add-env-var

A CLI tool to easily add environment variables to .env files. Generate random secrets, set custom values, and manage multiple environment files with ease. This will not add your .env file to your .gitignore so make sure you do that manually if relevant.

Features

• Automatic .env File Handling: Automatically creates a .env file if one doesn't exist in your current directory.
• Random Secret Generation: Generates cryptographically secure random secrets for your environment variables.
• Custom Variable Values: Set custom values for your environment variables directly from the command line.
• Overwrite Protection: Prompts for confirmation before overwriting existing variables.
• Multiple Variable Support: Add multiple environment variables in a single command.
• Custom Secret Length: Specify the length of the generated secrets.
• Custom Environment Files: Specify a different environment file instead of the default .env.
• Custom Secret Encoding: Specify the encoding for the generated secret: hex (default), base64, or base64url.

Installation

You can use add-env-var directly with npx (no installation required):

npx add-env-var --help

Or install it globally:

npm install -g add-env-var

Usage

Basic Usage

Add an environment variable with a generated random secret:

npx add-env-var YOUR_VARIABLE

This will add YOUR_VARIABLE with a generated secret to your .env file.

Adding Multiple Variables

You can add multiple variables at once:

npx add-env-var VAR1 VAR2 VAR3

This will generate random secrets for VAR1, VAR2, and VAR3.

Setting Custom Values

Set custom values for your environment variables:

npx add-env-var API_KEY=12345 SECRET_KEY=mysecret

This will set API_KEY to 12345 and SECRET_KEY to mysecret in your .env file.

Specifying Secret Length

Specify the length of the generated secrets (in bytes):

npx add-env-var TOKEN -l 64

This will generate a 64-byte (128 characters in hex) secret for TOKEN.

Using a Different Environment File

Specify a different environment file instead of the default .env:

npx add-env-var RANDOM_SECRET -f .env.local

This will add RANDOM_SECRET to the .env.local file.

Using a Different Encoding

Specify the encoding for the generated variable instead of the default hex:

npx add-env-var RANDOM_VAR -e base64url

This will generate a URL-safe Base64-encoded secret for RANDOM_VAR.

Options

• -l, --length <number>: Length of the generated secret (default is 32 bytes).
• -f, --file <filepath>: Specify a different environment file (default is .env).
• -e, --encoding <type>: Specify the encoding for the generated secret. Options are hex, base64, and base64url (default is hex).
• -h, --help: Display help information.
• -V, --version: Display the version number.

Examples

Example 1: Add a Variable with a Random Secret

npx add-env-var SESSION_SECRET

Adds SESSION_SECRET with a 32-byte random secret to .env.

Example 2: Add Multiple Variables with Custom Values

npx add-env-var API_KEY=abcdef123456 DB_HOST=localhost

Sets API_KEY to abcdef123456 and DB_HOST to localhost in .env.

Example 3: Specify Secret Length and File

npx add-env-var JWT_SECRET -l 64 -f .env.local

Generates a 64-byte secret for JWT_SECRET and adds it to .env.local.

Example 4: Generate Secret with Base64 Encoding

npx add-env-var API_TOKEN -e base64

Adds API_TOKEN with a Base64-encoded secret to .env.

Example 5: Overwrite an Existing Variable

If a variable already exists, you'll be prompted:

Variable API_KEY already exists in .env. Overwrite? (y/N)

Enter y to overwrite or n to skip.

Example 6: Using the Help Command

npx add-env-var --help

Displays all available options and usage information.