.com and has generated millions of impressions and clicks in Google SEO
Frequently Asked Questions
Stop dreaming.
Start building.
You could be running your own software business by next week.
👽 Pro tip: browse the docs, they're free to read!