Build with modules.

StackFoundry installs production SaaS capabilities as editable source code. Each module brings implementation files, dependency metadata, environment notes, docs, and a verification checklist.

1. Create a new app

Start from a preset when you want the fastest path. Presets are just bundles of modules, so they stay transparent and editable.

$ pnpm create stackfoundry my-app
$ cd my-app
$ pnpm dlx stackfoundry add drizzle-postgres
$ pnpm dlx stackfoundry add api-keys
$ pnpm dlx stackfoundry add stripe-billing

2. Add to an existing app

Install a single capability into an existing codebase. StackFoundry resolves registry dependencies first and records file hashes for future diffs.

$ pnpm dlx stackfoundry add stripe-billing
· resolving registry dependency drizzle-postgres
+ packages/db/src/schema/billing.ts
+ apps/web/src/app/api/webhooks/stripe/route.ts
+ .env.stackfoundry.stripe-billing.example

3. Choose module families

The registry is organized around real SaaS systems, not arbitrary snippets. Provider modules stay adapters around shared domain interfaces.

4. Author modules with contracts

A module manifest declares the contract for installable source: files, dependencies, environment variables, registry dependencies, status, and maintenance metadata.

{
  "name": "api-keys",
  "type": "module",
  "category": "developer-platform",
  "registryDependencies": ["drizzle-postgres"],
  "status": "experimental"
}

5. Review and update safely

StackFoundry records installed file hashes and refuses to overwrite changed files without explicit `--force`. The goal is to make generated source reviewable like any other app code.