Express / Hono / Fastify

{
  "scripts": {
    "dev": "vars run --env dev -- tsx src/index.ts",
    "start": "vars run --env prod -- node dist/index.js"
  }
}

import { vars } from '#vars'
import express from 'express'

const app = express()

app.get('/health', (req, res) => {
  res.json({
    app: vars.APP_NAME,
    port: vars.PORT,
    db: String(vars.DATABASE_URL), // prints <redacted>
  })
})

app.listen(vars.PORT, () => {
  console.log(`${vars.APP_NAME} on port ${vars.PORT}`)
})

env(dev, staging, prod)

public APP_NAME = "my-api"
public PORT : z.number() = 3000

DATABASE_URL : z.string().url() {
  dev     = "postgres://localhost/myapp"
  staging = "postgres://staging.db/myapp"
  prod    = "postgres://prod.db/myapp"
}

JWT_SECRET : z.string().min(32) {
  dev     = "dev-jwt-secret-placeholder-32-chars!!"
  staging = "stg-jwt-secret-placeholder-32-chars!!"
  prod    = "prod-jwt-secret-very-long-and-secure"
} (owner = "auth-team", expires = 2026-12-31)