No. The core is profile-scoped. Add organization, team, or multi-tenant behavior as a module in the product you build from it.

Global billing, no foreign entity

From download to your first international payment, in a weekend.

Q: Can I change the frontend stack?

The frontends are standard React + TypeScript projects. You can adapt or replace them, though you get the most value keeping the structure.

Q: Does it support multiple languages?

Yes. Internationalization is included: locale routing, translation files and language selectors across the frontends.

Q: Is authentication already implemented?

Yes. Authentication flows with Supabase, session handling and protected routes are implemented across the web app and admin panel.

Q: Which payment providers are integrated?

Stripe and Paddle, both wired end to end: checkout, signed webhooks and entitlements. You configure credentials in the admin panel and set a country-to-provider rule: typically Stripe at home and Paddle as merchant of record abroad, so VAT and sales tax are handled for you.

Q: What if it is not right for me?

Ask for a full refund within 14 days of the purchase, for any reason. Downloading, installing or activating the product does not void that right. Refunds are processed by the payment provider that handled your purchase.

Q: Can agencies use it for client projects?

Yes. The lifetime license on sale today covers client projects and unlimited commercial products, with no separate tiers. For large teams or special terms, talk to us before buying.

Q: Does it include deployment configuration?

Yes. Vercel-ready frontends and a containerized API. Deploy to whichever host you prefer.

Q: Can I customize the branding?

Yes. Colors, logo and themes live in config/branding.json, and name, slug and locales in config/product.json — from there they flow through the three apps.

Three frontends, an API and billing through two providers: Stripe on your home account, Paddle as merchant of record everywhere else. The code is yours, no lock-in.

Start now Explore the Architecture

React + TypeScript.NET 10 APIi18n includedCI/CD ready

Marketing SitePublic pages, pricing and SEO

React Web AppCustomer area with auth and billing

.NET APIProducts, plans, features and payments

Database · Auth · PaymentsPostgreSQL, Supabase, Stripe + Paddle

Admin PanelOperate products, plans and PSPs

Built to be shipped with AI coding agents

Why a foundation

Stop rebuilding the same SaaS foundation.

Start with the parts that make your product unique. The rest is already built and running.

Building from scratch

Authentication — ~5 days
Session handling — ~3 days
Admin structure — ~10 days
Product and pricing models — ~5 days
Global payments with two providers — ~15 days
Internationalization — ~5 days
Tests — ~5 days
CI/CD — ~3 days
Deployment structure — ~3 days
Documentation — ~3 days

Starting with CastorStack

Authentication — done
Session handling — done
Admin structure — done
Product and pricing models — done
Global payments with two providers — done
Internationalization — done
Tests — done
CI/CD — done
Deployment structure — done
Documentation — done

≈ 11 weeks of work before the first line of your product — or $147 and you start after that.

What's inside

Every layer of a real SaaS, already in place.

Three frontends, one API and the operational plumbing between them.

Marketing Site

Public site with pricing, SEO structure and i18n, connected to the product catalog.

Customer Web App

Authenticated customer area: dashboard, plan, usage and billing foundation.

Admin Panel

Operate products, plans, features, users, subscriptions and PSPs.

.NET API

.NET 10 API with EF Core, PostgreSQL and versioned endpoints.

Authentication

Supabase-backed auth with sessions and protected routes across apps.

Product Management

Products, plans and catalog managed from the admin panel.

Pricing & Features

Plans, feature flags and plan-feature bindings ready to model your offer.

Payment Providers

Stripe and Paddle wired end to end: checkout, signed webhooks and entitlements, with checkout binding per plan.

Internationalization

Locale routing, translation files and language selectors in every frontend.

Automated Testing

Vitest unit tests on the frontends, xUnit tests on the API and Playwright end-to-end suites.

Deployment

Vercel-ready frontends and a containerized API you can deploy anywhere.

Centralized Configuration

Branding, product, pricing and features driven by config files.

Extensible

Global billing

Sell worldwide without a local entity in every market.

Domestic customers are charged through Stripe. Everyone else goes through Paddle as merchant of record, so VAT and sales tax are handled for you.

