dotenvx

dotenvx is a modern and type-safe alternative to traditional .env files. It brings validation, type inference, schema support, and a minimal CLI — all in a single developer-friendly solution.

Why dotenvx?

Traditional .env files lack structure and safety:

• ❌ No type validation (everything is a string)
• ❌ No way to define required or optional values
• ❌ No default values or enums
• ❌ No documentation inside .env itself

dotenvx solves this by allowing both configuration and schema to live in the same file (.envx), with first-class support for validation, multiline values, conditional logic, and more.

Features

• ✅ Schema support with types, defaults, and requirements
• ✅ Validation on load, with meaningful errors
• ✅ Smart variable interpolation & ternary expressions
• ✅ Triple-quoted multiline values
• ✅ Built-in CLI (dotenvx) for automation and CI/CD use
• ✅ Type-safe runtime access via getEnvx()
• ✅ Compatible with process.env usage

Installation

pnpm add dotenvxjs
# or
npm install dotenvxjs

Programmatic Usage

import { loadEnvx, getEnvx } from "dotenvxjs";

// Loads and validates the .envx file (default is "./.envx")
loadEnvx();

const env = getEnvx();

console.log(env.PORT);        // typed access, number
console.log(env.API_URL);     // resolved with ternary + interpolation
console.log(env.NODE_ENV);    // enum value

Once loaded, all validated values are also available in process.env.

Runtime Usage with .env + .envx.meta.json

For production environments where .env files are already built (e.g. via dotenvx build or generate), you can safely use:

import { getEnv } from "dotenvxjs";

// Reads and validates .env + .envx.meta.json
const env = getEnv();

console.log(env.API_URL); // Typed and validated

This function:

• Does not modify process.env
• Requires both .env and .envx.meta.json
• Throws meaningful errors if types or required values don't match

Use this in environments where schema-based safety is still critical, but .envx isn’t available (e.g. containers or CI).

Example .envx File

DEV_MODE=false

API_URL=${DEV_MODE} ? "http://localhost:3000" : "https://api.example.com"
API_TOKEN=${DEV_MODE} ? "dev-token" : "prod-token"
FULL_API_URL="${API_URL}?token=${API_TOKEN}&env=${NODE_ENV}"

PORT=8080
DATABASE_NAME="my_db"

WELCOME_TEXT="""
Welcome to the new config system.
This supports multi-line values easily.
"""

# schema definition starts here
[DEV_MODE]
type="boolean"

[PORT]
type="number"
required=true

[API_URL]
type="string"

[NODE_ENV]
type="enum"
values=["production", "development", "test"]
default="development"
required=true

[DATABASE_NAME]
type="string"
required=true

[WEBSITE_URL]
type="url"
required=true
deprecated=true

CLI Usage

The dotenvx CLI is installed automatically with the package.

npx dotenvx build

Generates a .env file from your .envx:

npx dotenvx build

Options:

npx dotenvx check

Validates .envx against its declared schema:

npx dotenvx check

npx dotenvx print

Prints the parsed and interpolated .envx as JSON:

npx dotenvx print

npx dotenvx types

Generates a .ts file with full TypeScript typings based on the schema:

npx dotenvx types

Options:

npx dotenvx generate

Generates both .env and TypeScript types from your .envx file.

npx dotenvx generate

Options:

npx dotenvx watch

Watches your .envx file and auto-generates .env and TypeScript types on change.

npx dotenvx watch

Options:

About .envx.meta.json

Every time you run dotenvx build, generate, or types, a .envx.meta.json file is created.

This file contains the schema as JSON and is used at runtime to validate .env files via getEnv().

• Do not delete this file in production
• Can be safely committed or included in deployments

Configuration File

You can create an optional envx.config.js in your project root to provide defaults for CLI options.

// envx.config.js
export default {
  input: ".envx",
  outputs: {
    env: ".env",
    types: "src/envx.ts",
    metaFilePath: "./examples/", // Only Folder path (not include file name)
  },
  overwrite: true,
};

Type Definitions

If you're using npx dotenvx types, it will auto-generate typings you can import:

import { Envx } from "./envx.ts";

const env = getEnvx<Envx>();

Editor Integration

dotenvx is fully compatible with the official VSCode extension for .envx files, which provides:

• Syntax highlighting
• Auto-completion
• Inline validation errors and warnings
• Hover tooltips for schema metadata such as description and deprecated

Note: Fields like description and deprecated are only used by the VSCode extension for developer experience and do not affect runtime behavior or validation.

Roadmap

• <input checked="" disabled="" type="checkbox"> Ternary & interpolation support
• <input checked="" disabled="" type="checkbox"> CLI interface
• <input checked="" disabled="" type="checkbox"> Type-safe runtime API
• <input checked="" disabled="" type="checkbox"> Enum & default handling
• <input checked="" disabled="" type="checkbox"> VSCode syntax plugin
• <input disabled="" type="checkbox"> Web playground for .envx files
• <input disabled="" type="checkbox"> Linting rules and formatting

License

MIT © Trymagic