Rails for the agent era

Start with a Rails app your agent won’t redesign.

Rails Baseline is a production-ready SaaS foundation with authentication, accounts, billing, authorization, entitlements, Hotwire, Tailwind, and Kamal — plus the working patterns and architectural context coding agents need to extend it consistently.

Get launch access Explore the architecture

Founding release · $129 one-timePlanned standard price · $179

Repository

rails-baseline/
├── AGENTS.md
├── ARCHITECTURE.md
├── starter.yml
├── docs/
│   ├── contracts/
│   ├── recipes/
│   └── vendor/
├── app/
├── config/
├── db/
└── test/

AGENTS.mdcontext

Before making a non-trivial change:

01 Read ARCHITECTURE.md
02 Read the relevant contract
03 Inspect the closest implementation
04 Extend the existing pattern

Task

Add project exports.

Context found

tenant scoping
Pundit policy
entitlement pattern
background job pattern
tests

Ready to extend

01 / The expensive part moved

`rails new` is easy.
The next 100 decisions aren’t.

Codex, Claude, and Cursor can generate a Rails application from scratch in minutes.

That isn’t the expensive part anymore. A blank repository still gives the agent almost no local precedent for how your application is supposed to work.

Tenancy

How are records scoped?

Authorization

Where do permissions live?

Billing

Is Stripe state also product access?

Frontend

Does this interaction need Stimulus or React?

Jobs

How is tenant context restored?

Limits

Where does “25 projects” live?

Admin

What does a system administrator mean?

Integrations

What gets retried, and how?

Coding agents made scaffolding cheap. Architecture still isn’t.AI is very good at continuing strong patterns.
A new repository has no patterns to continue.

02 / Local precedent

The prompt should describe the feature. Not reinvent the application.

Blank reporails new my_saas

? tenancy
? authorization
? billing boundary
? service conventions
? public IDs
? frontend ownership
? jobs
? admin
? testing patterns

Every feature request is also an architecture prompt.

Rails Baselineexisting patterns found

Account + Membership
Pundit policies
billing boundary
Entitlements
Limits
tenant-aware jobs
public-ID pattern
Hotwire conventions
tests

The feature request can mostly remain a feature request.

03 / More than boilerplate

What comes next is part of the product.

Traditional Rails starter kits primarily answer: “What code can I avoid writing?” Rails Baseline also answers: “How should the code that comes next fit this application?”

Traditional starter

Authentication
Billing
Teams
Dashboard
UI primitives

Features you don’t have to build.

Rails Baseline

Working SaaS primitives
Canonical Rails patterns
Architectural contracts
Agent instructions
Extension recipes
Machine-readable starter context

A codebase worth continuing.

Most starter kits optimize for how much code they include.
Rails Baseline optimizes for how well the next 100,000 lines get written.

04 / Stable contracts

Stable answers for the decisions that repeat.

Boolean capability

Entitlements.enabled?(
  account: Current.account,
  key: :advanced_exports
)

Can this account use exports? Ask Entitlements.

Quantitative limit

Limits.value(
  account: Current.account,
  key: :projects
)

How many projects may it create? Ask Limits.

Authorization

authorize project

Can this user modify this project? Ask Pundit.

Tenant lookup

Current.account.projects.find_by!(
  public_id: params[:id]
)

Scope the record before deciding permission.

Which Stripe object exists underneath all of that? Ordinary product code should not care.

Billing

Stripe↓Pay↓Billing boundary↓Entitlements + Limits↓Product behavior

Identity & access

User↓Membership↓Account↓Tenant-owned data

05 / Pattern density

Your agent needs examples, not another vague prompt.

Rails Baseline provides strong local precedent for the architectural problems a SaaS application keeps encountering.

⌕

Search repository context…

⌘ K

01Need a tenant-owned resource
follow an existing account-scoped lookup
02Need authorization
follow the existing Pundit policy
03Need a paid capability
use Entitlements
04Need a plan quantity
use Limits
05Need background work
follow a tenant-aware Solid Queue job
06Need a sensitive operation
follow AuditEvent
07Need billing
follow the supported Pay pattern
08Need client-heavy UI
use the React-island recipe

The goal isn’t maximum code. It’s enough high-quality precedent that the next feature has something local to imitate.

06 / Familiar by design

It’s still a Rails app.

Rails Baseline does not hide Rails behind another framework. It looks familiar to an experienced Rails developer — and recognizable to coding agents already fluent in conventional Rails code.

Rails owns

routing
HTML
forms
navigation
authentication
CRUD
server state
Turbo interactions

React, when enabled, owns

complex client state
visualizations
editors
application-like islands

Optional, not foundational

Rails first. Hotwire first. React when you actually need React.

07 / Shipping in the founding release

Inspect the baseline.

A conventional Rails 8 SaaS foundation, with the operating context that keeps its conventions coherent as the application grows.

