Voici comment Lobechat applique la sécurité de type à ses variables d'environnement dans l'application Next

# Core package, no framework specific features
pnpm add @t3-oss/env-core zod
# or, with options preconfigured for Next.js
pnpm add @t3-oss/env-nextjs zod

// src/env.mjs
import { createEnv } from "@t3-oss/env-nextjs";
import { z } from "zod";
export const env = createEnv({
 /*
 * Serverside Environment variables, not available on the client.
 * Will throw if you access these variables on the client.
 */
 server: {
 DATABASE_URL: z.string().url(),
 OPEN_AI_API_KEY: z.string().min(1),
 },
 /*
 * Environment variables available on the client (and server).
 *
 * ? You'll get type errors if these are not prefixed with NEXT_PUBLIC_.
 */
 client: {
 NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY: z.string().min(1),
 },
 /*
 * Due to how Next.js bundles environment variables on Edge and Client,
 * we need to manually destructure them to make sure all are included in bundle.
 *
 * ? You'll get type errors if not all variables from `server` & `client` are included here.
 */
 runtimeEnv: {
 DATABASE_URL: process.env.DATABASE_URL,
 OPEN_AI_API_KEY: process.env.OPEN_AI_API_KEY,
 NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY:
 process.env.NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY,
 },
});

/*
* Serverside Environment variables, not available on the client.
* Will throw if you access these variables on the client.
*/
server: {
 DATABASE_URL: z.string().url(),
 OPEN_AI_API_KEY: z.string().min(1),
},

/*
 * Environment variables available on the client (and server).
 *
 * ? You'll get type errors if these are not prefixed with NEXT_PUBLIC_.
*/
client: {
 NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY: z.string().min(1),
},

/*
* Due to how Next.js bundles environment variables on Edge and Client,
* we need to manually destructure them to make sure all are included in bundle.
*
* ? You'll get type errors if not all variables from `server` & `client` are included here.
*/
runtimeEnv: {
 DATABASE_URL: process.env.DATABASE_URL,
 OPEN_AI_API_KEY: process.env.OPEN_AI_API_KEY,
 NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY:
 process.env.NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY,
},

// src/app/hello/route.ts
import { env } from "../env.mjs";
export const GET = (req: Request) => {
 const DATABASE_URL = env.DATABASE_URL;
 // use it…
};

import { createEnv } from '@t3-oss/env-nextjs';
import { z } from 'zod';
export const getServerDBConfig = () => {
 return createEnv({
 client: {
 NEXT_PUBLIC_ENABLED_SERVER_SERVICE: z.boolean(),
 },
 runtimeEnv: {
 DATABASE_DRIVER: process.env.DATABASE_DRIVER || 'neon',
 DATABASE_TEST_URL: process.env.DATABASE_TEST_URL,
 DATABASE_URL: process.env.DATABASE_URL,
DISABLE_REMOVE_GLOBAL_FILE: process.env.DISABLE_REMOVE_GLOBAL_FILE === '1',
KEY_VAULTS_SECRET: process.env.KEY_VAULTS_SECRET,
NEXT_PUBLIC_ENABLED_SERVER_SERVICE: process.env.NEXT_PUBLIC_SERVICE_MODE === 'server',
 },
 server: {
 DATABASE_DRIVER: z.enum(['neon', 'node']),
 DATABASE_TEST_URL: z.string().optional(),
 DATABASE_URL: z.string().optional(),
DISABLE_REMOVE_GLOBAL_FILE: z.boolean().optional(),
KEY_VAULTS_SECRET: z.string().optional(),
 },
 });
};
export const serverDBEnv = getServerDBConfig();

import { serverDBEnv } from '@/config/db';
//
let connectionString = serverDBEnv.DATABASE_URL;