Foundation Base
Production readyBusinessv1.0.0 · updated Jun 29, 2026
SA

Open Source SaaS template

A calm, complete base for subscription software.

A production-ready SaaS foundation with teams, billing, onboarding, settings, email, and clear agent guidance.

Runnable Agent-ready Install-ready Deploy-ready
foundationbase.app/demo/saasOpen full demo →

This is the real app, not a mockup. Whatever you enter in the demo stays in your browser and belongs to nobody.

What you get

One zip. Everything to own it.

SaaS Foundation is for builders who need a trusted subscription product starting point without spending weeks wiring common infrastructure. It includes workspaces, Stripe billing, onboarding, role-aware settings, transactional email, and project documentation made for AI-assisted customization.

  • Team workspaces and invitations
  • Stripe subscriptions and customer portal
  • Email and OAuth authentication
  • Settings and role boundaries
  • Deployment and testing guide
saas-foundation.zipMIT
saas-foundation/├── app/the running Next.js app├── agent/START_HERE, PROJECT_MAP, RULES, RECIPES, TESTS, DEPLOY├── CLAUDE.mdread automatically by Claude Code├── AGENTS.mdread automatically by Codex├── .cursor/rules/loaded automatically by Cursor└── README.mdrun it, then make it yours

Inside the app

What the running app actually looks like
SaaS Foundation: Workspace dashboard
Workspace dashboard — A quiet dashboard for teams, billing state, and product activity.

Customize with AI

Your agent already knows this codebase.

Agent instructions document billing, teams, auth, schema boundaries, test expectations, and safe product module additions.

CodexClaude CodeCursorGitHub Copilot

Prompts written against this app

Change the branding, copy, and layout for my SaaS Foundation app.
Add or remove fields so it matches my workflow.
Add export and import for my business data.
Add optional sync later without changing the local-first default.

Run it

5 min to your own copy.

  1. 01Create your editable app copy and unzip it.
  2. 02Run npm install.
  3. 03Run npm run dev and open http://localhost:3000.
  4. 04Read /agent/START_HERE.md before customizing.
  5. 05Swap the local-first storage boundary for your own backend when ready.
Full walkthrough, including deploy and install →
Where your data lives

SaaS Foundation data stays in this browser by default.

No account, backend, or cloud sync is included in the current package.

An agent can add optional sync later while preserving the local-first default.

Honest limitation

This package is standard-ready for Create My App and AI customization.

A full app-only PWA install route is not enabled yet for this app.

Verification receiptchecked Aug 2, 2026 at c11c184 · v1.0.0
Demo renderscaptured 2026-07-26, 29 KBpassed
Package installs and buildsinstalled, typechecked and built in 79s on node v24.13.0passed
Source package complete31 files, 49 KBpassed
Agent instructions included5 handoff files presentpassed
No network calls in app sourcestatic scan clean: no network calls, eval, or secrets in app sourcepassed
License matches the packageMIT, matching the file in the packagepassed

If this isn’t quite right

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Take SaaS Foundation and make it yours.

Free, MIT, 5 min to running. The demo above is exactly what lands in your folder.

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