better-env

Work With better-env In A Repo

Type-safe environment config modules

Follow this best practice to manage environment variables in TypeScript applications with full type safety and clear server/public boundaries.

better-env exports configSchema to define typed env modules and recommends placing them in feature-level config.ts files (for example src/lib/auth/config.ts and src/lib/database/config.ts).

Learn more:

• references/config-schema.md

Validate existence of all env variables in the current environment

Run env validation early so missing or invalid values fail fast before dev, build, or deploy steps.

better-env validate --environment <name> loads .env* files with Next.js semantics, discovers src/lib/*/config.ts modules, and checks every declared variable from your configSchema modules.

If your dotenv files intentionally include keys that are not referenced by config modules, add per-env suppressions in better-env.ts:

environments.<env>.ignoreUnused: string[]

These suppress only the selected local environment during validate. Adapter defaults are merged in automatically; for Vercel, VERCEL_OIDC_TOKEN is ignored by default in development, preview, and production.

Learn more:

• references/env-validation.md

Configure runtime syncing between local files and hosted providers

Use runtime configuration to keep local dotenv targets aligned with provider environments while preserving safe defaults.

Create better-env.ts with defineBetterEnv(...) and an adapter (vercelAdapter, netlifyAdapter, railwayAdapter, cloudflareAdapter, flyAdapter, or convexAdapter).

For a standard Vercel setup, prefer the minimal config:

export default defineBetterEnv({ adapter: vercelAdapter() });

Do not add an environments block when it only duplicates adapter defaults. Add environments only when you intentionally need custom mappings, custom env files, or per-environment ignoreUnused behavior.

Learn more:

• references/config.md
• references/runtime.md

Use the CLI for day-to-day environment operations

The CLI gives a consistent workflow for initialization, sync, validation, and remote variable management, which is great for local development and CI automation.

Choose the command runner to match the repo:

• Use npx in npm/pnpm-based repos (for example lockfiles like package-lock.json or pnpm-lock.yaml and scripts run via npm/pnpm).
• Use bunx in Bun-based repos (for example bun.lock and scripts run via bun).
• Keep commands aligned with the project's existing package manager/runtime conventions; do not mix runners unless the repo already does.

Recommended flow in a repo:

1. Run better-env init once to verify adapter prerequisites.
2. Run better-env pull --environment <name> to sync local env files.
3. Run better-env validate --environment <name> before app startup/build.
4. Use add, upsert, update, delete, and load for remote env changes.

Choose command behavior intentionally:

• upsert for idempotent automation and scripts
• add when duplicate keys should fail
• update when missing keys should fail
• delete to remove remote keys
• load for batch updates from dotenv files

Learn more:

• references/cli.md
• references/vercel-adapter.md