Built by the founder who scaled PromptHero to 4M+ monthly users

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

Auth
Live payments
Secure
Database
Backend
Tasks
Emails
Backups
RailsFast Demo
Works with
Claude AI
Cursor
OpenAI
Stripe

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.

Avoid the <span class='text-red-500'>spaghetti mess</span> of vibe coding

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.

Dodge the <span class='text-red-500'>ticking timebomb</span> of AI slop
Here's how to fix it
Start building from a <span class='block my-4 text-transparent bg-clip-text bg-gradient-to-t from-accent to-accent-light'>solid foundation</span> (not thin air)
Meet RailsFast

Start building from a solid foundation (not thin air)

Starting a vibe coding project from a blank slate is a recipe for failure: you're asking the AI to create complex systems (like auth and payments) from scratch, instead of leveraging existing, battle-tested solutions that have been engineered and checked by human experts – like in RailsFast. Give the AI a blank canvas, and it gets lost. Give it a proven, well-designed structure with clear boundaries, guardrails, and rich context... and it will absolutely smash it.

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.

Secure

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
Revenue ready

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
Easily scalable

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
But there's more

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
Easy to add

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
COMING SOON

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
COMING SOON

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
COMING SOON

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
COMING SOON

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 <span class='block text-transparent bg-clip-text bg-gradient-to-t from-accent to-accent-light'>UI components</span> to build at the speed of light

A library of UI components to build at the speed of light

RailsFast ships with a collection of UI components that are designed to work together, so you can quickly put together landing pages and user interfaces. They're designed for LLM usage with thorough docs, so you can just tell the AI to mix and match them like LEGO pieces, and you will get beautiful, high-conversion sales pages in no time (this landing page has been built this way!)
  • Hero
  • Navbar
  • Pricing cards
  • Features
  • Bento & grid
  • FAQ
  • Footer
  • Testimonials
  • ...and more
RailsFast is built with
Tailwind CSS

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 is your secret weapon

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!

Y Combinator recommends Rails tweet
YC recommends Rails for tech stack* (source)
Rails is the secret sauce of many to build unicorns: all these companies were built with Ruby on Rails
Airbnb
GitHub
Coinbase
Gusto
Instacart
Kickstarter
Soundcloud
Shopify
Stop getting <span class='text-transparent bg-clip-text bg-gradient-to-t from-accent to-accent-light'>surprise</span> Vercel bills. RailsFast runs on <span class='text-transparent bg-clip-text bg-gradient-to-t from-accent to-accent-light'>$5 servers</span>.

Stop getting surprise Vercel bills. RailsFast runs on $5 servers.

RailsFast is designed to run on flat-price VPS servers that will take you from zero to thousands of users predictably, without worrying about traffic spikes. If you go viral and start receiving lots of users, scaling up is trivial (and cheap!) Expect to pay dozens, not thousands of dollars. The typical RailsFast app can run on a $5-$15/mo VPS (PromptHero ran on $119/mo – serving millions!) And you can even fit multiple RailsFast projects in the same server!
Monthly price
Vercel and similar
😳 $1,000+
Surprise bills
Your own VPS server
The RailsFast Way
FLAT
Predictable, fixed price
It's easy: you'll get up and running with your own self-hosted VPS as part of the RailsFast quickstart. RailsFast doesn’t sell hosting, but we'll help you get your app in production on your own server in less than 15 minutes.
Battle-tested with <span class='text-transparent bg-clip-text bg-gradient-to-t from-accent to-accent-light'>millions of real users</span>
Made by a founder who's actually done it

Battle-tested with millions of real users

Most boilerplates are built by people who’ve never shipped or scaled a real product. RailsFast isn’t. I'm Javi (@rameerez), a software entrepreneur, and everything in RailsFast comes from a decade+ of learnings validated in the real world, years of building dozens of Rails-based startups and scaling them to millions of monthly 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 perfect email delivery screenshot SEO traffic screenshot RailsFast SEO traffic screenshot

RailsFast scores 10/10 email deliverability on mail-tester.com and has generated millions of impressions and clicks in Google SEO

