Environment Variables

saaskip uses @t3-oss/env-nextjs with zod for typed, validated environment variables.

How it works

Environment variables are defined in src/core/env/index.ts and validated at startup. Invalid or missing required variables throw a clear error before the app boots.

import { createEnv } from '@t3-oss/env-nextjs';
import z from 'zod';

export const env = createEnv({
  server: {
    NODE_ENV: z
      .enum(['development', 'test', 'production'])
      .default('development'),
    // add server-only vars here
  },
  client: {
    NEXT_PUBLIC_APP_URL: z.url(),
    // add client-accessible vars here
  },
  experimental__runtimeEnv: {
    NEXT_PUBLIC_APP_URL: process.env.NEXT_PUBLIC_APP_URL,
  },
});

Server vs Client

Scope	Prefix	Accessible where
server	none	Server only
client	NEXT_PUBLIC_	Server and client

WARNING

Never put secrets in client variables. They are exposed to the browser.

Adding a new variable

1. Add it to .env and .env.example
2. Add a zod schema in the appropriate section (server or client)
3. If client-side, add it to experimental__runtimeEnv
4. Import env where needed: import { env } from '@/core/env'

skipValidation

Validation is skipped in these cases:

• SKIP_ENV_VALIDATION env var is set
• Running on Vercel (VERCEL env var)
• During build (npm_lifecycle_event === 'build')
• In test mode (NODE_ENV === 'test')

This prevents CI and test runners from failing on missing env vars.

Reference

See .env.example for the full list of variables and their descriptions.