better-env

name	better-env
description	Better environment variable management for agents and humans with full type safety, CLI-based remote environment synchronization, and environment validation. Use when setting up typed config schemas, validating env variables, or managing remote env vars across Vercel, Netlify, Railway, Cloudflare, and Fly.io with 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, or cloudflareAdapter), then define environment mappings, env-file targets, and gitignore 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