Frequently Asked Questions

Of course! You don't need to be a Rails expert. In fact, the RailsFast quickstart starts from zero, without any assumptions about what your current knowledge about Ruby on Rails is. With that being said, as with everything in life, the more experience you have, the more value you will extract from it. AI writes very good Rails code, especially if you give it good context as we do in RailsFast, so odds are you'll do just fine. RailsFast is designed so you can get started with minimal technical knowledge, with the help of AI assisted coding. I believe you’ll quickly get the hang of it.
Yes! I believe RailsFast is a great learning tool. Through the docs, we'll take a very hands-on approach to start developing web applications, so this is a great way to get your hands dirty, and you'll learn by doing. On top of that, RailsFast sticks to the Rails standards (Rails omakase), so what you learn will be immediately valuable and transferable to any other Rails project you may work on.
I'll be honest: ideally, yes – at least to some degree. You should know the basics. You may get away with pure vibe coding (letting the AI write all the code without you checking anything), but I don't think that will lead to the best results. To be a good manager, you need to know what you're doing: that applies to AI-assisted coding and to every other job in life. There's nothing worse than being managed by someone who's clueless, so imagine how difficult it must be for an AI to follow orders of someone who keeps giving contradictory commands. I suggest you browse the RailsFast docs before purchasing to see if you're comfortable with the level of technical jargon used. You should be familiar with things like Git, ssh, and running terminal commands -- but you can (and should!) use AI to get up to speed if you don’t know what something means! I truly believe the barrier of entry is the lowest it's ever been, and you can learn 80% of what you need in a couple weeks thanks to AI. This is not specific to RailsFast, by the way, any other AI-first coding platform claiming you can build entire products with zero coding knowledge is outright lying to you. The technology is not quite there yet.
Yes! Check it out at railsfast.com/docs – it's quite thorough and it has a 15-minute quickstart that will leave you with an app already fully working in production!
Of course! You can build any kind of app, hobby project, web experience, B2C or B2B product you can think of! You can even build an iOS and Android app with the same RailsFast codebase if you use Hotwire Native!
Of course! RailsFast apps look and feel like any other modern SaaS. RailsFast uses Stimulus and Hotwire / Turbo (Rails-native technologies) to achieve interactive, dynamic experiences with minimal code! It truly feels like magic the first time you use it, especially if you come from React and the like, where everything is super verbose and covoluted. In any case, you can use any JavaScript library together with RailsFast, so you can build with the same level of interactivity with the tools you're more comfortable with!
Everything! RailsFast integrates with Stripe for payment processing, so we support both one-time payments and recurring subscriptions.
Yes! RailsFast is a living, breathing template by design, because it’s the exact same template I use for my own projects. In fact, I’m currently dogfooding it to myself by building new apps with it, and I’m updating it as I go, so you'll get updates as I build new stuff too. And since this is the exact stack I use for my own products, I made it easy to upgrade, so RailsFast will remain maintainable as your business grows.
Yes! First of all, the docs have extensive tutorials with videos to walk you through the whole process from 0 to deployed, onboarding, adding a feature etc. If you come across any problem, just reply to your RailsFast purchase email for support.
No. Most stores don't accept returns on digital goods, for good reason. Why? Well, because of the very nature of the product: you may purchase it, ask for a refund, and you'll always still keep a copy by default. I have no way of knowing whether you asked for a refund for a legit reason or with the intent of tricking me and getting the product for free. For that reason, all RailsFast sales are final. We cannot accept any returns on RailsFast: once purchased, it cannot be refunded. With that being said: if you truly had a problem and you really think you should get a refund, write to the support email and I'll evaluate it on a case by case basis, but the default answer is: no, there are no refunds.
Yes, and you have no idea how much this can scale on just a single server. I built PromptHero on the same stack, and it did 4M monthly visitors just fine: it ran on one single machine until several thousands of users a day, and I mainly just had to put the database on its own separate server to make it scale further. The total cost of running all the infrastructure was $120/mo. The technology RailsFast uses scales just fine. Other startups running on Ruby on Rails (not RailsFast) like Shopify have scaled the stack up to millions of requests per second. You'll run out of customers long before you run out of scaling capacity.
Yes! For UI, RailsFast uses Tailwind, which the AI excels at. You will be able to create entire pages in minutes, beautifully designed. Still to this day I get surprised how good the AI is at writing Tailwind screens over plain CSS or Bootstrap, for example. For interactivity, RailsFast uses Stimulus + Hotwire, both of which are very straightforward and well-documented. RailsFast links to their latest docs, and the AI does a fantastic job at writing clean, elegant, interactive components with it.
Yes, but! RailsFast uses JavaScript like any other website out there. You can use whatever frontend tool, library or framework you want along with RailsFast: React, Vue, Next, Nuxt, Svelte, Inertia – whatever you want. You can add anything, but I believe you won't need to: Rails ships by default with Hotwire and Stimulus, the recommended way of writing frontend for Rails apps. I really, really, really encourage you to try it. You can do everything a React/Vue/Svelte app can do, but with minimal JavaScript code. It feels like magic. The AI will glide through interfaces written with Hotwire + Stimulus because there’s so much less code to write and understand. But of course nothing is stopping you from adding more JS libraries: just pin them in the importmaps file and you're ready to go.
Not really, you're pretty much done after the 15 min quickstart. Yes, 15 minutes is all it takes to get started. That leaves you with an already hardened server, fully configured and ready for production workloads. To give you an idea: in the last ~year I never had to do any server-specific maintenance work. Docker handles all the difficult stuff for you under the scenes, so your app can essentially run wherever Docker can run. And if you want to upgrade your server, or just tear ir down and put it up again from scratch, or if you need to deploy elsewhere, you can just go over the 15-minute quickstart again and you'll have your app deployed in production again. This doesn't mean you should be completely hands-off about servers: of course, the more competent you are the most you will take advantage of your infrastructure, and the better you will be at managing a server – but the current baseline minimal requirements for running a VPS are pretty low, if not non-existent. And AI is extremely good at figuring out any server problem you may come across, so you'll be able to do anything you may have to do in your server while the AI holds your hand the entire time.
You can customize everything in RailsFast, including the components that make up the UI template! You can (and will!) tailor RailsFast to your own needs. But just so that we're on the same page: RailsFast is not just a front-end template, it’s an entire full-stack system. The frontend is just the tip of the iceberg, what’s really important is all the weight RailsFast is lifting for you behind the scenes. I suggest forgetting about the frontend for a minute: don't go for other template just because you like their design better, you can ask the AI to copy you any design with Tailwind in a matter of minutes. I'd argue the design of RailsFast, while sufficient, is the least relevant thing. AI can can redesign any screen easily however you want: have Cursor or Claude change any component for you, or bring and use your own Tailwind components you have from another project. I made RailsFast frontend components to allow you to put together pages faster, but what's important here is the entire full-stack system. You can swap the front cover any time.
RailsFast doesn't lock you in to anything. I make recommendations of services or technologies that work well with RailsFast and that you will probably like using. For example, I recommend deploying RailsFast apps to Hetzner, because the price and quality of their servers is just unbeatable. But if you don't like Hetzner for servers, you can switch to DigitalOcean, Linode or AWS at any moment. I recommend sticking to the defaults I outline in the docs, but there's nothing stopping you from changing anything at any point.

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!