Monorepo Backend Layout

Monorepo / Backend Layout

For repositories with a backend/ (or similar) directory, that directory is the backend app root.

Checklist Before Creating Any API or Lib File

1. Identify the backend app root (e.g. backend/).
2. Create files only under that root:
   • API routes: backend/src/app/api/...
   • Library code: backend/src/lib/...
   • (Or the project's actual layout—e.g. backend/src/app/... for Next.js App Router.)

Rules

• Never create src/ at the repository root for backend routes or libs.
• Never put routes under backend/lib/ if the project uses backend/src/lib/.
• Confirm the path convention (e.g. backend/src/lib/ not backend/lib/) before creating files.

Why This Matters

Creating routes or libs in the wrong place leads to 404s, repeated server restarts, and long debugging cycles. A single explicit layout rule prevents wrong-path creation.

Integration

• Reference in pre-implementation-check or progress when working in monorepos.
• Link from create-next-app-existing-dir when scaffolding backend in an existing directory.