Core

Rails 8.1
PostgreSQL
ERB
Hotwire
Turbo
Stimulus
Tailwind
Minitest

Identity & tenancy

Devise
email confirmation
password recovery
multi-account architecture
Memberships
owner / admin / member roles
account switching
first-party account invitations
Pundit

Billing & access

Pay
Stripe
account-level billing
application billing boundary
Entitlements
Limits

Operations

Solid Queue
Solid Cache
Solid Cable
Mission Control Jobs
AuditEvent
health checks
query/request context
Rails error-reporting boundary
CSP
rate limiting

Production

Docker
Kamal
GitHub Actions
RuboCop
Brakeman
PostgreSQL-backed tests

Agent context

AGENTS.md
ARCHITECTURE.md
contracts
recipes
vendor guidance
starter.yml
canonical working examples

08 / Explicitly optional

Complexity is optional.

Rails Baseline establishes how optional capabilities should join the architecture without forcing every application to carry them on day one.

React islands
API keys
public JSON API
OAuth
impersonation
usage billing
inbound webhooks
external error reporting

A baseline, not a kitchen sink.

09 / Repository-native context

The architecture lives in the repo.

No proprietary Rails Baseline agent is required. The repository itself carries the architecture.

Codex, Claude Code, Cursor, and other capable coding agents can consume the same local patterns and instructions.

Agent sessionrepository context enabled

›

Add CSV exports to projects.
Require advanced_exports.
Run it asynchronously.

ReadAGENTS.mdcomplete
Readdocs/contracts/entitlements.mdcomplete
Foundexisting tenant-aware jobcontext
Foundexisting Pundit patterncontext
Foundexisting export-style side effectcontext

Implement against existing contracts

10 / Who it’s for

For people who intend to keep building.

Experienced Rails developer

You know how to build these pieces. You just don’t need to make the same infrastructure decisions for every new product.

AI-heavy builder

Your coding agent writes meaningful implementation. You want it extending a codebase instead of inventing one.

Technical founder

You want to start quickly without owning an opaque generated pile of abstractions afterward.

Indie SaaS developer

You want the next few days spent on the thing customers might pay for.

11 / Clear boundaries

Opinionated without becoming another framework.

Not a Rails engine.: A Rails application.
Not an AI wrapper.: Agents consume the architecture; they are not the architecture.
Not a React SPA with Rails underneath.: Hotwire owns the default app.
Not 80 speculative features.: Optional capabilities stay optional.
Not generated code you’re afraid to touch.: The code is intended to be read and changed.

Built by Rob Race

Built from real Rails scar tissue.

Rails Baseline is built by Rob Race, a long-time Rails developer, senior software engineer, SaaS builder, and author of Build a SaaS App in Rails 8 .

The architecture draws from patterns that survived actual applications, along with the places those applications accumulated complexity that a new baseline can avoid.

Founding license

Start from the baseline.

Launching soon. One purchase, one opinionated Rails foundation, and the context to keep extending it.

Founding release^$129one-time

Planned standard price: ~~$179~~

Rails Baseline source code
Use for products you own
Current 1.x updates
Architecture and agent guidance
Extension recipes
Production deployment baseline

Get launch access

Purchase terms

Refund policy

Rails Baseline provides immediate access to the complete source code, so purchases are generally non-refundable once access has been granted.

If Rails Baseline materially differs from what was described, you encounter a problem that prevents you from reasonably using it, or you were charged incorrectly, contact me within 14 days. I’ll work with you to resolve the issue, and if the problem is with Rails Baseline and can’t reasonably be resolved, I’ll issue a refund.

Refunds aren’t offered for change of mind, deciding not to use the product, or expecting functionality that wasn’t included in the product description.

12 / Questions

Before you start.

Is this just another Rails SaaS starter kit?

It includes the SaaS primitives you expect, but the emphasis is different. Rails Baseline gives humans and coding agents enough architecture and working precedent that new features can extend the codebase consistently.

Why not ask Codex or Claude to build it from scratch?

You can. Code generation is no longer the expensive part. A blank repository still provides little local precedent for the dozens of architectural decisions a real SaaS application requires.

Do I have to use an AI coding agent?

No. Rails Baseline is a conventional Rails application first. Its contracts, recipes, and explicit patterns are useful to humans too.

Does it require React?

No. Rails views, Hotwire, Turbo, and Stimulus are the default. React is an optional island capability for interfaces with substantial client-side state.

Why Pay?

Pay provides a conventional Rails billing integration for Stripe while Rails Baseline keeps product capabilities and limits as application-owned concepts. The repository also documents the supported Pay API.

Is Rails Baseline a framework or Rails engine?

No. It is deliberately a normal Rails application.

Can I remove or replace parts?

Yes. The architecture distinguishes foundational concepts from optional capabilities so the application can evolve without depending on a proprietary Baseline runtime.

What does the founding license cover?

The initial founding license is intended for products you own.