mern-stack

name	mern-stack
description	Stack decisions for MERN apps (Next.js, pnpm monorepo). Reference before scaffolding or architecture work.

Locked decisions

Layer	Decision
Monorepo	pnpm workspaces
Frontend	Next.js (app router), TypeScript required
API	Next.js route handlers (app/api/) by default
Database	MongoDB + Mongoose
Validation	Zod (shared schemas in packages/shared)
Environments	local → non-prod → prod
Secrets	.env.local for dev; AWS for production
Containers	Not required unless deployment target forces it

Project layout

apps/web/                 # Next.js app
  app/api/                # API route handlers
  src/server/             # Server-only code
packages/shared/          # Zod schemas, types, utilities
.github/workflows/        # CI/CD
(root configs)            # eslint, prettier, tsconfig

When to add a separate API service

Only justified if:

• Long-running jobs exceed serverless timeouts
• WebSocket/persistent connections required
• Shared API serves multiple non-Next.js clients
• Compliance requires API isolation

Default: keep API in Next.js route handlers.

Reference

For versions, env setup, and deployment patterns, see reference/mern-stack-reference.md