Country-to-provider routing rule, configured in the admin panel
Signed webhooks from both providers unlock the same entitlements
One checkout endpoint: the API resolves which provider to use

Buyer's countryConfirmed at checkout

Routing ruleDomestic, international, fallback

StripeYour domestic account

PaddleMerchant of record

Webhook → accessEntitlement granted

Architecture

One monorepo. Clear boundaries.

Every app has a single responsibility, and shared concerns live in one place.

saas-core/

├─ apps/

│ ├─ marketing-site/ # Next.js

│ ├─ web-app/ # React + Vite

│ └─ admin-panel/ # React + Vite

├─ backend/api/ # .NET 10

├─ config/

│ ├─ branding.json

│ ├─ product.json

│ ├─ pricing.json

│ ├─ features.json

│ ├─ links.json

│ └─ seo.json

├─ docs/

├─ e2e/

├─ scripts/

└─ shared/

apps/

Three frontends with the same design language: marketing, customer app and admin.

backend/api/

.NET 10 backend: products, plans, features, users, subscriptions and payment providers.

config/

branding.json, product.json, pricing.json and features.json drive the whole product.

shared/ · docs/ · scripts/

Conventions, documentation and automation shared by every project.

Explore the full architecture

Stack

A stack teams already know.

No exotic dependencies. Proven tools, typed end to end.

Frontend

ReactNext.jsViteTypeScriptReact Routeri18nextVitest

Backend

.NET 10C#EF CorePostgreSQLSupabase Auth

Quality & Infra

Playwright E2ESentryVercelMigrationsEnv Config

How it works

From download to deploy, without detours.

Branding, product, pricing and features are centralized configuration, not scattered constants.

Download the code

One monorepo with frontends, API, database and scripts.

Configure your brand

Colors, logo and themes in config/branding.json; name, slug and locales in config/product.json.

Define products and pricing

Model plans and features from the admin panel or config files.

Connect auth and payments

Plug in Supabase credentials and your Stripe and Paddle keys. The integrations are already built.

Build your unique experience

Spend your time on the product, not on the boilerplate.

Deploy

Ship to Vercel or any host you choose, with no lock-in.

config/branding.json

{
  "primaryColor": "#7C4DFF",
  "secondaryColor": "#0D0D16",
  "logoText": "CastorStack",
  "themeModes": [
    "light",
    "dark",
    "system"
  ]
}

Guided onboarding

A guided path from zero to your first payment

Your purchase includes a 15-step onboarding trail in English, Spanish, and Portuguese. It takes you from an unopened package to a deployed product taking real payments. Every step ends with a verifiable check, written to be executed with an AI coding agent.

Who it's for

Built for people who ship SaaS.

Different goals, same starting point.

Solo founders

Validate your idea with a real working product instead of a prototype.

SaaS developers

Skip the plumbing and work on the features that set your product apart.

Freelancers

Deliver client SaaS projects with a professional baseline from day one.

Software agencies

Standardize how your team starts every SaaS engagement.

Internal product teams

Launch internal tools with auth, admin and billing structure ready.

Serial builders

Reuse the same foundation across multiple products without re-learning it.

In detail

What the foundation covers.

Grouped by the areas that matter when you're shipping.

Monorepo structure

Shared conventions

Centralized configuration

Documentation

Authentication flows

Protected routes

Session management

Customer dashboard foundation

Responsive layouts

Admin authentication

Product management

Feature management

Payment provider configuration

Country-to-provider routing

Operational controls

Discount coupons with validity, redemption caps and per-plan targeting

Automated tests

Deployment structure

Environment separation

Internationalization

Language selector

Translation files

Locale-based experience

Merchant-of-record billing via Paddle

Monorepo structure

Shared conventions

Centralized configuration

Documentation

Security

Built-in protections you can verify in the repo.

Concrete defaults in the API and database — not a generic enterprise badge.

Signed payment webhooks

Stripe and Paddle use HMAC signature checks, constant-time comparison, a five-minute replay window, and idempotent event handling.

Admin routes gated end to end

Every /api/v1/admin/* endpoint requires an authenticated admin session — verified route by route.

Encrypted PSP credentials

Payment provider secrets are encrypted with ASP.NET Data Protection, stored in the database, and never returned in plain text from the API.

