Show HN: Rails Baseline – a Rails SaaS starter with agent-readable architecture

Rails Baseline, a production-ready Rails 8 SaaS starter kit priced at $129 one-time (planned standard price $179), launched with agent-readable architecture documentation including AGENTS.md and ARCHITECTURE.md to guide coding agents in extending the codebase consistently. The kit includes authentication, accounts, billing, authorization, entitlements, Hotwire, Tailwind, and Kamal, and is designed to provide local precedent for AI coding agents such as Codex, Claude, and Cursor.

rails 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 for the agent era 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. Founding release · $129 one-time Planned standard price · $179 Repository rails-baseline/ ├── AGENTS.md ├── ARCHITECTURE.md ├── starter.yml ├── docs/ │ ├── contracts/ │ ├── recipes/ │ └── vendor/ ├── app/ ├── config/ ├── db/ └── test/ Before making a non-trivial change: ARCHITECTURE.md Task Context found 01 / The expensive part moved rails new is easy.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. How are records scoped? Where do permissions live? Is Stripe state also product access? Does this interaction need Stimulus or React? How is tenant context restored? Where does “25 projects” live? What does a system administrator mean? 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 rails new my saas Every feature request is also an architecture prompt. existing patterns found The feature request can mostly remain a feature request. 03 / More than boilerplate 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?” Features you don’t have to build. 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 Entitlements.enabled? account: Current.account, key: :advanced exports Can this account use exports? Ask Entitlements. Limits.value account: Current.account, key: :projects How many projects may it create? Ask Limits. authorize project Can this user modify this project? Ask Pundit. 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 Identity & access 05 / Pattern density Rails Baseline provides strong local precedent for the architectural problems a SaaS application keeps encountering. Search repository context… follow an existing account-scoped lookup follow the existing Pundit policy use Entitlements use Limits follow a tenant-aware Solid Queue job follow AuditEvent follow the supported Pay pattern 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 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 first. Hotwire first. React when you actually need React. 07 / Shipping in the founding release A conventional Rails 8 SaaS foundation, with the operating context that keeps its conventions coherent as the application grows. 08 / Explicitly optional Rails Baseline establishes how optional capabilities should join the architecture without forcing every application to carry them on day one. A baseline, not a kitchen sink. 09 / Repository-native context 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. Add CSV exports to projects. Require advanced exports . Run it asynchronously. 10 / Who it’s for You know how to build these pieces. You just don’t need to make the same infrastructure decisions for every new product. Your coding agent writes meaningful implementation. You want it extending a codebase instead of inventing one. You want to start quickly without owning an opaque generated pile of abstractions afterward. You want the next few days spent on the thing customers might pay for. 11 / Clear boundaries Built by Rob Race 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 https://buildasaasappinrails.com . 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 Launching soon. One purchase, one opinionated Rails foundation, and the context to keep extending it. Planned standard price: ~~$179~~ Purchase terms 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 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. 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. No. Rails Baseline is a conventional Rails application first. Its contracts, recipes, and explicit patterns are useful to humans too. No. Rails views, Hotwire, Turbo, and Stimulus are the default. React is an optional island capability for interfaces with substantial client-side state. 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. No. It is deliberately a normal Rails application. Yes. The architecture distinguishes foundational concepts from optional capabilities so the application can evolve without depending on a proprietary Baseline runtime. The initial founding license is intended for products you own. Rails Baseline Start from a Rails application whose architecture, working patterns, and agent context already agree with each other.