llenv

Lightweight CLI to apply environment variables from a single JSON config before launching any command. Zero dependencies — just Node.js.

Install

No installation needed! Use with npx:

npx @igormaka/llenv --help

Config

Create ~/.llenv/config.json:

{
  "defaultEnv": "litellm",
  "envs": {
    "litellm": {
      "ANTHROPIC_BASE_URL": "https://litellm.example.com",
      "ANTHROPIC_AUTH_TOKEN": "$LITELLM_KEY"
    },
    "litellm-local": {
      "ANTHROPIC_BASE_URL": "http://localhost:4000",
      "ANTHROPIC_AUTH_TOKEN": "sk-local-proxy-1234"
    },
    "ollama": {
      "ANTHROPIC_BASE_URL": "http://localhost:11434",
      "ANTHROPIC_AUTH_TOKEN": "ollama",
      "ANTHROPIC_MODEL": "llama3:latest"
    }
  }
}

• envs — object mapping environment names to their variables.
• defaultEnv (optional) — env to use when --env is omitted. If not set, the first entry in envs is used.

Variable interpolation

Values can reference existing environment variables using $VAR or ${VAR} syntax. Unset variables expand to an empty string.

{
  "envs": {
    "dev": {
      "DEBUG": "$SHOULD_DEBUG",
      "GREETING": "hello ${USER}"
    }
  }
}

SHOULD_DEBUG=1 npx @igormaka/llenv --env dev my-app
# DEBUG=1, GREETING=hello <your username>

Usage

# Launch with default env (litellm)
npx @igormaka/llenv claude

# Launch with a named env
npx @igormaka/llenv --env ollama claude

# Works with any command
npx @igormaka/llenv --env litellm-local npm start

# List available environments
npx @igormaka/llenv --list

# Preview env vars without running anything
npx @igormaka/llenv --show ollama

Options

| Flag | Description | |------|-------------| | --env <name> | Use a named env from config | | --list | List available environments | | --show [name] | Print resolved vars without executing | | --help | Show help |

Override config path

Set LLENV_CONFIG to use a different config file:

LLENV_CONFIG=./my-config.json npx @igormaka/llenv --env prod my-app

Try it out

Clone the repo to try example configs:

git clone https://github.com/igor-makarov/llenv.git
cd llenv

LLENV_CONFIG=./examples/simple.json npx @igormaka/llenv --list
LLENV_CONFIG=./examples/simple.json npx @igormaka/llenv --show dev
LLENV_CONFIG=./examples/simple.json npx @igormaka/llenv --env prod printenv APP_ENV

# Variable interpolation
SHOULD_DEBUG=1 LLENV_CONFIG=./examples/interpolation.json npx @igormaka/llenv --show dev