No raw SQL in the API

Entity Framework Core is the only database access path — no string-built queries that open injection surfaces.

RLS enforced by migration

Supabase tables ship with row-level security and privilege hardening, with a regression test that fails the build if a table is left exposed.

Strict CORS defaults

Allowed origins are explicit and credentials are disabled — CSRF against cookie sessions is ruled out by configuration.

Checkout redirect allowlist

returnTo URLs must match configured allowed origins so checkout cannot become an open redirect.

Preview

Three frontends, one visual language.

Same design system, different jobs.

Marketing Site

Sell the product: hero, pricing and SEO-ready pages.

Customer Web App

Simple, value-oriented area for the end customer.

Admin Panel

Dense, operational cockpit for the people running the SaaS.

Extensibility

Change configuration, not scattered code.

Product identity and commercial rules live in versioned config files.

config/product.json

{
  "slug": "castorstack",
  "name": "CastorStack",
  "tagline": "A production-ready foundation to build and launch SaaS products.",
  "locales": [
    "en",
    "es",
    "pt"
  ],
  "defaultLocale": "en",
  "demoMode": true
}

config/pricing.json

{
  "currency": "USD",
  "plans": [
    {
      "id": "starter",
      "name": "Starter",
      "priceMonthly": 0
    },
    {
      "id": "growth",
      "name": "Growth",
      "priceMonthly": 199
    }
  ]
}

These samples are read from the real config/ files at build time. pricing.json is an install seed: after seeding, plans and prices live in the admin panel.

Pricing

One license. One whole foundation.

One license, and the whole codebase is yours: authentication, global billing, admin tools and a .NET API, in code you own.

Who built this

There is a person behind this codebase

Danilo Rodrigues

One of the founders of CastorStack and DanTI Digital, software engineer for 13+ years.

I built this template to ship SaaS products without rebuilding the foundation every time. It's the same code I use for my own products.

More about the maker What shipped recently DanTI Digital

FAQ

Frequently asked questions

Is CastorStack a no-code product?

No. It's a code-first foundation for developers: a monorepo with React frontends, a .NET API and configuration files you own and extend.

Can I change the frontend stack?

Does it support multiple languages?

Is authentication already implemented?

Which payment providers are integrated?

What if it is not right for me?

Is it multi-tenant?

Can agencies use it for client projects?

Does it include deployment configuration?

Can I customize the branding?

Is the backend included?

Does the template ship with my product's emails?

Do my domain logic and pricing policy come ready to go?

Are legal documents and compliance for my product included?

Is product analytics included?

Is end-customer support included?

Blog

Latest articles

September 16, 2026

Your next SaaS should start with the product, not the boilerplate.

Get the codebase and spend your first week on what makes your product different.

Get CastorStack View Documentation

From download to your first international payment, in a weekend.

Stop rebuilding the same SaaS foundation.

Building from scratch

Starting with CastorStack

Every layer of a real SaaS, already in place.

Marketing Site

Customer Web App

Admin Panel

.NET API

Authentication

Product Management

Pricing & Features

Payment Providers

Internationalization

Automated Testing

Deployment

Centralized Configuration

Sell worldwide without a local entity in every market.

One monorepo. Clear boundaries.

A stack teams already know.

Frontend

Backend

Quality & Infra

From download to deploy, without detours.

A guided path from zero to your first payment

Built for people who ship SaaS.

Solo founders

SaaS developers

Freelancers

Software agencies

Internal product teams

Serial builders

What the foundation covers.

Built-in protections you can verify in the repo.

Signed payment webhooks

Admin routes gated end to end

Encrypted PSP credentials

No raw SQL in the API

RLS enforced by migration

Strict CORS defaults

Checkout redirect allowlist

Three frontends, one visual language.

Change configuration, not scattered code.

One license. One whole foundation.

There is a person behind this codebase

Danilo Rodrigues

Frequently asked questions

Latest articles

Your Next Customer Might Be an AI Agent, Not a Person

The Email That Decides Whether Your User Stays or Leaves

Per-seat pricing is losing ground

Your next SaaS should start with the product, not the boilerplate.

One license. One whole foundation.

Lifetime License